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Sunscreen has been used for thousands of years to protect skin from ultraviolet radiation. However, the use of modern commercial sunscreen containing oxybenzone, ZnO, and TiO2 has raised concerns due to their negative effects on human health and the environment. In this study, we aim to establish an efficient microbial platform for production of shinorine, a UV light absorbing compound with anti-aging properties. First, we methodically selected an appropriate host for shinorine production by analyzing central carbon flux distribution data from prior studies alongside predictions from genome-scale metabolic models (GEMs). We enhanced shinorine productivity through CRISPRi-mediated downregulation and utilized shotgun proteomics to pinpoint potential competing pathways. Simultaneously, we improved the shinorine biosynthetic pathway by refining its design, optimizing promoter usage, and altering the strength of ribosome binding sites. Finally, we conducted amino acid feeding experiments under various conditions to identify the key limiting factors in shinorine production. The study combines meta-analysis of 13C-metabolic flux analysis, GEMs, synthetic biology, CRISPRi-mediated gene downregulation, and omics analysis to improve shinorine production, demonstrating the potential of Pseudomonas putida KT2440 as platform for shinorine production.

Sorghum bicolor is among the most important cereals globally and a staple crop for smallholder farmers in sub-Saharan Africa. Approximately 20% of sorghum yield is lost annually in Africa due to infestation with the root parasitic weed Striga hermonthica. Existing Striga management strategies are not singularly effective and integrated approaches are needed. Here, we demonstrate the functional potential of the soil microbiome to suppress Striga infection in sorghum. We associate this suppression with microbiome-mediated induction of root endodermal suberization and aerenchyma formation and with depletion of haustorium-inducing factors, compounds required for the initial stages of Striga infection. We further identify specific bacterial taxa that trigger the observed Striga-suppressive traits. Collectively, our study describes the importance of the soil microbiome in the early stages of root infection by Striga and pinpoints mechanisms of Striga suppression. These findings open avenues to broaden the effectiveness of integrated Striga management practices.

Machine learning applied to large compendia of transcriptomic data has enabled the decomposition of bacterial transcriptomes to identify independently modulated sets of genes, such iModulons represent specific cellular functions. The identification of iModulons enables accurate identification of genes necessary and sufficient for cross-species transfer of cellular functions. We demonstrate cross-species transfer of: 1) the biotransformation of vanillate to protocatechuate, 2) a malonate catabolic pathway, 3) a catabolic pathway for 2,3-butanediol, and 4) an antimicrobial resistance to ampicillin found in multiple Pseudomonas species to Escherichia coli. iModulon-based engineering is a transformative strategy as it includes all genes comprising the transferred cellular function, including genes without functional annotation. Adaptive laboratory evolution was deployed to optimize the cellular function transferred, revealing mutations in the host. Combining big data analytics and laboratory evolution thus enhances the level of understanding of systems biology, and synthetic biology for strain design and development.

We sequenced and comprehensively analysed the genomic architecture of 98 fluorescent pseudomonads isolated from different symptomatic and asymptomatic tissues of almond and a few other Prunus spp. Phylogenomic analyses, genome mining, field pathogenicity tests, and in vitro ice nucleation and antibiotic sensitivity tests were integrated to improve knowledge of the biology and management of bacterial blast and bacterial canker of almond. We identified Pseudomonas syringae pv. syringae, P. cerasi, and P. viridiflava as almond canker pathogens. P. syringae pv. syringae caused both canker and foliar (blast) symptoms. In contrast, P. cerasi and P. viridiflava only caused cankers, and P. viridiflava appeared to be a weak pathogen of almond. Isolates belonging to P. syringae pv. syringae were the most frequently isolated among the pathogenic species/pathovars, composing 75% of all pathogenic isolates. P. cerasi and P. viridiflava isolates composed 8.3 and 16.7% of the pathogenic isolates, respectively. Laboratory leaf infiltration bioassays produced results distinct from experiments in the field with both P. cerasi and P. syringae pv. syringae, causing significant necrosis and browning of detached leaves, whereas P. viridiflava conferred moderate effects. Genome mining revealed the absence of key epiphytic fitness-related genes in P. cerasi and P. viridiflava genomic sequences, which could explain the contrasting field and laboratory bioassay results. P. syringae pv. syringae and P. cerasi isolates harboured the ice nucleation protein, which correlated with the ice nucleation phenotype. Results of sensitivity tests to copper and kasugamycin showed a strong linkage to putative resistance genes. Isolates harbouring the ctpV gene showed resistance to copper up to 600 μg/ml. In contrast, isolates without the ctpV gene could not grow on nutrient agar amended with 200 μg/ml copper, suggesting ctpV can be used to phenotype copper resistance. All isolates were sensitive to kasugamycin at the label-recommended rate of 100μg/ml.

Background Objectives Materials and Methods Results Conclusions and Clinical Relevance Silver sulfadiazine (SSD) is commonly formulated into otic preparations to treat otitis externa, although evidence of stability and antimicrobial efficacy with long‐term storage is lacking.To evaluate the effect of storage time on chemical stability and in vitro antimicrobial activity of SSD diluted in sterile water, including two 1% suspensions using SSD pharmaceutical‐grade powder stored at room temperature (RT) in plastic or sterile glass bottles, and a 1:9 dilution using prescription SSD 1% cream stored at RT in a sterile glass bottle.Liquid chromatography–tandem mass spectrometry (LC–MS/MS) assessed chemical stability. Trimethoprim/sulfamethoxazole‐susceptible and trimethoprim/sulfamethoxazole‐resistant strains of Staphylococcus pseudintermedius (SP), meticillin‐resistant (MR) SP, S. schleiferi (SS), MRSS, Pseudomonas aeruginosa, Proteus mirabilis and Escherichia coli evaluated by 24 h time–kill analysis assessed in vitro antimicrobial efficacy. Each assessment was performed at zero, one, three and six months of storage.LC–MS/MS showed no significant change in concentration over time for any suspension. When adjusted for time and species/strain, all SSD suspensions showed significant reductions in colony forming units (cfu)/mL at 24 h (p < 0.001). Including all suspensions, a bactericidal effect (minimum 3‐log cfu/mL reduction at 24 h) occurred against 94% of total isolates, with failure against 33 of 552 isolates (6%). Bactericidal failure was more likely with the cream‐based suspension (p < 0.05) and at six months (p < 0.01).Powder‐based and cream‐based SSD/sterile water suspensions showed no significant change in concentration and demonstrated in vitro antimicrobial activity for six months. Bactericidal failure was more likely with the cream‐based suspension and after six months of storage. [ABSTRACT FROM AUTHOR]

Background: cultivated and wild plants are used to treat different ailments. The Astragalus genus is found in temperate and dry climates; thus, it is found in Egypt and the arab world. Astragalus caprinus has a good amount of bioactive chemicals, which may help explain its therapeutic effects in reducing the risk of consequences from disease. Method: The phytochemical investigation of the herb and roots of Astragalus caprinus L. included the analytical characterization for the petroleum ether components by GC/MS, unsaponifiable matter (unsap. fraction), and fatty acids (FAME) investigation by GLC analysis. Main flavonoids were chromatographically isolated from ethyl acetate and n-butanol extracts. In vitro antimicrobial activity has been tested against the Gram-positive bacteria Staphylococcus aureus and Streptococcus mutans for different plant extracts, the Gram-negative bacteria Pseudomonas aeruginosa and Klebsiella pneumonia, the fungus Candida albicans and Aspergillus niger, and the Escherichia coli bacterium. Metabolite cytotoxicity was examined using the MTT assay against HepG-2 (human liver carcinoma) and MCF-7 (breast carcinoma). Results: Identifying the important components of the herb and root petroleum ether extracts was achieved. Using column chromatography, luteolin, cosmosiin (apigenin-7-O-glucoside), and cynaroside (luteolin-7-O-glucoside) were separated and identified using UV, NMR, and Mass Spectroscopy. Root extracts displayed potential antimicrobial activity against most of the tested pathogens. Both extracts (herb and roots) were active against the MCF-7 cell line and HepG-2 cell line with IC50 62.5 ± 0.64 and 72.4 ± 2.3 µg/ml, and 75.9 ± 2.5 and 96.8 ± 4.2 µg/ml, respectively. Conclusion: Astragalus caprinus seems to be a promising source of bioactive compounds that could potentially aid in preventing disease complications and address common health issues in developing countries. Moreover, the various parts of this plant could be utilized as natural raw materials for producing health-boosting products that could address common health issues in developing countries. [ABSTRACT FROM AUTHOR]

