Two transporters cooperate to secrete amphipathic peptides from the cytoplasmic and membranous milieus.

Diverse organisms secrete amphipathic biomolecules for competitive gains. However, how cells cope with producing these membrane-permeabilizing molecules is unclear. We focused on the PSM family of secreted amphipathic peptides in the pathogen Staphylococcus aureus that uses two ABC transporters, PmtCD and AbcA, to export peptides across the bacterial cell membrane. We found that increased peptide hydrophobicity favors PSM secretion through PmtCD over AbcA and that only PmtCD protected cells against amphipathic peptides. We propose a two-system model in which PmtCD and AbcA independently export PSMs from either membrane or cytosolic environments, respectively. Our model provides a rationale for the encoding of multiple transport systems on diverse biosynthetic gene clusters used to produce distinct amphipathic molecules. In addition, our data serve as a guide for selectively blocking PSM secretion to achieve antimicrobial or antivirulence approaches and to disrupt established roles of PSM-mediated virulence.

Host Sorbitol and Bacterial Sorbitol Utilization Promote Clostridioides difficile Infection in Inflammatory Bowel Disease.

BACKGROUND & AIMS: Inflammatory bowel disease (IBD) is a widespread gastrointestinal inflammatory disorder with globally increasing incidence. Clostridioides difficile infection (CDI) often occurs in patients with intestinal dysbiosis, such as after antibiotic therapy. Patients with IBD have increased incidence of CDI and the clinical outcome of IBD is reportedly worsened by CDI. However, the underlying reasons remain poorly understood. METHODS: We performed a retrospective single-center and a prospective multicenter analysis of CDI in patients with IBD, including genetic typing of C difficile isolates. Furthermore, we performed a CDI mouse model to analyze the role of the sorbitol metabolization locus that we found distinguished the main IBD- and non-IBD-associated sequence types (STs). Moreover, we analyzed sorbitol concentration in the feces of patients with IBD and healthy individuals. RESULTS: We detected a significant association of specific lineages with IBD, particularly increased abundance of ST54. We found that in contrast to the otherwise clinically predominant ST81, ST54 harbors a sorbitol metabolization locus and was able to metabolize sorbitol in vitro and in vivo. Notably, in the mouse model, ST54 pathogenesis was dependent on intestinal inflammation-induced conditions and the presence of sorbitol. Furthermore, we detected significantly increased sorbitol concentrations in the feces of patients with active IBD vs patients in remission or healthy controls. CONCLUSIONS: Sorbitol and sorbitol utilization in the infecting C difficile strain play major roles for the pathogenesis and epidemiology of CDI in patients with IBD. CDI in patients with IBD may thus be avoided or improved by elimination of dietary sorbitol or suppression of host-derived sorbitol production.

A Wave of Regulatory T Cells into Neonatal Skin Mediates Tolerance to Commensal Microbes.

The skin is a site of constant dialog between the immune system and commensal bacteria. However, the molecular mechanisms that allow us to tolerate the presence of skin commensals without eliciting destructive inflammation are unknown. Using a model system to study the antigen-specific response to S. epidermidis, we demonstrated that skin colonization during a defined period of neonatal life was required for establishing immune tolerance to commensal microbes. This crucial window was characterized by an abrupt influx of highly activated regulatory T (Treg) cells into neonatal skin. Selective inhibition of this Treg cell wave completely abrogated tolerance. Thus, the host-commensal relationship in the skin relied on a unique Treg cell population that mediated tolerance to bacterial antigens during a defined developmental window. This suggests that the cutaneous microbiome composition in neonatal life is crucial in shaping adaptive immune responses to commensals, and disrupting these interactions might have enduring health implications.

Efficacy and safety of the VASCADE® MVP venous vascular closure device in patients undergoing percutaneous left atrial appendage occlusion with WATCHMAN.

