Search

Importance: Patients with limited English proficiency (LEP) experience disparities in prehospital care. On-scene interactions between patients with LEP and emergency medical services (EMS) providers (ie, firefighters/emergency medical technicians [EMTs] and paramedics) are critical to high-quality care and have been minimally explored., Objective: To identify EMS-perceived barriers and facilitators to providing high-quality prehospital care for patients with LEP., Design, Setting, and Participants: In this qualitative study, semi-structured focus groups were conducted with firefighters/EMTs and paramedics with all levels of experience from urban areas with a high proportion of residents with LEP from July to September 2018. Data were analyzed from July 2018 to May 2019., Exposures: Providing prehospital care for patients with LEP., Main Outcomes and Measures: The main outcomes were barriers and facilitators to prehospital care for patients with LEP, assessed using thematic analysis. Four domains of interest were examined: (1) overall impressions of interactions with patients with LEP, (2) barriers and facilitators to communication, (3) barriers and facilitators to providing care, and (4) ideas for improving prehospital care for patients with LEP., Results: Thirty-nine EMS providers participated in 8 focus groups: 26 firefighters/EMTs (66%) and 13 paramedics (33%). The median age of participants was 46 years (range, 23-63 years), and 35 (90%) were male. Participants described barriers to optimal care as ineffective interpretation, cultural differences, high-stress scenarios (eg, violent events), unclear acuity of patient's condition, provider bias, and distrust of EMS. Perceived facilitators to optimal care included using an on-scene interpreter, high-acuity disease, relying on objective clinical findings, building trust and rapport, and conservative decision-making regarding treatment and transport. Providers reported transporting most patients with LEP to hospitals regardless of illness severity due to concern for miscommunication and unrecognized problems. Better speed and technology for interpretation, education for communities and EMS providers, and community-EMS interactions outside emergencies were cited as potential strategies for improvement., Conclusions and Relevance: In this study, EMS providers described many barriers to high-quality care during prehospital emergency response for patients with LEP yet were unaware that these barriers impacted quality of care. Barriers including ineffective interpretation, provider bias, distrust of EMS, and cultural differences may contribute to outcome disparities and overutilization of resources. Future work should focus on the development of targeted interventions to improve modifiable barriers to care, such as improving interpretation and cultural humility and increasing trust.

Abstract: The proper description of former populations is one of the most difficult tasks in anthropology. Archaeological material is often limited due to fragmented and sometimes poorly preserved bone material resulting in incomplete data. Published skeletal raw data are available from the past, but much of this data is either unavailable or not used for scientific studies. The authors seek to elicit more information about prehistoric times by using this dataset to introduce a new method. The purpose is to provide an approach to reconstruct a former population in respect to robusticity and health status. For this in the pilot study the Body Mass Index (BMI) and Frame Index (FI) of early medieval South-West Germany have been analysed. The FI, in contrast to the BMI, has not yet been used for robusticity analysis utilizing only skeletal remains. As far as we know, this is the first time that the FI has been calculated using archaeological material. Due to unknown soft-tissue thickness we introduce the Osseous Frame Index (OFI). The measured OFI reveals new insights in (pre-)historic populations and allows comparisons with modern reference samples. Our OFI calculations are relatively similar to modern calculations. Males have a higher robusticity than females, slightly increasing during life-time compared to females. These calculations provide a better historical understanding of human body composition.

Hypertrophic osteoarthropathy (HOA) is rarely diagnosed in archaeological human skeletons. Here, we report on the well-preserved skeleton of a middle-adult man from the early Medieval settlement site of Lauchheim (Germany) that exhibits pronounced multi-layered shell-like periosteal new bone formation in a bilaterally symmetric fashion on the long bones, the skeletal elements of the pelvis and those of the pectoral girdle. In addition, the two distal phalanges recovered show signs of osteoclastic resorption on their distal tuberosities. The distribution and morphology of the observed lesions are consistent with a diagnosis of HOA. The adult age at death of the individual and the co-occurrence of "healed" and "active" lesions suggest a secondary form of HOA. Given that only skeletal remains were available for study, the underlying (pulmonary or non-pulmonary) primary disease cannot be definitively ascertained in the present case. No osseous changes were found on the ribs, but signs of osteoclastic resorption were observed on the dorsal surface of the sternal body, which might indicate a retrosternal or mediastinal location of the primary disease. Thus far, only a few archaeological case studies of secondary HOA reported signs of the presumed underlying primary disease, which was of a pulmonary nature in each of the individuals., (Copyright © 2017 Elsevier Inc. All rights reserved.)

Objectives: To compare emergency medical services (EMS) utilization between culturally and linguistically diverse (CALD) and non-CALD patients in Victoria, Australia. Methods: A retrospective study of EMS attendances and transports in Victoria from January 2015 to June 2019, utilizing linked EMS, hospital emergency and admissions data. The CALD and non-CALD patients who received EMS care and transport to a Victorian public emergency department were included. The incidence of EMS use for CALD and non-CALD patients based on the 2016 Census population and expressed per 100,000 person-years. Results: In 1,261,167 included patients, there were 272,100 (21.6%) CALD and 989,067 (78.4%) non-CALD patients. Before adjustment for age and sex, EMS utilization for CALD patients was 13% lower than non-CALD patients (incidence rate ratio [IRR] 0.87, 95% CI: 0.87–0.87). When stratified by age groups, CALD patients aged under 70 years had significantly lower rates of EMS utilization than non-CALD patients, while CALD patients aged 75 years or older were more likely than non-CALD patients to use EMS (IRR 1.08, 95% CI: 1.07–1.09). The CALD patients were less likely to utilize EMS for trauma/external injury (IRR = 0.67, 95% CI: 0.66–0.68) and mental health/alcohol/drug problems (IRR = 0.39, 95% CI: 0.38–0.40). After adjustment for differences in the age and sex distribution of CALD and non-CALD populations, CALD patients were 51% less likely to utilize EMS than non-CALD patients (IRR 0.49, 95% CI: 0.42–0.56). Conclusions: The CALD patients used EMS less frequently than non-CALD patients with significant variation observed across age groups, countries of birth, and clinical presentation. Further research is needed to understand the factors that may be contributing to these disparities. [ABSTRACT FROM AUTHOR]

