117 results on '"Ralstonia"'
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2. Ralstonia mannitolilytica infection in a tertiary care center: An outbreak report.
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Alshuhri S, Alosaimi A, Alnafee K, Alkahtany J, Alhamami S, Hejazi B, Khier B, Aoqailey S, Alrshaid B, Alghnnam F, Bohol M, Alhowaiti S, Aldhlawi Z, Althawadi S, Alghamdi S, and Aljumaah S
- Abstract
Background: This paper describes an outbreak of Ralstonia mannitolilytica infection declared at our facility between January-2021 and January-2022., Methods: To identify the source of the outbreak, we applied widespread epidemiological investigations and infection control measures, including device isolation, environmental sampling, and pulsed-field gel electrophoresis typing., Results: Thirty-six cases of R mannitolilytica infection were identified, mostly adults (78%) and males (75%). Initially, neurological procedures were a common risk factor among cases, leading to sampling of related environmental settings. Cases with other medical procedures started to be reported. The pulsed-field gel electrophoresis results showed most R mannitolilytica isolates were indistinguishable, which expanded our investigation to all hospital areas. The outbreak source was traced to a specific lot of contaminated sodium chloride solution, which was recalled from all hospital units. The findings were reported to the Saudi Food and Drug Authority to communicate with the manufacturer and other health care organizations involved. No new cases of R mannitolilytica were identified thereafter., Conclusions: It is essential to regularly monitor the compliance of manufacturers and suppliers with regulations related to the safety of solutions administered in medical practice. An extended incubation period might be considered to enhance the identification of R. mannitolilytica in future outbreaks., (Copyright © 2024 Association for Professionals in Infection Control and Epidemiology, Inc. Published by Elsevier Inc. All rights reserved.)
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- 2024
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3. A bacterial effector manipulates plant metabolism, cell death, and immune responses via independent mechanisms.
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Zhao A, Xian L, Franco Ortega S, Yu G, and Macho AP
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- Plant Diseases microbiology, Plant Diseases immunology, Nicotiana microbiology, Nicotiana immunology, Virulence, Plant Proteins metabolism, Glutamate Decarboxylase metabolism, Homeostasis, Cell Death, Plant Immunity, Ralstonia solanacearum pathogenicity, Ralstonia solanacearum physiology, gamma-Aminobutyric Acid metabolism, Bacterial Proteins metabolism
- Abstract
Bacterial pathogens inject effector proteins inside plant cells to manipulate cellular functions and achieve a successful infection. The soil-borne pathogen Ralstonia solanacearum (Smith), the causal agent of bacterial wilt disease, secretes > 70 different effectors inside plant cells, although only a handful of them have been thoroughly characterized. One of these effectors, named RipI, is required for full R. solanacearum pathogenicity. RipI associates with plant glutamate decarboxylases (GADs) to promote the accumulation of gamma-aminobutyric acid (GABA), which serves as bacterial nutrient. In this work, we found that RipI can also suppress plant immune responses to bacterial elicitors, which seems to be unrelated to the ability of RipI to induce GABA accumulation and plant cell death. A detailed characterization of the RipI features that contribute to its virulence activities identified two residues at the C-terminal domain that mediate RipI interaction with plant GADs and the subsequent promotion of GABA accumulation. These residues are also required for the appropriate homeostasis of RipI in plant cells and the induction of cell death, although they are partially dispensable for the suppression of plant immune responses. Altogether, we decipher and uncouple the virulence activities of an important bacterial effector at the biochemical level., (© 2024 The Authors. New Phytologist © 2024 New Phytologist Foundation.)
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- 2024
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4. Novel Ralstonia species from human infections: improved matrix-assisted laser desorption/ionization time-of-flight mass spectrometry-based identification and analysis of antimicrobial resistance patterns.
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Steyaert S, Peeters C, Wieme AD, Muyldermans A, Vandoorslaer K, Spilker T, Wybo I, Piérard D, LiPuma JJ, and Vandamme P
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- Humans, Cystic Fibrosis microbiology, Gram-Negative Bacterial Infections microbiology, Gram-Negative Bacterial Infections drug therapy, Drug Resistance, Multiple, Bacterial genetics, Drug Resistance, Bacterial, Genome, Bacterial genetics, Whole Genome Sequencing, Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization methods, Ralstonia drug effects, Ralstonia genetics, Ralstonia isolation & purification, Ralstonia classification, Anti-Bacterial Agents pharmacology, Microbial Sensitivity Tests
- Abstract
A collection of 161 Ralstonia isolates, including 90 isolates from persons with cystic fibrosis, 27 isolates from other human clinical samples, 8 isolates from the hospital environment, 7 isolates from industrial samples, and 19 environmental isolates, was subjected to matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) identification and yielded confident species level identification scores for only 62 (39%) of the isolates, including four that proved misidentified subsequently. Whole-genome sequence analysis of 32 representative isolates for which no confident MALDI-TOF MS species level identification was obtained revealed the presence of seven novel Ralstonia species, including three and four that were isolated from cystic fibrosis or other human clinical samples, respectively, and provided the basis for updating an in-house MALDI-TOF MS database. A reanalysis of all mass spectra with the updated MALDI-TOF MS database increased the percentage of isolates with confident species level identification up to 77%. The antimicrobial susceptibility of 30 isolates mainly representing novel human clinical and environmental Ralstonia species was tested toward 17 antimicrobial agents and demonstrated that the novel Ralstonia species were generally multi-resistant, yet susceptible to trimethoprim/sulfamethoxazole, ciprofloxacin, and tigecycline. An analysis of genomic antimicrobial resistance genes in 32 novel and publicly available genome sequences revealed broadly distributed beta-lactam resistance determinants.IMPORTANCEThe present study demonstrated that a commercial matrix-assisted laser desorption/ionization time-of-flight mass spectrometry identification database can be tailored to improve the identification of Ralstonia species. It also revealed the presence of seven novel Ralstonia species, including three and four that were isolated from cystic fibrosis or other human clinical samples, respectively. An analysis of minimum inhibitory concentration values demonstrated that the novel Ralstonia species were generally multi-resistant but susceptible to trimethoprim/sulfamethoxazole, ciprofloxacin, and tigecycline., Competing Interests: The authors declare no conflict of interest.
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- 2024
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5. Phenotypic and genetic characterization of a lipolytic Ralstonia mannitolilytica isolate from petroleum-contaminated soil in Iraq.
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Abdulkareem RS, Musafer HK, and Al-Ezee AMM
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- RNA, Ribosomal, 16S genetics, Phylogeny, Iraq, Lipase genetics, Soil, Petroleum microbiology, Ralstonia
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Background: Lipases play a crucial role in various industrial applications, and microbial lipases, particularly those from bacteria, possess significant properties. With increasing concerns about the environmental and health impacts of hydrocarbons from pipelines and refineries, there is a growing need to mitigate the risks associated with these compounds., Methods: In this study, 40 bacterial isolates were recovered from contaminated soil samples collected from multiple refineries across Iraq. Using the Vitek system, bacterial isolates were identified up to the species level, revealing that only 12 isolates exhibited lipase-producing capabilities., Results: Among the lipase-producing isolates, Ralstonia mannitolilytica demonstrated the highest extracellular lipase activity, as determined by an olive oil plate assay supplemented with rhodamine B. Confirmation of the species identity was achieved through 16S rRNA gene sequencing, with the obtained sequence deposited under accession number LC772176.1. Further sequence analysis revealed single nucleotide polymorphisms (SNPs) in the genome of Ralstonia mannitolilytica strain H230303-10_N19_7x_R2 (CP011257.1, positions 1,311,102 and 1,311,457). Additionally, the presence of the lipase gene was confirmed through amplification and sequencing using a thermocycler PCR. Sequence analysis of the gene, aligned using Geneious Prime software, identified SNPs (CP010799, CP049132, AY364601, CP011257, and CP023537), and a phylogenetic tree was constructed based on genetic characterization., Conclusion: Our findings highlight the potential of Ralstonia mannitolilytica as a promising candidate for lipase production and contribute to our understanding of its genetic diversity and biotechnological applications in hydrocarbon degradation and industrial processes., (© 2024. The Author(s), under exclusive licence to Springer Nature B.V.)
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- 2024
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6. Complete sequence of carbapenem-resistant Ralstonia mannitolilytica clinical isolate co-producing novel class D β-lactamase OXA-1176 and OXA-1177 in Japan.
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Hayashi W, Kaiju H, Kayama S, Yu L, Zuo H, Sugawara Y, Azuma K, Takahashi A, Hata Y, and Sugai M
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- Humans, Aged, Meropenem, Doripenem, Japan, beta-Lactamases genetics, beta-Lactamases metabolism, Bacterial Proteins genetics, Anti-Bacterial Agents pharmacology, Anti-Bacterial Agents therapeutic use, Imipenem, Microbial Sensitivity Tests, Carbapenems pharmacology, Carbapenems therapeutic use, Escherichia coli genetics, Escherichia coli metabolism, Ralstonia
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In 2020, the Ralstonia mannitolilytica strain JARB-RN-0044 was isolated from a midstream urine sample of an elderly hospitalized patient in Japan and was highly resistant to carbapenem (i.e., imipenem, meropenem, and doripenem). Whole-genome sequencing revealed that the complete genome consists of two replicons, a 3.5-Mb chromosome and a 1.5-Mb large non-chromosomal replicon which has not been reported in R. mannitolilytica, and referred to as the "megaplasmid" in this study based on Cluster of Orthologous Group of proteins functional analysis. The strain JARB-RN-0044 harbored two novel OXA-60 and OXA-22 family class D β-lactamase genes bla
OXA-1176 and blaOXA-1177 on the megaplasmid. Cloning experiments indicated that Escherichia coli recombinant clone expressing blaOXA-1176 gene showed increased minimum inhibitory concentrations (MICs) of imipenem, meropenem, and doripenem, indicating that blaOXA-1176 gene encodes carbapenemase. In contrast, E. coli recombinant clone expressing blaOXA-1177 gene showed increased MICs of piperacillin and cefazolin, but not of carbapenem. Interestingly, the 44.6 kb putative prophage region containing genes encoding phage integrase, terminase, head and tail protein was identified in the downstream region of blaOXA-1176 gene, and comparative analysis with some previously reported R. mannitolilytica isolates revealed that the prophage region was unique to strain JARB-RN-0044. The existence of a highly carbapenem-resistant R. mannitolilytica isolate may raise human health concerns in Japan, where the population is rapidly aging.IMPORTANCE Ralstonia mannitolilytica is an aerobic non-fermenting Gram-negative rod commonly found in aquatic environments and soil. The bacteria can occasionally cause severe hospital-acquired bloodstream infections in immunocompromised patients and it has been recently recognized as an emerging opportunistic human pathogen. Furthermore, some R. mannitolilytica isolates are resistant to various antimicrobial agents, including β-lactams and aminoglycosides, making antimicrobial therapy challenging and clinically problematic. However, clinical awareness of this pathogen is limited. To our knowledge, in Japan, there has been only one report of a carbapenem-resistant R. mannitolilytica clinical isolate from urine by Suzuki et al. in 2015. In this study, whole-genome sequencing analysis revealed the presence and genetic context of novel blaOXA-1176 and blaOXA-1177 genes on the 1.5 Mb megaplasmid from highly carbapenem-resistant R. mannitolilytica isolate and characterized the overall distribution of functional genes in the chromosome and megaplasmid. Our findings highlight the importance of further attention to R. mannitolilytica isolate in clinical settings., Competing Interests: The authors declare no conflict of interest.- Published
- 2024
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7. Draft genomes of two phylotype I and II Ralstonia solanacearum species complex (RSSC) isolates causing bacterial wilt in tomato plants from Costa Rica.
