Autolysin-mediated peptidoglycan hydrolysis is required for the surface display of Staphylococcus aureus cell wall-anchored proteins.

Peptidoglycan hydrolases, or autolysins, play a critical role in cell wall remodeling and degradation, facilitating bacterial growth, cell division, and cell separation. In Staphylococcus aureus, the so-called "major" autolysin, Atl, has long been associated with host adhesion; however, the molecular basis underlying this phenomenon remains understudied. To investigate, we used the type V glycopeptide antibiotic complestatin, which binds to peptidoglycan and blocks the activity of autolysins, as a chemical probe of autolysin function. We also generated a chromosomally encoded, catalytically inactive variant of the Atl enzyme. Autolysin-mediated peptidoglycan hydrolysis, in particular Atl-mediated daughter cell separation, was shown to be critical for maintaining optimal surface levels of S. aureus cell wall-anchored proteins, including the fibronectin-binding proteins (FnBPs) and protein A (Spa). As such, disrupting autolysin function reduced the affinity of S. aureus for host cell ligands, and negatively impacted early stages of bacterial colonization in a systemic model of S. aureus infection. Phenotypic studies revealed that Spa was sequestered at the septum of complestatin-treated cells, highlighting that autolysins are required to liberate Spa during cell division. In summary, we reveal the hydrolytic activities of autolysins are associated with the surface display of S. aureus cell wall-anchored proteins. We demonstrate that by blocking autolysin function, type V glycopeptide antibiotics are promising antivirulence agents for the development of strategies to control S. aureus infections.

A genetic platform to investigate the functions of bacterial drug efflux pumps.

Efflux pumps are a serious challenge for the development of antibacterial agents. Overcoming efflux requires an in-depth understanding of efflux pump functions, specificities and the development of inhibitors. However, the complexities of efflux networks have limited such studies. To address these challenges, we generated Efflux KnockOut-35 (EKO-35), a highly susceptible Escherichia coli strain lacking 35 efflux pumps. We demonstrate the use of this strain by constructing an efflux platform comprising EKO-35 strains individually producing efflux pumps forming tripartite complexes with TolC. This platform was profiled against a curated diverse compound collection, which enabled us to define physicochemical properties that contribute to transport. We also show the E. coli drug efflux network is conditionally essential for growth, and that the platform can be used to investigate efflux pump inhibitor specificities and efflux pump interplay. We believe EKO-35 and the efflux platform will have widespread application for the study of drug efflux.

Comprehensive care programmes for children with medical complexity.

BACKGROUND: Children with medical complexity (CMC) represent a small, but growing, proportion of all children. Regardless of their underlying diagnosis, by definition, all CMC have similar functional limitations and high healthcare needs. It has been suggested that improving aspects of healthcare delivery for CMC improves health- and quality of life-related outcomes for children and their families and reduces healthcare-related expenditure. As a result, dedicated comprehensive care programmes have been established at many hospitals to meet the needs of CMC; however, it is unclear if such programmes are effective. OBJECTIVES: Our main objective was to assess the effectiveness of comprehensive care programmes that aim to improve care coordination and other aspects of health care for CMC and to assess whether the effectiveness of such programmes differs according to the programme setting and structure. We aimed to assess their effectiveness in relation to child and parent health, functioning, and quality of life, quality of care, number of healthcare encounters, unmet healthcare needs, and total healthcare-related costs. SEARCH METHODS: We searched CENTRAL, MEDLINE, Embase, and CINAHL in May 2023. We also searched reference lists, trial registries, and the grey literature. SELECTION CRITERIA: Randomised and non-randomised trials, controlled before-after studies, and interrupted time series studies were included. Studies that compared enrolment in a comprehensive care programme with non-enrolment in such a programme/treatment as usual were included. Participants were children that met the criteria for the definition of CMC, which is: having (i) a chronic condition, (ii) functional limitations, (iii) increased health and other service needs, and (iv) increased healthcare costs. Studies that included the following types of outcomes were included: health; quality of care; utilisation, coverage and access; resource use and costs; equity; and adverse outcomes. DATA COLLECTION AND ANALYSIS: Two review authors independently extracted data, assessed the risk of bias in each included study, and evaluated the certainty of evidence according to GRADE criteria. Where possible, data were represented in forest plots and pooled. We were unable to undertake a meta-analysis for comparisons and outcomes, so we used a structured synthesis approach. MAIN RESULTS: We included four studies with a total of 912 CMC as participants. All included studies were randomised controlled trials conducted in hospitals in the USA or Canada. Participants varied across the included studies; however, all four studies included children with complex and chronic illness and high healthcare needs. While the primary aim of the intervention was similar across all four studies, the components of the interventions differed: in the four studies, the intervention involved some element of care coordination; in two of the studies, it involved the child receiving care from a multidisciplinary team, while in one study, the intervention was primarily centred on access to an advanced practice nurse care coordinator and another study involved nurse a practitioner-paediatrician dyad partnering with families. The risk of bias in the four studies varied across domains, with issues primarily relating to the lack of blinding of participants, personnel, and outcome assessors, inadequate allocation concealment, and incomplete outcome data. Comprehensive care for CMC compared to usual care may make little to no difference to child health, functioning, and quality of life at 12 or 24 months (three studies with 404 participants) and we assessed the evidence for the outcomes in this category (child health-related quality of life and functional status) as being of low certainty. For CMC, comprehensive care probably makes little or no difference to parent health, functioning, and quality of life compared to usual care at 12 months (one study with 117 participants) and we assessed the evidence for this outcome as being of moderate certainty. Comprehensive care for CMC compared to usual care may slightly improve child and family satisfaction with, and perceptions of, care and service delivery at 12 months (three studies with 453 participants); however, we assessed the evidence for these outcomes as being of low certainty. For CMC, comprehensive care probably makes little or no difference to the number of healthcare encounters (emergency department visits) and the number of hospitalised days (hospital admissions) compared to usual care at 12 months (three studies with 668 participants), and we assessed the evidence for these outcomes as being of moderate certainty. Three of the included studies (668 participants) reported cost outcomes and had conflicting results, with one study reporting significantly lower healthcare costs at 12 months in the intervention group compared to the control group, one reporting no differences between groups, and the other study reporting a greater increase in total healthcare costs in the intervention group compared to the control group. Overall, comprehensive care may make little or no difference to overall healthcare costs in CMC; however, the methods used to measure total healthcare costs varied across studies and the certainty of the evidence relating to this outcome is low. No studies assessed the costs to the family. AUTHORS' CONCLUSIONS: The findings of this review should be treated with caution due to the limited amount and quality of the published research that was available to be included. Overall, the certainty of the evidence for the effectiveness of comprehensive care for CMC ranged from low to moderate across outcomes and there is currently insufficient evidence on which to draw strong conclusions. There is a need for more high-quality randomised trials with consistency of the target population and intervention components, methods of reporting outcomes, and follow-up periods, as well as full cost analyses, taking into account both costs to the family and costs to the healthcare system.