Salmonella typhimurium responds to a variety of environmental stresses by accumulating the alternative sigma factor sigmaS. The repertoire of sigmaS -dependent genes that are subsequently expressed confers tolerance to a variety of potentially lethal conditions including low pH and stationary phase. The mechanism(s) responsible for triggering sigmaS accumulation are of considerable interest, because they help to ensure survival of the organism during encounters with suboptimal environments. Two genes associated with regulating sigmaS levels in S. typhimurium have been identified. The first is clpP, encoding the protease known to be responsible for degrading sigmaS in Escherichia coli. The second is dksA, encoding a protein of unknown function not previously associated with regulating sigmaS levels. As predicted, clpP mutants accumulated large amounts of sigmaS even in log phase. However, dksA mutants failed to accumulate sigmaS in stationary phase and exhibited lower accumulation during acid shock in log phase. DksA appears to be required for the optimal translation of rpoS based upon dksA mutant effects on rpoS transcriptional and translational lacZ fusions. The region of rpoS mRNA between codons 8 and 73 is required to see the effects of dksA mutations. This distinguishes the role of DksA from that of HF-I (hfq ) in rpoS translation, as the HF-I target area occurs well upstream of the rpoS start codon. DksA appears to be involved in the expression of several genes in addition to rpoS based on two-dimensional SDS-PAGE analysis of whole-cell proteins. As a result of their effects on gene expression, mutations in clpP and dksA decreased the virulence of S. typhimurium in mice, consistent with a role for sigmaS in pathogenesis.

Salmonella enterica serovar Derby causes foodborne disease (FBD) outbreaks worldwide, mainly from contaminated pork but also from chickens. During a major epidemic of FBD in Uruguay due to S. enteritidis from poultry, we conducted a large survey of commercially available eggs, where we isolated many S. enteritidis strains but surprisingly also a much larger number (ratio 5:1) of S. Derby strains. No single case of S. Derby infection was detected in that period, suggesting that the S. Derby egg strains were impaired for human infection. We sequenced fourteen of these egg isolates, as well as fifteen isolates from pork or human infection that were isolated in Uruguay before and after that period, and all sequenced strains had the same sequence type (ST40). Phylogenomic analysis was conducted using more than 3,500 genomes from the same sequence type (ST), revealing that Uruguayan isolates clustered into four distantly related lineages. Population structure analysis (BAPS) suggested the division of the analyzed genomes into nine different BAPS1 groups, with Uruguayan strains clustering within four of them. All egg isolates clustered together as a monophyletic group and showed differences in gene content with the strains in the other clusters. Differences included variations in the composition of mobile genetic elements, such as plasmids, insertion sequences, transposons, and phages, between egg isolates and human/pork isolates. Egg isolates showed an acid susceptibility phenotype, reduced ability to reach the intestine after oral inoculation of mice, and reduced induction of SPI-2 ssaG gene, compared to human isolates from other monophyletic groups. Mice challenge experiments showed that mice infected intraperitoneally with human/pork isolates died between 1-7 days p.i., while all animals infected with the egg strain survived the challenge. Altogether, our results suggest that loss of genes functions, the insertion of phages and the absence of plasmids in egg isolates may explain why these S. Derby were not capable of producing human infection despite being at that time, the main serovar recovered from eggs countrywide. [ABSTRACT FROM AUTHOR]

Comparison of the 87Sr/86Sr signatures of archaeological osteological material with features of geological provinces can be applied to determine the places of birth and living of individuals. Such reconstructions were conducted for both humans and domestic animals at the Late Bronze–Early Iron Age sites of the Crimea. The Crimean Peninsula is an interesting testing polygon for such research because it is characterized by a diverse geological situation within a relatively small area. The initial data allowed us to distinguish between three groups of mobility at the Bai-Kiyat I settlement and two groups at the Dolgii Bugor site. The Bai-Kiyat I site is located on the seacoast, so the proxy line for this area will correspond to the value of the ratio of strontium isotopes in seawater (0.7092). The inhabitants of this settlement, including a child from a burial on the settlement, are characterized by this value of strontium isotopes. Other groups include nonlocal people. The data obtained indicate that the steppe zone of the Northern Black Sea region was an ecumene, within which active mobility of groups of people was registered. This mobility is associated primarily with the pastoral type of economy in the period from the Chalcolithic to the Early Iron Age. [ABSTRACT FROM AUTHOR]

Succinate is a potent immune signalling molecule that is present in the mammalian gut and within macrophages. Both of these infection niches are colonised by the pathogenic bacterium Salmonella enterica serovar Typhimurium during infection. Succinate is a C4-dicarboyxlate that can serve as a source of carbon for bacteria. When succinate is provided as the sole carbon source for in vitro cultivation, Salmonella and other enteric bacteria exhibit a slow growth rate and a long lag phase. This growth inhibition phenomenon was known to involve the sigma factor RpoS, but the genetic basis of the repression of bacterial succinate utilisation was poorly understood. Here, we use an experimental evolution approach to isolate fast-growing mutants during growth of S. Typhimurium on succinate containing minimal medium. Our approach reveals novel RpoS-independent systems that inhibit succinate utilisation. The CspC RNA binding protein restricts succinate utilisation, an inhibition that is antagonised by high levels of the small regulatory RNA (sRNA) OxyS. We discovered that the Fe-S cluster regulatory protein IscR inhibits succinate utilisation by repressing the C4-dicarboyxlate transporter DctA. Furthermore, the ribose operon repressor RbsR is required for the complete RpoS-driven repression of succinate utilisation, suggesting a novel mechanism of RpoS regulation. Our discoveries shed light on the redundant regulatory systems that tightly regulate the utilisation of succinate. We speculate that the control of central carbon metabolism by multiple regulatory systems in Salmonella governs the infection niche-specific utilisation of succinate. Author summary: During infection, Salmonella enterica serovar Typhimurium must efficiently utilise the nutrients provided by the host and the microbiota. Within host niches colonised by Salmonella, key carbon source is succinate, which is abundant in both the gut and within macrophages. Although S. Typhimurium possesses all the molecular machinery to import and catabolise succinate, the utilisation of this carbon source is strongly inhibited under laboratory conditions. Here, we have used diverse genetic approaches to discover that several distinct genetic regulatory systems act in concert to repress succinate utilisation by Salmonella. Our study sheds new light on how carbon source utilisation is managed by this important model enteropathogenic bacterium. [ABSTRACT FROM AUTHOR]