Pyomelanin, a polymeric pigment in Pseudomonas, arises mainly from alterations in tyrosine degradation. The chemical structure of pyomelanin remains elusive due to its heterogeneous nature. Here, we report strain‐specific differences in pyomelanin structural features across Pseudomonas using PAO1 and PA14 reference strains carrying mutations in hmgA (a gene involved in pyomelanin synthesis), a melanogenic P. aeruginosa clinical isolate (PAM), and a melanogenic P. extremaustralis (PexM). UV spectra showed dual peaks for PAO1 and PA14 mutants and single peaks for PAM and PexM. FTIR phenol : alcohol ratio changes and complex NMR spectra indicated non‐linear polymers. UVC radiation survival increased with pyomelanin addition, correlating with pigment absorption attenuation. P. extremaustralis UVC survival varied with melanin source, with PAO1 pyomelanin being the most protective. These findings delineate structure‐based pyomelanin subgroups, having distinct physiological effects. [ABSTRACT FROM AUTHOR]

Integrated pest management (IPM) is a comprehensive approach to managing diseases, focusing on combining various strategies to reduce pathogen populations effectively and in an environmentally conscious way. We investigated the effects of IPM on beneficial microbial populations and its relationship with pathogen populations in both direct-seeded rice (DSR) and transplanted rice (TR) systems. This study demonstrates that IPM practices have significantly higher populations of beneficial microbes, such as Trichoderma harzianum and Pseudomonas fluorescens, and lower level of the pathogen Fusarium verticillioides compared to non-IPM (farmer practices). The average mean population of T. harzianum was 6.38 x 10³ CFU/g in IPM compared to 3.22 x 10³ CFU/g in non-IPM during 2019 in TR at Bambawad. P. fluorescens mean population in 2019 was significantly higher in IPM (4.67 x 10³ CFU/g) than in non-IPM (3.82 x 10³ CFU/g) at the Karnal location in DSR. The F. verticillioides populations were significantly lower in IPM fields (9.46 x 10³ CFU/g) compared to non-IPM fields (11.48 x 10³ CFU/g) during 2017 at Haridwar in TR. Over three years, a significant increase in the populations of beneficial microbes in IPM plots was observed in all three locations of both TR and DSR, highlighting the sustainable impact of IPM practices. Disease dynamics analysis revealed that IPM effectively managed key diseases in both DSR and TR systems, with significant correlations between microbial density and disease severity. A significant positive correlation was recorded between F. verticillioides population and bakanae incidence at all three locations. Sheath blight incidence was negatively correlated with P. fluorescens population in both TR and DSR. In DSR, bacterial blight and brown spot diseases are reduced with the increased population of T. harzianum. Bioagents T. harzianum and P. fluorescens reduced disease incidence, underscoring the role of beneficial microbes in disease suppression and their importance for sustainable production using IPM practices. [ABSTRACT FROM AUTHOR]

Background: In recent years, antibiotic resistance has emerged as a global health concern in bacterial infections such as urinary tract infections (UTIs). Uropathogenic Escherichia coli is the most frequent organism responsible for both simple and complex UTIs. Staphylococcus aureus and Pseudomonas aeruginosa are frequently associated with complicated UTIs. Sri Lanka has significant resources of medicinal plants used to cure UTIs in Ayurvedic and traditional medicine. Methods: Agar well diffusion and broth microdilution methods were used to determine the antibacterial activity of the methanolic extract of ten medicinal plants against P. aeruginosa ATCC27853, S.aureus ATCC25923, E.coli ATCC25922 and their UTI positive strains extracted from positive culture plates. As a preliminary toxicity assay, the Brine Shrimp Lethality Assay (BSLA) was used to determine its cytotoxicity. Results: The methanolic fruits extract of P. emblica demonstrated the highest antibacterial activity against both E. coli ATCC25922 and E. coli UTI-positive strains. B. diffusa roots extract exhibited the highest activity against S. aureus ATCC25923, while T. chebula fruits extract showed the highest activity against the S. aureus UTI-positive strain. T. involucrata roots extract displayed the highest activity against P. aeruginosa ATCC27853, and Z. officinale rhizomes extract showed the highest activity against the P. aeruginosa UTI-positive strain. Moreover, the plant mixture showed the most substantial antibacterial effect against P. aeruginosa ATCC27853. However, the methanolic seed extract of C. melo did not exhibit any antimicrobial effects against the selected organisms. All plant material, including the plant mixture, showed cytotoxicity according to the BSLA. Conclusion: All the methanolic extracts including P. emblica fruits, O. tenuiflorum whole plant, T. chebula fruits, Z. officinale rhizome, T. terrestris roots, T. involucrata roots, A. lanata whole plant. B. diffusa roots and A. falcatus roots showed antimicrobial effects against selected strains except C. melo seed extract. The results of the present study evidently supports the traditional and ayurvedic use of these plants for the treatment of UTIs. This paves the way for another praise for new plant-based therapeutic product development for the treatment of UTIs. However, further toxicity studies are needed for medicinal dose determination. [ABSTRACT FROM AUTHOR]

Background: Pseudomonas juntendi is a newly identified opportunistic pathogen, of which we have limited understanding. P. juntendi strains are often multidrug resistant, which complicates clinical management of infection. Methods: A strain of Pseudomonas juntendi (strain L4326) isolated from feces was characterized by MALDI-TOF-MS and Average Nucleotide Identity BLAST. This strain was further subject to whole-genome sequencing and Maximum Likelihood phylogenetic analysis. The strain was phenotypically characterized by antimicrobial susceptibility testing and conjugation assays. Results: We have isolated the novel P. juntendi strain L4236, which was multidrug resistant, but retained sensitivity to amikacin. L4236 harbored a megaplasmid that encoded blaOXA−1 and a novel blaIMP−1 resistance gene variant. P. juntendi strain L4236 was phylogenetically related to P. juntendi strain SAMN30525517. Conclusion: A rare P. juntendi strain was isolated from human feces in southern China with a megaplasmid coharboring blaIMP−1−like and blaOXA−1. Antimicrobial selection pressures may have driven acquisition of drug-resistance gene mutations and carriage of the megaplasmid. [ABSTRACT FROM AUTHOR]

The antibiofilm and antimicrobial properties of tropical honey types including Malaysian stingless bee honey remain explicitly unexplored when compared with Apies honey. The antibiofilm and antimicrobial activities of the Malaysian Trigona honey were characterized with two stinging bee honey types (Centaurea hyalolepis and Citrus honeys) from Jordan. The antibiofilm and antimicrobial investigations were conducted on a set of seven microbial strains; five bacterial species of Pseudomonas aeruginosa ATCC 10145, Streptococcus pyogenes ATCC 19615, Staphylococcus aureus ATCC 25923, Escherichia coli ATCC 25922, Klebsiella pneumoniae ATCC 13883, and two fungal strains Candida albicans ATCC 10231 and Candida krusei ATCC 14243. The antimicrobial investigations revealed a broad spectrum activity for Trigona honey against Gram-positive, Gram-negative, and fungal strains over the two honey types. One-way ANOVA showed a significant difference (p < 0.001) in the zone of inhibition ranging from 9 to 25 mm and minimum inhibition activity (MIC) ranged from 9.4–29.6% (w/v) against the microbial strains. Moreover, the addition of honey to established biofilms has induced a degradation activity in the biofilm mass. Two-way ANOVA showed a significant biofilm degradation proportion (p < 0.001) ranging from 1.3% to 91.3% following treatment with Trigona honey and the other honey types in relevance to the concentration ranging from 10% to 50% (w/v). Moreover, the antibiofilm activity was highly consistent with MIC affecting bacterial growth inhibition. In conclusion, a robust antimicrobial and antibiofilm activity for Trigona stingless bee honey over the stinging bee Centaurea hyalolepis and Citrus honeys is noticed which endows the usage of Trigona honey in the antimicrobial industry. [ABSTRACT FROM AUTHOR]

Background: Pseudomonas juntendi is a newly identified opportunistic pathogen, of which we have limited understanding. P. juntendi strains are often multidrug resistant, which complicates clinical management of infection. Methods: A strain of Pseudomonas juntendi (strain L4326) isolated from feces was characterized by MALDI-TOF-MS and Average Nucleotide Identity BLAST. This strain was further subject to whole-genome sequencing and Maximum Likelihood phylogenetic analysis. The strain was phenotypically characterized by antimicrobial susceptibility testing and conjugation assays. Results: We have isolated the novel P. juntendi strain L4236, which was multidrug resistant, but retained sensitivity to amikacin. L4236 harbored a megaplasmid that encoded blaOXA−1 and a novel blaIMP−1 resistance gene variant. P. juntendi strain L4236 was phylogenetically related to P. juntendi strain SAMN30525517. Conclusion: A rare P. juntendi strain was isolated from human feces in southern China with a megaplasmid coharboring blaIMP−1−like and blaOXA−1. Antimicrobial selection pressures may have driven acquisition of drug-resistance gene mutations and carriage of the megaplasmid. [ABSTRACT FROM AUTHOR]