BACKGROUND: The VASCADE MVP venous vascular closure system is commonly used for percutaneous venotomy closure in catheter-based procedures utilizing sheath sizes 6-12 French. However, its application with larger sheaths such as ones required in left atrial appendage occlusion (LAAO) has yet to be explored. AIMS: This study compared the efficacy and safety of VASCADE MVP versus conventional Figure-of-8 sutures (Fo8) for femoral venotomy closure in patients undergoing Watchman LAAO. METHODS: This single-center retrospective analysis included patients who underwent post-LAAO femoral venotomy closure with either VASCADE MVP or Fo8 sutures. The primary efficacy endpoint was time to hemostasis (TTH). Primary safety endpoints were 30-day access site-related readmissions and major complications. Minor access-site-related complications were also assessed. RESULTS: 107 patients underwent post-LAAO femoral venotomy closure with VASCADE MVP, of which 101 were successful (94.4%). 99 patients underwent conventional closure with Fo8 sutures and supplemental manual pressure. Baseline characteristics were similar between groups. TTH was significantly shorter with VASCADE MVP (152.9 vs. 335.8 s, p = 0.001). Major safety outcomes were comparable. However, the conventional group experienced a higher incidence of ecchymosis (16.2% vs 4.7%, p = 0.007) and 30-day all-cause readmission (18.2% vs 8.4%, p = 0.038). CONCLUSIONS: VASCADE MVP significantly reduced TTH compared to Fo8 sutures after LAAO. While demonstrating a similar safety profile, VASCADE MVP may offer a more efficient approach to femoral vein closure in this patient population.

Single-Operator Left atrial appendage Occlusion utilizing Conscious sedation TEE, Lack of Outpatient pre-imaging, and Same-day Expedited discharge (SOLO-CLOSE): A comparison with conventional approach.

BACKGROUND: Left atrial appendage occlusion (LAAO) with WATCHMAN currently requires preprocedural imaging, general anesthesia, and inpatient overnight admission. We sought to facilitate simplification of LAAO. AIMS: We describe and compare SOLO-CLOSE (single-operator LAA occlusion utilizing conscious sedation TEE, lack of outpatient pre-imaging, and same-day expedited discharge) with the conventional approach (CA). METHODS: A single-center retrospective analysis of 163 patients undergoing LAAO between January 2017 and April 2022 was conducted. The SOLO-CLOSE protocol was enacted on December 1, 2020. Before this date, we utilized the CA. The primary efficacy endpoint was defined as successful LAAO with ≤5 mm peri-device leak at time of closure. The primary safety endpoint was the composite incidence of all-cause deaths, any cerebrovascular accident (CVA), device embolization, pericardial effusion, or major postprocedure bleeding within 7 days of the index procedure. Procedure times, 7-day readmission rates, and cost analytics were collected as well. RESULTS: Baseline characteristics were similar in both cohorts. Congestive heart failure (37.5% vs. 11.1%) and malignancy (28.8% vs. 12.5%) were higher in SOLO-CLOSE. Median CHA2D2SVASc score was 5 in both cohorts. The primary efficacy endpoint was met 100% in both cohorts. Primary safety endpoint was similar between cohorts (p = 0.078). Mean procedure time was 30 min shorter in SOLO-CLOSE (p < 0.01). Seven-day readmissions for SOLO-CLOSE was zero. After SOLO-CLOSE implementation, there was a 188% increase in positive contribution margin per case. CONCLUSIONS: The SOLO-CLOSE methodology offers similar efficacy and safety when compared to the CA, while improving clinical efficiency, reducing procedural times, and increasing economic benefit.

Pathogen elimination by probiotic Bacillus via signalling interference.

Probiotic nutrition is frequently claimed to improve human health. In particular, live probiotic bacteria obtained with food are thought to reduce intestinal colonization by pathogens, and thus to reduce susceptibility to infection. However, the mechanisms that underlie these effects remain poorly understood. Here we report that the consumption of probiotic Bacillus bacteria comprehensively abolished colonization by the dangerous pathogen Staphylococcus aureus in a rural Thai population. We show that a widespread class of Bacillus lipopeptides, the fengycins, eliminates S. aureus by inhibiting S. aureus quorum sensing-a process through which bacteria respond to their population density by altering gene regulation. Our study presents a detailed molecular mechanism that underlines the importance of probiotic nutrition in reducing infectious disease. We also provide evidence that supports the biological significance of probiotic bacterial interference in humans, and show that such interference can be achieved by blocking a pathogen's signalling system. Furthermore, our findings suggest a probiotic-based method for S. aureus decolonization and new ways to fight S. aureus infections.