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Galiano-Murillo F, Salas-Lara V, Echandi C, Brenes-Guillén L, and Uribe-Lorío L
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Bacteria from RSSC hold agricultural significance as they are the causal agents of bacterial wilt. Here, we report the draft genomes of two bacteria extracted from vascular tissues of infected tomato plants. Isolate RALF-MA was classified as Ralstonia pseudosolanacearum (phylotype I) and RALSA-MA as Ralstonia solanacearum (phylotype II)., Competing Interests: The authors declare no conflict of interest.
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- 2024
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8. Development of antibody to virulence factor flagellin and its evaluation in screening Ralstonia pseudosolanacearum.
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Bhatt S, Raj SMP, Faridi N, Pathak D, Agarwal A, and Mishra SP
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- Animals, Mice, Rabbits, Virulence Factors genetics, Ralstonia, Antibodies, Flagellin genetics, Ralstonia solanacearum
- Abstract
The bacterial wilt disease caused by Ralstonia pseudosolanacearum presents a notable economic risk to a variety of crucial crops worldwide. During preliminary isolation of this phytopathogen, several colonies of other saprophytic bacteria may be mistaken with it. So, the present study aims to address this issue by proposing the application of immunogenic proteins, particularly flagellin (FliC), to enable a rapid and early identification of bacterial wilt. In this study, a novel approach is unveiled for the early detection of R. pseudosolanacearum. The study exploits the immunogenic attributes of flagellin (FliC), by generating polyclonal antibodies against recombinant FliC within model organisms-rabbits and mice. The efficacy of these antibodies is meticulously assessed through discerning techniques, including DAS-ELISA and Western blot analyses, which elucidate their remarkable specificity in identifying various R. pseudosolanacearum strains. Furthermore, the introduction of antibody-coated latex agglutinating reagents offers an additional layer of confirmation, substantiating the feasibility of establishing a laboratory-based toolkit for swift screening and unambiguous identification of the bacterial wilt pathogen. This study presents a significant stride toward enhancing early diagnostic capabilities, potentially revolutionizing agricultural practices by safeguarding crop yield and quality through proactive pathogen detection and mitigation strategies., (© 2024. The Author(s) under exclusive licence to Sociedade Brasileira de Microbiologia.)
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- 2024
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9. Fahr's syndrome associated with hypoparathyroidism: A case report.
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Sarna MK, Goel P, Bhargava V, and Parakh R
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- Adult, Middle Aged, Humans, Basal Ganglia Diseases diagnosis, Basal Ganglia Diseases diagnostic imaging, Calcinosis etiology, Calcinosis complications, Neurodegenerative Diseases complications, Neurodegenerative Diseases diagnosis, Hypoparathyroidism complications, Hypoparathyroidism diagnosis
- Abstract
Fahr's syndrome affects fewer than 1 in 100,000 people. It is an inherited neurological disorder, which is distinguished by atypical calcium deposition in the movement-controlling areas of brain, that is thalamus, dentate nucleus, basal ganglia, cerebellum, cerebral cortex, hippocampus and subcortical white matter. The majority of patients often experience extrapyramidal symptoms, cerebellar signs, speech difficulty, dementia and neuropsychiatric manifestations. This disease's molecular genetics have not been thoroughly investigated. Typically, young to middle-aged adults are affected though basal ganglia calcification in hypoparathyroidism is quite uncommon. Laboratory results and radiographic brain imaging helps in reaching the diagnosis. The treatment is mainly symptomatic. We present a case of Fahr's syndrome associated with hypoparathyroidism., Competing Interests: Declaration of conflicting interestsThe authors declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.
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- 2023
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10. Antibacterial activity and action mechanism of curcusionol from Carex siderosticta Hance against Ralstonia nicotianae.
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Ren X, Zhou J, Liu T, Zhong C, Wang Y, Yan H, and Feng J
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- Ralstonia, Plant Diseases microbiology, Bacteria, Anti-Bacterial Agents pharmacology, Anti-Bacterial Agents chemistry, Nicotiana, Microbial Sensitivity Tests, Carex Plant, Ralstonia solanacearum
- Abstract
Background: Tobacco bacterial wilt is a typical soil-borne disease caused by Ralstonia nicotianae, which causes huge losses in tobacco production every year. The crude extract of Carex siderosticta Hance was shown to have antibacterial activity against R. nicotianae during our search, and the natural antibacterial components were sought after using bioassay-guided fractionation of the compounds., Result: Ethanol extract of Carex siderosticta Hance with the minimum inhibitory concentration (MIC) value of 100 μg/mL against R. nicotianae in vitro. The potential of these compounds as antibactericides against R. nicotianae were assessed. Curcusionol (1), showed the highest antibacterial activity against R. nicotianae with MIC value of 12.5 μg/mL in vitro. In the protective effect tests, the control effect of curcusionol (1) was 92.31 and 72.60%, respectively, after application of 7 and 14 days, at a concentration of 1500 μg/mL, being comparable to that of streptomycin sulfate at a concentration of 500 μg/mL, confirming that curcusionol (1) showed the potential for the development of new antibacterial drugs. RNA-sequencing, scanning electron microscopy (SEM) and transmission electron microscopy (TEM) analysis confirmed that curcusionol mainly destroys R. nicotianae cell membrane structure and affects quorum sensing (QS) to inhibit pathogenic bacteria., Conclusion: This study revealed that the antibacterial activity of Carex siderosticta Hance makes it a botanical bactericide against R. nicotianae, while curcusionol as lead structures for antibacterial development is obvious by its potent antibacterial activity. © 2023 Society of Chemical Industry., (© 2023 Society of Chemical Industry.)
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- 2023
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11. Bioinformatic Analysis Reveals the Role of Translation Elongation Efficiency Optimisation in the Evolution of Ralstonia Genus.
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Korenskaia AY, Matushkin YG, Mustafin ZS, Lashin SA, and Klimenko AI
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Translation efficiency modulates gene expression in prokaryotes. The comparative analysis of translation elongation efficiency characteristics of Ralstonia genus bacteria genomes revealed that these characteristics diverge in accordance with the phylogeny of Ralstonia . The first branch of this genus is a group of bacteria commonly found in moist environments such as soil and water that includes the species R. mannitolilytica , R. insidiosa , and R. pickettii , which are also described as nosocomial infection pathogens. In contrast, the second branch is plant pathogenic bacteria consisting of R. solanacearum , R. pseudosolanacearum , and R. syzygii . We found that the soil Ralstonia have a significantly lower number and energy of potential secondary structures in mRNA and an increased role of codon usage bias in the optimization of highly expressed genes' translation elongation efficiency, not only compared to phytopathogenic Ralstonia but also to Cupriavidus necator , which is closely related to the Ralstonia genus. The observed alterations in translation elongation efficiency of orthologous genes are also reflected in the difference of potentially highly expressed gene' sets' content among Ralstonia branches with different lifestyles. Analysis of translation elongation efficiency characteristics can be considered a promising approach for studying complex mechanisms that determine the evolution and adaptation of bacteria in various environments.
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- 2023
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12. GmFLS2 contributes to soybean resistance to Ralstonia solanacearum.
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Chen Y, Zhao A, Wei Y, Mao Y, Zhu JK, and Macho AP
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- Glycine max, Virulence, Plant Diseases, Ralstonia solanacearum
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- 2023
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13. Getting to the root of Ralstonia invasion.
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Rivera-Zuluaga K, Hiles R, Barua P, Caldwell D, and Iyer-Pascuzzi AS
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- Virulence, Plants, Plant Diseases microbiology, Ralstonia, Ralstonia solanacearum genetics
- Abstract
Plant diseases caused by soilborne pathogens are a major limiting factor in crop production. Bacterial wilt disease, caused by soilborne bacteria in the Ralstonia solanacearum Species Complex (Ralstonia), results in significant crop loss throughout the world. Ralstonia invades root systems and colonizes plant xylem, changing plant physiology and ultimately causing plant wilting in susceptible varieties. Elucidating how Ralstonia invades and colonizes plants is central to developing strategies for crop protection. Here we review Ralstonia pathogenesis from root detection and attachment, early root colonization, xylem invasion and subsequent wilting. We focus primarily on studies in tomato from the last 5-10 years. Recent work has identified elegant mechanisms Ralstonia uses to adapt to the plant xylem, and has discovered new genes that function in Ralstonia fitness in planta. A picture is emerging of an amazingly versatile pathogen that uses multiple strategies to make its surrounding environment more hospitable and can adapt to new environments., Competing Interests: Declaration of interest None., (Copyright © 2022 Elsevier Ltd. All rights reserved.)
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- 2023
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14. A bacterial type III effector targets plant vesicle-associated membrane proteins.
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Wang K, Yu W, Yu G, Zhang L, Xian L, Wei Y, Perez-Sancho J, Xue H, Rufian JS, Zhuang H, Kwon C, and Macho AP
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- R-SNARE Proteins genetics, R-SNARE Proteins metabolism, Bacterial Proteins genetics, Bacterial Proteins metabolism, Plant Diseases microbiology, Plants metabolism, Nicotiana microbiology, Plant Immunity genetics, Arabidopsis, Ralstonia solanacearum, Arabidopsis Proteins genetics, Arabidopsis Proteins metabolism
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The soilborne bacterial pathogen Ralstonia solanacearum is one of the most destructive plant pathogens worldwide, and its infection process involves the manipulation of numerous plant cellular functions. In this work, we found that the R. solanacearum effector protein RipD partially suppressed different levels of plant immunity triggered by R. solanacearum elicitors, including specific responses triggered by pathogen-associated molecular patterns and secreted effectors. RipD localized in different subcellular compartments in plant cells, including vesicles, and its vesicular localization was enriched in cells undergoing R. solanacearum infection, suggesting that this specific localization may be particularly relevant during infection. Among RipD-interacting proteins, we identified plant vesicle-associated membrane proteins (VAMPs). We also found that overexpression of Arabidopsis thaliana VAMP721 and VAMP722 in Nicotiana benthamiana leaves promoted resistance to R. solanacearum, and this was abolished by the simultaneous expression of RipD, suggesting that RipD targets VAMPs to contribute to R. solanacearum virulence. Among proteins secreted in VAMP721/722-containing vesicles, CCOAOMT1 is an enzyme required for lignin biosynthesis, and mutation of CCOAOMT1 enhanced plant susceptibility to R. solanacearum. Altogether our results reveal the contribution of VAMPs to plant resistance against R. solanacearum and their targeting by a bacterial effector as a pathogen virulence strategy., (© 2023 The Authors. Molecular Plant Pathology published by British Society for Plant Pathology and John Wiley & Sons Ltd.)