Acetylcholinesterase inhibitors for autistic spectrum disorders.

BACKGROUND: Autism spectrum disorder (autism) is a neurodevelopmental condition characterised by impairments in social communication and interaction, plus restricted, repetitive patterns of behaviour and interests. Whilst some people embrace autism as part of their identity, others struggle with their difficulties, and some seek treatment. There are no current interventions that result in complete reduction of autism features. Acetylcholine is a neurotransmitter for the cholinergic system and has a role in attention, novelty seeking, and memory. Low levels of acetylcholine have been investigated as a potential contributor to autism symptomatology. Donepezil, galantamine, and rivastigmine (commonly referred to as acetylcholinesterase inhibitors) all inhibit acetylcholinesterase, and have slightly different modes of action and biological availability, so their effectiveness and side-effect profiles may vary. The effect of various acetylcholinesterase inhibitor on core autism features across the lifespan, and possible adverse effects, have not been thoroughly investigated. OBJECTIVES: To evaluate the efficacy and harms of acetylcholinesterase inhibitors for people with the core features (social interaction, communication, and restrictive and repetitive behaviours) of autism. To assess the effects of acetylcholinesterase inhibitors on non-core features of autism. SEARCH METHODS: In November 2022, we searched CENTRAL, MEDLINE, Embase, eight other databases, and two trials registers. We also searched the reference lists of included studies and relevant reviews, and contacted authors of relevant studies. SELECTION CRITERIA: Randomised controlled trials (RCTs), comparing acetylcholinesterase inhibitors (e.g. galantamine, donepezil, or rivastigmine) of varying doses, delivered orally or via transdermal patch, either as monotherapy or adjunct therapy, with placebo. People of any age, with a clinical diagnosis of autism were eligible for inclusion. DATA COLLECTION AND ANALYSIS: We used standard methodological procedures expected by Cochrane. Our primary outcomes were core features of autism and adverse effects. Secondary outcomes were language, irritability, hyperactivity, and general health and function. We used GRADE to assess certainty of evidence. MAIN RESULTS: We included two RCTs (74 participants). One study was conducted in Iran, the second in the USA, although exact location in the USA is unclear. Galantamine plus risperidone versus placebo plus risperidone One study compared the effects of galantamine plus risperidone to placebo plus risperidone (40 participants, aged 4 years to 12 years). Primary and secondary outcomes of interest were measured postintervention, using subscales of the Aberrant Behavior Checklist (score 0 to 3; higher scores = greater impairment). Very low-certainty evidence showed there was little to no difference between the two groups postintervention for social communication (mean difference (MD) -2.75, 95% confidence interval (CI) -5.88 to 0.38), and restricted and repetitive behaviour (MD -0.55, 95% CI -3.47 to 2.37). Overall autism features were not assessed. Adverse events may be higher in the galantamine plus risperidone group (75%) compared with the placebo plus risperidone group (35%): odds ratio 5.57, 95% CI 1.42 to 21.86, low-certainty evidence. No serious adverse events were reported. Low-certainty evidence showed a small difference in irritability (MD -3.50, 95% CI -6.39 to -0.61), with the galantamine plus risperidone group showing a greater decline on the irritability subscale than the placebo group postintervention. There was no evidence of a difference between the groups in hyperactivity postintervention (MD -5.20, 95% CI -10.51 to 0.11). General health and function were not assessed. Donepezil versus placebo One study compared donepezil to placebo (34 participants aged 8 years to 17 years). Primary outcomes of interest were measured postintervention, using subscales of the Modified Version of The Real Life Rating Scale (scored 0 to 3; higher scores = greater impairment). Very low-certainty evidence showed no evidence of group differences immediately postintervention in overall autism features (MD 0.07, 95% CI -0.19 to 0.33), or in the autism symptom domains of social communication (MD -0.02, 95% CI -0.34 to 0.30), and restricted and repetitive behaviours (MD 0.04, 95% CI -0.27 to 0.35). Significant adverse events leading to study withdrawal in at least one participant was implied in the data analysis section, but not explicitly reported. The evidence is very uncertain about the effect of donepezil, compared to placebo, on the secondary outcomes of interest, including irritability (MD 1.08, 95% CI -0.41 to 2.57), hyperactivity (MD 2.60, 95% CI 0.50 to 4.70), and general health and function (MD 0.03, 95% CI -0.48 to 0.54) postintervention. Across all analyses within this comparison, we judged the evidence to be very low-certainty due to high risk of bias, and very serious imprecision (results based on one small study with wide confidence intervals). The study narratively reported adverse events for the study as a whole, rather than by treatment group. AUTHORS' CONCLUSIONS: Evidence about the effectiveness of acetylcholinesterase inhibitors as a medication to improve outcomes for autistic adults is lacking, and for autistic children is very uncertain. There is a need for more evidence of improvement in outcomes of relevance to clinical care, autistic people, and their families. There are a number of ongoing studies involving acetylcholinesterase inhibitors, and future updates of this review may add to the current evidence.