The gram-negative facultative intracellular pathogen Salmonella enterica serotype Choleraesuis, also known as S. Choleraesuis, is a major financial loss for the pig business. C500 is a vaccine strain that has been used for preventing S. Choleraesuis infection in pigs for many years in China. Although it possessed good immunogenicity and protection efficacy, it still showed severe side effects. The truncation of the key gene rpoS in C500 was believed to take the major responsibility for its attenuation. To achieve a good balance between attenuation and immunogenicity, rpoS was restored to an active state, and other essential virulent genes of crp, fur, phoP, and aroA were evaluated for their effects of deletion on safety and immunogenicity. Animal experiments demonstrated that C5001 (C500 rpoS+ Δcrp10) and C5002 (C500 rpoS+ Δfur9) showed an excellent ability to induce an immune response. To further decrease the endotoxic activity, the combination mutations of ΔpagL7 ΔpagP81::Plpp lpxE ΔlpxR9 were introduced into the mutant strains to generate 1′-dephosphorylated lipid A. Animal experiments showed that SC3 (C500 rpoS+ Δfur9 ΔpagL7 ΔpagP81:: Plpp lpxE ΔlpxR9) induced higher levels of IgG and secreted IgA antibodies and provided a higher protection rate than SC1 (C500 ΔpagL7 ΔpagP81:: Plpp lpxE ΔlpxR9) and SC2 (C500 rpoS+ Δcrp10 ΔpagL7 ΔpagP81:: PlpplpxE ΔlpxR9). We also evaluated the ability of SC3 (C500 rpoS+ Δfur9 ΔpagL7 ΔpagP81:: Plpp lpxE ΔlpxR9) as a vaccine carrier to deliver heterologous protein antigens and polysaccharide antigens. The results indicated that SC3 (C500 rpoS+ Δfur9 ΔpagL7 ΔpagP81:: Plpp lpxE ΔlpxR9) showed an excellent ability to deliver heterologous antigens and induce the host to produce high levels of antibodies. Together, these results indicate that we constructed a safe and efficient attenuated strain of the S. Choleraesuis vaccine, which demonstrated strong resistance to infection with wild-type S. Choleraesuis and can be employed as a universal vector for the delivery of recombinant antigens. [ABSTRACT FROM AUTHOR]

Familial hemophagocytic lymphohistiocytosis (FHL) is an inherited, often fatal immune deficiency characterized by severe systemic hyperinflammation. Although allogeneic bone marrow transplantation can be curative, more effective therapies are urgently needed. FHL is caused by inactivating mutations in proteins that regulate cellular immunity. Here, we used an adeno-associated virus–based CRISPR-Cas9 system with an inhibitor of nonhomologous end joining to repair such mutations in potentially long-lived T cells ex vivo. Repaired CD8 memory T cells efficiently cured lethal hyperinflammation in a mouse model of Epstein-Barr virus–triggered FHL2, a subtype caused by perforin-1 (Prf1) deficiency. Furthermore, repair of PRF1 and Munc13-4 (UNC13D)—whose deficiency causes the FHL subtype FHL3—in mutant memory T cells from two critically ill patients with FHL restored T cell cytotoxicity. These results provide a starting point for the treatment of genetic T cell immune dysregulation syndromes with repaired autologous T cells. Editor's summary: Familial hemophagocytic lymphohistiocytosis (FHL) is a spectrum of inherited, potentially fatal inflammatory diseases caused by loss-of-function mutations in the NK cell and T cell cytotoxic machinery. Although FHL can be treated with hematopoietic stem cell transplantation (HSCT), mortality is still high and more effective therapeutic approaches are needed. Li et al. developed an adeno-associated virus (AAV)–based CRISPR-Cas9 system combined with nonhomologous end joining (NHEJ) inhibition to repair T cells from a perforin (Prf1)–deficient Epstein-Barr virus (EBV)–triggered mouse model of FHL (FHL2). Repaired T cells could prevent or cure FHL2-like disease caused by EBV-driven B cell hyperproliferation. Moreover, this CRISPR-Cas9 system could be used to mend T cells from pediatric patients with FHL2 (PRF1 deficiency) and FHL3 (Munc13-4/UNC13D deficiency). This work demonstrates that gene repair of autologous T cells is a potentially promising treatment for human FHL. —Seth Thomas Scanlon [ABSTRACT FROM AUTHOR]