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- 2023
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15. A case of meningitis caused by Ralstonia insidiosa, a rare opportunistic pathogen.
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Liao L, Lin D, Liu Z, Gao Y, and Hu K
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- Humans, Cefepime, Ralstonia, Anti-Bacterial Agents therapeutic use, Levofloxacin, Meningitis
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Background: Ralstonia is a genus of Gram-negative opportunistic bacteria that can survive in many kinds of solutions and cause a variety of infections. Ralstonia spp. have increasingly been isolated and reported to cause infections in recent years, thanks to the development of identification methods such as matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) and gene sequencing. However, infections caused by Ralstonia insidiosa are still rare. Only a few cases of respiratory infections and bloodstream infections have been reported, none of which involved meningitis. To the best of our knowledge, this is the first reported case of meningitis caused by R. insidiosa worldwide. It is necessary to report and review this case., Case Presentation: We report a case of meningitis caused by R. insidiosa following lumbar surgery in China. The patient exhibited symptoms of headache, dizziness, and recurrent fever. The fever remained unresolved after empiric antibiotic therapy with intravenous cefotaxime and vancomycin in the initial days. Cerebrospinal fluid (CSF) culture yielded Gram-negative non-fermentative bacteria, which were identified as R. insidiosa. As there was a lack of antibiotic susceptibility testing results, clinical pharmacists conducted a literature review to select appropriate antibiotics. The patient's condition improved after receiving effective treatment with intravenous cefepime and levofloxacin., Conclusions: Uncommon pathogens, such as R. insidiosa, should be considered in postoperative central nervous system (CNS) infections, particularly in cases with unsatisfactory results of empiric anti-infective therapy. This is the first reported case of meningitis caused by R. insidiosa worldwide. MALDI-TOF MS provides rapid and accurate identification of this pathogen. The antibiotic susceptibility testing results of R. indiosa may be interpreted based on the breakpoints for Pseudomonas spp., Burkholderia cepacia spp., and Acinetobacter spp. Our case presents a potential option for empiric therapy against this pathogen, at least in the local area. This is crucial to minimize the severity and mortality rates associated with meningitis. Standardized antibiotic susceptibility testing and breakpoints for the Ralstonia genus should be established in the future as cases accumulate. Cefepime and levofloxacin may be potential antibiotics for infections caused by R. indiosa., (© 2023. BioMed Central Ltd., part of Springer Nature.)
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- 2023
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16. Lead or cadmium co-contamination alters benzene and toluene degrading bacterial communities.
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Konya A, Fiddler BA, Bunch O, Hess KZ, Ferguson C, and Krzmarzick MJ
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- Benzene metabolism, Toluene metabolism, Cadmium metabolism, RNA, Ribosomal, 16S genetics, Lead metabolism, Hydrocarbons metabolism, Bacteria metabolism, Biodegradation, Environmental, Metals, Heavy, Soil Pollutants metabolism
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Co-contamination of hydrocarbons with heavy metals in soils often complicates and hinders bioremediation. A comprehensive characterization of site-specific degraders at contaminated sites can help determine if in situ bioremediation processes are sufficient. This study aimed to identify differences in benzene and toluene degradation rates and the microbial communities enriched under aerobic conditions when different concentrations of Cd and Pb are introduced. Microcosms were used to study the degradation of 0.23 mM benzene or 0.19 mM toluene under various concentrations of Pb (up to 240 µM) and Cd (up to 440 µM). Soil collected from a stormwater retention basin receiving runoff from a large parking lot was utilized to seed the microcosms. The hydrocarbon degradation time and rates were measured. After further rounds of amendment and degradation of benzene and toluene, 16S rRNA gene amplicon sequencing and quantitative PCR were used to ascertain the microbial communities enriched under the various concentrations of the heavy metals. The initial degradation time for toluene and benzene was 7 to 9 days and 10 to 13 days, respectively. Degradation rates were similar for each hydrocarbon despite the concentration and presence of metal co-contaminant, however, the enriched microbial communities under each condition differed. Microcosms without metal co-contaminant contained a diversity of putative benzene and toluene degrading bacteria. Cd strongly reduced the richness of the microbial communities. With higher levels of heavy metals, genera such as Ralstonia, Cupriavidus, Azoarcus, and Rhodococcus became more dominant under various conditions. The study finds that highly efficient benzene- and toluene-degrading consortia can develop under variations of heavy metal co-contamination, but the consortia are dependent on the heavy metal type and concentrations., (© 2023. The Author(s), under exclusive licence to Springer Nature B.V.)
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- 2023
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17. Presence of Ralstonia pseudosolanacearum (Phylotype I) in Aquatic Environments in the Netherlands.
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Vogelaar MAW, van de Bilt JLJ, Blom NI, Pel MJC, van Doorn BJA, Landman NM, Gorkink-Smits PPMA, Raaymakers TM, Vreeburg RAM, and Bergsma-Vlami M
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- Netherlands, Ralstonia, Ralstonia solanacearum, Solanum lycopersicum
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Ralstonia pseudosolanacearum , a European Union quarantine organism, was until recently absent in the aquatic environments and outdoor cultivation systems of the region. This bacterium was only sporadically reported in restricted greenhouse cultivation systems in some EU countries. In this paper, we report the first findings of R. pseudosolanacearum (phylotype I) in surface water in two distinct geographic locations in the Netherlands in 2020. In 2021, the population of R. pseudosolanacearum in surface water ranged from 10
4 to 106 CFU/liter. An inoculum reservoir for R. pseudosolanacearum in these aquatic environments was the wild bittersweet plant where population densities ranged from 105 to 107 CFU/ml concentrated bittersweet extract. The virulence of the R. pseudosolanacearum isolates from surface water and bittersweet was confirmed by a pathogenicity test on Solanum lycopersicum cv. Moneymaker plants, resulting in wilting and necrosis of the plants. Sequence analysis of the egl locus of R. pseudosolanacearum isolates from surface water and bittersweet revealed that these isolates are closely related to R. pseudosolanacearum (phylotype I) isolates found previously in the Netherlands on rose. R. pseudosolanacearum (phylotype I) has a very broad host plant range, including potato, many ornamentals, and other economically important crops. This highlights the risk for various host plants grown in the vicinity of the geographic locations where R. pseudosolanacearum has been found and shows the importance of unraveling the epidemiological parameters of the survival, establishment, and spread of R. pseudosolanacearum in temperate climates., Competing Interests: The author(s) declare no conflict of interest.- Published
- 2023
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18. Exploring breast tissue microbial composition and the association with breast cancer risk factors.
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German R, Marino N, Hemmerich C, Podicheti R, Rusch DB, Stiemsma LT, Gao H, Xuei X, Rockey P, and Storniolo AM
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- Pregnancy, Humans, Female, Dysbiosis, RNA, Ribosomal, 16S genetics, Lactobacillus genetics, Breast Neoplasms etiology, Breast Neoplasms genetics
- Abstract
Background: Microbial dysbiosis has emerged as an important element in the development and progression of various cancers, including breast cancer. However, the microbial composition of the breast from healthy individuals, even relative to risk of developing breast cancer, remains unclear. Here, we performed a comprehensive analysis of the microbiota of the normal breast tissue, which was analyzed in relation to the microbial composition of the tumor and adjacent normal tissue., Methods: The study cohorts included 403 cancer-free women (who donated normal breast tissue cores) and 76 breast cancer patients (who donated tumor and/or adjacent normal tissue samples). Microbiome profiling was obtained by sequencing the nine hypervariable regions of the 16S rRNA gene (V1V2, V2V3, V3V4, V4V5, V5V7, and V7V9). Transcriptome analysis was also performed on 190 normal breast tissue samples. Breast cancer risk score was assessed using the Tyrer-Cuzick risk model., Results: The V1V2 amplicon sequencing resulted more suitable for the analysis of the normal breast microbiome and identified Lactobacillaceae (Firmicutes phylum), Acetobacterraceae, and Xanthomonadaceae (both Proteobacteria phylum) as the most abundant families in the normal breast. However, Ralstonia (Proteobacteria phylum) was more abundant in both breast tumors and histologically normal tissues adjacent to malignant tumors. We also conducted a correlation analysis between the microbiome and known breast cancer risk factors. Abundances of the bacterial taxa Acetotobacter aceti, Lactobacillus vini, Lactobacillus paracasei, and Xanthonomas sp. were associated with age (p < 0.0001), racial background (p < 0.0001), and parity (p < 0.0001). Finally, transcriptome analysis of normal breast tissues showed an enrichment in metabolism- and immune-related genes in the tissues with abundant Acetotobacter aceti, Lactobacillus vini, Lactobacillus paracasei, and Xanthonomas sp., whereas the presence of Ralstonia in the normal tissue was linked to dysregulation of genes involved in the carbohydrate metabolic pathway., Conclusions: This study defines the microbial features of normal breast tissue, thus providing a basis to understand cancer-related dysbiosis. Moreover, the findings reveal that lifestyle factors can significantly affect the normal breast microbial composition., (© 2023. The Author(s).)
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- 2023
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19. A urokinase-associated outbreak of Ralstonia mannitolilytica bloodstream infections in haemodialysis patients in north-eastern Italy, January to April 2023.
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Fabricci M, Trinca A, Talotti L, Busetti M, Fotakis EA, Merakou C, Koncan R, Ghiotti A, Negri C, Di Maso V, Bosco M, Antonelli A, Coppi M, Rossolini GM, Giuliani C, Scarpis E, Gregoretti B, Licastro D, Luzzati R, and Costantino V
- Subjects
- Humans, Urokinase-Type Plasminogen Activator genetics, Urokinase-Type Plasminogen Activator therapeutic use, Renal Dialysis adverse effects, Disease Outbreaks, Gram-Negative Bacterial Infections diagnosis, Gram-Negative Bacterial Infections drug therapy, Gram-Negative Bacterial Infections epidemiology, Sepsis epidemiology
- Abstract
An outbreak of Ralstonia mannitolilytica bloodstream infections occurred in four hospitals in north-eastern Italy, involving 20 haemodialysis patients with tunnelled central vascular catheter access. We identified as the outbreak source a batch of urokinase vials imported from India contaminated with R. mannitolilytica. Whole genome sequences of the clinical and urokinase strains were highly related, and only urokinase-treated patients were reported with R. mannitolilytica infections (attack rate = 34%; 95% confidence interval: 22.1-47.4). Discontinuation of the contaminated urokinase terminated the outbreak.