Plastics have been consistently produced for their practicality and convenience; however, unmanaged plastics often end up in the ocean and decompose into nano-plastics through photolytic decomposition and weathering, negatively affecting marine life. This can eventually affect humans via the food chain, highlighting the need for effective solutions. Microbial biodegradation has been proposed as a solution to minimize the impact of nano-plastics on the environment, and degradation byproducts can be used in microbial metabolic pathways. In this study, 57 bacterial strains were isolated and identified from a waste treatment facility. Bacterial strains with lipase activity were selected on Tween80 agar plates. Additionally, strains capable of growing on minimal salt agar plates supplemented with low-density polyethylene (LDPE) beads were selected. Incubation in a minimal salt medium with LDPE beads as the sole carbon source led to the selection of Pseudomonas plecoglossicida SYp2123, which is capable of degrading LDPE. This strain was subjected to high cell density culture, and Fourier-transform infrared spectroscopy revealed chemical changes on the surface of LDPE beads. Additionally, field-emission scanning electron microscopy confirmed substantial biodegradation of the surface. P. plecoglossicida SYp2123 was able to degrade LDPE beads. This discovery shows that P. plecoglossicida can potentially be used as an environmentally friendly approach for tackling issues associated with polyethylene waste. [ABSTRACT FROM AUTHOR]

To determine the content of phenolcarboxylic acids using gas chromatography–mass spectrometer (GC–MS) in the obtained extract, conduct a study of the antimicrobial, antifungal, and antioxidant activities of Rubus idaeus shoot lipophilic extract. The quantification of phenolcarboxylic was accomplished through GC–MS, antioxidant activity was assessed by potentiometric method, antimicrobial and antifungal activities were determined by well method. The 8 compounds were identified by the GC–MS method. The vanillic acid (2.59 ± 0.08 mg/100 g), benzoic acid (1.51±0.08 mg/100 g), and ferulic acid (0.79±0.04 mg/100 g) dominated in the obtained lipophilic R. idaeus shoot extract. Bacillus subtilis (17.00 ± 0.50 mm) was the most sensitive to lipophilic extract, whereas Proteus vulgaris was the most resistant to the lipophilic extract. Moreover, Candida albicans was medium sensitive to lipophilic extract (13.50 ± 0.50 mm). The antioxidant activity was 1.00 mmol-equiv./mdry res; according to Maslov's antioxidant level classification it has low level. The lipophilic extract from R. idaeus shoots contains various phenolcarboxylic acids, including vanillic acid, benzoic acid, ferulic acid, p-hydroxybenzoic acid, syringic acid, gentisic acid, salicylic acid, and phenylacetic acid, with the highest concentrations observed for vanillic, benzoic, and ferulic acids. This study highlights the antimicrobial and antifungal properties of the R. idaeus shoot lipophilic extract. However, the obtained lipophilic extract showed a relatively low level of antioxidant activity. Consequently, the derivatives of phenolcarboxylic acids play a substantial role in the antimicrobial and antifungal effects, whereas their contribution to antioxidant activity appears to be limited. [ABSTRACT FROM AUTHOR]

Background: Postmenopausal osteoporosis (PMO) is a chronic condition characterized by decreased bone strength. This study aims to investigate the effects and mechanisms of the combination of Butyricicoccus pullicaecorum (Bp) and 3-hydroxyanthranilic acid (3-HAA) on PMO. Methods: The effects of Bp and 3-HAA on PMO were evaluated in ovariectomized (OVX) rats by assessing stereological parameters, femur microstructure, and autophagy levels. The T helper (Th) 17/Regulatory T (Treg) cells of rats were detected using flow cytometric analysis. Furthermore, the impact of Bp and 3-HAA on the gut microbiota of rats was assessed using 16S rRNA gene sequencing. The correlation between the gut microbiota of rats and Th17/Treg immune factors, as well as femoral stereo parameters, was separately assessed using Spearman rank correlation analysis. Results: Bp and 3-HAA treatments protected OVX rats by promoting osteogenesis and inhibiting autophagy. Compared to the Sham group, OVX rats showed an increase in Th17 cells and a decrease in Treg cells. Bp and 3-HAA reversed these changes. Enterorhabdus and Pseudomonas were significantly enriched in OVX rats. Bp and 3-HAA regulated the gut microbiota of OVX rats, enriching pathways related to nutrient metabolism and immune function. There was a correlation between the gut microbiota and the Th17/Treg, as well as femoral stereo parameters. The concurrent administration of Bp and 3-HAA medication facilitated the enrichment of gut microbiota associated with the improvement of PMO. Conclusion: The combination therapy of Bp and 3-HAA can prevent PMO by modulating the gut microbiota and restoring Th17/Treg immune homeostasis. [ABSTRACT FROM AUTHOR]

To characterize the spoilage of tilapia under super-chilled storage, the bacterial profile and odor and volatile compounds were analyzed. Results showed that the shelf life and bacterial profile of tilapia from different sources varied remarkably, with Pseudomonas being the most dominant organism in tilapia under super-chilled storage (−1.5°C). The correlation analysis showed that the volatile compounds from the spoiled samples were closely related to the bacterial profile. Therefore, no volatile compounds or the response of the electronic nose significantly correlated with sensory spoilage although some of them correlated with that of some specific samples. On the other hand, the total volatile basic nitrogen (TVB-N) was significantly correlated with the sensory spoilage of all samples. In conclusion, under super-chilled storage, the volatile compounds in tilapia, except TVB-N, are sample dependent due to the variation of bacterial profile and therefore cannot be used as a spoilage indicator. [ABSTRACT FROM AUTHOR]

Introduction: Cholesteatoma usually harbors a poly-microbial infection. As the diversity of bacterial pathogens in the Indian COM is unknown, we set out to identify the bacteria associated with cholesteatoma disease in different patients of North India using targeted metagenomic analysis of the 16 S rRNA gene. Methods: We recruited 15 patients of cholesteatomatous chronic otitis media (COM), who underwent surgical disease clearance. We divided these patients into four groups based on the four clinic-radiological stages categorized as per the EAONO/JOS joint consensus statement classification. Representative samples were extracted during the surgery and sent for bacterial culture and sensitivity and 16 S rRNA gene metagenomic analysis. Results: While 12 (80%) of the patients belonged to clinical Stage I/II; one patient had an extracranial complication (stage III) and two patients had an intracranial complication (stage IV). Our detailed bacterial metagenomics analyses showed that while phylum Proteobacteria was most abundant (reads up to ∼ 95%) in specimens from nine patients, phylum Firmicutes was most abundant (up to ∼ 80%) in specimens from four patients. Gamma (γ) Proteobacteria and Epsilon (ε) Proteobacteria were the most abundant class amongst Proteobacteria. Class Tissierellia stood out as the most abundant Firmicutes (40–60%), followed by Clostridia (20%) and Bacilli (10%). There was negligible difference in the bacterial profiles across all four clinical stages. Conclusion: Cholesteatoma is primarily associated with Proteobacteria and Firmicutes phyla, even in complicated disease. Further studies with a larger sample size are required to validate our findings. [ABSTRACT FROM AUTHOR]

The bacteriophage Pseudomonas phage Ka1 was isolated from the water of a tributary stream of Lake Baikal, in the area of discharge of treated wastewater of the city of Slyudyanka. The bacteriophage genome contains 46 092 bp and has a 50% G+C pairs (AN OP455935.1). It exhibits 91% identity with the Pseudomonas phage PSA37 genome, belonging to Bruynoghevirus from the class Caudoviricetes suggesting that Ka1 is a new representative of Luz24-like phages (Bruynoghevirus). The bacteriophage lyzes 62% of P. aeruginosa clinical isolates and increases the efficiency of gentamicin, ciprofloxacin, imipenem and meropenem by 4–8-fold against these bacteria. Integrases, transposases and recombinases have not been identified in the genome of the bacteriophage Pseudomonas phage Ka1; which allows using it in the complex therapy of infections caused by P. aeruginosa. [ABSTRACT FROM AUTHOR]

The results of study of the effects of the Pseudomonas sp. OBA 2.4.1 PGPB strain resistant to NiCl2 (up to 3 mM), Pb(CH3COO)2 (up to 5 mM), and glyphosate (up to 8 mg/mL) on Pisum sativum L. plants at different concentrations of the heavy metals and the herbicide are reported. It was found that this strain had a positive effect on the root length of pea seedlings in the presence of heavy metals indicating an increase in the plant resistance to nickel and lead stress. However, no such effect was observed in the experiment with glyphosate, which confirmed the high toxicity of this compound. The results obtained demonstrated that the Pseudomonas sp. OBA 2.4.1 strain promoted the growth of Pisum sativum L. under nickel and lead stress; these findings can further be used for the development of complex biopreparations intended both for the protection of agricultural plants from the effects of heavy metals and for remediation of contaminated soils. [ABSTRACT FROM AUTHOR]