Mechanisms of cardiac collapse at high temperature in a marine teleost (Girella nigrians).

Heat-induced mortality in ectotherms may be attributed to impaired cardiac performance, specifically a collapse in maximum heart rate (fHmax), although the physiological mechanisms driving this phenomenon are still unknown. Here, we tested two proposed factors which may restrict cardiac upper thermal limits: noxious venous blood conditions and oxygen limitation. We hypothesized elevated blood [K+] (hyperkalemia) and low oxygen (hypoxia) would reduce cardiac upper thermal limits in a marine teleost (Girella nigricans), while high oxygen (hyperoxia) would increase thermal limits. We also hypothesized higher acclimation temperatures would exacerbate the harmful effects of an oxygen limitation. Using the Arrhenius breakpoint temperature test, we measured fHmax in acutely warmed fish under control (saline injected) and hyperkalemic conditions (elevated plasma [K+]) while exposed to hyperoxia (200% air saturation), normoxia (100% air saturation), or hypoxia (20% air saturation). We also measured ventricle lactate content and venous blood oxygen partial pressure (PO2) to determine if there were universal thresholds in either metric driving cardiac collapse. Elevated [K+] was not significantly correlated with any cardiac thermal tolerance metric. Hypoxia significantly reduced cardiac upper thermal limits (Arrhenius breakpoint temperature [TAB], peak fHmax, temperature of peak heart rate [TPeak], and temperature at arrhythmia [TARR]). Hyperoxia did not alter cardiac thermal limits compared to normoxia. There was no evidence of a species-wide threshold in ventricular [lactate] or venous PO2. Here, we demonstrate that oxygen limits cardiac thermal tolerance only in instances of hypoxia, but that other physiological processes are responsible for causing temperature-induced heart failure when oxygen is not limited.

Exploring functional interplay amongst Escherichia coli efflux pumps.

Bacterial efflux pumps exhibit functional interplay that can translate to additive or multiplicative effects on resistance to antimicrobial compounds. In diderm bacteria, two different efflux pump structural types - single-component inner membrane efflux pumps and cell envelope-spanning multicomponent systems - cooperatively export antimicrobials with cytoplasmic targets from the cell. Harnessing our recently developed efflux platform, which is built upon an extensively efflux-deficient strain of Escherichia coli, here we explore interplay amongst a panel of diverse E. coli efflux pumps. Specifically, we assessed the effect of simultaneously expressing two efflux pump-encoding genes on drug resistance, including single-component inner membrane efflux pumps (MdfA, MdtK and EmrE), tripartite complexes (AcrAB, AcrAD, MdtEF and AcrEF), and the acquired TetA(C) tetracycline resistance pump. Overall, the expression of two efflux pump-encoding genes from the same structural type did not enhance resistance levels regardless of the antimicrobial compound or efflux pump under investigation. In contrast, a combination of the tripartite efflux systems with single-component pumps sharing common substrates provided multiplicative increases to antimicrobial resistance levels. In some instances, resistance was increased beyond the product of resistance provided by the two pumps individually. In summary, the developed efflux platform enables the isolation of efflux pump function, facilitating the identification of interactions between efflux pumps.