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- 2023
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20. Pulmonary microbiota signatures adjacent to adenocarcinoma, squamous cell carcinoma and benign lesion.
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Li J, Wu G, Yang J, Yan J, Li D, Wang Q, Xia Y, Zhu J, Guo B, Cheng F, Sun J, Cao H, and Zhang F
- Abstract
Introduction: The occurrence and progression of lung cancer are influenced by pulmonary microbiota, yet the relationship between changes in the pulmonary microbiota and lung cancer remains unclear., Methods: To investigate the correlation between pulmonary microbiota and the signature of lung lesions, we analyzed the microbial composition at sites adjacent to the stage 1 adenocarcinoma, squamous carcinoma and benign lesion tissues in 49 patients by using 16S ribosomal RNA gene sequencing. We then conducted Linear discriminant analysis, receiver operating characteristic (ROC) curve analysis and PICRUSt prediction based on 16S sequencing results., Results: Overall, the microbiota composition at sites close to lung lesions showed significant differences between different lesion types. Based on the results of LEfSe analysis, Ralstonia, Acinetobacter and Microbacterium are the dominant genera of lung adenocarcinoma (LUAD), lung squamous carcinoma (LUSC) and benign lesions (BENL), respectively. Furthermore, we determined the diagnostic value of the abundance ratio of Ralstonia to Acinetobacter in adenocarcinoma patients through ROC curve analysis. The PICRUSt analysis revealed 15 remarkably different metabolic pathways in these lesion types. In LUAD patients, the increase of the pathway associated with xenobiotic biodegradation may be due to the continuous proliferation of microbe with degradation ability of xenobiotics, which implied that LUAD patients are often exposed to harmful environment., Discussion: The abundance of Ralstonia was related to the development of lung cancer. By measuring the abundance of microbiota in diseased tissues, we can distinguish between different types of lesions. The differences in pulmonary microbiota between lesion types are significant in understanding the occurrence and development of lung lesions., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2023 Li, Wu, Yang, Yan, Li, Wang, Xia, Zhu, Guo, Cheng, Sun, Cao and Zhang.)
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- 2023
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21. Ralstonia chuxiongensis sp. nov., Ralstonia mojiangensis sp. nov., and Ralstonia soli sp. nov., isolated from tobacco fields, are three novel species in the family Burkholderiaceae .
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Lu CH, Zhang YY, Jiang N, Chen W, Shao X, Zhao ZM, Lu WL, Hu X, Xi YX, Zou SY, Wei QJ, Lin ZL, Gong L, Gai XT, Zhang LQ, Li JY, Jin Y, and Xia ZY
- Abstract
Competing Interests: XS and LG are employed by the Puer Branch of Yunnan Tobacco Company, Z-MZ and Y-XX are employed by the Baoshan Branch of Yunnan Tobacco Company, W-LL is employed by the Zhaotong Branch of Yunnan Tobacco Company, XH is employed by the Chuxiong Branch of Yunnan Tobacco Company, and Z-LL is employed by the China National Tobacco Corporation Yunnan Company, respectively. The remaining authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.
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- 2023
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22. New insights into the characteristic skin microorganisms in different grades of acne and different acne sites.
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Guo Z, Yang Y, Wu Q, Liu M, Zhou L, Zhang L, and Dong D
- Abstract
Background: The increasing maturity of sequencing technology provides a convenient approach to studying the role of skin microorganisms in acne pathogenesis. However, there are still too few studies about the skin microbiota of Asian acne patients, especially a lack of detailed analysis of the characteristics of the skin microbiota in the different acne sites., Methods: In this study, a total of 34 college students were recruited and divided into the health, mild acne, and severe acne groups. The bacterial and fungal flora of samples were separately detected by 16S and 18S rRNA gene sequencing. The biomarkers of different acne grades and different acne sites [forehead, cheek, chin, torso (including chest and back)] were excavated., Results and Discussion: Our results indicated that there was no significant difference in species diversity between groups. The genera like Propionibacterium, Staphylococcus, Corynebacterium , and Malassezia , which have a relatively high abundance in the skin microbiota and were reported as the most acne-associated microbes, were no obvious differences between groups. On the contrary, the abundance of less reported Gram-negative bacteria ( Pseudomonas , Ralstonia , and Pseudidiomarina ) and Candida has a significant alteration. Compared with the health group and the mild group, in the severe group, the abundance of Pseudomonas and Ralstonia sharply reduced while that of Pseudidiomarina and Candida remarkably raised. Moreover, different acne sites have different numbers and types of biomarkers. Among the four acne sites, the cheek has the greatest number of biomarkers including Pseudomonas , Ralstonia , Pseudidiomarina , Malassezia , Saccharomyces , and Candida , while no biomarker was observed for the forehead. The network analysis indicated that there might be a competitive relationship between Pseudomonas and Propionibacterium . This study would provide a new insight and theoretical basis for precise and personalized acne microbial therapy., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2023 Guo, Yang, Wu, Liu, Zhou, Zhang and Dong.)
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- 2023
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23. Proposal to classify Ralstonia solanacearum phylotype I strains as Ralstonia nicotianae sp. nov., and a genomic comparison between members of the genus Ralstonia .
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Liu JY, Zhang JF, Wu HL, Chen Z, Li SY, Li HM, Zhang CP, Zhou YQ, and Lu CH
- Abstract
A Gram-negative, aerobic, rod-shaped, motile bacterium with multi-flagella, strain RS
T , was isolated from bacterial wilt of tobacco in Yuxi city of Yunnan province, China. The strain contains the major fatty acids of C16:0 , summed feature 3 (C16:1 ω 7 c and/or C16:1 ω 6 c ), and summed feature 8 (C18:1 ω 7 c and/or C18:1 ω 6 c ). The polar lipid profile of strain RST consists of diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine, and unidentified aminophospholipid. Strain RST contains ubiquinones Q-7 and Q-8. 16S rRNA gene sequence (1,407 bp) analysis showed that strain RST is closely related to members of the genus Ralstonia and shares the highest sequence identities with R. pseudosolanacearum LMG 9673T (99.50%), R. syzygii subsp. indonesiensis LMG 27703T (99.50%), R. solanacearum LMG 2299T (99.28%), and R. syzygii subsp. celebesensis LMG 27706T (99.21%). The 16S rRNA gene sequence identities between strain RST and other members of the genus Ralstonia were below 98.00%. Genome sequencing yielded a genome size of 5.61 Mbp and a G + C content of 67.1 mol%. The genomic comparison showed average nucleotide identity (ANIb) values between strain RST and R. pseudosolanacearum LMG 9673T , R. solanacearum LMG 2299T , and R. syzygii subsp. indonesiensis UQRS 627T of 95.23, 89.43, and 91.41%, respectively, and the corresponding digital DNA-DNA hybridization (dDDH) values (yielded by formula 2) were 66.20, 44.80, and 47.50%, respectively. In addition, strains belonging to R. solanacearum phylotype I shared both ANIb and dDDH with strain RST above the species cut-off values of 96 and 70%, respectively. The ANIb and dDDH values between the genome sequences from 12 strains of R. solanacearum phylotype III (Current R. pseudosolanacearum ) and those of strain RST were below the species cut-off values. Based on these data, we concluded that strains of phylotype I, including RST , represent a novel species of the genus Ralstonia , for which the name Ralstonia nicotianae sp. nov. is proposed. The type strain of Ralstonia nicotianae sp. nov. is RST (=GDMCC 1.3533T = JCM 35814T )., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2023 Liu, Zhang, Wu, Chen, Li, Li, Zhang, Zhou and Lu.)- Published
- 2023
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24. The genus Ralstonia : The new kid on the block.
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Rajni E, Goel P, Sarna MK, Jorwal A, Sharma C, and Rijhwani P
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- Humans, Ralstonia, Critical Care, Disease Outbreaks, Gram-Negative Bacterial Infections diagnosis, Gram-Negative Bacterial Infections drug therapy
- Abstract
The genus Ralstonia comprises of aerobic, gram-negative, oxidase positive, nonfermentative, largely environmental organisms. They are an emerging pathogen in the hospital setting and are increasingly associated with opportunistic infections and outbreaks. We hereby present a case series of six patients diagnosed with bacteraemia caused by Ralstonia spp. and a brief review of literature. These cases highlight that isolation of a nonfermenting gram-negative bacillus from blood culture of a patient admitted in critical care setting should not be ignored as mere contaminant. Clinicians and microbiologists need to work as a team to combat this novel bug.
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- 2023
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25. Plant-Pathogenic Ralstonia Phylotypes Evolved Divergent Respiratory Strategies and Behaviors To Thrive in Xylem.
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Truchon AN, Dalsing BL, Khokhani D, MacIntyre A, McDonald BR, Ailloud F, Klassen J, Gonzalez-Orta ET, Currie C, Prior P, Lowe-Power TM, and Allen C
- Subjects
- Nitrates metabolism, Nitrous Oxide metabolism, Xylem microbiology, Water metabolism, Plant Diseases microbiology, Ralstonia, Ralstonia solanacearum
- Abstract
Bacterial pathogens in the Ralstonia solanacearum species complex (RSSC) infect the water-transporting xylem vessels of plants, causing bacterial wilt disease. Strains in RSSC phylotypes I and III can reduce nitrate to dinitrogen via complete denitrification. The four-step denitrification pathway enables bacteria to use inorganic nitrogen species as terminal electron acceptors, supporting their growth in oxygen-limited environments such as biofilms or plant xylem. Reduction of nitrate, nitrite, and nitric oxide all contribute to the virulence of a model phylotype I strain. However, little is known about the physiological role of the last denitrification step, the reduction of nitrous oxide to dinitrogen by NosZ. We found that phylotypes I and III need NosZ for full virulence. However, strains in phylotypes II and IV are highly virulent despite lacking NosZ. The ability to respire by reducing nitrate to nitrous oxide does not greatly enhance the growth of phylotype II and IV strains. These partial denitrifying strains reach high cell densities during plant infection and cause typical wilt disease. However, unlike phylotype I and III strains, partial denitrifiers cannot grow well under anaerobic conditions or form thick biofilms in culture or in tomato xylem vessels. Furthermore, aerotaxis assays show that strains from different phylotypes have different oxygen and nitrate preferences. Together, these results indicate that the RSSC contains two subgroups that occupy the same habitat but have evolved divergent energy metabolism strategies to exploit distinct metabolic niches in the xylem. IMPORTANCE Plant-pathogenic Ralstonia spp. are a heterogeneous globally distributed group of bacteria that colonize plant xylem vessels. Ralstonia cells multiply rapidly in plants and obstruct water transport, causing fatal wilting and serious economic losses of many key food security crops. The virulence of these pathogens depends on their ability to grow to high cell densities in the low-oxygen xylem environment. Plant-pathogenic Ralstonia can use denitrifying respiration to generate ATP. The last denitrification step, nitrous oxide reduction by NosZ, contributes to energy production and virulence for only one of the three phytopathogenic Ralstonia species. These complete denitrifiers form thicker biofilms in culture and in tomato xylem, suggesting they are better adapted to hypoxic niches. Strains with partial denitrification physiology form less biofilm and are more often planktonic. They are nonetheless highly virulent. Thus, these closely related bacteria have adapted their core metabolic functions to exploit distinct microniches in the same habitat.