Thermophilic cell factories have remarkably broad potential for industrial applications, but are limited by a lack of genetic manipulation tools and recalcitrance to transformation. Here, we identify a thermophilic type I-B CRISPR-Cas system from Parageobacillus thermoglucosidasius and find it displays highly efficient transcriptional repression or DNA cleavage activity that can be switched by adjusting crRNA length to less than or greater than 26 bp, respectively, without ablating Cas3 nuclease. We then develop an orthogonal tool for genome editing and transcriptional repression using this type I-B system in both thermophile and mesophile hosts. Empowered by this tool, we design a strategy to screen the genome-scale targets involved in transformation efficiency and established dynamically controlled supercompetent P. thermoglucosidasius cells with high efficiency (~ 108 CFU/μg DNA) by temporal multiplexed repression. We also demonstrate the construction of thermophilic riboflavin cell factory with hitherto highest titers in high temperature fermentation by genome-scale identification and combinatorial manipulation of multiple targets. This work enables diverse high-efficiency genetic manipulation in P. thermoglucosidasius and facilitates the engineering of thermophilic cell factories. Thermophilic genetic manipulation tools are limited. Here the authors report a thermophilic type I-B CRISPR-Cas system and show it displays efficient transcriptional repression or DNA cleavage activity: they develop a tool for genome editing and transcriptional repression in both thermophile and mesophile hosts. [ABSTRACT FROM AUTHOR]

Introduction: The frame index (FI), based on measurements of elbow breadth and height, is the body frame size parameter most frequently used in child and adolescent populations to assess skeletal robustness. In 2018, the first FI reference percentiles were elaborated with data of boys and girls aged 0–18 years from different European populations. In Argentina, the FI reference values were published in 2022. Objective: The present study aims to compare the Argentine (AR) and European (EU) FI reference percentiles to evaluate possible variation in bone robustness between populations. Methods: The values of the 3rd, 50th and 97th percentiles of the AR and EU FI references for boys and girls aged 4–14 years were compared using the Wilcoxon test (p <.05). Percentage differences between means (PDM) were calculated to analyze the magnitude of the differences between both references. The R 3.2.0 program was used to plot the percentile curves. Results: The FI reference values were lower in AR than in EU in both the 3rd and the 50th percentiles, regardless of sex and age. Conversely, the AR reference values of the 97th percentile were higher than the EU values at most ages. Conclusions: The comparison of the AR and EU FI references showed similar age and sex growth patterns. However, differences in percentile values between populations were observed, highlighting the importance of having local references for the evaluation of skeletal robustness. [ABSTRACT FROM AUTHOR]

Contaminated fresh produce has been routinely linked to outbreaks of Salmonellosis. Multiple studies have identified Salmonella enterica factors associated with successful colonization of diverse plant niches and tissues. It has also been well documented that S. enterica can benefit from the conditions generated during plant disease by host-compatible plant pathogens. In this study, we compared the capacity of two common S. enterica research strains, 14028s and LT2 (strain DM10000) to opportunistically colonize the leaf apoplast of two model plant hosts Arabidopsis thaliana and Nicotiana benthamiana during disease. While S. enterica 14028s benefited from co-colonization with plant-pathogenic Pseudomonas syringae in both plant hosts, S. enterica LT2 was unable to benefit from Pto co-colonization in N. benthamiana. Counterintuitively, LT2 grew more rapidly in ex planta N. benthamiana apoplastic wash fluid with a distinctly pronounced biphasic growth curve in comparison with 14028s. Using allelic exchange, we demonstrated that both the N. benthamiana infection-depedent colonization and apoplastic wash fluid growth phenotypes of LT2 were associated with mutations in the S. enterica rpoS stress-response sigma factor gene. Mutations of S. enterica rpoS have been previously shown to decrease tolerance to oxidative stress and alter metabolic regulation. We identified rpoS-dependent alterations in the utilization of L-malic acid, an abundant carbon source in N. benthamiana apoplastic wash fluid. We also present data consistent with higher relative basal reactive oxygen species (ROS) in N. benthamiana leaves than in A. thaliana leaves. The differences in basal ROS may explain the host-dependent disease co-colonization defect of the rpoS-mutated LT2 strain. Our results indicate that the conducive environment generated by pathogen modulation of the apoplast niche can vary from hosts to host even with a common disease-compatible pathogen. [ABSTRACT FROM AUTHOR]

This paper explores experiences and perceptions of physical impairment and disability in early medieval England, contrasting pre-Christian (AD 5th-early 7th centuries) and Christian (AD late 8th-11th centuries) communities through a combination of bioarchaeological, clinical, funerary, historical, and theoretical analyses. By comparing understandings of physical impairment and disability in the pre-Christian and Christian periods, this paper investigates how political rearrangements and the growing power of the Church might have influenced changing contemporary perceptions of physical impairment and disability. This research has found that the funerary treatment of individuals with physical impairment in the pre-Christian period was extremely variable within and between cemeteries, and there is evidence for arguably positive, normative, and potentially negative burial treatment. Although mortuary treatment of Christian-era individuals with physical impairment was somewhat variable, this variation was much more subtle. This reflects the overall Christian-era pattern in burial form, and strongly negative or positive mortuary treatment was not identified among the individuals with physical impairment. Based on this evidence, it is proposed that administrative and judicial standardisation, conversion to Christianity, and the spread of Christian morals and doctrine influenced the reduction in mortuary variability observed in individuals with physical impairment and/or disability in the 8th-11th centuries in England. [ABSTRACT FROM AUTHOR]

Background: Protein degradation systems play crucial roles in all the kingdoms of life. Their natural function is to eliminate proteins that are improperly synthesized, damaged, aggregated, or short-lived, ensuring the timely and accurate regulation of the response to abrupt environmental changes. Thus, proteolysis plays an important role in protein homeostasis, quality control, and the control of regulatory processes, such as adaptation and cell development. Except for the lysosome, ATPases Associated with various cellular Activities (AAA+) ATPase–protease complex is another major protein degradation system in the cell. Methods and Results: The AAA+ ATPase–protease complex is a giant energy-dependent protease complex found in almost all kinds of cells, including bacteria, archaea and eukarya. Based on sequence analysis of ClpQ (HslV) and 20S proteasome beta subunits, it was found that bacterial ClpQ possess multiple same highly conserved motifs with 20S proteasome beta subunits of archaea and eukaryote. In this review, we also discussed the structure and functional mechanism, protein degradation signals and pathogenic role of proteasome / Clp protease complex in prokaryotes. Conclusion: Bacterial protein degradation systems play important roles in stress tolerance, protein quality control, DNA protection, transcription and pathogenicity of bacteria. But our current knowledge of the bacterial protease system is incomplete, and further research into the Clp protease complex and associated protein degradation signals will extend our understanding of the metabolism, physiology, reproduction, and pathogenicity of bacteria. [ABSTRACT FROM AUTHOR]