It was known that UVc irradiation increases the reactive oxygen species' (ROS) levels in bacteria hence the intervention of antioxidant enzymes and causes also changes in fatty acids (FAs) composition enabling bacteria to face antibiotics. Here, we intended to elucidate an interrelationship between SOD and susceptibility to antibiotics by studying FA membrane composition of UVc-treated P. aeruginosa PAO1 and its isogenic mutants (sodM, sodB and sod MB) membrane, after treatment with antibiotics. Swarmer mutants defective in genes encoding superoxide dismutase were pre-exposed to UVc radiations and then tested by disk diffusion method for their contribution to antibiotic tolerance in comparison with the P. aeruginosa wild type (WT). Moreover, fatty acid composition of untreated and UVc-treated WT and sod mutants was examined by Gaz chromatography and correlated to antibiotic resistance. Firstly, it has been demonstrated that after UVc exposure, swarmer WT strain, sodM and sodB mutants remain resistant to polymixin B, a membrane target antibiotic, through membrane unsaturation supported by the intervention of Mn-SOD after short UVc exposure and cyclopropanation of unsaturated FAs supported by the action of Fe-SOD after longer UVc exposure. However, resistance for ciprofloxacin is correlated with increase in saturated FAs. This correlation has been confirmed by a molecular docking approach showing that biotin carboxylase, involved in the initial stage of FA biosynthesis, exhibits a high affinity for ciprofloxacin. This investigation has explored the correlation of antibiotic resistance with FA content of swarmer P.aeruginosa pre-exposed to UVc radiations, confirmed to be antibiotic target dependant. [ABSTRACT FROM AUTHOR]

Previous research has demonstrated the ability of isolate Pseudomonas thivervalensis SC5 to express the enzyme 1-aminocyclopropane-1-carboxylate deaminase (ACC), which regulates ethylene levels, one of the most important phytohormones in the regulation of plant growth and development. Thus, the present study evaluated the agronomic efficiency of a biological conditioner based on P. thivervalensis SC5 in the growth and productivity increases of corn in Brazil. It was found that corn was highly responsive to the inoculation of P. thivervalensis SC5, with increments ranging from 10.1 to 40.6% in the production of dry shoot biomass (DSB) compared to the control, while for grain yield the increments ranged from 9.0 to 27.8%. The increments are related to the levels and accumulations of N and P in the shoots of the plants. This suggested the participation of P. thivervalensis SC5 in mechanisms of soil modulation and nutrient acquisition. The inoculation of P. thivervalensis SC5 provided average increments in FDA hydrolysis ranging from 16.7 to 47.4% compared to the control, confirming the ability of this strain to increase the supply of nutrients to plants. Therefore, it is concluded that Pseudomonas thivervalensis SC5 participates in key mechanisms in the soil-plant system, with a consequent improvement in soil quality and other plant-related parameters. [ABSTRACT FROM AUTHOR]

One of the complications after total hip arthroplasty (THA) or total knee arthroplasty (TKA) is periprosthetic joint infection (PJI). Numerous studies have been performed to explore the value of biological parameters in the early identification of infection rates after THA and TKA. This study investigates alterations in inflammatory markers associated with PJI. This retrospective study focused on a cohort of patients with hip and knee arthroplasty treated between 2016 and 2022. CRP, ESR, and fibrinogen were observed preoperatively, on days one, three, six, and twenty-one postoperatively. From a total of 4076 THA and TKA performed during this period, 62 patients were identified with periprosthetic infections. We also identified the pathogens responsible for infections in order to assess if asymptomatic preoperative infections were involved in PJI. In patients with acute infections following TKA, days one and three postoperative recorded a CRP value below the expected range. The value of CRP in patients with early infection after THA was significantly increased on day six postoperative. ESR and fibrinogen values were not statistically significantly correlated with early PJI. The CRP level in acute PJI shows different patterns than those shown in the literature. [ABSTRACT FROM AUTHOR]

This study aimed to isolate and characterize Pseudomonas native strains from the rhizospheric soil of Minthostachys verticillata plants to evaluate their potential as plant growth-promoting rhizobacteria (PGPR). A total of 22 bacterial isolates were obtained and subjected to various biochemical tests, as well as assessments of plant growth-promoting traits such as phosphate solubilization, hydrogen cyanide production, biocontrol properties through antibiosis, and indole acetic production. Genotypic analysis via 16S rRNA gene sequencing and phylogenetic tree construction identified the strains, with one particular strain named SM 33 showing significant growth-promoting effects on M. verticillata seedlings. This strain, SM 33, showed high similarity to Stutzerimonas stutzeri based on 16S rRNA gene sequencing and notably increased both shoot fresh weight and root dry weight of the plants. These findings underscore the potential application of native Pseudomonas strains in enhancing plant growth and health, offering promising avenues for sustainable agricultural practices. [ABSTRACT FROM AUTHOR]

Featured Application: Pseudomonas jordanii strain G34 is a newly identified bacterial species with unique genomic features that holds great potential as a biofertilizer to boost wheat productivity in saline soils.Pseudomonas jordanii strain G34 is a moderately halophilic endophytic bacterium isolated from the root tissue of durum wheat plants growing in the saline environment of the Jordan Valley's Ghor Sweimeh region. Microscopic and biochemical analyses of P. jordanii strain G34 revealed that it is a Gram-negative, non-motile rod. It also exhibits capsule formation, catalase and oxidase positive reactions, indole positivity, citrate utilization, and non-glucose fermenting capability. Pseudomonas jordanii strain G34 showed growth-promoting effects on durum wheat seedlings grown under severe salinity stress conditions up to a 200 mM NaCl concentration. The draft genome of P. jordanii strain G34 comprises 5,142,528 base pairs (bp) and possesses a G + C content of 64.0%. It contains 57 RNA coding genes and is predicted to encode a total of 4675 protein-coding genes. Putative genes linked to various aspects of the bacterial endophyte lifestyle were identified including ion transport, motility, secretion, adhesion, delivery systems, and plant cell wall modification. Performing a comprehensive phylogenomic analysis identified P. jordanii as a new species, with its closest relative being P. argentinensis LMG 22563, sharing only around 40.2% digital DNA-DNA hybridization identity. Pseudomonas jordanii strain G34 holds great potential for future use as a biofertilizer in saline environments. [ABSTRACT FROM AUTHOR]

Purpose: Bronchoalveolar lavage is commonly used in clinical practice for unresolved pneumonia. However, bronchoalveolar lavage is not suitable for all patients as it is an invasive procedure and can worsen oxygenation. The diagnostic value of bronchial wash and sputum has been debated extensively over the years. In this study, we aim to compare the diagnostic value in several pathogens of bronchoalveolar lavage and bronchial wash, and secondarily bronchoalveolar lavage and sputum. Methods: We retrospectively included all adult patients in our hospital who underwent bronchoalveolar lavage, bronchial wash, and where sputum sampling was done between January 1st of 2018 and December 31st of 2021. The intraclass correlation coefficient was computed for the three tests. Results: In total, 308 patients were included. We found a level of correlation of 0.819 and 0.865, respectively, between bronchoalveolar lavage and bronchial wash for two pathogens: Staphylococcus aureus and Pseudomonas aeruginosa. For Stenotrophomonas maltophilia and Aspergillus fumigatus, we found an intraclass correlation coefficient of 0.568 and 0.624, respectively. Between bronchoalveolar lavage and sputum, we found varying levels of agreement. Conclusion: Our study shows reasonably well agreement levels between bronchoalveolar lavage and bronchial wash, suggesting that bronchial wash could potentially be an alternative to bronchoalveolar lavage. [ABSTRACT FROM AUTHOR]

Pseudomonas aeruginosa causes chronic lung infection in cystic fibrosis (CF), resulting in structural lung damage and progressive pulmonary decline. P. aeruginosa in the CF lung undergoes numerous changes, adapting to host-specific airway pressures while establishing chronic infection. P. aeruginosa undergoes lipid A structural modification during CF chronic infection that is not seen in any other disease state. Lipid A, the membrane anchor of LPS (i.e., endotoxin), comprises the majority of the outer membrane of Gram-negative bacteria and is a potent Toll-like receptor 4 (TLR4) agonist. The structure of P. aeruginosa lipid A is intimately linked with its recognition by TLR4 and subsequent immune response. Prior work has identified P. aeruginosa strains with altered lipid A structures that arise during chronic CF lung infection; however, the impact of the P. aeruginosa lipid A structure on airway disease has not been investigated. Here, we show that P. aeruginosa lipid A lacks PagL-mediated deacylation during human airway infection using a direct-from-sample mass spectrometry approach on human BAL fluid. This structure triggers increased proinflammatory cytokine production by primary human macrophages. Furthermore, alterations in lipid A 2-hydroxylation impact cytokine response in a site-specific manner, independent of CF transmembrane conductance regulator function. It is interesting that there is a CF-specific reduction in IL-8 secretion within the epithelial-cell compartment that only occurs in CF bronchial epithelial cells when infected with CF-adapted P. aeruginosa that lacks PagL-mediated lipid A deacylation. Taken together, we show that P. aeruginosa alters its lipid A structure during acute lung infection and that this lipid A structure induces stronger signaling through TLR4. [ABSTRACT FROM AUTHOR]

