Judith Johnson

A bacteriophage encoding a pathogenicity island, a type-IV pilus and a phage receptor in cholera bacteria.

The virulence properties of many pathogenic bacteria are due to proteins encoded by large gene clusters called pathogenicity islands,, which are found in a variety of human pathogens including Escherichia coli, Salmonella, Shigella, Yersinia, Helicobacter pylori, Vibrio cholerae, and animal and plant pathogens such as Dichelobacter nodosus and Pseudomonas syringae. Although the presence of pathogenicity islands is a prerequisite for many bacterial diseases, little is known about their origins or mechanism of transfer into the bacterium. The bacterial agent of epidemic cholera, Vibrio cholerae , contains a bacteriophage known as cholera-toxin phage (CTXφ), which encodes the cholera toxin, and a large pathogenicity island called the VPI (for V. cholerae pathogenicity island) which itself encodes a toxin-coregulated pilus that functions as a colonization factor and as a CTXφ receptor. We have now identified the VPI pathogenicity island as the genome of another filamentous bacteriophage, VPIφ. We show that VPIφ is transferred between V. cholerae strains and provide evidence that the TcpA subunit of the toxin-coregulated type IV pilus is in fact a coat protein of VPIφ. Our results are the first description of a phage that encodes a receptor for another phage and of a virus–virus interaction that is necessary for bacterial pathogenicity.

Resilience to suicidality: The buffering hypothesis

Recent years have seen a growing interest into resilience to suicidality, which has been described as a perception or set of beliefs which buffer individuals from suicidality in the face of stressors. The current review extends this research by introducing the buffering hypothesis, a framework for the investigation of resilience to suicidality. The key proposal of this is that psychological resilience factors should be viewed as existing on a separate dimension to risk which acts to moderate the impact of risk on suicidality. Furthermore, like risk factors, resilience factors are bipolar, with their positive pole conferring resilience and their negative pole acting to amplify suicidality. Seventy-seven studies were identified which investigated (a) whether psychological moderators of risk exist and (b) the particular psychological constructs which may act as moderators. The review found strong support for the existence of psychological moderators and indicated a moderating impact of attributional style, perfectionism, agency and hopelessness. These findings support the buffering hypothesis and suggest that a range of psychological factors may confer resilience to suicidality. These results suggest that the identification of moderators may improve estimates of suicide risk and that the development of buffering factors could be a key focus of suicide interventions.

Risk Factors for Colonization with Extended-Spectrum β-Lactamase–producing Bacteria and Intensive Care Unit Admission

Coexisting conditions and previous antimicrobial drug exposure predict colonization.

Resilience as positive coping appraisals: Testing the schematic appraisals model of suicide (SAMS)

AIMS The Schematic Appraisals Model of Suicide (SAMS) suggests that positive self-appraisals may be important for buffering suicidal thoughts and behaviours, potentially providing a key source of resilience. The current study aimed to explore whether positive self-appraisals buffered individuals from suicidality in the face of stressful life events. METHOD 78 participants who reported experiencing some degree of suicidality were recruited from a student population. They completed a battery of questionnaires including measures of suicidality, stressful life events and positive self-appraisals. RESULTS Positive self-appraisals moderated the association between stressful life events and suicidality. For those reporting moderate or high levels of positive self-appraisals, raised incidence of stressful life events did not lead to increases in suicidality. DISCUSSION These results support the SAMS framework, and suggest that positive self-appraisals may confer resilience to suicide. Positive self-appraisals may be a promising avenue for further resilience research, and an important area to target for suicide interventions.

Multilocus Sequence Typing Compared to Pulsed-Field Gel Electrophoresis for Molecular Typing of Pseudomonas aeruginosa

ABSTRACT For hospital epidemiologists, determining a system of typing that is discriminatory is essential for measuring the effectiveness of infection control measures. In situations in which the incidence of resistant Pseudomonas aeruginosa is increasing, the ability to discern whether it is due to patient-to-patient transmission versus an increase in patient endogenous strains is often made on the basis of molecular typing. The present study compared the discriminatory abilities of pulsed-field gel electrophoresis (PFGE) and multilocus sequence typing (MLST) for 90 P. aeruginosa isolates obtained from cultures of perirectal surveillance swabs from patients in an intensive care unit. PFGE identified 85 distinct types and 76 distinct groups when similarity cutoffs of 100% and 87%, respectively, were used. By comparison, MLST identified 60 sequence types that could be clustered into 11 clonal complexes and 32 singletons. By using the Simpson index of diversity (D), PFGE had a greater discriminatory ability than MLST for P. aeruginosa isolates (D values, 0.999 versus 0.975, respectively). Thus, while MLST was better for detecting genetic relatedness, we determined that PFGE was more discriminatory than MLST for determining genetic differences in P. aeruginosa.