Development and validation of a high-throughput whole cell assay to investigate Staphylococcus aureus adhesion to host ligands.

Staphylococcus aureus adhesion to the host's skin and mucosae enables asymptomatic colonization and the establishment of infection. This process is facilitated by cell wall-anchored adhesins that bind to host ligands. Therapeutics targeting this process could provide significant clinical benefits; however, the development of anti-adhesives requires an in-depth knowledge of adhesion-associated factors and an assay amenable to high-throughput applications. Here, we describe the development of a sensitive and robust whole cell assay to enable the large-scale profiling of S. aureus adhesion to host ligands. To validate the assay, and to gain insight into cellular factors contributing to adhesion, we profiled a sequence-defined S. aureus transposon mutant library, identifying mutants with attenuated adhesion to human-derived fibronectin, keratin, and fibrinogen. Our screening approach was validated by the identification of known adhesion-related proteins, such as the housekeeping sortase responsible for covalently linking adhesins to the cell wall. In addition, we also identified genetic loci that could represent undescribed anti-adhesive targets. To compare and contrast the genetic requirements of adhesion to each host ligand, we generated a S. aureus Genetic Adhesion Network, which identified a core gene set involved in adhesion to all three host ligands, and unique genetic signatures. In summary, this assay will enable high-throughput chemical screens to identify anti-adhesives and our findings provide insight into the target space of such an approach.

New generation antidepressants for depression in children and adolescents: a network meta-analysis.