Negative emotional reactivity to minority stress: measure development and testing.

The purpose of the present investigation was to develop and test a measure of negative emotional reactivity to racial/ethnic minoritized stress. In Study 1, we developed item content for a measure of negative emotional reactivity to racial/ethnic minoritized stress. We then evaluated item performance and produced a refined 15-item scale among a large sample of racial/ethnic minority adults (N = 1,343). Results supported a unidimensional construct and high levels of internal consistency. The factor structure and internal consistency were replicated and extended to a sample of Latinx persons who smoke (N = 338) in Study 2. There was evidence of convergent validity of the Emotional Reactivity to Minoritized Stress (ERMS) total score in terms of theoretically consistent and statistically significant relations with indices of mental health problems, social determinants of health, and substance use processes. There was also evidence that the ERMS demonstrated divergent validity in that it was negatively associated with psychological well-being, health literacy, subjective social status in Study 1, and positive abstinence expectancies in Study 2. Overall, the present study establishes the reliability and validity of measuring individual differences in negative emotional reactivity to racial/ethnic minority stress with the ERMS and that such responsivity is associated with behavioral health problems.

Bacterial virulence plays a crucial role in MRSA sepsis.

Bacterial sepsis is a major global cause of death. However, the pathophysiology of sepsis has remained poorly understood. In industrialized nations, Staphylococcus aureus represents the pathogen most commonly associated with mortality due to sepsis. Because of the alarming spread of antibiotic resistance, anti-virulence strategies are often proposed to treat staphylococcal sepsis. However, we do not yet completely understand if and how bacterial virulence contributes to sepsis, which is vital for a thorough assessment of such strategies. We here examined the role of virulence and quorum-sensing regulation in mouse and rabbit models of sepsis caused by methicillin-resistant S. aureus (MRSA). We determined that leukopenia was a predictor of disease outcome during an early critical stage of sepsis. Furthermore, in device-associated infection as the most frequent type of staphylococcal blood infection, quorum-sensing deficiency resulted in significantly higher mortality. Our findings give important guidance regarding anti-virulence drug development strategies for the treatment of staphylococcal sepsis. Moreover, they considerably add to our understanding of how bacterial sepsis develops by revealing a critical early stage of infection during which the battle between bacteria and leukocytes determines sepsis outcome. While sepsis has traditionally been attributed mainly to host factors, our study highlights a key role of the invading pathogen and its virulence mechanisms.

Sodium Oxybate for Alcohol Dependence: A Network Meta-Regression Analysis Considering Population Severity at Baseline and Treatment Duration.

AIMS: The estimated effect of sodium oxybate (SMO) in the treatment of alcohol dependence is heterogeneous. Population severity and treatment duration have been identified as potential effect modifiers. Population severity distinguishes heavy drinking patients with <14 days of abstinence before treatment initiation (high-severity population) from other patients (mild-severity population). Treatment duration reflects the planned treatment duration. This study aimed to systematically investigate the effect of these potential effect moderators on SMO efficacy in alcohol-dependent patients. METHODS: Network meta-regression allows for testing potential effect modifiers. It was selected to investigate the effect of the above factors on SMO efficacy defined as continuous abstinence (abstinence rate) and the percentage of days abstinent (PDA). Randomized controlled trials for alcohol dependence with at least one SMO group conducted in high-severity and mild-severity populations were assigned to a high-severity and mild-severity group of studies, respectively. RESULTS: Eight studies (1082 patients) were retained: four in the high-severity group and four in the mild-severity group. The high-severity group was associated with larger SMO effect sizes than the mild-severity group: abstinence rate risk ratio (RR) 3.16, P = 0.004; PDA +26.9%, P < 0.001. For PDA, longer treatment duration was associated with larger SMO effect size: +11.3% per extra month, P < 0.001. In the high-severity group, SMO showed benefit: abstinence rate RR 2.91, P = 0.03; PDA +16.9%, P < 0.001. In the mild-severity group, SMO showed benefit only in PDA for longer treatment duration: +23.9%, P < 0.001. CONCLUSIONS: In the retained studies with alcohol-dependent patients, high-severity population and longer treatment duration were associated with larger SMO effect sizes.