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- 2023
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26. Spherical pneumonia caused by Ralstonia mannitolilytica: a case report and literature review.
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Ma J, Zhang C, Dang K, Liao Y, Feng X, and Zhou P
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- Female, Humans, Adult, Lung diagnostic imaging, Ralstonia, Bronchoalveolar Lavage Fluid, High-Throughput Nucleotide Sequencing, Pneumonia diagnosis, Pneumonia drug therapy, Pulmonary Atelectasis, Lung Neoplasms
- Abstract
Background: Spherical pneumonia is an extremely rare condition that is difficult to diagnose. It is a specific type of lung infection that often manifests as a round or round-like mass on chest imaging. Spherical pneumonia is easily misdiagnosed as a pulmonary tumor; therefore, awareness of this disease must be strengthened., Case Presentation: The patient was a 29-year-old female who had persistent cough and sputum for approximately 1 month and fever for 5 days. Chest computed tomography (CT) at our hospital revealed a mass in the lower lobe of the right lung near the hilar region, with obstructive pulmonary atelectasis and obstructive pneumonia. Although lung cancer was suspected, Ralstonia mannitolilytica was detected by metagenomic next-generation sequencing (mNGS) of bronchoalveolar lavage fluid, and no cancer cells or Mycobacterium tuberculosis were detected. Finally, the patient was diagnosed with spherical pneumonia caused by R. mannitolilytica. Anti-infective treatment, symptomatic treatment, and administration of a traditional Chinese medicine decoction were performed based on the syndrome differentiation. After 10 days of treatment, chest CT revealed few lesions in the lower lobe of the right lung, which were significantly reduced compared with those in the past., Conclusions: Spherical pneumonia caused by R. mannitolilytica has not yet been reported and differential diagnosis is key in clinical diagnosis. When spherical pneumonia is difficult to diagnose, mNGS may be a better alternative., (© 2023. The Author(s).)
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- 2023
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27. Acute focal bacterial nephritis caused by Ralstonia insidiosa in a 9-year-old boy.
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Yamamoto S, Tate M, Hotokebuchi N, and Nakamura K
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- Male, Humans, Child, Bacteria, Acute Disease, Ralstonia, Nephritis microbiology
- Published
- 2023
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28. Outbreak of Ralstonia bacteraemia among chronic kidney disease patients in a haemodialysis unit in the Philippines.
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Aranas DR, Demot BA, and Cajulao TPT
- Subjects
- Humans, Male, Female, Aged, Hemodialysis Units, Hospital, Philippines, Renal Dialysis, Ralstonia, Disease Outbreaks prevention & control, Cross Infection diagnosis, Cross Infection epidemiology, Cross Infection prevention & control, Renal Insufficiency, Chronic epidemiology, Bacteremia diagnosis, Bacteremia epidemiology
- Abstract
Ralstonia insidiosa is an opportunistic pathogen considered an emerging problem among clinically vulnerable populations such as those with chronic kidney disease. This study presents three cases of Ralstonia bacteraemia among chronic kidney disease patients in a haemodialysis unit in Baguio City, the Philippines. Case 1 was an elderly male who experienced chills during two concurrent dialysis sessions. Case 2 was a young female who also experienced chills and dizziness during a dialysis session; as this was thought to be related to hypotension, she was admitted. Case 3 was an elderly female with known hypertension and diabetes who had been newly diagnosed with chronic kidney disease; she was brought to the emergency department hypotensive, dyspnoeic and disoriented with deranged laboratory parameters and was admitted to the intensive care unit. All three cases had blood cultures positive for R. insidiosa with an attack rate of 1.67%. Drug and device tracing were conducted and environmental samples collected to identify the source of infection. A sample from the faucet of the reprocessing machine in the haemodialysis unit that was positive for Ralstonia spp . was the source of the outbreak. Control measures were implemented and the haemodialysis unit was thoroughly cleaned. No further cases were reported, with active surveillance continuing until January 2022. Taken with previously published outbreaks, these findings suggest that medical products and devices can be contaminated with Ralstonia spp . and cause illness. Early identification of cases and the source of infection is required to prevent large outbreaks in this vulnerable population., Competing Interests: The authors have no conflicts of interest to declare., ((c) 2022 The authors; licensee World Health Organization.)
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- 2022
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29. Validating Methods To Eradicate Plant-Pathogenic Ralstonia Strains Reveals that Growth In Planta Increases Bacterial Stress Tolerance.
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Hayes MM, Dewberry RJ, Babujee L, Moritz R, and Allen C
- Subjects
- Chlorine, Hydrogen Peroxide, Canada, Plant Diseases prevention & control, Plant Diseases microbiology, Ralstonia, Ralstonia solanacearum physiology
- Abstract
Plant-pathogenic bacteria in the Ralstonia solanacearum species complex (RSSC) cause highly destructive bacterial wilt disease of diverse crops. Wilt disease prevention and management is difficult because RSSC persists in soil, water, and plant material. Growers need practical methods to kill these pathogens in irrigation water, a common source of disease outbreaks. Additionally, the R. solanacearum race 3 biovar 2 (R3bv2) subgroup is a quarantine pest in many countries and a highly regulated select agent pathogen in the United States. Plant protection officials and researchers need validated protocols to eradicate R3bv2 for regulatory compliance. To meet these needs, we measured the survival of four R3bv2 and three phylotype I RSSC strains following treatment with hydrogen peroxide, stabilized hydrogen peroxide (Huwa-San), active chlorine, heat, UV radiation, and desiccation. No surviving RSSC cells were detected after cultured bacteria were exposed for 10 min to 400 ppm hydrogen peroxide, 50 ppm Huwa-San, 50 ppm active chlorine, or temperatures above 50°C. RSSC cells on agar plates were eradicated by 30 s of UV irradiation and killed by desiccation on most biotic and all abiotic surfaces tested. RSSC bacteria did not survive the cell lysis steps of four nucleic acid extraction protocols. However, bacteria in planta were more difficult to kill. Stems of infected tomato plants contained a subpopulation of bacteria with increased tolerance of heat and UV light, but not oxidative stress. This result has significant management implications. We demonstrate the utility of these protocols for compliance with select agent research regulations and for management of a bacterial wilt outbreak in the field. IMPORTANCE Bacteria in the Ralstonia solanacearum species complex (RSSC) are globally distributed and cause destructive vascular wilt diseases of many high-value crops. These aggressive pathogens spread in diseased plant material and via contaminated soil, tools, and irrigation water. A subgroup of the RSSC, race 3 biovar 2, is a European and Canadian quarantine pathogen and a U.S. select agent subject to stringent and constantly evolving regulations intended to prevent pathogen introduction or release. We validated eradication and inactivation methods that can be used by (i) growers seeking to disinfest water and manage bacterial wilt disease outbreaks, (ii) researchers who must remain in compliance with regulations, and (iii) regulators who are expected to define containment practices. Relevant to all these stakeholders, we show that while cultured RSSC cells are sensitive to relatively low levels of oxidative chemicals, desiccation, and heat, more aggressive treatment, such as autoclaving or incineration, is required to eradicate plant-pathogenic Ralstonia growing inside plant material.
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- 2022
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30. Ralstonia wenshanensis sp. nov., a novel bacterium isolated from a tobacco field in Yunnan, China.
- Author
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Lu CH, Chen W, Yin HH, Lin ZL, Li JY, Ma JH, Gai XT, Jiang N, Cao ZH, Qian L, Zhang LQ, Jin Y, and Xia ZY
- Subjects
- Nicotiana, Ralstonia genetics, RNA, Ribosomal, 16S genetics, China, Sequence Analysis, DNA, Base Composition, Phylogeny, Bacterial Typing Techniques, DNA, Bacterial genetics, Bacteria genetics, Fatty Acids chemistry, Phospholipids
- Abstract
A Gram-negative, aerobic, motile with paired polar flagella and rod-shaped bacterium strain (56D2
T ) was isolated from tobacco planting soil in Yunnan, PR China. Major fatty acids were C16 : 1 ω 7 c (summed feature 3), C16 : 0 and C18 : 1 ω 7 c (summed feature 8). The polar lipid profile of strain 56D2T consisted of diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylglycerol, one unidentified aminophospholipid and one unidentified glycolipid. Moreover, strain 56D2T contained ubiquinone Q-8 as the sole respiratory quinone. 16S rRNA gene sequence analysis showed that strain 56D2T was closely related to members of the genus Ralstonia and the two type strains with the highest sequence identities were R. mannitolilytica LMG 6866T (98.36 %) and R. pickettii K-288T (98.22 %). The 16S rRNA gene sequence identities between strain 56D2T and other members of the genus Ralstonia were below 98.00 %. Genome sequencing revealed a genome size of 5.87 Mb and a G+C content of 63.7 mol%. The average nucleotide identity values between strain 56D2T and R. pickettii K-288T , R. mannitolilytica LMG 6866T and R. insidiosa CCUG 46789T were less than 95 %, and the in silico DNA-DNA hybridization values (yielded by formula 2) were less than 70 %. Based on these data, we conclude that strain 56D2T represents a novel species of the genus Ralstonia , for which the name Ralstonia wenshanensis sp. nov. is proposed. The type strain of Ralstonia wenshanensis sp. nov. is 56D2T (=CCTCC AB 2021466T =GDMCC 1.2886T =JCM 35178T ).- Published
- 2022
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31. Ralstonia pickettii and Pseudomonas aeruginosa Bloodstream Infections Associated With Contaminated Extracorporeal Membrane Oxygenation Water Heater Devices.
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Baker MA, Rhee C, Tucker R, Vaidya V, Holtzman M, Seethala RR, Bentain-Melanson M, Lenox J, Smith AR, Gassett A, Huntley M, Sater M, Reilly K, and Klompas M
- Subjects
- Humans, Pseudomonas aeruginosa, Water, Ralstonia pickettii, Extracorporeal Membrane Oxygenation, Bacteremia, Pseudomonas Infections
- Abstract
We report on probable factory-based contamination of portable water heaters with waterborne pathogens and 2 bloodstream infections potentially attributable to off-label use of these water heaters to warm extracorporeal membrane oxygenation circuits. Great caution is warranted when using water-based devices to care for critically ill patients., Competing Interests: Potential conflicts of interest. M. B., C. R., and M. K. have received grant funding from the Centers for Disease Control and Prevention within the past 3 years for research on severe acute respiratory syndrome coronavirus 2 prevention and transmission and currently receive grant funding for research on unrelated topics. C. R. and M. K. also have grant funding from AHRQ. M. K. receives funding from the Massachusetts Department of Public Health to support public health surveillance. M. K. has received royalties from UpToDate, Inc., for chapters on preventing nosocomial pneumonia and other unrelated topics. C. R. has received royalties from UpToDate, Inc., for chapters related to procalcitonin use. M. H. H. and M. R. S. are employees of Day Zero Diagnostics. A. S. received consulting fees from Inspira Technologies. R. S. reports consulting fees from BD. C. R. reports consulting fees from Pfizer and Cytovale. M. B. reports holding a leadership or fiduciary role on the SHEA Guidelines Committee. All other authors report no potential conflicts., (© The Author(s) 2022. Published by Oxford University Press on behalf of the Infectious Diseases Society of America. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)
- Published
- 2022
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32. An outbreak of Ralstonia insidiosa bloodstream infections caused by contaminated heparinized syringes.