BACKGROUND: Major depressive disorders have a significant impact on children and adolescents, including on educational and vocational outcomes, interpersonal relationships, and physical and mental health and well-being. There is an association between major depressive disorder and suicidal ideation, suicide attempts, and suicide. Antidepressant medication is used in moderate to severe depression; there is now a range of newer generations of these medications. OBJECTIVES: To investigate, via network meta-analysis (NMA), the comparative effectiveness and safety of different newer generation antidepressants in children and adolescents with a diagnosed major depressive disorder (MDD) in terms of depression, functioning, suicide-related outcomes and other adverse outcomes. The impact of age, treatment duration, baseline severity, and pharmaceutical industry funding was investigated on clinician-rated depression (CDRS-R) and suicide-related outcomes. SEARCH METHODS: We searched the Cochrane Common Mental Disorders Specialised Register, the Cochrane Library (Central Register of Controlled Trials (CENTRAL) and Cochrane Database of Systematic Reviews (CDSR)), together with Ovid Embase, MEDLINE and PsycINFO till March 2020. SELECTION CRITERIA: Randomised trials of six to 18 year olds of either sex and any ethnicity with clinically diagnosed major depressive disorder were included. Trials that compared the effectiveness of newer generation antidepressants with each other or with a placebo were included. Newer generation antidepressants included: selective serotonin reuptake inhibitors; selective norepinephrine reuptake inhibitors (SNRIs); norepinephrine reuptake inhibitors; norepinephrine dopamine reuptake inhibitors; norepinephrine dopamine disinhibitors (NDDIs); and tetracyclic antidepressants (TeCAs). DATA COLLECTION AND ANALYSIS: Two reviewers independently screened titles/abstracts and full texts, extracted data, and assessed risk of bias. We analysed dichotomous data as Odds Ratios (ORs), and continuous data as Mean Difference (MD) for the following outcomes: depression symptom severity (clinician rated), response or remission of depression symptoms, depression symptom severity (self-rated), functioning, suicide related outcomes and overall adverse outcomes. Random-effects network meta-analyses were conducted in a frequentist framework using multivariate meta-analysis. Certainty of evidence was assessed using Confidence in Network Meta-analysis (CINeMA). We used "informative statements" to standardise the interpretation and description of the results. MAIN RESULTS: Twenty-six studies were included. There were no data for the two primary outcomes (depressive disorder established via clinical diagnostic interview and suicide), therefore, the results comprise only secondary outcomes. Most antidepressants may be associated with a "small and unimportant" reduction in depression symptoms on the CDRS-R scale (range 17 to 113) compared with placebo (high certainty evidence: paroxetine: MD -1.43, 95% CI -3.90, 1.04; vilazodone: MD -0.84, 95% CI -3.03, 1.35; desvenlafaxine MD -0.07, 95% CI -3.51, 3.36; moderate certainty evidence: sertraline: MD -3.51, 95% CI -6.99, -0.04; fluoxetine: MD -2.84, 95% CI -4.12, -1.56; escitalopram: MD -2.62, 95% CI -5.29, 0.04; low certainty evidence: duloxetine: MD -2.70, 95% CI -5.03, -0.37; vortioxetine: MD 0.60, 95% CI -2.52, 3.72; very low certainty evidence for comparisons between other antidepressants and placebo). There were "small and unimportant" differences between most antidepressants in reduction of depression symptoms (high- or moderate-certainty evidence). Results were similar across other outcomes of benefit. In most studies risk of self-harm or suicide was an exclusion criterion for the study. Proportions of suicide-related outcomes were low for most included studies and 95% confidence intervals were wide for all comparisons. The evidence is very uncertain about the effects of mirtazapine (OR 0.50, 95% CI 0.03, 8.04), duloxetine (OR 1.15, 95% CI 0.72, 1.82), vilazodone (OR 1.01, 95% CI 0.68, 1.48), desvenlafaxine (OR 0.94, 95% CI 0.59, 1.52), citalopram (OR 1.72, 95% CI 0.76, 3.87) or vortioxetine (OR 1.58, 95% CI 0.29, 8.60) on suicide-related outcomes compared with placebo. There is low certainty evidence that escitalopram may "at least slightly" reduce odds of suicide-related outcomes compared with placebo (OR 0.89, 95% CI 0.43, 1.84). There is low certainty evidence that fluoxetine (OR 1.27, 95% CI 0.87, 1.86), paroxetine (OR 1.81, 95% CI 0.85, 3.86), sertraline (OR 3.03, 95% CI 0.60, 15.22), and venlafaxine (OR 13.84, 95% CI 1.79, 106.90) may "at least slightly" increase odds of suicide-related outcomes compared with placebo. There is moderate certainty evidence that venlafaxine probably results in an "at least slightly" increased odds of suicide-related outcomes compared with desvenlafaxine (OR 0.07, 95% CI 0.01, 0.56) and escitalopram (OR 0.06, 95% CI 0.01, 0.56). There was very low certainty evidence regarding other comparisons between antidepressants. AUTHORS' CONCLUSIONS: Overall, methodological shortcomings of the randomised trials make it difficult to interpret the findings with regard to the efficacy and safety of newer antidepressant medications. Findings suggest that most newer antidepressants may reduce depression symptoms in a small and unimportant way compared with placebo. Furthermore, there are likely to be small and unimportant differences in the reduction of depression symptoms between the majority of antidepressants. However, our findings reflect the average effects of the antidepressants, and given depression is a heterogeneous condition, some individuals may experience a greater response. Guideline developers and others making recommendations might therefore consider whether a recommendation for the use of newer generation antidepressants is warranted for some individuals in some circumstances. Our findings suggest sertraline, escitalopram, duloxetine, as well as fluoxetine (which is currently the only treatment recommended for first-line prescribing) could be considered as a first option. Children and adolescents considered at risk of suicide were frequently excluded from trials, so that we cannot be confident about the effects of these medications for these individuals. If an antidepressant is being considered for an individual, this should be done in consultation with the child/adolescent and their family/caregivers and it remains critical to ensure close monitoring of treatment effects and suicide-related outcomes (combined suicidal ideation and suicide attempt) in those treated with newer generation antidepressants, given findings that some of these medications may be associated with greater odds of these events. Consideration of psychotherapy, particularly cognitive behavioural therapy, as per guideline recommendations, remains important.

Old problems and new solutions: antibiotic alternatives in food animal production.

The antimicrobial resistance crisis is a Global Health challenge that impacts humans, animals, and the environment alike. In response to increased demands for animal protein and by-products, there has been a substantial increase in the use of antimicrobial agents in the animal industry. Indeed, they are extensively used to prevent, control, and (or) treat disease in animals. In addition to infection control, in-feed supplementation with antimicrobials became common practice for growth promotion of livestock. Unfortunately, the global overuse of antimicrobials has contributed to the emergence and spread of resistance. As such, many countries have implemented policies and approaches to eliminate the use of antimicrobials as growth promoters in food animals, which necessitates the need for alternate and One Health strategies to maintain animal health and welfare. This review summarizes the antimicrobial resistance crisis from Global Health and One Health perspectives. In addition, we outline examples of potential alternate strategies to circumvent antimicrobial use in animal husbandry practices, including antivirulence agents, bacteriophages, and nutritional measures to control bacterial pathogens. Overall, these alternate strategies require further research and development efforts, including assessment of efficacy and the associated development, manufacturing, and labor costs.

Will nurse leaders help eradicate 'hair racism' from nursing and health services?

