19 research outputs found

    The diversity, evolution and ecology of Salmonella in venomous snakes

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    BACKGROUND: Reptile-associated Salmonella bacteria are a major, but often neglected cause of both gastrointestinal and bloodstream infection in humans globally. The diversity of Salmonella enterica has not yet been determined in venomous snakes, however other ectothermic animals have been reported to carry a broad range of Salmonella bacteria. We investigated the prevalence and diversity of Salmonella in a collection of venomous snakes and non-venomous reptiles. METHODOLOGY/PRINCIPLE FINDINGS: We used a combination of selective enrichment techniques to establish a unique dataset of reptilian isolates to study Salmonella enterica species-level evolution and ecology and used whole-genome sequencing to investigate the relatedness of phylogenetic groups. We observed that 91% of venomous snakes carried Salmonella, and found that a diverse range of serovars (n = 58) were carried by reptiles. The Salmonella serovars belonged to four of the six Salmonella enterica subspecies: diarizonae, enterica, houtanae and salamae. Subspecies enterica isolates were distributed among two distinct phylogenetic clusters, previously described as clade A (52%) and clade B (48%). We identified metabolic differences between S. diarizonae, S. enterica clade A and clade B involving growth on lactose, tartaric acid, dulcitol, myo-inositol and allantoin. SIGNIFICANCE: We present the first whole genome-based comparative study of the Salmonella bacteria that colonise venomous and non-venomous reptiles and shed new light on Salmonella evolution. Venomous snakes examined in this study carried a broad range of Salmonella, including serovars which have been associated with disease in humans such as S. Enteritidis. The findings raise the possibility that venomous snakes could be a reservoir for Salmonella serovars associated with human salmonellosis

    Stepwise evolution of Salmonella Typhimurium ST313 causing bloodstream infection in Africa

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    Bloodstream infections caused by nontyphoidal Salmonella are a major public health concern in Africa, causing ~49,600 deaths every year. The most common Salmonella enterica pathovariant associated with invasive nontyphoidal Salmonella disease is Salmonella Typhimurium sequence type (ST)313. It has been proposed that antimicrobial resistance and genome degradation has contributed to the success of ST313 lineages in Africa, but the evolutionary trajectory of such changes was unclear. Here, to define the evolutionary dynamics of ST313, we sub-sampled from two comprehensive collections of Salmonella isolates from African patients with bloodstream infections, spanning 1966 to 2018. The resulting 680 genome sequences led to the discovery of a pan-susceptible ST313 lineage (ST313 L3), which emerged in Malawi in 2016 and is closely related to ST313 variants that cause gastrointestinal disease in the United Kingdom and Brazil. Genomic analysis revealed degradation events in important virulence genes in ST313 L3, which had not occurred in other ST313 lineages. Despite arising only recently in the clinic, ST313 L3 is a phylogenetic intermediate between ST313 L1 and L2, with a characteristic accessory genome. Our in-depth genotypic and phenotypic characterization identifies the crucial loss-of-function genetic events that occurred during the stepwise evolution of invasive S. Typhimurium across Africa

    Scope of centres of expertise for rare diseases in European countries where they exist

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    International audienc

    The impact of individual and organizational resources on nurse outcomes and intent to quit

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    AIM: To examine the impact of an individual resource factor (psychological capital) and an organizational resource (management support) on nurses\u27 intentions to quit. BACKGROUND: Nursing work can be stressful and as a consequence, nurses suffer greater stress and stress-related sickness, including depression, than the general population. Stress can be mitigated in the workplace depending on the availability of resources in the workplace. Resources can come from the organization or the individual themselves. DESIGN: The study is quantitative using a cross-sectional design. METHODS: The study analyzed data from 242 nurses working in five Australian hospitals in the one regional network during 2013. FINDINGS: The predictors explained almost half of the variance of nurses\u27 intent to quit. Psychological capital had the dual benefits of reducing nurses\u27 perceptions of psychological distress and simultaneously increasing their job satisfaction. CONCLUSION: Psychological capital is an example of the personal resources a nurse brings to work. Nurse managers can now understand the impact of a new form of protective resources that influence the levels of strain felt by nurses. If nurses present with low psychological capital, then up-skilling nurses with these personal attributes will positively impact on their health and wellbeing and, in turn, enhance the care of patients. This article is protected by copyright. All rights reserved

    Abusive supervision and links to nurse intentions to quit

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    Purpose: To investigate forms of abusive supervision, namely personal attacks, task attacks, and isolation, and their links to outcomes for nurses, including job satisfaction, psychological strain, and intentions to quit. Design: Cross‐sectional survey design. Data collected from July to November 2012. Methods: Two hundred and fifty public sector nurses employed at five general acute Australian hospitals completed the survey (response rate of 33%). Findings: Structural equation modeling on the forms of abusive supervision (personal, task, isolation) and nurse outcomes indicated goodness of fit statistics that confirmed a well‐fitting model, explaining 40% of the variance in intent to quit, 30% in job satisfaction, and 33% in strain. An indirect relationship from personal attacks to intentions to quit, via strain, was observed. Task attacks were related directly, and indirectly via job satisfaction, to increased intentions to quit. Surprisingly, isolation was positively related to job satisfaction. Conclusions: Abusive supervision impacted nurse outcomes. Specifically, personal abuse had personal and health impacts; work‐focused abuse had work‐oriented effects. Applying appraisal theory suggests that personal attacks are primarily assessed as stressful and unchangeable; task‐oriented attacks are assessed as stressful, but changeable; and isolation is assessed as benign. The findings highlight the impact of abusive supervision, especially task attacks, on outcomes important to nurse retention. Clinical Relevance: The findings can be used to devise programs to educate, train, and support supervisors and their subordinates to adhere to zero tolerance policies toward antisocial workplace behaviors and encourage reporting incidents

    Salmonella enterica Serovar Panama, an Understudied Serovar Responsible for Extraintestinal Salmonellosis Worldwide

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    International audienceIn recent years nontyphoidal Salmonella has emerged as one of the pathogens most frequently isolated from the bloodstream in humans. Only a small group of Salmonella serovars cause this systemic infection, known as invasive nonty-phoidal salmonellosis. Here, we present a focused minireview on Salmonella enterica serovar Panama, a serovar responsible for invasive salmonellosis worldwide. S. Pan-ama has been linked with infection of extraintestinal sites in humans, causing septi-cemia, meningitis, and osteomyelitis. The clinical picture is often complicated by antimicrobial resistance and has been associated with a large repertoire of transmission vehicles, including human feces and breast milk. Nonhuman sources of S. Pan-ama involve reptiles and environmental reservoirs, as well as food animals, such as pigs. The tendency of S. Panama to cause invasive disease may be linked to certain serovar-specific genetic factors
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