Background: Lepionurus sylvestris Blume has a long history of folklore medicinal usage against various ailments. However, studies on these plants were neglected particularly their pharmacological potential. Methods: The crude extract was identified using LC-MS analysis. In vitro assays were carried out to determine the properties of antioxidant, anti-microbial, and anti-cancer. Further, network pharmacology was proposed to evaluate the potential targets of the compounds against breast cancer and type II diabetes. Molecular docking and molecular dynamic simulation were used to determine the potential compounds for the drug formulation of diabetes. Results: Various bioactive compounds were identfied using LC-MS and Galiposin, Fujikinetin, Boeravinone B, 4-Deoxybryaquinone, and Norbaeocystin were described for the first time from the plant. Determination of antioxidant potential showed that the IC50 value of ABTS, DPPH, and phosphomolybdate was 24.33 µg/ml, 37.81 µg/ml, 60.35 µg/ml, and reducing power assays 1.185. The antibacterial activity against Streptococcus pyogenes, Staphylococcus aureus, Pseudomonas aeruginosa, and Escherichia coli was determined, and the minimum inhibition concentration (MIC) was found to be 5.3 mg/ml, 3.47 mg/ml, 3.33 mg/ml, and 2.7 mg/ml respectively, revealing the extracts as effective antibacterial agents. The IC50 values for the plant extract were determined to be 26 µg/ml, 30.52 µg/ml, and 24.39 µg/ml for HeLa, MCF-7, and K-562 cells, respectively, and the increasing concentration of the plant extract increased LDH release. Furthermore, the in silico network pharmacology, molecular docking which had the highest docking score for GAPDH and HIF-1 target proteins of -9.3 kcal/mol, and − 11.3 kcal/mol binding affinities, and molecular dynamic simulation analysis revealed the bioactive compound Boeravinone B present in the plant was significant for the treatment of various ailments. Conclusion: Based on our findings, plant extracts could be a promising option for developing new drug formulations. [ABSTRACT FROM AUTHOR]

Plant-beneficial Pseudomonas bacteria hold the potential to be used as inoculants in agriculture to promote plant growth and health through various mechanisms. The discovery of new strains tailored to specific agricultural needs remains an open area of research. In this study, we report the isolation and characterization of four novel Pseudomonas species associated with the wheat rhizosphere. Comparative genomic analysis with all available Pseudomonas type strains revealed species-level differences, substantiated by both digital DNADNA hybridization and average nucleotide identity, underscoring their status as novel species. This was further validated by the phenotypic differences observed when compared to their closest relatives. Three of the novel species belong to the P. fluorescens species complex, with two representing a novel lineage in the Pseudomonas phylogeny. Functional genome annotation revealed the presence of specific features contributing to rhizosphere colonization, including flagella and components for biofilm formation. The novel species have the genetic potential to solubilize nutrients by acidifying the environment, releasing alkaline phosphatases and their metabolism of nitrogen species, indicating potential as biofertilizers. Additionally, the novel species possess traits that may facilitate direct promotion of plant growth through the modulation of the plant hormone balance, including the ACC deaminase enzyme and auxin metabolism. The presence of biosynthetic clusters for toxins such as hydrogen cyanide and nonribosomal peptides suggests their ability to compete with other microorganisms, including plant pathogens. Direct inoculation of wheat roots significantly enhanced plant growth, with two strains doubling shoot biomass. Three of the strains effectively antagonized fungal phytopathogens (Thielaviopsis basicola, Fusarium oxysporum, and Botrytis cinerea), demonstrating their potential as biocontrol agents. Based on the observed genetic and phenotypic differences from closely related species, we propose the following names for the four novel species: Pseudomonas grandcourensis sp. nov., type strain DGS24T (= DSM 117501T = CECT 31011T), Pseudomonas purpurea sp. nov., type strain DGS26T (= DSM 117502T = CECT 31012T), Pseudomonas helvetica sp. nov., type strain DGS28T (= DSM 117503T = CECT 31013T) and Pseudomonas aestiva sp. nov., type strain DGS32T (= DSM 117504T = CECT 31014T). [ABSTRACT FROM AUTHOR]

Biofilms are known to be critical for Legionella settlement in engineered water systems and are often associated with Legionnaire's Disease events. One of the key features of biofilms is their heterogeneous three-dimensional structure which supports the establishment of microbial interactions and confers protection to microorganisms. This work addresses the impact of Legionella pneumophila colonization of a Pseudomonas fluorescens biofilm, as information about the interactions between Legionella and biofilm structures is scarce. It combines a set of meso- and microscale biofilm analyses (Optical Coherence Tomography, Episcopic Differential Interference Contrast coupled with Epifluorescence Microscopy and Confocal Laser Scanning Microscopy) with PNA-FISH labelled L. pneumophila to tackle the following questions: (a) does the biofilm structure change upon L. pneumophila biofilm colonization?; (b) what happens to L. pneumophila within the biofilm over time and (c) where is L. pneumophila preferentially located within the biofilm? Results showed that P. fluorescens structure did not significantly change upon L. pneumophila colonization, indicating the competitive advantage of the first colonizer. Imaging of PNA-labelled L. pneumophila showed that compared to standard culture recovery it colonized to a greater extent the 3-day-old P. fluorescens biofilms, presumably entering in VBNC state by the end of the experiment. L. pneumophila was mostly located in the bottom regions of the biofilm, which is consistent with the physiological requirements of both bacteria and confers enhanced Legionella protection against external aggressions. The present study provides an expedited methodological approach to address specific systematic laboratory studies concerning the interactions between L. pneumophila and biofilm structure that can provide, in the future, insights for public health Legionella management of water systems. [ABSTRACT FROM AUTHOR]

The decline in amphibian populations in recent decades may be linked to the occurrence of infectious diseases such as chytridiomycosis, which is caused by the chytrid fungus Batrachochytrium dendrobatidis (Bd). It is known that symbiotic bacteria protect the host due to their inhibitory nature. However, how the population dynamics of amphibians is affected by additional effects provided by symbiotic bacteria has not been analyzed in depth. In this paper, a model is proposed to describe the interaction among susceptible amphibians, susceptible amphibians with symbiotic bacteria and amphibians with chytrid fungus. When the modeling takes into account the additional reproductive benefits that the symbiont Pseudomonas sp. grants to the host, multiple endemic equilibrium points can exist if R0 < 1 (R0 is the basic reproduction number for Bd). In this scenario, the existence of a subcritical bifurcation at R0 = 1, which can occur in two different disease-free equilibrium points, gives rise to complex dynamics and stability scenarios. Particularly, the analysis of the model shows that a sudden increase of fungus-infected amphibians can occur even when R0 < 1 due to bistability phenomena. In this scenario, the existence of a subcritical bifurcation, which translates for the fungus into colonization even for values of R0 less than one, represents an advantage for the chytrid fungus Batrachochytrium dendrobatidis since the pathogen should benefit from remaining as close as possible to an endemic equilibrium. To control the fungal infection, R0 must be reduced to a value below one until the endemic equilibrium points disappear. Finally, we show that the amphibian population can reach a critical population level close to an extinction scenario when R0 increases. [ABSTRACT FROM AUTHOR]

Biosensors for wound dressings can enable point‐of‐care monitoring of wound bed health by exhibiting a color change visible to the naked eye, to alert healthcare providers of the presence of pathogenic bacteria. Here, a polydiacetylene‐based electrospun nanofibrous wound dressing for the detection of Pseudomonas aeruginosa is reported. Using conventional blend electrospinning, two diacetylene monomers—10,12‐pentacosadiynoic acid (PCDA) and 10,12‐tricosadiynoic acid (TCDA)—are separately electrospun alongside polyurethane as a supporting matrix polymer. The differences in side‐chain length impact the sensitivity of the nanofibers in detecting P. aeruginosa. Furthermore, two DNA aptamers are conjugated to the polydiacetylenes to achieve targeted detection of P. aeruginosa. The aptamer‐modified dressings show improved sensitivity of detection toward eight strains of P. aeruginosa compared to the unmodified membranes. Furthermore, the aptamer‐modified membranes do not respond to non‐target bacteria methicillin‐resistant Staphylococcus aureus (MRSA), Staphylococcus aureus, and Escherichia coli within 3 h of direct contact. Reducing the chain‐length of the diacetylene monomer by substituting PCDA with TCDA boosts the colorimetric response by a factor of >2x compared to the aptamer‐modified PCDA membranes, at the cost of reduced specificity. The aptamer‐conjugated polydiacetylene membranes show promise for application in point‐of‐care wound dressings for improved specificity of detection of bacterial infections. [ABSTRACT FROM AUTHOR]