AIMS: Nurse managers play key roles in creating and enforcing organisational hair policies and practices. This challenging paper will provoke discussion, debate and hopefully the dismantling of racist hair policies that disproportionately target black students and nurses. BACKGROUND: Black people have suffered from centuries of hair racism that continues today. Unfortunately, many nurse leaders underestimate the significance of this issue, while perpetuating the injustice. EVALUATION: This paper is based on research literature, media reports and authors' lived experiences regarding hair racism experienced by black people and nurses in particular. KEY ISSUES: Nurse managers often create and police organisational hair policies and dress codes. As health services pledge to eradicate racism 'in principle', ending discriminatory hair policies offers nurse managers a practical way to make this principle a reality. CONCLUSIONS: Hair racism is real and damaging for many black nurses and has no place in a modern health service. Rather than designing and policing such structural racism, nurse managers can be instrumental in ending it. IMPLICATIONS FOR NURSING MANAGEMENT: Health service hair policies targeting black nurses especially are not 'neutral'. Nurse managers can challenge this institutional discrimination, demonstrating health services' commitment to ending racism in all of its guises.

The Evolutionary Conservation of Escherichia coli Drug Efflux Pumps Supports Physiological Functions.

Bacteria harness an impressive repertoire of resistance mechanisms to evade the inhibitory action of antibiotics. One such mechanism involves efflux pump-mediated extrusion of drugs from the bacterial cell, which significantly contributes to multidrug resistance. Intriguingly, most drug efflux pumps are chromosomally encoded components of the intrinsic antibiotic resistome. In addition, in terms of xenobiotic detoxification, bacterial efflux systems often exhibit significant levels of functional redundancy. Efflux pumps are also considered to be highly conserved; however, the extent of conservation in many bacterial species has not been reported and the majority of genes that encode efflux pumps appear to be dispensable for growth. These observations, in combination with an increasing body of experimental evidence, imply alternative roles in bacterial physiology. Indeed, the ability of efflux pumps to facilitate antibiotic resistance could be a fortuitous by-product of ancient physiological functions. Using Escherichia coli as a model organism, we here evaluated the evolutionary conservation of drug efflux pumps and we provide phylogenetic analysis of the major efflux families. We show the E. coli drug efflux system has remained relatively stable and the majority (∼80%) of pumps are encoded in the core genome. This analysis further supports the importance of drug efflux pumps in E. coli physiology. In this review, we also provide an update on the roles of drug efflux pumps in the detoxification of endogenously synthesized substrates and pH homeostasis. Overall, gaining insight into drug efflux pump conservation, common evolutionary ancestors, and physiological functions could enable strategies to combat these intrinsic and ancient elements.

Surviving anoxia: the maintenance of energy production and tissue integrity during anoxia and reoxygenation.

The development of anoxia within tissues represents a significant challenge to most animals because of the decreased capacity for aerobic ATP production, the associated loss of essential cellular functions and the potential for detrimental tissue oxidation upon reoxygenation. Despite these challenges, there are many animals from multiple phyla that routinely experience anoxia and can fully recover. In this Review, we integrate knowledge gained from studies of anoxia-tolerant species across many animal taxa. We primarily focus on strategies used to reduce energy requirements, minimize the consequences of anaerobic ATP production and reduce the adverse effects of reactive oxygen species, which are responsible for tissue damage with reoxygenation. We aim to identify common strategies, as well as novel solutions, to the challenges of anoxia exposure. This Review chronologically examines the challenges faced by animals as they enter anoxia, as they attempt to maintain physiological function during prolonged anoxic exposure and, finally, as they emerge from anoxia. The capacity of animals to survive anoxia is also considered in relation to the increasing prevalence of anoxic zones within marine and freshwater environments, and the need to understand what limits survival.

Characterisation of the effect of day length, and associated differences in dietary intake, on the gut microbiota of Soay sheep.

Differences in the rumen bacterial community have been previously reported for Soay sheep housed under different day length conditions. This study extends this previous investigation to other organs of the digestive tract, as well as the analysis of ciliated protozoa and anaerobic fungi. The detectable concentrations of ciliated protozoa and anaerobic fungi decreased with increased day length in both the rumen and large colon, unlike those of bacteria where no effect was observed. Conversely, bacterial community composition was affected by day length in both the rumen and large colon, but the community composition of the detectable ciliated protozoa and anaerobic fungi was not affected. Day length-associated differences in the bacterial community composition extended to all of the organs examined, with the exception of the duodenum and the jejunum. It is proposed that differences in rumen fill and ruminal 'by-pass' nutrients together with endocrinological changes cause the observed effects of day length on the different gut microbial communities.

Impacts of Deepwater Horizon Crude Oil on Mahi-Mahi (Coryphaena hippurus) Heart Cell Function.