The Cas13a system has great potential in RNA interference and molecular diagnostic fields. However, lacking guidelines for crRNA design hinders practical applications of the Cas13a system in RNA editing and single nucleotide polymorphism identification. This study posits that crRNAs with hairpin spacers improve the specificity of CRISPR/Cas13a system (termed hs‐CRISPR). Gibbs free energy analysis suggests that the hairpin‐spacer crRNAs (hs‐crRNAs) suppress Cas13a's affinity to off‐target RNA. A hepatitis B virus DNA genotyping platform is established to further validate the high‐specificity of hs‐CRISPR/Cas13a system. Compared to ordinary crRNA, hs‐crRNAs increase the specificity by threefold without sacrificing the sensitivity of the CRISPR/Cas13a system. Furthermore, the mechanism of the Cas13a/hs‐crRNA/target RNA composition is elucidated with theoretical simulations. This work builds on the fundamental understanding of Cas13a activation and offers significant improvements for the rational design of crRNA for the CRISPR/Cas13a system. [ABSTRACT FROM AUTHOR]

Organophosphonates are molecules that contain a very chemically stable carbon-phosphorus (C-P) bond. Microorganisms can utilize phosphonates as potential source of crucial elements for their growth, as developed several pathways to metabolize these compounds. One among these pathways is catalyzed by C-P lyase complex, which has a broad substrate specifity; therefore, it has a wide application in degradation of herbicides deposited in the environment, such as glyphosate. This multi-enzyme system accurately recognized in Escherichia coli and genetic studies have demonstrated that it is encoded by phn operon containing 14 genes (phnC-phnP). The phn operon is a member of the Pho regulon induced by phosphate starvation. Ability to degradation of phosphonates is also found in other microorganisms, especially soil and marine bacteria, that have homologous genes to those in E. coli. Despite the existence of differences in structure and composition of phn gene cluster, each of these strains contains phnGHIJKLM genes necessary in the C-P bond cleavage mechanism. The review provides a detailed description and summary of achievements on the C-P lyase enzymatic pathway over the last 50 years. [ABSTRACT FROM AUTHOR]

Meat curing, fermentation, and drying are both preservation technologies, and traditional manufacturing practices. Despite being considered a safe food, due to the several hurdles that prevent pathogen growth, dry-cured meat manufacturing may not ensure complete pathogen elimination. Besides, the final products are still susceptible to microbial contamination. Salmonella enterica is noteworthy among the pathogenic microorganisms that can contaminate these products. To survive hypertonic/hyperosmotic, acid, and low aw/desiccation stresses intrinsically associated with dry-curing, Salmonella has evolved with highly sophisticated mechanisms, comprising sensors/receptors, signaling cascade systems, and enzymes/transcription factors that ensure their tolerance and survival despite many harsh environmental conditions. Links between osmotic and acid stresses, such as the dissociable sigma factor of RNA polymerase, which regulates gene transcription, and mutual membrane receptors like the two-component system EnvZ/OmpR, which senses abiotic conditions, lead to stress cross-protection. Furthermore, virulence gene expression seems to be triggered by sublethal stresses on pre-adapted Salmonella cells, increasing their adherence and invasiveness of host cells. These are evidence that the ability to tolerate stresses enhances Salmonella pathogenicity and compromises the safety of dry-cured meats, by sheltering the pre-exposed and, subsequently, more virulent, stressed bacterial cells. [ABSTRACT FROM AUTHOR]

Fluctuating environments force bacteria to constantly adapt and optimize the uptake of substrates to maintain cellular and nutritional homeostasis. Our recent findings revealed that LrgAB functions as a pyruvate uptake system in Streptococcus mutans , and its activity is modulated in response to glucose and oxygen levels. Here, we show that the composition of the growth medium dramatically influences the magnitude and pattern of lrgAB activation. Specifically, tryptone (T) medium does not provide a preferred environment for stationary phase lrgAB activation, which is independent of external pyruvate concentration. The addition of pyruvate to T medium can elicit P lrgA activation during exponential growth, enabling the cell to utilize external pyruvate for improvement of cell growth. Through comparison of the medium composition and a series of GFP quantification assays for measurement of P lrgA activation, we found that acetate and potassium (K+) play important roles in eliciting P lrgA activation at stationary phase. Of note, supplementation of pooled human saliva to T medium induced lrgAB expression at stationary phase and in response to pyruvate, suggesting that LrgAB is likely functional in the oral cavity. High concentrations of acetate inhibit cell growth, while high concentrations of K+ negatively regulate lrgAB activation. qPCR analysis also revealed that growth in T medium (acetate/K+ limited) significantly affects the expression of genes related to the catabolic pathways of pyruvate, including the Pta/AckA pathway (acetate metabolism). Lastly, stationary phase lrgAB expression is not activated when S. mutans is cultured in T medium, even in a strain that overexpresses lytST. Taken together, these data suggest that lrgAB activation and pyruvate uptake in S. mutans are connected to acetate metabolism and potassium uptake systems, important for cellular and energy homeostasis. They also suggest that these factors need to be implemented when planning metabolic experiments and analyzing data in S. mutans studies that may be sensitive to stationary growth phase. [ABSTRACT FROM AUTHOR]