Background/purpose(s): The continuously increasing carbapenem resistance within Enterobacterales and Pseudomonas poses a threat to public health, nevertheless, the molecular characteristics of which in southern China still remain limited. And carbapenemase identification is a key factor in effective early therapy of carbapenem-resistant bacteria infections. We aimed to determine the molecular characteristics of these pathogens and compare commercial combined disc tests (CDTs) with the modified carbapenem inactivation method (mCIM) and EDTA-CIM (eCIM) in detecting and distinguishing carbapenemases using whole genome sequencing (WGS). Methods: A total of 78 Enterobacterales, 30 Pseudomonas were obtained from two tertiary hospitals in southern China. Susceptibility tests were conducted using an automated VITEK2 compact system with confirmation via the Kirby-Bauer method. The WGS was conducted on all clinical isolates and the molecular characteristics were analyzed by screening the whole genome sequences. CDTs with or without cloxacillin, mCIM, and eCIM, were performed and compared by taking WGS results as the benchmark. Results: A total of 103 carbapenem non-susceptible and 5 carbapenem susceptible bacteria were determined, with Klebsiella pneumoniae (42.7%), Pseudomonas aeruginosa (23.3%) and Escherichia coli (18.4%) being most prevalent. Carbapenemase genes were detected in 58 (56.3%) of the 103 carbapenem-non-susceptible clinical isolates, including 46 NDM, 6 KPC, 3 IMP, 1 IPM+VIM, 1NDM+KPC, and 1 OXA-181. Carbapenemase-producing isolates were detected more frequently in Enterobacterales (76.3%). Among K. pneumoniae, the major sequence types were st307 and st11, while among E. coli and P. aeruginosa, the most prevalent ones were st410 and st242 respectively. For carbapenemase detection in Enterobacterales, the mCIM method achieved 100.00% (95% CI, 92.13-100.00%) sensitivity and 94.44% (70.63-99.71%) specificity (kappa, 0.96); for Pseudomonas, detection sensitivity was 100% (5.46-100.00%), and 100% (84.50-100.00%) specificity (kappa, 0.65). Commercial CDT carbapenemase detection sensitivity for Enterobacterales was 96.49% (86.84-99.39%), and 95.24% (74.13-99.75%) specificity (kappa, 0.90); for Pseudomonas, carbapenemase detection sensitivity was 100.00% (5.46-100.00%) and 37.93% (21.30-57.64%) specificity (kappa, 0.04). When cloxacillin testing was added, CDT specificity reached 84.61% (64.27-94.95%). Conclusion: The molecular epidemiology of carbapenem-non-susceptible isolates from pediatric patients in Southern China exhibited distinctive characteristics. Both the mCIM-eCIM combination and CDT methods effectively detected and differentiated carbapenemases among Enterobacterales isolates, and the former performed better than CDT among Pseudomonas. [ABSTRACT FROM AUTHOR]

Gram-negative antibiotic resistance continues to grow as a global problem due to the evolution and spread of β-lactamases. The early β-lactamase inhibitors (BLIs) are characterized by spectra limited to class A β-lactamases and ineffective against carbapenemases and most extended spectrum β-lactamases. In order to address this therapeutic need, newer BLIs were developed with the goal of treating carbapenemase producing, carbapenem resistant organisms (CRO), specifically targeting the Klebsiella pneumoniae carbapenemase (KPC). These BL/BLI combination drugs, avibactam/avibactam, meropenem/vaborbactam, and imipenem/relebactam, have proven to be indispensable tools in this effort. However, non-KPC mechanisms of resistance are rising in prevalence and increasingly challenging to treat. It is critical for clinicians to understand the unique spectra of these BL/BLIs with respect to non-KPC CRO. In Part 1of this 2-part series, we describe the non-KPC attributes of the newer BL/BLIs with a focus on utility against Enterobacterales and Pseudomonas aeruginosa. [ABSTRACT FROM AUTHOR]

Background: One of the most widely used medicinal plants in Iranian traditional medicine, Rosa × damascena Herrm. (mohammadi flower) that the people of Kashan use as a sedative and to treat nervous diseases and constipation. In this research, the yield, chemical composition and antimicrobial activity of the essential oil of this plant were evaluated for the first time from Azaran region, Kashan. Methods: The essential oil was extracted by means of hydrodistillation (Clevenger), and its chemical compounds were identified and determined by GC/MS. The antimicrobial activity of the essential oil was determined by the diffusion method in agar, the minimum growth inhibitory concentration (MIC) and the minimum concentration capable of killing bacterial/fungal microorganisms (MBC/MFC). Results: The results showed that the yield of essential oil was 0.1586 ± 0.0331% (w/w). Based on the results of the chemical composition analysis of R. x damascena essential oil, 19 different compounds (98.96%) were identified. The dominant and main components of the essential oil were oleic acid (48.08%), palmitic acid (15.44%), stearic acid (10.17%), citronellol (7.37%) and nonadecane (3.70%). Based on the results of diffusion in agar, the highest zone of inhibition against Candida albicans (ATCC 10231) was ~ 9.5 mm. The strongest inhibitory activity of R. x damascena essential oil against Gram-negative Proteus mirabilis (ATCC 43071) was with the diameter of the inhibition zone (~ 9 mm), which was equal to the strength of rifampin (~ 9 mm). Conclusion: Therefore, this essential oil is a promising natural option rich in fatty acids, which can be a potential for the production of natural antimicrobials against infectious diseases, especially urinary tract infections. [ABSTRACT FROM AUTHOR]

The contamination of food by spoilage microorganisms and/or pathogens is a concern in the food industry. Pseudomonas species, Gram-negative, aerobic, and psychrotrophic bacteria, can develop in food products stored at low temperatures. The species causing spoilage in raw meat include Pseudomonas fragi, Pseudomonas fluorescens, Pseudomonas putida, and Pseudomonas lundensis. Psychrotrophic pseudomonads cause bad odors, off-tastes, discoloration, and mucus production in raw meat stored under refrigeration and aerobic conditions. Some Pseudomonas species that develop in meats stored at low temperatures are strong biofilm producers. The spoilage activities of pseudomonads are linked to a cell-to-cell communication system known as quorum sensing (QS). The QS system is responsible for encoding genes related to pathogenicity by sensing population density through molecules produced under adverse conditions. Understanding the spoilage mechanisms of pseudomonads in meat is important for inhibiting their development. Research on the QS system of meat pseudomonads is limited. This review discusses the biodiversity, spoilage properties, biofilm formation abilities, and QS effects of Pseudomonas species on meat spoilage. [ABSTRACT FROM AUTHOR]

The metagenome-assembled genome (MAG) sequences of Pseudomonas putida PP14A and PP20A were obtained by metagenomic sequencing from the gut microbiomes of a female and a male patient both 24 years old from the same household presenting to a health outreach laboratory with complaint of headache, and occasional diarrhoea in Mararaba, Nasarawa State, Nigeria. The phylogenetic relationship observed between the two PP MAGs with other Pseudomonas spp MAGs from human, points to the global spread of Pseudomonas putida through human activity and migration. [ABSTRACT FROM AUTHOR]

Heterocyclic amines (HAs) are a group of mutagenic and carcinogenic compounds produced from the processing of high‐protein foods, which include 2‐amino‐3‐methylimidazo[4, 5‐f]quinoline (IQ) showing the strongest carcinogenic effect. Camels are able to digest HAs in foods, which provide rich microbial resources for the study. Thus, camel rumen and intestinal microbiota were used to degrade IQ, and the dominant microorganisms and their degradation characteristics were investigated. After three generations of culture with IQ as the sole carbon source, the highest abundance in rumen and intestinal microbes was found in the Proteobacteria phylum. The strains of third generation of the rumen contents were mainly attributed to the genera Brevundimonas and Pseudomonas, and the dominant genera in intestine were Ochrobactrum, Bacillus, and Pseudomonas. Microorganisms were further isolated and purified from the third generation cultures. These 27 strains from the rumen (L1–L27) and 23 strains from the intestine (C1–C23) were obtained. Among them, four strains with the most effective degrading abilities were as follows: L6 (28.55% of IQ degrading rate) and C1 (25.19%) belonged to the genus Ochrobactrum, L15 (23.41%) belonged to the genus Pseudomonas, and C16 (20.89%) were of the genus Bacillus. This study suggested the application of abundant microbial resources from camels' digestive tract to biodegrade foodborne toxins. [ABSTRACT FROM AUTHOR]