Deepwater Horizon crude oil is comprised of polycyclic aromatic hydrocarbons that cause a number of cardiotoxic effects in marine fishes across all levels of biological organization and at different life stages. Although cardiotoxic impacts have been widely reported, the mechanisms underlying these impairments in adult fish remain understudied. In this study, we examined the impacts of crude oil on cardiomyocyte contractility and electrophysiological parameters in freshly isolated ventricular cardiomyocytes from adult mahi-mahi (Coryphaena hippurus). Cardiomyocytes directly exposed to oil exhibited reduced contractility over a range of environmentally relevant concentrations (2.8-12.9 µg l-1∑PAH). This reduction in contractility was most pronounced at higher stimulation frequencies, corresponding to the upper limits of previously measured in situ mahi heart rates. To better understand the mechanisms underlying impaired contractile function, electrophysiological studies were performed, which revealed oil exposure prolonged cardiomyocyte action potentials and disrupted potassium cycling (9.9-30.4 µg l-1∑PAH). This study is the first to measure cellular contractility in oil-exposed cardiomyocytes from a pelagic fish. Results from this study contribute to previously observed impairments to heart function and whole-animal exercise performance in mahi, underscoring the advantages of using an integrative approach in examining mechanisms of oil-induced cardiotoxicity in marine fish.

Teaching mental health first aid in the school setting: a novel approach to improving outcomes for common adolescent mental disorders.

PURPOSE OF REVIEW: Common adolescent mental disorders, such as depression, often go untreated and severely impact health and educational outcomes. The purpose of this review is to describe what is currently known about school-based mental health interventions and to describe a new intervention, Mental Health First Aid training. RECENT FINDINGS: Universal and selective prevention and treatment programmes have been widely evaluated, though population-level dissemination remains elusive. A novel approach is to train adolescents in how to recognise early signs of mental disorder onset, decrease stigmatising beliefs and barriers to help-seeking, and to use appropriate first aid strategies for assisting peers in mental health crisis, such as those with depression and suicidal ideation. SUMMARY: Teaching adolescents the skills necessary to recognise and respond to mental health problems and mental health crises may provide life-long skills that prompt lower stigmatising beliefs, greater support of peers and appropriate, timely help-seeking.

Oil Exposure Impairs In Situ Cardiac Function in Response to ß-Adrenergic Stimulation in Cobia (Rachycentron canadum).

Aqueous crude oil spills expose fish to varying concentrations of dissolved polycyclic aromatic hydrocarbons (PAHs), which can have lethal and sublethal effects. The heart is particularly vulnerable in early life stages, as PAH toxicity causes developmental cardiac abnormalities and impaired cardiovascular function. However, cardiac responses of juvenile and adult fish to acute oil exposure remain poorly understood. We sought to assess cardiac function in a pelagic fish species, the cobia (Rachycentron canadum), following acute (24 h) exposure to two ecologically relevant levels of dissolved PAHs. Cardiac power output (CPO) was used to quantify cardiovascular performance using an in situ heart preparation. Cardiovascular performance was varied using multiple concentrations of the ß-adrenoceptor agonist isoproterenol (ISO) and by varying afterload pressures. Oil exposure adversely affected CPO with control fish achieving maximum CPO's (4 mW g-1 Mv) greater than that of oil-exposed fish (1 mW g-1 Mv) at ISO concentrations of 1 × 10-6 M. However, the highest concentration of ISO (1 × 10-5 M) rescued cardiac function. This indicates an interactive effect between oil-exposure and ß-adrenergic stimulation and suggests if animals achieve very large increases in ß-adrenergic stimulation it could play a compensatory role that may mitigate some adverse effects of oil-exposure in vivo.

Suicide Prevention Public Service Announcements (PSAs): Examples from Around the World.

Media campaigns have received increased attention as an intervention for combating suicide. Suicide prevention campaigns involving public service announcements (PSAs) have not been well described and have been subject to minimal evaluation. This study aimed to identify suicide prevention PSAs from around the world and analyze and describe their content. We searched the Internet for short, English-language PSAs that had been screened as part of suicide prevention campaigns and identified 35. Most commonly, these PSAs focused on the general population and/or people who might be at risk of suicide, and had a particular emphasis on young people. Almost 60% promoted open discussion about suicide, around 50% indicated that the life of a suicidal person was important, about 40% acknowledged the suffering associated with suicidal thoughts and feelings, about 25% stressed that suicide is preventable, and about 20% focused on the devastating impact of suicide for those left behind. Most PSAs promoted some sort of support for people at risk of suicide, usually a helpline or website. Although these messages appeared appropriate and practical there is a lack of research on the impact that they may have on people with varying degrees of suicide risk. Further work is needed to ensure that they are consistent with theories of behavior change, and that they are having their desired impacts.

Introducing a novel mechanism to control heart rate in the ancestral Pacific hagfish.

Although neural modulation of heart rate is well established among chordate animals, the Pacific hagfish (Eptatretus stoutii) lacks any cardiac innervation, yet it can increase its heart rate from the steady, depressed heart rate seen in prolonged anoxia to almost double its normal normoxic heart rate, an almost fourfold overall change during the 1-h recovery from anoxia. The present study sought mechanistic explanations for these regulatory changes in heart rate. We provide evidence for a bicarbonate-activated, soluble adenylyl cyclase (sAC)-dependent mechanism to control heart rate, a mechanism never previously implicated in chordate cardiac control.