Underscoring the F in FoMO: How does anxiety sensitivity contribute to fear of missing out?

Fear of missing out (FoMO) is a prevalent phenomenon associated with a range of mental health symptoms, such as depression and anxiety. To our knowledge, the question of whether FoMO can be explained by other well-known mechanistic variables-namely, loneliness, rumination, and anxiety sensitivity (AS) - has not been previously evaluated. The current study investigated the predictive power of loneliness, rumination, and AS for explaining variance in FoMO within two independent samples of undergraduate students at a large Northeastern university. Participants completed an online battery of questionnaires. In Study 1, it was found that loneliness and rumination offered significant prediction of FoMO when AS was not considered in the model; however, when these three predictors were considered together, only AS offered significant, non-redundant prediction. Study 2 revealed that both rumination and AS offered significant prediction of FoMO, with AS offering stronger unique prediction. Such findings provide a new frame for understanding the nature of the relatively new concept of FoMO, and in particular, suggest that it may be important to consider AS and rumination in future studies.

Climate change views examined through a behavioral medicine frame: are there potential target mechanisms for change beyond political ideology?

The threat of climate change is associated with both profound health consequences and failures by many individuals to take preventive actions. Behavioral science research on health behavior engagement may serve as a lens through which to better understand attitudes associated with the threat of climate change. This study was designed to examine individual differences in attitudinal responses to climate change, understanding the degree to which these responses can be predicted by both political beliefs and more readily modified psychological factors commonly associated with health behavior engagement: locus of control, anxiety sensitivity, delay discounting, and intolerance of uncertainty. Participants (N = 234) were US adults (62% male; 57% Non-Hispanic White; 44% Democrat) who completed an online survey. Stepwise multiple linear regressions examined which variables provided non-redundant prediction in models of climate change beliefs and concerns. In addition to providing support for the role of political affiliation and related ideology in climate change views (9-23% variance), this study underscores the importance of a behavioral health frame in understanding climate change concerns and beliefs. Known risk factors for negative health behaviors - prominently, locus of control, anxiety sensitivity, and delay discounting - contributed strongly to the understanding of these views, accounting for 4-28% of variance. Our findings encourage greater attention to health behavior-related constructs for understanding attitudes relevant to climate change action.

Critical Assessment of the Prospects of Quorum-Quenching Therapy for Staphylococcus aureus Infection.

Staphylococcus aureus is an important pathogen that causes a high number of infections and is one of the leading causes of death in hospitalized patients. Widespread antibiotic resistance such as in methicillin-resistant S. aureus (MRSA) has prompted research into potential anti-virulence-targeted approaches. Targeting the S. aureus accessory gene regulator (Agr) quorum-sensing system, a master regulator of virulence, is the most frequently proposed anti-virulence strategy for S. aureus. While much effort has been put into the discovery and screening for Agr inhibitory compounds, in vivo analysis of their efficacy in animal infection models is still rare and reveals various shortcomings and problems. These include (i) an almost exclusive focus on topical skin infection models, (ii) technical problems that leave doubt as to whether observed in vivo effects are due to quorum-quenching, and (iii) the discovery of counterproductive biofilm-increasing effects. Furthermore, potentially because of the latter, invasive S. aureus infection is associated with Agr dysfunctionality. Altogether, the potential of Agr inhibitory drugs is nowadays seen with low enthusiasm given the failure to provide sufficient in vivo evidence for their potential after more than two decades since the initiation of such efforts. However, current Agr inhibition-based probiotic approaches may lead to a new application of Agr inhibition strategies in preventing S. aureus infections by targeting colonization or for otherwise difficult-to-treat skin infections such as atopic dermatitis.

Virulence Mechanisms of Staphylococcal Animal Pathogens.