Defeat and entrapment in schizophrenia: The relationship with suicidal ideation and positive psychotic symptoms

The current study tests whether perceptions of defeat and entrapment are the psychological mechanisms underlying the link between positive psychotic symptoms and suicidal ideation in schizophrenia. A sample of 78 patients with schizophrenia spectrum disorders completed self-report measures and a clinical interview. Of this sample, 21.8% reported a single past suicide attempt and 50% reported multiple past attempts. It was found that perceptions of defeat and entrapment, conceptualised as a single variable, accounted for a large proportion (31%) of the variance in suicidal ideation and behaviour. Defeat and entrapment also mediated the relationship between positive symptom severity and suicidal ideation. This result held whilst controlling for levels of hopelessness and depression. Secondary analyses suggested that suspiciousness in particular was linked to suicidal ideation. The results support a socio-cognitive model (The Schematic Appraisals Model of Suicide: SAMS) of suicide in psychosis.

Psychological resilience in young and older adults

The goal of the current study was to investigate psychological resilience in the older adults (>64 years) compared with that of the young ones (<26 years).

Healthcare Staff Wellbeing, Burnout, and Patient Safety: A Systematic Review

Objective To determine whether there is an association between healthcare professionals’ wellbeing and burnout, with patient safety. Design Systematic research review. Data Sources PsychInfo (1806 to July 2015), Medline (1946 to July 2015), Embase (1947 to July 2015) and Scopus (1823 to July 2015) were searched, along with reference lists of eligible articles. Eligibility Criteria for Selecting Studies Quantitative, empirical studies that included i) either a measure of wellbeing or burnout, and ii) patient safety, in healthcare staff populations. Results Forty-six studies were identified. Sixteen out of the 27 studies that measured wellbeing found a significant correlation between poor wellbeing and worse patient safety, with six additional studies finding an association with some but not all scales used, and one study finding a significant association but in the opposite direction to the majority of studies. Twenty-one out of the 30 studies that measured burnout found a significant association between burnout and patient safety, whilst a further four studies found an association between one or more (but not all) subscales of the burnout measures employed, and patient safety. Conclusions Poor wellbeing and moderate to high levels of burnout are associated, in the majority of studies reviewed, with poor patient safety outcomes such as medical errors, however the lack of prospective studies reduces the ability to determine causality. Further prospective studies, research in primary care, conducted within the UK, and a clearer definition of healthcare staff wellbeing are needed. Implications This review illustrates the need for healthcare organisations to consider improving employees’ mental health as well as creating safer work environments when planning interventions to improve patient safety. Systematic Review Registration PROSPERO registration number: CRD42015023340.

Resilience to suicidal ideation in psychosis: Positive self-appraisals buffer the impact of hopelessness

Recent years have seen growing interest into concepts of resilience, but minimal research has explored resilience to suicide and none has investigated resilience to suicide amongst clinical groups. The current study aimed to examine whether a proposed resilience factor, positive self-appraisals of the ability to cope with emotions, difficult situations and the ability to gain social support, could buffer against the negative impact of hopelessness amongst individuals with psychosis-spectrum disorders when measured cross-sectionally. Seventy-seven participants with schizophrenia-spectrum disorders completed self-report measures of suicidal ideation, hopelessness and positive self-appraisals. Positive self-appraisals were found to moderate the association between hopelessness and suicidal ideation. For those reporting high levels of positive self-appraisals, increased levels of hopelessness were significantly less likely to lead to suicidality. These results provide cross-sectional evidence suggest that positive self-appraisals may buffer individuals with psychosis against the pernicious impact of a well known clinical risk factor, hopelessness. Accounting for positive self-appraisals may improve identification of individuals at high risk of suicidality, and may be an important area to target for suicide interventions.

Multilocus Sequence Typing versus Pulsed-Field Gel Electrophoresis for Characterization of Extended-Spectrum Beta-Lactamase-Producing Escherichia coli Isolates

ABSTRACT Extended-spectrum beta-lactamase (ESBL)-producing Escherichia coli strains are emerging pathogens. Molecular typing of ESBL-producing E. coli is useful for surveillance purposes, to monitor outbreaks and track nosocomial spread. Although pulsed-field gel electrophoresis (PFGE) is the current “gold standard” for bacterial molecular typing, multilocus sequence typing (MLST) may offer advantages. Forty ESBL-producing E. coli isolates were selected at random from a cohort of intensive care unit patients who had active surveillance perirectal cultures done. PFGE identified 19 unique PFGE types (PT) among the 40 isolates; MLST identified 22 unique sequence types. MLST had greater discriminatory ability than PFGE for ESBL-producing E. coli. Simpsons indices of diversity for PFGE and MLST were 0.895 and 0.956, respectively. There were five clonal complexes (CCs) (isolates with differences of no more than two loci) that each contained multiple PT, but each PT was found in only one CC, indicating genetic consistency within a CC. MLST has clear utility in studies of ESBL-producing E. coli, based on a greater discriminatory ability and reproducibility than PFGE and the ability to a priori define genetically related bacterial strains.