Bacteria have evolved complex sensing and signaling systems to react to their changing environments, most of which are present in all domains of life. Canonical bacterial sensing and signaling modules, such as membrane-bound ligand-binding receptors and kinases, are very well described. However, there are distinct sensing mechanisms in bacteria that are less studied. For instance, the sensing of internal or external cues can also be mediated by changes in protein conformation, which can either be implicated in enzymatic reactions, transport channel formation or other important cellular functions. These activities can then feed into pathways of characterized kinases, which translocate the information to the DNA or other response units. This type of bacterial sensory activity has previously been termed protein activity sensing. In this review, we highlight the recent findings about this non-canonical sensory mechanism, as well as its involvement in metabolic functions and bacterial motility. Additionally, we explore some of the specific proteins and protein-protein interactions that mediate protein activity sensing and their downstream effects. The complex sensory activities covered in this review are important for bacterial navigation and gene regulation in their dynamic environment, be it host-associated, in microbial communities or free-living. [ABSTRACT FROM AUTHOR]

Copyright of Advancements of Microbiology is the property of Sciendo and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Not all Salmonella enterica serovars cause the same disease. S. enterica represents an incredibly diverse species comprising >2,600 unique serovars. While some S. enterica serovars are host-restricted, others infect a wide range of hosts. The diseases that nontyphoidal Salmonella (NTS) serovars cause vary considerably, with some serovars being significantly more likely to cause invasive disease in humans than others. Furthermore, while genomic analyses have advanced our understanding of the genetic diversity of these serovars, they have not been able to fully account for the observed clinical differences. One overarching challenge is that much of what is known about Salmonella 's general biology and virulence strategies is concluded from studies examining a select few serovars, especially serovar Typhimurium. As targeted control strategies have been implemented to control select serovars, an increasing number of foodborne outbreaks involving serovars that are less frequently associated with human clinical illness are being detected. Harnessing what is known about the diversity of NTS serovars represents an important factor in achieving the ultimate goal of reducing salmonellosis-associated morbidity and mortality worldwide. In this review we summarize the current understanding of the differences and similarities among NTS serovars, highlighting the virulence mechanisms, genetic differences, and sources that characterize S. enterica diversity and contribute to its success as a foodborne pathogen. [ABSTRACT FROM AUTHOR]

Abstract Introduction Non-pharmacological interventions preferably precede pharmacological interventions in acute agitation. Reviews of pharmacological interventions remain descriptive or compare only one compound with several other compounds. The goal of this study is to compute a systematic review and meta-analysis of the effect on restoring calmness after a pharmacological intervention, so a more precise recommendation is possible. Method A search in Pubmed and Embase was done to isolate RCT's considering pharmacological interventions in acute agitation. The outcome is reaching calmness within maximum of 2 h, assessed by the psychometric scales of PANSS-EC, CGI or ACES. Also the percentages of adverse effects was assessed. Results Fifty-three papers were included for a systematic review and meta-analysis. Most frequent studied drug is olanzapine. Changes on PANNS-EC and ACES at 2 h showed the strongest changes for haloperidol plus promethazine, risperidon, olanzapine, droperidol and aripiprazole. However, incomplete data showed that the effect of risperidon is overestimated. Adverse effects are most prominent for haloperidol and haloperidol plus lorazepam. Conclusion Olanzapine, haloperidol plus promethazine or droperidol are most effective and safe for use as rapid tranquilisation. Midazolam sedates most quickly. But due to increased saturation problems, midazolam is restricted to use within an emergency department of a general hospital. [ABSTRACT FROM AUTHOR]

Objective: The authors compared the efficacy of standard-of-care treatment plus intranasal esketamine or placebo for rapid reduction of symptoms of major depression, including suicidality, among individuals at imminent suicide risk.Method: In a double-blind, multicenter, proof-of-concept study, 68 participants were randomly assigned to receive esketamine (84 mg) or placebo twice weekly for 4 weeks, in addition to comprehensive standard-of-care treatment. The primary efficacy endpoint was change in score from baseline to 4 hours after initial dose on the Montgomery-Åsberg Depression Rating Scale (MADRS). Clinician global judgment of suicide risk (from the Suicide Ideation and Behavior Assessment Tool) was also assessed. Secondary endpoints included these measures at 24 hours and double-blind endpoint at day 25.Results: A significantly greater improvement in MADRS score was observed in the esketamine group compared with the placebo group at 4 hours (least-square mean difference=-5.3, SE=2.10; effect size=0.61) and at ∼24 hours (least-square mean difference=-7.2, SE=2.85; effect size=0.65), but not at day 25 (least-square mean difference=-4.5, SE=3.14; effect size=0.35). Significantly greater improvement was also observed in the esketamine group on the MADRS suicidal thoughts item score at 4 hours (effect size=0.67), but not at 24 hours (effect size=0.35) or at day 25 (effect size=0.29). Between-group reductions in clinician global judgment of suicide risk scores were not statistically different at any time point. The most common adverse events among participants in the esketamine group were nausea, dizziness, dissociation, unpleasant taste, and headache.Conclusions: These preliminary findings indicate that intranasal esketamine compared with placebo, given in addition to comprehensive standard-of-care treatment, may result in significantly rapid improvement in depressive symptoms, including some measures of suicidal ideation, among depressed patients at imminent risk for suicide. [ABSTRACT FROM AUTHOR]

Abstract: Acetate, a non‐food based substrate obtained from multiple biological and chemical ways, is now being paid great attention in bio‐manufacturing and have a strong potential to compete with sugar‐based carbon source. In this study, acetate can be efficiently converted to succinate by engineered Escherichia coli strains via the combination of several metabolic engineering strategies, including reducing OAA decarboxylation, engineering TCA cycle, enhancement of acetate assimilation pathway and increasing aerobic ATP supply through cofactor engineering. The engineered strain HB03(pTrc99a‐gltA, pBAD33‐Trc‐fdh) accumulated 30.9 mM of succinate in 72 hr and the yield reached the maximum theoretical yield (∼0.50 mol/mol). In the resting‐cell experiments, the yield of succinate in HB03(pTrc99a‐gltA) and HB03(pTrc99a‐gltA, pBAD33‐Trc‐fdh) dropped dramatically, although the productivity of succinate increased due to the high cell density. Further deletion of icdA, formed HB04(pTrc99a‐gltA) and HB04(pTrc99a‐gltA, pBAD33‐Trc‐fdh), increased the yield of succinate in the resting‐cell experiments. The highest concentration of succinate achieved 194 mM and the yield reached 0.44 mol/mol in 16 hr by HB04(pTrc99a‐gltA, pBAD33‐Trc‐fdh). The results showed the metabolically engineered E. coli strains have great potential to produce succinate from acetate. [ABSTRACT FROM AUTHOR]