Staphylococci are major causes of infections in mammals. Mammals are colonized by diverse staphylococcal species, often with moderate to strong host specificity, and colonization is a common source of infection. Staphylococcal infections of animals not only are of major importance for animal well-being but have considerable economic consequences, such as in the case of staphylococcal mastitis, which costs billions of dollars annually. Furthermore, pet animals can be temporary carriers of strains infectious to humans. Moreover, antimicrobial resistance is a great concern in livestock infections, as there is considerable antibiotic overuse, and resistant strains can be transferred to humans. With the number of working antibiotics continuously becoming smaller due to the concomitant spread of resistant strains, alternative approaches, such as anti-virulence, are increasingly being investigated to treat staphylococcal infections. For this, understanding the virulence mechanisms of animal staphylococcal pathogens is crucial. While many virulence factors have similar functions in humans as animals, there are increasingly frequent reports of host-specific virulence factors and mechanisms. Furthermore, we are only beginning to understand virulence mechanisms in animal-specific staphylococcal pathogens. This review gives an overview of animal infections caused by staphylococci and our knowledge about the virulence mechanisms involved.

CO2 reactivity as a biomarker of exposure-based therapy non-response: study protocol.

BACKGROUND: Exposure-based therapy is an effective first-line treatment for anxiety-, obsessive-compulsive, and trauma- and stressor-related disorders; however, many patients do not improve, resulting in prolonged suffering and poorly used resources. Basic research on fear extinction may inform the development of a biomarker for the selection of exposure-based therapy. Growing evidence links orexin system activity to deficits in fear extinction and we have demonstrated that reactivity to an inhaled carbon dioxide (CO2) challenge-a safe, affordable, and easy-to-implement procedure-can serve as a proxy for orexin system activity and predicts fear extinction deficits in rodents. Building upon this basic research, the goal for the proposed study is to validate CO2 reactivity as a biomarker of exposure-based therapy non-response. METHODS: We will assess CO2 reactivity in 600 adults meeting criteria for one or more fear- or anxiety-related disorders prior to providing open exposure-based therapy. By incorporating CO2 reactivity into a multivariate model predicting treatment non-response that also includes reactivity to hyperventilation as well as a number of related predictor variables, we will establish the mechanistic specificity and the additive predictive utility of the potential CO2 reactivity biomarker. By developing models independently within two study sites (University of Texas at Austin and Boston University) and predicting the other site's data, we will validate that the results are likely to generalize to future clinical samples. DISCUSSION: Representing a necessary stage in translating basic research, this investigation addresses an important public health issue by testing an accessible clinical assessment strategy that may lead to a more effective treatment selection (personalized medicine) for patients with anxiety- and fear-related disorders, and enhanced understanding of the mechanisms governing exposure-based therapy. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT05467683 (20/07/2022).

Is Ignorance Bliss? Examining the Effect of News Media Exposure on Anxiety and Depression During the COVID-19 Pandemic.

ABSTRACT: There has been a widespread increase in affective disorders after the emergence of the COVID-19 pandemic. In the current study, we investigated the effects of exposure to and perceived accuracy of news media and demographic characteristics on anxiety and depressive symptoms. We conducted an online survey of US adults (N = 480) using hierarchical linear regression models to understand the predictive roles of duration and frequency of news media exposure, as well as the perceived accuracy of COVID-19 portrayal by the news media, on anxiety and depression. Increased exposure duration predicted greater anxiety, and decreased frequency of exposure and perceived overreaction in the news media coverage of COVID-19 were linked to greater anxiety and depression. Perceived accuracy moderated the relationship of exposure frequency to both affective outcomes. Accordingly, our data support the importance of adequate levels of accurate and trusted information to help mitigate the overall mental health burden of the pandemic.

COVID-19 vaccine acceptance: influential roles of political party and religiosity.

Given recent declines in US vaccination rates and the emergence of COVID-19 vaccines, identifying sociodemographic influencers of vaccine willingness holds importance for developing effective public health campaigns aimed at enhancing nationwide COVID-19 vaccine acceptance. The present study utilized a hierarchical binary logistic regression model to assess demographic variables (age, gender, race/ethnicity, pre-existing medical conditions), political party membership, religious affiliation, level of religiosity, and fear of COVID-19 as predictors of COVID-19 vaccine acceptance ('Yes', would receive a vaccine or 'No', would not receive a vaccine) in a national sample of US adults (N = 249). Participants were recruited from Amazon's Mechanical Turk (MTurk) and completed several online questionnaires pertaining to mental health, health behaviors, and responses to the COVID-19 pandemic. Both Democratic party membership and decreased level of religiosity predicted acceptance of a COVID-19 vaccine. This investigation supports political party membership and religiosity as influencers of COVID-19 vaccine willingness and suggests that these variables could represent potential targets for public health interventions aimed at increasing vaccine adoption.