- Author
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Tüzemen NÜ, Önal U, Kazak E, Tezgeç N, Eren H, Şimşek H, Bakkaloğlu Z, Ünaldı Ö, Çelebi S, Yılmaz E, Hacımustafaoğlu M, Akalın EH, and Özakın C
- Subjects
- Disease Outbreaks, Humans, Ralstonia, Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization, Syringes, Cross Infection microbiology, Sepsis
- Abstract
Introduction: Ralstonia insidiosa, a gram-negative waterborne bacteria able to survive and grow in any type of water source, can cause nosocomial infections, and are considered emerging pathogens of infectious diseases in hospital settings. In this study, we report an outbreak of R. insidiosa at our center related to contaminated heparinized syringes., Material and Methods: The present study was conducted in a tertiary care university hospital in Turkey. An outbreak analysis was performed between September 2021 and December 2021. Microbiological samples were obtained from environmental sources and from patient blood cultures. Species identification was performed using matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS). To investigate the clonality of strains, all confirmed isolates were sent to the National Reference Laboratory and pulsed-field gel electrophoresis (PFGE) was used to perform molecular typing., Results: Seventeen R. insidiosa isolates were identified from the blood cultures of 13 patients from various wards and intensive care units. Isolates from seven patient blood cultures and two heparinized blood gas syringes were characterized by PFGE. All isolates were found to belong to the same clone of R. insidiosa., Conclusion: R. insidiosa was identified as the cause of a nosocomial infection outbreak in our hospital, which was then rapidly controlled by the infection-control team. When rare waterborne microorganisms grow in blood or other body fluid cultures, clinicians and the infection-control team should be made aware of a possible outbreak., (Copyright © 2022 Japanese Society of Chemotherapy and The Japanese Association for Infectious Diseases. Published by Elsevier Ltd. All rights reserved.)
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- 2022
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33. Ralstonia Strains from Potato-Growing Regions of Kenya Reveal Two Phylotypes and Epidemic Clonality of Phylotype II Sequevar 1 Strains.
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Sharma K, Iruegas-Bocardo F, Abdurahman A, Alcalá-Briseño RI, Garrett KA, Goss EM, Ngundo G, Kreuze J, Atieno E, and Munguti F
- Subjects
- Kenya epidemiology, Phylogeny, Plant Diseases microbiology, Ralstonia, Ralstonia solanacearum genetics, Solanum tuberosum microbiology
- Abstract
Bacterial wilt, caused by the Ralstonia solanacearum species complex (RSSC), is the most destructive potato disease in Kenya. Studies were conducted to (i) determine the molecular diversity of RSSC strains associated with bacterial wilt of potato in Kenya, (ii) generate an RSSC distribution map for epidemiological inference, and (iii) determine whether phylotype II sequevar 1 strains exhibit epidemic clonality. Surveys were conducted in 2018 and 2019, in which tubers from wilting potato plants and stem samples of potential alternative hosts were collected for pathogen isolation. The pathogen was phylotyped by multiplex PCR and 536 RSSC strains typed at a sequevar level. Two RSSC phylotypes were identified, phylotype II (98.4%, n = 506 [sequevar 1 ( n = 505) and sequevar 2 ( n = 1)]) and phylotype I (1.6%, n = 30 [sequevar 13 ( n = 9) and a new sequevar ( n = 21)]). The phylotype II sequevar 1 strains were haplotyped using multilocus tandem repeat sequence typing (TRST) schemes. The TRST scheme identified 51 TRST profiles within the phylotype II sequevar 1 strains with a modest diversity index (HGDI = 0.87), confirming the epidemic clonality of RSSC phylotype II sequevar 1 strains in Kenya. A minimum spanning tree and mapping of the TRST profiles revealed that TRST27 '8-5-12-7-5' is the primary founder of the clonal complex of RSSC phylotype II sequevar 1 and is widely distributed via latently infected seed tubers. [Formula: see text] Copyright © 2022 The Author(s). This is an open access article distributed under the CC BY-NC-ND 4.0 International license.
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- 2022
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34. Genome-wide identification of type III effectors and other virulence factors in Ralstonia pseudosolanacearum causing bacterial wilt in ginger (Zingiber officinale).
- Author
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Suraby EJ, Sruthi KB, and Antony G
- Subjects
- Phylogeny, Plant Diseases, Ralstonia, Virulence Factors, Zingiber officinale, Ralstonia solanacearum
- Abstract
Ralstonia pseudosolanacearum causes bacterial wilt in ginger, reducing ginger production worldwide. We sequenced the whole genome of a highly virulent phylotype I, race 4, biovar 3 Ralstonia pseudosolanacearum strain GRsMep isolated from a severely infected ginger field in India. R. pseudosolanacearum GRsMep genome is organised into two replicons: chromosome and megaplasmid with a total genome size of 5,810,605 bp. This strain encodes approximately 72 effectors which include a combination of core effectors as well as highly variable, diverse repertoire of type III effectors. Comparative genome analysis with GMI1000 identified conservation in the genes involved in the general virulence mechanism. Our analysis identified type III effectors, RipBJ and RipBO as present in GRsMep but absent in the reported genomes of other strains infecting Zingiberaceae family. GRsMep contains 126 unique genes when compared to the pangenome of the Ralstonia strains that infect the Zingiberaceae family. The whole-genome data of R. pseudosolanacearum strain will serve as a resource for exploring the evolutionary processes that structure and regulate the virulence determinants of the strain. Pathogenicity testing of the transposon insertional mutant library of GRsMep through virulence assay on ginger plants identified a few candidate virulence determinants specific to bacterial wilt in ginger., (© 2022. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)
- Published
- 2022
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35. Transmission of Blood Disease in Banana.
- Author
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Ray JD, Subandiyah S, Prakoso AB, Rincón-Flórez VA, Carvalhais LC, and Drenth A
- Subjects
- Bacteria, Humans, Plant Diseases microbiology, Ralstonia, Hematologic Diseases, Musa microbiology
- Abstract
Banana Blood disease is a bacterial wilt caused by Ralstonia syzygii subsp. celebesensis and is an economically important disease in Indonesia and Malaysia. Transmission of this pathogen is hypothesized to occur through insects mechanically transferring bacteria from diseased to healthy banana inflorescences and other pathways involving pruning tools, water movement, and root-to-root contact. This study demonstrates that the ooze from the infected male bell and the sap from various symptomatic plant parts are infective, and the cut surfaces of a bunch peduncle, petiole, corm, pseudostem, and the rachis act as infection courts for R. syzygii subsp. celebesensis. In addition, evidence is provided that R. syzygii subsp. celebesensis is highly tool transmissible, that the bacterium can be transferred from the roots of a diseased plant to the roots of a healthy plant and transferred from the mother plant to the sucker. We provide evidence that local dispersal of Blood disease occurs predominantly through mechanical transmission by insects, birds, bats, or human activities from diseased to healthy banana plants and that long-distance dispersal occurs through the movement of contaminated planting material. Disease management strategies to prevent crop losses associated with this emerging disease are discussed based on our findings.
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- 2022
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36. The NEL Family of Bacterial E3 Ubiquitin Ligases.
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Bullones-Bolaños A, Bernal-Bayard J, and Ramos-Morales F
- Subjects
- Bacteria metabolism, Bacterial Proteins metabolism, Ubiquitin genetics, Ubiquitin metabolism, Type III Secretion Systems genetics, Ubiquitin-Protein Ligases metabolism
- Abstract
Some pathogenic or symbiotic Gram-negative bacteria can manipulate the ubiquitination system of the eukaryotic host cell using a variety of strategies. Members of the genera Salmonella , Shigella , Sinorhizobium , and Ralstonia , among others, express E3 ubiquitin ligases that belong to the NEL family. These bacteria use type III secretion systems to translocate these proteins into host cells, where they will find their targets. In this review, we first introduce type III secretion systems and the ubiquitination process and consider the various ways bacteria use to alter the ubiquitin ligation machinery. We then focus on the members of the NEL family, their expression, translocation, and subcellular localization in the host cell, and we review what is known about the structure of these proteins, their function in virulence or symbiosis, and their specific targets.
- Published
- 2022
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37. Draft Genome Sequence of Ralstonia syzygii subsp. celebesensis from Indonesia, the Causal Agent of Blood Disease of Banana.
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Prakoso AB, Joko T, Soffan A, Sari JP, Ray JD, Drenth A, and Subandiyah S
- Subjects
- Genome, Plant, Indonesia, Phylogeny, Plant Diseases, Ralstonia, Hematologic Diseases genetics, Musa genetics
- Published
- 2022
- Full Text
- View/download PDF
38. Meroterpenoids Possibly Produced by a Bacterial Endosymbiont of the Tropical Basidiomycete Echinochaete brachypora .
- Author
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Hassan K, Chepkirui C, Llanos-López NA, Matasyoh JC, Decock C, Marin-Felix Y, and Stadler M
- Subjects
- Anti-Bacterial Agents chemistry, Bacteria metabolism, Fungi metabolism, Basidiomycota chemistry, Polyporaceae metabolism
- Abstract
A mycelial culture of the African basidiomycete Echinochaete cf. brachypora was studied for biologically active secondary metabolites, and four compounds were isolated from its crude extract derived from shake flask fermentations, using preparative high-performance liquid chromatography (HPLC). The pure metabolites were identified using extensive nuclear magnetic resonance (NMR) spectroscopy and high-resolution mass spectrometry (HR-MS). Aside from the new metabolites 1-methoxyneomarinone ( 1 ) and (E)-3-methyl-5-(-12,13,14-trimethylcyclohex-10-en-6-yl)pent-2-enoic acid ( 4 ), the known metabolites neomarinone ( 2 ) and fumaquinone ( 4 ) were obtained. Such compounds had previously only been reported from Actinobacteria but were never isolated from the cultures of a fungus. This observation prompted us to evaluate whether the above metabolites may actually have been produced by an endosymbiontic bacterium that is associated with the basidiomycete. We have indeed been able to characterize bacterial 16S rDNA in the fungal mycelia, and the production of the metabolites stopped when the fungus was sub-cultured on a medium containing antibacterial antibiotics. Therefore, we have found strong evidence that compounds 1 - 4 are not of fungal origin. However, the endofungal bacterium was shown to belong to the genus Ralstonia , which has never been reported to produce similar metabolites to 1 - 4 . Moreover, we failed to obtain the bacterial strain in pure culture to provide final proof for its identity. In any case, the current report is the first to document that polyporoid Basidiomycota are associated with endosymbionts and constitutes the first report on secondary metabolites from the genus Echinochaete .