Summary: The ability to survive conditions of low water activity is critical for the survival of many bacteria in the environment and facilitates disease transmission through food and contaminated surfaces. However, the molecular mechanisms that enable bacteria to withstand this condition remain poorly understood. Here we describe a network of regulators in Escherichia coli that are important for this bacterium to survive dehydration. We found that the transcriptional regulator DksA and the general stress response regulator RpoS play a critical role. From a plasmid genomic library screen, we identified two additional regulators, Crl and ArcZ, that promote dehydration tolerance through modulation of RpoS. We also found that LexA, RecA and ArcA contribute to survival. Our results identify key regulators that enable E. coli to tolerate dehydration and suggest a hierarchical network is involved in protection against cellular damage associated with this stress. [ABSTRACT FROM AUTHOR]

Introduction: ClpXP protease is an important proteolytic system in Salmonella enterica serovar typhimurium ( S. typhimurium). Inactivation of ClpXP by deletion of clpP resulted in overproduction of RpoS and a growth defect phenotype. Only one report has indicated that deleting rpoS can restore the growth of a S. typhimurium clpP mutant to the wild-type level. Whether overproduction of RpoS is responsible for the growth deficiency resulting from clpP disruption and how ClpXP affects the cell metabolism of S. typhimurium remain to be elucidated. Objectives: The aim of this study is to investigate the effect of ClpXP on cell metabolism of S. typhimurium and explore the possible co-effect of RpoS associated with ClpXP in cell metabolism. Method: We constructed a clpP rpoS double deletion mutant TT-19 (Δ clpP Δ rpoS TT-1) using a two-step phage transduction technique. We then compared the metabolite fingerprints of Salmonella rpoS deletion mutant TT-14 (Δ rpoS TT-1), clpP deletion mutant TT-16 (Δ clpP TT-1), and clpP rpoS double deletion mutant TT-19 (Δ clpP Δ rpoS TT-1) with those of the wild-type strain TT-1 by using gas chromatography coupled with mass spectrometry (GC-MS). Results: Deletion of rpoS recovered only a part of the growth of Salmonella clpP mutant. Further metabolome analysis indicated that clpP disruption changed the levels of 16 extra- and 19 intracellular substances, while the extracellular concentrations of 4 compounds (serine, l-5-oxoproline, l-glutamic acid, and l-tryptophan) and intracellular concentrations of 10 compounds ( l-isoleucine, glycine, serine, l-methionine, l-phenylalanine, malic acid, citric acid, urea, putrescine, and 6-hydroxypurine) returned to their wild-type levels when rpoS was also deleted. Conclusion: ClpXP affects the cell metabolism of S. typhimurium partially in an RpoS-dependent manner. [ABSTRACT FROM AUTHOR]

Bacteria have developed various stress response pathways to improve their assimilation and allocation of limited nutrients, such as nitrogen and phosphate. While both the nitrogen stress response (NSR) and phosphate stress response (PSR) have been studied individually, there are few experiments reported that characterize effects of multiple stresses on one or more pathways in Sinorhizobium meliloti, a facultatively symbiotic, nitrogen-fixing bacteria. The PII proteins, GlnB and GlnK, regulate the NSR activity, but analysis of global transcription changes in a PII deficient mutant suggest that the S. meliloti PII proteins may also regulate the PSR. PII double deletion mutants grow very slowly and pseudoreversion of the slow growth phenotype is common. To understand this phenomenon better, transposon mutants were isolated that had a faster growing phenotype. One mutation was in phoB, the response regulator for a two component regulatory system that is important in the PSR. phoB::Tn5 mutants had different phenotypes in the wild type compared to a PII deficient background. This led to the hypothesis that phosphate stress affects the NSR and conversely, that nitrogen stress affects the PSR. Our results show that phosphate availability affects glutamine synthetase activity and expression, which are often used as indicators of NSR activity, but that nitrogen availability did not affect alkaline phosphatase activity and expression, which are indicators of PSR activity. We conclude that the NSR is co-regulated by nitrogen and phosphate, whereas the PSR does not appear to be co-regulated by nitrogen in addition to its known phosphate regulation. [ABSTRACT FROM AUTHOR]

Salmonella enterica is a foodborne zoonotic pathogen of significant public health concern. We have characterized the virulence and antimicrobial resistance gene content of 95 Salmonella isolates from 11 serovars by DNA microarray recovered from UK livestock or imported meat. Genes encoding resistance to sulphonamides (sul1, sul2), tetracycline [tet(A), tet(B)], streptomycin (strA, strB), aminoglycoside (aadA1, aadA2), beta-lactam (blaTEM), and trimethoprim (dfrA17) were common. Virulence gene content differed between serovars; S. Typhimurium formed two subclades based on virulence plasmid presence. Thirteen isolates were selected by their virulence profile for pathotyping using the Galleria mellonella pathogenesis model. Infection with a chicken invasive S. Enteritidis or S. Gallinarum isolate, a multidrug resistant S. Kentucky, or a S. Typhimurium DT104 isolate resulted in high mortality of the larvae; notably presence of the virulence plasmid in S. Typhimurium was not associated with increased larvae mortality. Histopathological examination showed that infection caused severe damage to the Galleria gut structure. Enumeration of intracellular bacteria in the larvae 24 h postinfection showed increases of up to 7 log above the initial inoculum and transmission electron microscopy (TEM) showed bacterial replication in the haemolymph. TEM also revealed the presence of vacuoles containing bacteria in the haemocytes, similar to Salmonella containing vacuoles observed in mammalian macrophages; although there was no evidence from our work of bacterial replication within vacuoles. This work shows that microarrays can be used for rapid virulence genotyping of S. enterica and that the Galleria animal model replicates some aspects of Salmonella infection in mammals. These procedures can be used to help inform on the pathogenicity of isolates that may be antibiotic resistant and have scope to aid the assessment of their potential public and animal health risk. [ABSTRACT FROM AUTHOR]