Look Who's Talking: Host and Pathogen Drivers of Staphylococcus epidermidis Virulence in Neonatal Sepsis.

Preterm infants are at increased risk for invasive neonatal bacterial infections. S. epidermidis, a ubiquitous skin commensal, is a major cause of late-onset neonatal sepsis, particularly in high-resource settings. The vulnerability of preterm infants to serious bacterial infections is commonly attributed to their distinct and developing immune system. While developmentally immature immune defences play a large role in facilitating bacterial invasion, this fails to explain why only a subset of infants develop infections with low-virulence organisms when exposed to similar risk factors in the neonatal ICU. Experimental research has explored potential virulence mechanisms contributing to the pathogenic shift of commensal S. epidermidis strains. Furthermore, comparative genomics studies have yielded insights into the emergence and spread of nosocomial S. epidermidis strains, and their genetic and functional characteristics implicated in invasive disease in neonates. These studies have highlighted the multifactorial nature of S. epidermidis traits relating to pathogenicity and commensalism. In this review, we discuss the known host and pathogen drivers of S. epidermidis virulence in neonatal sepsis and provide future perspectives to close the gap in our understanding of S. epidermidis as a cause of neonatal morbidity and mortality.

An investigation of racial and ethnic differences in e-cigarette beliefs and use characteristics.

In this study we provide information on e-cigarette use characteristics in relation to racial and ethnic characteristics in a sample of 535 adult e-cigarette users. We also evaluated how anxiety sensitivity (AS; fear of anxiety) interacted with race/ethnicity to predict vaping outcomes. We found an association between greater AS and higher e-cigarette dependence for White, but not Black, participants. A similar trend was observed for level of risk perception. Also, Hispanic status was associated with higher perception of e-cigarette benefits. Overall, the present study contributes to the understanding of factors linked to e-cigarette use.

Contribution of Staphylococcal Enterotoxin B to Staphylococcus aureus Systemic Infection.

Staphylococcal enterotoxin B (SEB), which is produced by the major human pathogen, Staphylococcus aureus, represents a powerful superantigenic toxin and is considered a bioweapon. However, the contribution of SEB to S. aureus pathogenesis has never been directly demonstrated with genetically defined mutants in clinically relevant strains. Many isolates of the predominant Asian community-associated methicillin-resistant S. aureus lineage sequence type (ST) 59 harbor seb, implying a significant role of SEB in the observed hypervirulence of this lineage. We created an isogenic seb mutant in a representative ST59 isolate and assessed its virulence potential in mouse infection models. We detected a significant contribution of seb to systemic ST59 infection that was associated with a cytokine storm. Our results directly demonstrate that seb contributes to S. aureus pathogenesis, suggesting the value of including SEB as a target in multipronged antistaphylococcal drug development strategies. Furthermore, they indicate that seb contributes to fatal exacerbation of community-associated methicillin-resistant S. aureus infection.

Investigation of the predictive influence of personal and gubernatorial politics on COVID-19 related behaviors and beliefs.

Given the varied emotional and behavioral responses to the COVID-19 pandemic across the United States, further attention to the personal and societal influences on such responses is necessary. We investigated the predictive influence of personal political affiliation and the congruity of personal and governor political affiliation on COVID-19 emotional and behavioral responses, with specific attention to the influence of intolerance of uncertainty (IU) on emotional response. These factors were assessed in two studies of adults in the United States (N = 480, N = 272). We utilized a series of hierarchical linear and logistic regressions to assess predictors of 4 outcomes: (1) trust in governor's response to the pandemic, (2) COVID-19 related worry, and the (3) usage and (4) perceived efficacy of protective health behaviors (e.g., wearing a mask). Across these studies, we found that IU predicted increased COVID-19 related worry. Further, age and personal political affiliation, but not concordance with governor affiliation, predicted COVID-19 behavioral responses. These findings are discussed in relation to the potential importance of linking health messaging to personal characteristics.