Cognitive behavioural therapy (CBT), third-wave CBT and interpersonal therapy (IPT) based interventions for preventing depression in children and adolescents.

BACKGROUND: Depression is common in young people. It has a marked negative impact and is associated with self-harm and suicide. Preventing its onset would be an important advance in public health. This is an update of a Cochrane review that was last updated in 2011. OBJECTIVES: To determine whether evidence-based psychological interventions (including cognitive behavioural therapy (CBT), interpersonal therapy (IPT) and third wave CBT)) are effective in preventing the onset of depressive disorder in children and adolescents. SEARCH METHODS: We searched the specialised register of the Cochrane Common Mental Disorders Group (CCMDCTR to 11 September 2015), which includes relevant randomised controlled trials from the following bibliographic databases: The Cochrane Library (all years), EMBASE (1974 to date), MEDLINE (1950 to date) and PsycINFO (1967 to date). We searched conference abstracts and reference lists of included trials and reviews, and contacted experts in the field. SELECTION CRITERIA: We included randomised controlled trials of an evidence-based psychological prevention programme compared with any comparison control for young people aged 5 to 19 years, who did not currently meet diagnostic criteria for depression. DATA COLLECTION AND ANALYSIS: Two authors independently assessed trials for inclusion and rated their risk of bias. We adjusted sample sizes to take account of cluster designs and multiple comparisons. We contacted trial authors for additional information where needed. We assessed the quality of evidence for the primary outcomes using GRADE. MAIN RESULTS: We included 83 trials in this review. The majority of trials (67) were carried out in school settings with eight in colleges or universities, four in clinical settings, three in the community and four in mixed settings. Twenty-nine trials were carried out in unselected populations and 53 in targeted populations.For the primary outcome of depression diagnosis at medium-term follow-up (up to 12 months), there were 32 trials with 5965 participants and the risk of having a diagnosis of depression was reduced for participants receiving an intervention compared to those receiving no intervention (risk difference (RD) -0.03, 95% confidence interval (CI) -0.05 to -0.01; P value = 0.01). We rated this evidence as moderate quality according to the GRADE criteria. There were 70 trials (73 trial arms) with 13,829 participants that contributed to the analysis for the primary outcome of depression symptoms (self-rated) at the post-intervention time point, with results showing a small but statistically significant effect (standardised mean difference (SMD) -0.21, 95% CI -0.27 to -0.15; P value < 0.0001). This effect persisted to the short-term assessment point (up to three months) (SMD -0.31, 95% CI -0.45 to -0.17; P value < 0.0001; 16 studies; 1558 participants) and medium-term (4 to 12 months) assessment point (SMD -0.12, 95% CI -0.18 to -0.05; P value = 0.0002; 53 studies; 11,913 participants); however, the effect was no longer evident at the long-term follow-up. We rated this evidence as low to moderate quality according to the GRADE criteria.The evidence from this review is unclear with regard to whether the type of population modified the overall effects; there was statistically significant moderation of the overall effect for depression symptoms (P value = 0.0002), but not for depressive disorder (P value = 0.08). For trials implemented in universal populations there was no effect for depression diagnosis (RD -0.01, 95% CI -0.03 to 0.01) and a small effect for depression symptoms (SMD -0.11, 95% CI -0.17 to -0.05). For trials implemented in targeted populations there was a statistically significantly beneficial effect of intervention (depression diagnosis RD -0.04, 95% CI -0.07 to -0.01; depression symptoms SMD -0.32, 95% CI -0.42 to -0.23). Of note were the lack of attention placebo-controlled trials in targeted populations (none for depression diagnosis and four for depression symptoms). Among trials implemented in universal populations a number used an attention placebo comparison in which the intervention consistently showed no effect. AUTHORS' CONCLUSIONS: Overall the results show small positive benefits of depression prevention, for both the primary outcomes of self-rated depressive symptoms post-intervention and depression diagnosis up to 12 months (but not beyond). Estimates of numbers needed to treat to benefit (NNTB = 11) compare well with other public health interventions. However, the evidence was of moderate to low quality using the GRADE framework and the results were heterogeneous. Prevention programmes delivered to universal populations showed a sobering lack of effect when compared with an attention placebo control. Interventions delivered to targeted populations, particularly those selected on the basis of depression symptoms, had larger effect sizes, but these seldom used an attention placebo comparison and there are practical difficulties inherent in the implementation of targeted programmes. We conclude that there is still not enough evidence to support the implementation of depression prevention programmes.Future research should focus on current gaps in our knowledge. Given the relative lack of evidence for universal interventions compared with attention placebo controls and the poor results from well-conducted effectiveness trials of universal interventions, in our opinion any future such trials should test a depression prevention programme in an indicated targeted population using a credible attention placebo comparison group. Depressive disorder as the primary outcome should be measured over the longer term, as well as clinician-rated depression. Such a trial should consider scalability as well as the potential for the intervention to do harm.