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- 2022
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39. Host-Associated Phages Disperse across the Extraterrestrial Analogue Antarctica.
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Rahlff J, Bornemann TLV, Lopatina A, Severinov K, and Probst AJ
- Subjects
- Antarctic Regions, Ecosystem, Metagenomics, Prophages genetics, Bacteriophages genetics
- Abstract
Extreme Antarctic conditions provide one of the closest analogues of extraterrestrial environments. Since air and snow samples, especially from polar regions, yield DNA amounts in the lower picogram range, binning of prokaryotic genomes is challenging and renders studying the dispersal of biological entities across these environments difficult. Here, we hypothesized that dispersal of host-associated bacteriophages (adsorbed, replicating, or prophages) across the Antarctic continent can be tracked via their genetic signatures, aiding our understanding of virus and host dispersal across long distances. Phage genome fragments (PGFs) reconstructed from surface snow metagenomes of three Antarctic stations were assigned to four host genomes, mainly Betaproteobacteria , including Ralstonia spp. We reconstructed the complete genome of a temperate phage with nearly complete alignment to a prophage in the reference genome of Ralstonia pickettii 12D. PGFs from different stations were related to each other at the genus level and matched similar hosts. Metagenomic read mapping and nucleotide polymorphism analysis revealed a wide dispersal of highly identical PGFs, 13 of which were detected in seawater from the Western Antarctic Peninsula at a distance of 5,338 km from the snow sampling stations. Our results suggest that host-associated phages, especially of Ralstonia sp., disperse over long distances despite the harsh conditions of the Antarctic continent. Given that 14 phages associated with two R. pickettii draft genomes isolated from space equipment were identified, we conclude that Ralstonia phages are ideal mobile genetic elements to track dispersal and contamination in ecosystems relevant for astrobiology. IMPORTANCE Host-associated phages of the bacterium Ralstonia identified in snow samples can be used to track microbial dispersal over thousands of kilometers across the Antarctic continent, which functions as an extraterrestrial analogue because of its harsh environmental conditions. Due to the presence of these bacteria carrying genome-integrated prophages on space-related equipment and the potential for dispersal of host-associated phages demonstrated here, our work has implications for planetary protection, a discipline in astrobiology interested in preventing contamination of celestial bodies with alien biomolecules or forms of life.
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- 2022
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- View/download PDF
40. Osteomyelitis Caused by Ralstonia mannitolilytica, a Rare Opportunistic Pathogen.
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Papagrigorakis E, Vavourakis M, Vlachos C, Zachariou D, Galanis A, Marougklianis V, Polyzois V, and Pneumaticos S
- Abstract
Ralstonia spp. are non-fermenting aerobic gram-negative rods found in humid environments, whose role as opportunistic human pathogens has lately been recognized. Ralstonia mannitolilytica is one of the three members of the Ralstonia genus (together with Ralstonia pickettii and Ralstonia insidiosa ). Bone infections by Ralstonia spp. are very rare. We report a case of femoral osteomyelitis caused by R. mannitolilytica . Among literature search, only eight cases of bone infection due to the Ralstonia genus have been described, in all of which the causative agent was identified as R. pickettii . To our knowledge, this is the first reported case of osteomyelitis attributed to R. mannitolilytica . Despite its low virulence, Ralstonia has specific characteristics that promote its spread and shows high antibiotic resistance, partly due to its ability to create a biofilm. Identification of Ralstonia spp. poses unique difficulties as the distinction between the species of the genus is not straightforward. Additionally, the bacteria may be misidentified as other closely related species. Recent data suggests that modern spectrometry and gene sequencing techniques are essential to avoid these pitfalls. Susceptibility data about the genus is limited and based on a small number of case reports, therefore there is no standardized antibiotic susceptibility testing and European Committee on Antimicrobial Susceptibility Testing (EUCAST) breakpoints exist. The report aims is to provide useful information on the antibiotic selection and treatment suggestions to be followed for bone infections caused by the Ralstonia genus, along with a review on the literature of this emerging opportunistic pathogen., Competing Interests: The authors have declared that no competing interests exist., (Copyright © 2022, Papagrigorakis et al.)
- Published
- 2022
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41. Susceptibility of the Banana Inflorescence to Blood Disease.
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Ray JD, Subandiyah S, Rincón-Flórez VA, Prakoso AB, Carvalhais LC, and Drenth A
- Subjects
- Inflorescence, Plant Diseases microbiology, Ralstonia, Hematologic Diseases, Musa microbiology
- Abstract
The bacterium Ralstonia syzygii subsp. celebesensis causes Blood disease of banana, a vascular wilt of economic significance in Indonesia and Malaysia. Blood disease has expanded its geographic range in the last 20 years and is an emerging threat to Southeast Asian banana production. Many aspects of the disease cycle and biology are not well understood, including the ability of different parts of the female and male inflorescence of banana to act as infection courts. This study confirms that the banana varieties of Cavendish, and Kepok 'Kuning' are susceptible to Blood disease and that an inoculum concentration of 10
2 CFU/ml of R. syzygii subsp. celebesensis is adequate to initiate disease after pseudostem inoculation. Data show that infection occurs through both the male and female parts of a banana inflorescence and the rachis when snapped to remove the male bell. The infection courts are the female flowers, the male bell bract scar, the male bell flower cushion, the snapped rachis, and deflowered fingers. The location of these infection courts concurs with the dye studies demonstrating that dye externally applied to these plants parts enters the plant vascular system. Thus, the hypothesis is supported that infection of R. syzygii subsp. celebesensis occurs through open xylem vessels of the male and female parts of the banana inflorescence.- Published
- 2022
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42. A bacterial endosymbiont of the fungus Rhizopus microsporus drives phagocyte evasion and opportunistic virulence.
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Itabangi H, Sephton-Clark PCS, Tamayo DP, Zhou X, Starling GP, Mahamoud Z, Insua I, Probert M, Correia J, Moynihan PJ, Gebremariam T, Gu Y, Ibrahim AS, Brown GD, King JS, Ballou ER, and Voelz K
- Subjects
- Animals, Bacteria, Fungi, Humans, Mammals, Mice, Phagocytes, Rhizopus, Virulence, Zebrafish, Amoeba, Dictyostelium
- Abstract
Opportunistic infections by environmental fungi are a growing clinical problem, driven by an increasing population of people with immunocompromising conditions. Spores of the Mucorales order are ubiquitous in the environment but can also cause acute invasive infections in humans through germination and evasion of the mammalian host immune system. How they achieve this and the evolutionary drivers underlying the acquisition of virulence mechanisms are poorly understood. Here, we show that a clinical isolate of Rhizopus microsporus contains a Ralstonia pickettii bacterial endosymbiont required for virulence in both zebrafish and mice and that this endosymbiosis enables the secretion of factors that potently suppress growth of the soil amoeba Dictyostelium discoideum, as well as their ability to engulf and kill other microbes. As amoebas are natural environmental predators of both bacteria and fungi, we propose that this tri-kingdom interaction contributes to establishing endosymbiosis and the acquisition of anti-phagocyte activity. Importantly, we show that this activity also protects fungal spores from phagocytosis and clearance by human macrophages, and endosymbiont removal renders the fungal spores avirulent in vivo. Together, these findings describe a new role for a bacterial endosymbiont in Rhizopus microsporus pathogenesis in animals and suggest a mechanism of virulence acquisition through environmental interactions with amoebas., Competing Interests: Declaration of interests The authors declare no competing interests., (Copyright © 2022 The Author(s). Published by Elsevier Inc. All rights reserved.)
- Published
- 2022
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43. Ralstonia mannitolilytica sepsis in neonatal intensive care unit - Be(a)ware of the multidrug resistant nosocomial bug.
- Author
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Rajendran UD, Sundaramoorthy S, and Sethuraman G
- Subjects
- Humans, Infant, Newborn, Intensive Care Units, Neonatal, Ralstonia, Cross Infection diagnosis, Cross Infection drug therapy, Cross Infection epidemiology, Gram-Negative Bacterial Infections diagnosis, Gram-Negative Bacterial Infections drug therapy, Gram-Negative Bacterial Infections epidemiology, Sepsis diagnosis, Sepsis drug therapy, Sepsis epidemiology
- Abstract
Ralstonia mannitolilytica , an emerging opportunistic pathogen is rarely isolated in neonatal units. We have elaborated our experience of managing its recent septic outbreak affecting four neonates in our intensive care unit over a span of five days. Three of the four had extremely low birth weight and had secondary clinical deterioration in the form of recurrent apnoea requiring intubation. All had thrombocytopenia. Their median age at clinical deterioration was 8 (4-12) days. The organism was multidrug resistant, but uniformly sensitive to flouroquinolones and co-trimoxazole, on which all recovered. Environmental samples were negative for the organism. There were no further positive cases. Early recognition and appropriate choice of drug will aid in fast recovery.
- Published
- 2022
- Full Text
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44. Genome-Wide Identification of Tomato Xylem Sap Fitness Factors for Three Plant-Pathogenic Ralstonia Species.
- Author
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Georgoulis SJ, Shalvarjian KE, Helmann TC, Hamilton CD, Carlson HK, Deutschbauer AM, and Lowe-Power TM
- Abstract
Plant-pathogenic Ralstonia spp. colonize plant xylem and cause wilt diseases on a broad range of host plants. To identify genes that promote growth of diverse Ralstonia strains in xylem sap from tomato plants, we performed genome-scale genetic screens (random barcoded transposon mutant sequencing screens [RB-TnSeq]) in three strains spanning the genetic, geographical, and physiological range of plant-pathogenic Ralstonia : Ralstonia solanacearum IBSBF1503, Ralstonia pseudosolanacearum GMI1000, and Ralstonia syzygii PSI07. Contrasting mutant fitness phenotypes in culture media versus in xylem sap suggest that Ralstonia strains are adapted to ex vivo xylem sap and that culture media impose foreign selective pressures. Although wild-type Ralstonia grew in sap and in rich medium with similar doubling times and to a similar carrying capacity, more genes were essential for growth in sap than in rich medium. Each strain required many genes associated with envelope remodeling and repair processes for full fitness in xylem sap. These genes were associated with peptidoglycan peptide formation ( murI ), secretion of periplasmic proteins ( tatC ), periplasmic protein folding ( dsbA ), synthesis of osmoregulated periplasmic glucans ( mdoGH ), and lipopolysaccharide (LPS) biosynthesis. Mutant strains with mutations in four genes had strong, sap-specific fitness defects in all strain backgrounds: murI , thiC , purU , and a lipoprotein (RSc2007). Many amino acid biosynthesis genes were required for fitness in both minimal medium and xylem sap. Multiple mutants with insertions in virulence regulators had gains of fitness in culture media and neutral fitness in sap. Our genome-scale genetic screen identified Ralstonia fitness factors that promote growth in xylem sap, an ecologically relevant condition. IMPORTANCE Traditional transposon mutagenesis genetic screens pioneered molecular plant pathology and identified core virulence traits like the type III secretion system. TnSeq approaches that leverage next-generation sequencing to rapidly quantify transposon mutant phenotypes are ushering in a new wave of biological discovery. Here, we have adapted a genome-scale approach, random barcoded transposon mutant sequencing (RB-TnSeq), to discover fitness factors that promote growth of three related bacterial strains in a common niche, tomato xylem sap. Fitness of the wild type and mutants show that Ralstonia spp. are adapted to grow well in xylem sap from their natural host plant, tomato. Our screen identified multiple sap-specific fitness factors with roles in maintaining the bacterial envelope. These factors include putative adaptations to resist plant defenses that may include antimicrobial proteins and specialized metabolites that damage bacterial membranes.