Sunscreen has been used for thousands of years to protect skin from ultraviolet radiation. However, the use of modern commercial sunscreen containing oxybenzone, ZnO, and TiO 2 has raised concerns due to their negative effects on human health and the environment. In this study, we aim to establish an efficient microbial platform for production of shinorine, a UV light absorbing compound with anti-aging properties. First, we methodically selected an appropriate host for shinorine production by analyzing central carbon flux distribution data from prior studies alongside predictions from genome-scale metabolic models (GEMs). We enhanced shinorine productivity through CRISPRi-mediated downregulation and utilized shotgun proteomics to pinpoint potential competing pathways. Simultaneously, we improved the shinorine biosynthetic pathway by refining its design, optimizing promoter usage, and altering the strength of ribosome binding sites. Finally, we conducted amino acid feeding experiments under various conditions to identify the key limiting factors in shinorine production. The study combines meta-analysis of 13C-metabolic flux analysis, GEMs, synthetic biology, CRISPRi-mediated gene downregulation, and omics analysis to improve shinorine production, demonstrating the potential of Pseudomonas putida KT2440 as platform for shinorine production. • Meta-Analysis of 13C-MFA and GEMs show P. putida to be an ideal host for shinorine production. • CRISPRi-mediated gene downregulation of PP_1444 improves shinorine production. • Shinorine was produced at high titers and amino acid supplementation improved the titer. • Shinorine accumulates exclusively in the supernatant in P. putida cultures. [ABSTRACT FROM AUTHOR]

Objective: The aim of this study was to evaluate the antibiotic resistance of microorganisms isolated in cases of culture-positive nosocomial late-onset neonatal sepsis in the neonatal intensive care unit. Materials and Methods: Infants admitted to our neonatal intensive care unit between October 2015 and June 2022 were retrospectively screened. A total of 458 different cultures from 386 sepsis incidents in 250 infants were analyzed. Results: Over an 8-year period, 407 cases of culture-positive nosocomial late-onset neonatal sepsis were reviewed in a total of 4244 infants. Twenty-one cases were excluded due to insufficient data. The incidence of culture-positive nosocomial sepsis was 6.3%. Coagulase-negative Staphylococcus and Staphylococcus aureus were the most common gram-positive bacteria found in cultures. Resistance to ampicillin and cephalosporin treatments was high, while resistance to vancomycin, teicoplanin, and linezolid was low. Klebsiella spp. were the most frequent gram-negative bacteria isolated in cultures and showed high resistance to non-carbapenembased regimens. The only fungal microorganisms isolated in cultures were Candida spp., which had a high mortality rate despite their low resistance profile. The mortality rate due to nosocomial sepsis was 19.6%. Conclusion: Our study demonstrated that microorganisms and their antibiotic resistance profiles changed over time in the newborn intensive care unit. Gram-negative pathogens exhibited high antibiotic resistance, while fungi had high mortality rates. It is essential to adjust empirical antibiotic regimens for nosocomial sepsis based on thorough surveillance. [ABSTRACT FROM AUTHOR]

The acyltransferase from Pseudomonas protegens (PpATase) catalyzes in nature the reversible transformation of monoacetylphloroglucinol to diacetylphloroglucinol and phloroglucinol. Interestingly, this enzyme has been shown to catalyze the promiscuous transformation of 3‐hydroxyphenyl acetate to 2′,4′‐dihydroxyacetophenone, representing a biological version of the Fries rearrangement. In the present study, we report a mechanistic investigation of this activity of PpATase using quantum chemical calculations. A detailed mechanism is proposed, and the energy profile for the reaction is presented. The calculations show that the acylation of the enzyme is highly exothermic, while the acetyl transfer back to the substrate is only slightly exothermic. The deprotonation of the C6−H of the substrate is rate‐limiting, and a remote aspartate residue (Asp137) is proposed to be the general base group in this step. Analysis of the binding energies of various acetyl acceptors shows that PpATase can promote both intramolecular and intermolecular Fries rearrangement towards diverse compounds. [ABSTRACT FROM AUTHOR]

In early spring of 2020–2022, rot symptoms were observed on onion growing in Iwate and Akita Prefectures. The symptoms exhibited water-soaking rot on leaves, or light brown soft rot on leaf sheaths and bulbs, bringing death of whole plants. From lesions, LOPAT group IVa bacteria were isolated. Based on pathogenicity, bacteriological properties, and sequences of 16S rRNA and housekeeping genes, isolates were identified as Pseudomonas kitaguniensis. This is the first report of bacterial rot of onion caused by P. kitaguniensis. P. kitaguniensis caused strong rot on onion bulbs at 15–25 °C than 30 °C, different from other closely related species. [ABSTRACT FROM AUTHOR]

Background: Postoperative urinary tract infection is a common complication that not only significantly prolongs the hospital stay and amplifies the economic burden on patients, but also affects their quality of life and prognosis. This study aimed to investigate risk factors and distribution of pathogenic bacteria in urinary tract infections among bladder cancer patients who underwent cutaneous ureterostomy following radical cystectomy. Methods: A total of 137 bladder cancer patients, who underwent cutaneous ureterostomy after radical cystectomy at our hospital from November 2018 to October 2022, were enrolled in this retrospective study. Univariate and multivariate logistic regression analyses were employed to investigate the risk factors associated with postoperative urinary tract infection and the distribution of pathogenic bacteria among the infected patients. Results: The results of both univariate and multivariate analyses confirmed that age, proficiency in ostomy knowledge, frequency of ureteral stent tube replacement, ureteral stent tube dislodgement, urine immersion at the outer end of the ureteral stent tube, and the interval of ostomy bag replacement were independent risk factors for urinary tract infection after radical cystectomy and cutaneous ureterostomy in bladder cancer patients. A total of 55 pathogenic bacteria were isolated from 52 patients with infections. Predominantly, these were gram-negative bacteria (34 strains, 61.8%), with Proteus mirabilis having the highest proportion. Conclusion: Urinary tract infections after radical cystectomy and cutaneous ureterostomy predominantly involve gram-negative bacteria. This is correlated with factors such as the age of bladder cancer patients, the level of nursing education, the duration of ureteral stent tubes and ostomy bag usage, as well as issues related to impaired urine drainage. [ABSTRACT FROM AUTHOR]

The study investigated the bacteria associated with two species of gobies (Periophthalmus papilio and Bostrychus africanus) from two Creeklets; Iwofe and Bakana of the New Calabar River. Determination of bacterial loads, species characterization and composition in fish parts (skin, intestine and gills) were done using standard microbiological procedures. Results revealed a total of eight bacterial species: Bacillus subtilis, B. licheniformis, B. megaterium, Staphylococcus aureus, Escherichia coli, Micrococcus sp, Pseudomonas sp and Proteus sp. The total viable counts of bacterial isolated from Periophthalmus papilio revealed 6.4 × 107 and 9.2 × 107 cfu/g from the skin, 4.8 × 108 and 2.2 × 108 cfu/g from the intestine and 5.2 × 107 and 7.1 × 107 cfu/g from the gills in Bakana and Iwofe Creeklets respectively. The total heterotrophic bacterial counts of Bostrychus africanus showed 2.5 × 107 and 8.5 × 107 cfu/g from the skin, 2.8 × 108and 1.5 × 108 cfu/g from the intestine and 1.5 × 107 and 6.0 × 107cfu/g from the gills from Bakana and Iwofe Creeklets respectively. Bacillus subtilis, Staphylococcus aureus and Escherichia coli had the highest frequency of occurrence (20%) while Pseudomonas and Proteus sp. occurred twice (5%). Analysis of variance (ANOVA) on the data showed that there was no significant difference at p =0.05 between the bacteria isolated from the two fish species collected from Iwofe and Bakana Creeklets. Some bacterial flora (Bacillus sp) isolated in the present study composed of potential pathogenic organisms of public health interest. Thus, the cooking process applied to fishes before consumption should employ temperatures that can eliminate these pathogens. [ABSTRACT FROM AUTHOR]

The phytochemical constituents in Priva cordifolia leaf extracts and their antibacterial activity against Escherichia coli and Pseudomonas sp. were determined along with antioxidant property. HepG2 cells were used to test the hepatoprotective and cytoprotective effects of P. cordifolia leaf extracts by evaluating the levels of liver enzymes AST and ALT. The inhibitory zone against E. coli and Pseudomonas sp. by the ethanolic extract was effective than the aqueous extract. At 100 µg mL−1, the ethanolic extract had the highest Fe3+ reducing ability of 89.52% and improved cell viability and decreased AST and ALT levels in CCl4-damaged HepG2 cells. [ABSTRACT FROM AUTHOR]