Background. Although chronic infections by typhoidal Salmonella are well-known, prolonged human infections by nontyphoidal Salmonella (NTS) are poorly characterized. Methods. We retrospectively analyzed 48 345 culture-confirmed NTS infections that occurred in Israel 1995-2012. A casecontrol study was performed to identify risk factors associated with persistent infections. Whole-genome-sequencing, pulsed-field gel electrophoresis (PFGE), and a mouse infection model were used to study genetic and phenotypic differences between samepatient persistent, recurring isolates. Results. In total, 1047 cases of persistent NTS infections, comprising 2.2% of all reported cases of salmonellosis, were identified. The persistence periods ranged between 30 days to 8.3 years. The majority (93%) of the persistently infected patients were immunocompetent, and 65% were symptomatic with relapsing diarrhea, indicating a distinct clinical manifestation from the asymptomatic carriage of typhoidal Salmonella. Four NTS serovars (Mbandaka, Bredeney, Infantis and Virchow) were found to be significantly more frequently associated with persistence than others. Comparative genomics between early and later isolates obtained from the same patients confirmed clonal infection and showed 0 to 10 SNPs between persistent isolates. A different composition of mobile genetic elements ( plasmids and phages) or amino acid substitutions in global regulators was identified in multiple cases. These changes resulted in differences in phenotype and virulence between early and later same-patient isolates. Conclusions. These results illuminate the overlooked clinical manifestation of persistent salmonellosis that can serve as a human reservoir for NTS infections. Additionally, we demonstrate mechanisms of in-host microevolution and exhibit their potential to shape Salmonella pathogenicity, antimicrobial resistance and host-pathogen interactions. [ABSTRACT FROM AUTHOR]

The expression of genes within Salmonella Pathogenicity Islands 1 and 2 (SPI1, SPI2) is required to facilitate invasion and intracellular replication respectively of S. Typhimurium in host cell lines. Control of their expression is complex and occurs via a variety of factors operating at transcriptional and post-transcriptional levels in response to the environmental stimuli found within the host. Several of the factors that modulate SPI1 and SPI2 expression are involved in the redistribution or modification of RNA polymerase (RNAP) specificity. These factors include the bacterial alarmone, ppGpp, the alternative sigma factor, RpoS, and the RNAP accessory protein, DksA. In this report we show not only how these three factors modulate SPI1 and SPI2 expression but also how they contribute to the ‘phased’ expression of SPI1 and SPI2 during progress through late-log and stationary phase in aerobic rich broth culture conditions. In addition, we demonstrate that the expression of at least one SPI1-encoded protein, SipC is subject to DksA-dependent post-transcriptional control. [ABSTRACT FROM AUTHOR]

Background Salmonellae are food-borne pathogens of great health and economic importance. To pose a threat to humans, Salmonellae normally have to cope with a series of stressful conditions in the food chain, including low temperature. In the current study, we evaluated the importance of the Clp proteolytic complex and the carbon starvation protein, CsrA, for the ability of Salmonella Typhimurium to grow at low temperature. Results A clpP mutant was severely affected in growth and formed pin point colonies at 10°C. Contrary to this, rpoS and clpP/rpoS mutants were only slightly affected. The clpP mutant formed cold resistant suppressor mutants at a frequency of 2.5 x 10-3 and these were found not to express RpoS. Together these results indicated that the impaired growth of the clpP mutant was caused by high level of RpoS. Evaluation by microscopy of the clpP mutant revealed that it formed filamentous cells when grown at 10°C, and this phenotype too, disappered when rpoS was mutated in parallel indicating a RpoS-dependency. A csrA (sup) mutant was also growth attenuated a low temperature. An rpoS/csrA (sup) double mutant was also growth attenuated, indicating that the phenotype of the csrA mutant was independent from RpoS. Conclusions The cold sensitivity of clpP mutant was associated with increased levels of RpoS and probably caused by toxic levels of RpoS. Although a csrA mutant also accumulated high level of RpoS, growth impairment caused by lack of csrA was not related to RpoS levels in a similar way. [ABSTRACT FROM AUTHOR]

LeuO is a quiescent LysR-type regulator belonging to the H- NS regulon. Activation of leuO transcription represses expression of pathogenicity island 1 ( SPI-1) in S almonella enterica serovar Typhimurium and inhibits invasion of epithelial cells. Loss of HilE suppresses LeuO-mediated downregulation of SPI-1. Activation of leuO transcription reduces the level of HilD protein, and loss of HilE restores the wild type HilD level. Hence, LeuO-mediated downregulation of SPI-1 may involve inhibition of HilD activity by HilE, a view consistent with the fact that HilE is a HilD inhibitor. In vivo analyses using β-galactosidase fusions indicate that LeuO activates hilE transcription. In vitro analyses by slot blotting, electrophoretic mobility shift analysis and DNase I footprinting show that LeuO binds the hilE promoter region. Although residual SPI-1 repression by LeuO is observed in the absence of HilE, the LeuO- HilE- HilD 'pathway' appears to be the major mechanism. Because both leuO and SPI-1 are repressed by H- NS, activation of leuO transcription may provide a backup mechanism for SPI-1 repression under conditions that impair H- NS-mediated silencing. [ABSTRACT FROM AUTHOR]