- Published
- 2021
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45. Complete Genome Sequence of Ralstonia syzygii subsp. indonesiensis Strain LLRS-1, Isolated from Wilted Tobacco in China.
- Author
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Lu CH, Li JY, Mi MG, Lin ZL, Jiang N, Gai XT, Jun-Hong M, Lei LP, and Xia ZY
- Subjects
- China, Phylogeny, Plant Diseases, Ralstonia, Ralstonia solanacearum, Nicotiana
- Abstract
Here, we present the complete genome sequence and annotation of Ralstonia syzygii subsp. indonesiensis strain LLRS-1, which caused bacterial wilt on flue-cured tobacco in Yunnan Province, southwest China. Strain LLRS-1 is the first R. syzygii strain identified to be pathogenic to tobacco in China. The completely assembled genome of strain LLRS-1 consists of a 3,648,314-bp circular chromosome and a 2,046,405-bp megaplasmid with 5,190 protein-coding genes, 55 transfer RNAs, 28 small RNAs, 3 structural RNAs (5S, 16S, and 23S), and a G+C content of 67.05%.
- Published
- 2021
- Full Text
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46. Differential Expression Pattern of Pathogenicity-Related Genes of Ralstonia pseudosolanacearum YQ Responding to Tissue Debris of Casuarina equisetifolia .
- Author
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Zhou X, Wang Y, Li C, Xu Y, Su X, Yang T, and Zhang X
- Subjects
- Phylogeny, Ralstonia, Virulence, Plant Diseases, Ralstonia solanacearum genetics
- Abstract
Ralstonia solanacearum species complex (RSSC) contains a group of destructive plant pathogenic bacteria, causing bacterial wilt of >200 species of crops and trees, such as Casuarina equisetifolia , worldwide. RSSC can survive in the soil environment for a long time and start infection after activation by host plants. This study conducted a transcriptome analysis on the expression pattern of the pathogenicity-related genes of a new isolated RSSC strain YQ ( Ralstonia pseudosolanacearum phylotype I-16) in response to C. equisetifolia cladophyll (a branch of a stem that resembles and functions as a leaf) and root debris under in vitro culture. The cladophyll debris induced more genes up-regulated than the root debris, including pathogenicity-related genes involved in motility, effectors, type III secretion systems, quorum sensing, and plant cell wall degradation. Besides, many differentially expressed genes were related to transcriptional regulator such as cyclic dimeric guanosine monophosphate. Moreover, the cultures with cladophyll debris induced a faster wilting in bioassays, and the cell swimming was enhanced by cladophyll exudate. C. equisetifolia cladophylls could activate the expression of pathogenicity-related genes of strain YQ and accelerate infection. Our findings suggest that litterfall management in C. equisetifolia forests, or even other plantations, should receive attention to prevent the induction of bacterial wilt disease caused by RSSC.
- Published
- 2021
- Full Text
- View/download PDF
47. Ralstonia mannitolilytica sepsis after elective cesarean delivery: a case report.
- Author
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Zhou S, Tang D, Wei S, Hu Z, Wang X, and Luo D
- Subjects
- Adult, Cross Infection microbiology, Elective Surgical Procedures adverse effects, Female, Gram-Negative Bacterial Infections therapy, Humans, Postoperative Complications, Pregnancy, Sepsis therapy, Treatment Outcome, Cesarean Section adverse effects, Gram-Negative Bacterial Infections etiology, Ralstonia, Sepsis microbiology
- Abstract
Background: Ralstonia mannitolilytica, a newly emerging opportunistic pathogen worldwide, has been reported to be responsible for human pneumonia, septicemia and meningitis. This is the first report of a case of Ralstonia mannitolilytica sepsis after elective cesarean delivery., Case Presentation: A 25-year-old woman, gravida 1 para 0, was scheduled for an elective cesarean delivery at 39
+ 1 weeks of gestation. Sudden high fever and decreased blood pressure occurred a short time after the operation. Ralstonia mannitolilytica was identified in her blood culture 5 days after the operation. Based on the presence of sepsis and septic shock, massive fluid replacement, blood transfusion, vasoactive agents, imipenem/cilastatin and cefoperazone sulbactam sodium were applied. She was discharged after intensive care without complications., Conclusions: Although the incidence of sepsis due to Ralstonia mannitolilytica is relatively low, once infection occurs in a puerpera, severe symptoms develop abruptly. Thus, prompt diagnosis and appropriate treatment are key to the cure., (© 2021. The Author(s).)- Published
- 2021
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48. Phosphorus availability increases pathobiome abundance and invasion of rhizosphere microbial networks by Ralstonia.
- Author
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Li P, Liu M, Li G, Liu K, Liu T, Wu M, Saleem M, and Li Z
- Subjects
- Bacteria, Ralstonia, Soil chemistry, Soil Microbiology, Phosphorus, Rhizosphere
- Abstract
Soil disease-suppressiveness depends on complex interactions among pathogens, native microbiota, and physicochemical properties, while these interactions remain understudied. Comparing field and microcosm experiments, we investigated the significance of these interactions in disease emergence or suppression using structural equation modelling (SEM) and receiver operating characteristic curve (ROC) analyses. We observed significant differences in the relative abundance of pathogenic and beneficial microbes, alpha and beta diversity indices between disease-conducive and -suppressive rhizosphere soils. The pathogenic (Ralstonia) and beneficial (Bacillus) taxa dominated disease-conducive and -suppressive rhizosphere soils, respectively. Moreover, the co-occurrences of Ralstonia with native microorganisms were positive and negative in the disease-conducive and -suppressive soils, respectively. These results suggest the supportive (Rudaea) and suppressive (Enterobacter, Bacillus) role of indigenous microbes in the invasion of soil and plant systems by Ralstonia. The SEM and ROC analysis predicted that Ralstonia invaded rhizospheric microbial networks and caused peanut wilt under high than low soil phosphorus conditions. Our results suggest the importance of soil phosphorus availability in altering the microbial interactions, thus leading to soil invasion by Ralstonia. Thus, we conclude by saying that feeding soil with high amounts of available phosphorus could deplete plant-beneficial microbes and increase the pathobiome abundance that may compromise plant health., (© 2021 Society for Applied Microbiology and John Wiley & Sons Ltd.)
- Published
- 2021
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- View/download PDF
49. Characterization of clinical Ralstonia strains and their taxonomic position.
- Author
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Fluit AC, Bayjanov JR, Aguilar MD, Cantón R, Tunney MM, Elborn JS, van Westreenen M, and Ekkelenkamp MB
- Subjects
- Humans, Multilocus Sequence Typing, Phylogeny, RNA, Ribosomal, 16S genetics, Ralstonia genetics
- Abstract
To improve understanding of the role of Ralstonia in cystic fibrosis (CF), whole genomes of 18 strains from clinical samples were sequenced using Illumina technology. Sequences were analysed by core genome Multi-Locus Sequence Typing, Average Nucleotide Identity based on BLAST (ANIb), RAST annotation, and by ResFinder. Phylogenetic analysis was performed for the 16S rRNA gene, and the OXA-22 and OXA-60 ß-lactamase families. The minimal inhibitory concentrations (MICs) were determined using broth microdilution. ANIb data for the 18 isolates and 54 strains from GenBank, supported by phylogenetic analysis, showed that 8 groups of clusters (A-H), as well as subgroups that should be considered as species or subspecies. Groups A-C contain strains previously identified as Ralstonia solanacearum and Ralstonia pseudosolanacearum. We propose that group A is a novel species. Group B and C are Ralstonia syzygii, Ralstonia solanacearum, respectively. Group D is composed of Ralstonia mannitolilytica and Group E of Ralstonia pickettii. Group F and G should be considered novel species. Group H strains belong to R. insidiosa. OXA-22 and OXA-60 family ß-lactamases were encoded by all strains. Co-trimoxazole generally showed high activity with low MICs (≤1 mg/l) as did ciprofloxacin (≤0.12 mg/l). MICs against the other antibiotics were more variable, but generally high. RAST annotation revealed limited differences between the strains, and virulence factors were not identified. The taxonomy of the genus Ralstonia is in need of revision, but sequencing additional isolates is needed. Antibiotic resistance levels are high. Annotation did not identify potential virulence factors., (© 2021. The Author(s).)
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- 2021
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50. Complete Genome Resources for Ralstonia Bacterial Wilt Strains UW763 (Phylotype I); Rs5 and UW700 (Phylotype II); and UW386, RUN2474, and RUN2279 (Phylotype III).
- Author
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Steidl OR, Truchon AN, Hayes MM, and Allen C
- Subjects
- Phylogeny, Plant Diseases, Ralstonia, Solanum lycopersicum, Ralstonia solanacearum genetics, Solanum tuberosum
- Abstract
We share whole genome sequences of six strains from the Ralstonia solanacearum species complex, a diverse group of Betaproteobacteria that cause plant vascular wilt diseases. Using single-molecule real-time technology, we sequenced and assembled full genomes of Rs5 and UW700, two phylotype IA-sequevar 7 (IIA-7) strains from the southeastern United States that are closely related to the R. solanacearum species type strain, K60, but were isolated >50 years later. Four sequenced strains from Africa include a soil isolate from Nigeria (UW386, III-23), a tomato isolate from Senegal (UW763, I-14), and two potato isolates from the Madagascar highlands (RUN2474, III-19 and RUN2279, III-60). This resource will support studies of the genetic diversity, ecology, virulence, and microevolution of this globally distributed group of high-impact plant pathogens.[Formula: see text] Copyright © 2021 The Author(s). This is an open access article distributed under the CC BY-NC-ND 4.0 International license.
- Published
- 2021
- Full Text
- View/download PDF
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