The article focuses on the importance of sea bass, which is preferred by consumers in Turkey and worldwide. However, seafood can deteriorate rapidly under unfavorable conditions during storage due to their nutrient content, water content, and weakness in connective tissues. Temperature changes, inappropriate processing methods during transportation, and temperature changes during storage in markets are reported to cause losses in seafood quality. The deterioration of seafood, especially in seafood stored under inappropriate conditions because of temperature, causes changes contrary to consumer preferences because of the rapid growth of microorganisms, especially odor changes in seafood. This study examines the models related to the discipline of predictive microbiology, which are stated to provide an accurate shelf life prediction of the rate of microbiological spoilage and emphasize the importance of mathematical predictions of these models for seafood. Furthermore, the paper observes that machine learning algorithms such as Random Forest, Decision Tree, k-Nearest Neighbors, AdaBoost, Gradient Tree Boosting, Random Forest, Decision Tree, k-Nearest Neighbors, AdaBoost, and Gradient Tree Boosting have been used to predict the shelf life of seafood products. Finally, how to augment the limited data in a laboratory study to evaluate the shelf life of sea bass stored at different temperatures, how to prove the consistency of the augmented data with the original data, and how to optimize successful machine learning methods for robust problem-solving processes between different engineering fields are explained in detail. The results show that the optimized Extra Tree algorithm is the most successful for Pseudomonas quantity estimation with an R2 metric value of 0.9940 and TVC quantity estimation with an R2 metric value of 0.9910, while the other algorithms are less successful than this algorithm. These results show that machine learning methods can be a rapid, powerful, and effective tool for shelf life prediction of sea bass. Additionally, it should be emphasized that the number of input parameters (temperature, number of the bacteria) are of utmost significant for augmentation of the data for development and application of the machine learning algorithms. [ABSTRACT FROM AUTHOR]

Pseudomonas bacteria are renowned for their remarkable capacity to synthesize antibiotics, namely mupirocin, gluconic acid, pyrrolnitrin, and 2,4-diacetylphloroglucinol (DAPG). While these substances are extensively employed in agricultural biotechnology to safeguard plants against harmful bacteria and fungi, their potential for human medicine and healthcare remains highly promising for common science. However, the challenge of obtaining stable producers that yield higher quantities of these antibiotics continues to be a pertinent concern in modern biotechnology. Although the interest in antibiotics of Pseudomonas bacteria has persisted over the past century, many uncertainties still surround the regulation of the biosynthetic pathways of these compounds. Thus, the present review comprehensively studies the genetic organization and regulation of the biosynthesis of these antibiotics and provides a comprehensive summary of the genetic organization of antibiotic biosynthesis pathways in pseudomonas strains, appealing to both molecular biologists and biotechnologists. In addition, attention is also paid to the application of antibiotics in plant protection. [ABSTRACT FROM AUTHOR]

Phosphorus constitutes a crucial macronutrient for crop growth, yet its availability often limits food production. Efficient phosphorus management is crucial for enhancing crop yields and ensuring food security. This study aimed to enhance the efficiency of a short-chain polyphosphate (PolyP) fertilizer by integrating it with plant growth-promoting bacteria (PGPB) to improve nutrient solubilization and wheat growth. Specifically, the study investigated the effects of various bacterial strains on wheat germination and growth when used in conjunction with PolyP. To achieve this, a greenhouse experiment was conducted in which the wheat rhizosphere was amended with a short-chain PolyP fertilizer. Based on the morphological aspect, eight bacteria, designated P1 to P8, were isolated and further characterized. Plant growth-promoting traits were observed in all bacterial strains, as they presented the ability to produce Indole Acetic Acid (IAA) in significant amounts ranging from 7.5 ± 0.3 µg/mL to 44.1 ± 2 µg/mL, expressed by B. tropicus P4 and P. soyae P1, respectively. They also produced ammonia, hydrogen cyanide (HCN), and siderophores. Their effect against the plant pathogen Fusarium culmorum was also assessed, with P. reinekei P2 demonstrating the highest biocontrol activity as it presented a total inhibitory effect. Additionally, some strains exhibited the ability to solubilize/hydrolyze phosphorus, potassium, and zinc. In vivo, the initial growth potential of wheat seeds indicated that those inoculated with the isolated strains exhibited elevated germination rates and enhanced root growth. Based on their plant growth-promoting traits and performance in the germination assay, three strains were selected for producing the best results, specifically phosphorus hydrolyzation/solubilization, zinc solubilization, IAA production, HCN, and siderophores production. Wheat seeds were inoculated by drenching in a bacterial suspension containing 1010 CFU/mL of log phase culture, and an in planta bioassay was conducted in a growth chamber using three selected strains (Pseudomonas soyae P1, Pseudomonas reinekei P2, and Bacillus tropicus P4), applied either individually or with PolyP on a P-deficient soil (28 mg/kg of P Olsen). Our findings demonstrated that the combination of Pseudomonas soyae P1 and PolyP achieved the highest shoot biomass, averaging 41.99 ± 0.87 g. Notably, applying P. soyae P1 or Bacillus tropicus P4 alone yielded similar results to the use of PolyP alone. At the heading growth stage, the combination of Bacillus tropicus P4 and PolyP significantly increased the Chlorophyll Content Index (CCI) to 37.02 µmol/m2, outperforming both PolyP alone (24.07 µmol/m2) and the control (23.06 µmol/m2). This study presents an innovative approach combining short-chain PolyP with bacterial biostimulants to enhance nutrient availability and plant growth. By identifying and characterizing effective bacterial strains, it offers a sustainable alternative to conventional fertilizers. [ABSTRACT FROM AUTHOR]

Microorganisms have significant potential to control fungal contamination in various foods. However, the identification of strains that exhibit robust antifungal activity poses challenges due to highly context-dependent responses. Therefore, to fully exploit the potential of isolates as antifungal agents, it is crucial to systematically evaluate them in a variety of biotic and abiotic contexts. Here, we present an adaptable and scalable method using a robotic platform to study the properties of 1022 isolates obtained from maple sap. We tested the antifungal activity of isolates alone or in pairs on M17 + lactose (LM17), plate count agar (PCA), and sucrose–allantoin (SALN) culture media against Kluyveromyces lactis, Candida boidinii, and Saccharomyces cerevisiae. Microorganisms exhibited less often antifungal activity on SALN and PCA than LM17, suggesting that the latter is a better screening medium. We also analyzed the results of ecological interactions between pairs. Isolates that showed consistent competitive behaviors were more likely to show antifungal activity than expected by chance. However, co-culture rarely improved antifungal activity. In fact, an interaction-mediated suppression of activity was more prevalent in our dataset. These findings highlight the importance of incorporating both biotic and abiotic factors into systematic screening designs for the bioprospection of microorganisms with environmentally robust antifungal activity. [ABSTRACT FROM AUTHOR]

The present study, conducted from August to November 2022 in district Okara, Pakistan, focused on assessing the bacterial characterization in oral saliva swabs of black rats (Rattus rattus). DNA extraction was performed using the QIAamp DNA Microbiome kit, and the 16S rRNA gene was amplified using universal primers to amplify variable regions (V) V1 to V8 of 1380 bp. The identified bacterial phyla were as follows: Proteobacteria 98%, Firmicutes 1%, Actinobacteria 0.4%, and Bacteroidetes 0.05%. The bacterial classes included Gammaproteobacteria 95%, Alpha Enterobacterales 3%, and Bacilli 1%. The relative abundance of different bacterial orders was Pseudomonadales 40%, Enterobacterales 30%, Xanthomonadales 25%, Sphingomonadales 3%, Lactobacillales 1%, Micrococcales 0.4%, and Bacteroidales 0.05%. The identified families followed the order of Pseudomonadaceae 40%, Enterobacteriaceae 30%, Xanthomonadaceae 25%, and Sphingomonadaceae 3%. The percentage distribution of Pseudomonas was 40%, Stenotrophomonas 25%, Sphingomonas 3%, Pantoea 2%, and Porphyromonas 0.05%. This knowledge enhances our understanding of bacterial infections in rodents, serving as crucial baseline data for bacterial species. The high prevalence of potentially pathogenic bacteria like Pseudomonas suggests a significant risk of zoonotic diseases that could affect both local wildlife and human populations. It is crucial that future studies should focus on identified bacterial communities in other rodent species and small mammals to compare their roles in disease ecology. This ongoing research could identify specific species that are particularly significant in zoonotic transmission, thereby guiding future studies and public health measures. [ABSTRACT FROM AUTHOR]