Mechanisms of Staphylococcus aureus survival of trimethoprim-sulfamethoxazole-induced thymineless death.

Trimethoprim-sulfamethoxazole (SXT) is commonly used to treat diverse Staphylococcus aureus infections, including those associated with cystic fibrosis (CF) pulmonary disease. Studies with Escherichia coli found that SXT impairs tetrahydrofolate production, leading to DNA damage, stress response induction, and accumulation of reactive oxygen species (ROS) in a process known as thymineless death (TLD). TLD survival can occur through the uptake of exogenous thymidine, countering the effects of SXT; however, a growing body of research has implicated central metabolism as another potentially important determinant of bacterial survival of SXT and other antibiotics. Here, we conducted studies to better understand the mechanisms of TLD survival in S. aureus. We found that thymidine abundances in CF sputum were insufficient to prevent TLD of S. aureus, highlighting the importance of alternative survival mechanisms in vivo. In S. aureus cultured in vitro with SXT and low thymidine, we frequently identified adaptive mutations in genes encoding carbohydrate, nucleotide, and amino acid metabolism, supporting reduced metabolism as a common survival mechanism. Although intracellular ROS levels rose with SXT treatment in vitro, survival was not improved in the presence of ROS scavengers, unlike in E. coli. SXT challenge induced the SOS response, which was alleviated by added thymidine. Finally, an inactivating mutation in the phosphotransferase gene ptsI conferred both limitation in cellular ATP and improved survival against TLD. Collectively, these results suggest that alterations in core metabolic functions, particularly those that reduce ATP levels, predominantly confer S. aureus survival and persistence during SXT treatment, potentially identifying novel targets for co-treatment.IMPORTANCEStaphylococcus aureus is a ubiquitous organism and one of the leading causes of human infections, many of which are difficult to treat due to persistence, antibiotic resistance, or antibiotic tolerance. As our arsenal of effective antibiotics dwindles, the need for improved treatments becomes increasingly urgent, necessitating a better understanding of the precise mechanisms by which pathogens evade our most critical antimicrobial agents. Here, we report a systematic characterization of the mechanisms of S. aureus survival to treatment with the first-line antistaphylococcal antibiotic trimethoprim-sulfamethoxazole, identifying pathways and candidate targets for enhancing the efficacy of available antimicrobial agents.

Redlining and Time to Viral Suppression Among Persons With HIV.

Importance: Structural racism in the US is evidenced in the discriminatory practice of historical racial redlining when neighborhoods were valued, in part, based on the community's racial and ethnic compositions. However, the influence of these systemic practices in the context of the HIV epidemic is not well understood. Objective: To assess the effect of redlining on time to viral suppression among people newly diagnosed with HIV. Design, Setting, and Participants: Observational study that included individuals diagnosed with HIV from January 1, 2011, to December 31, 2019, in New Orleans, Louisiana. At the time of their HIV diagnosis, these individuals lived in neighborhoods historically mapped by the Home Owners' Loan Corporation (HOLC). The HOLC lending risk maps classified neighborhoods into 1 of 4 color-coded grades: A (best), B (still desirable), C (definitely declining), and D (hazardous). Main Outcome and Measures: The primary outcome of interest was time to viral suppression (estimated as the time from the diagnosis date to the date of the first recorded viral load that was <200 copies/mL). Individual-level demographic factors were used to evaluate time to viral suppression along with a neighborhood measure of gentrification (based on US census tract-level characteristics for educational attainment, housing development and value, and household income) and a Cox gamma frailty model with census tract used as the frailty term. Results: Of 1132 individuals newly diagnosed with HIV, 871 (76.9%) were men and 620 (54.8%) were 25 to 44 years of age. Of the 697 individuals living in historically redlined neighborhoods (HOLC grade D), 100 (14.6%) were living in neighborhoods that were gentrifying. The median time to viral suppression was 193 days (95% CI, 167-223 days) for persons with HIV living in redlined neighborhoods compared with 164 days (95% CI, 143-185 days) for the 435 persons with HIV living in HOLC grade A, B, or C (nonredlined) neighborhoods. Among persons with HIV living in gentrifying neighborhoods, those living in redlined neighborhoods had a longer time to viral suppression compared with persons living in nonredlined neighborhoods (hazard ratio, 0.54 [95% CI, 0.36-0.82]). Conclusions and Relevance: These findings suggest the enduring effects of systemic racism on present-day health outcomes among persons with HIV. Regardless of their neighborhood's contemporary level of gentrification, individuals diagnosed with HIV while living in historically redlined neighborhoods may experience a significantly longer time to viral suppression.

Clinical and in vitro models identify distinct adaptations enhancing Staphylococcus aureus pathogenesis in human macrophages.

Staphylococcus aureus is a facultative intracellular pathogen of human macrophages, which facilitates chronic infection. The genotypes, pathways, and mutations influencing that phenotype remain incompletely explored. Here, we used two distinct strategies to ascertain S. aureus gene mutations affecting pathogenesis in macrophages. First, we analyzed isolates collected serially from chronic cystic fibrosis (CF) respiratory infections. We found that S. aureus strains evolved greater macrophage invasion capacity during chronic human infection. Bacterial genome-wide association studies (GWAS) identified 127 candidate genes for which mutation was significantly associated with macrophage pathogenesis in vivo. In parallel, we passaged laboratory S. aureus strains in vitro to select for increased infection of human THP-1 derived macrophages, which identified 15 candidate genes by whole-genome sequencing. Functional validation of candidate genes using isogenic transposon mutant knockouts and CRISPR interference (CRISPRi) knockdowns confirmed virulence contributions from 37 of 39 tested genes (95%) implicated by in vivo studies and 7 of 10 genes (70%) ascertained from in vitro selection, with one gene in common to the two strategies. Validated genes included 17 known virulence factors (39%) and 27 newly identified by our study (61%), some encoding functions not previously associated with macrophage pathogenesis. Most genes (80%) positively impacted macrophage invasion when disrupted, consistent with the phenotype readily arising from loss-of-function mutations in vivo. This work reveals genes and mechanisms that contribute to S. aureus infection of macrophages, highlights differences in mutations underlying convergent phenotypes arising from in vivo and in vitro systems, and supports the relevance of S. aureus macrophage pathogenesis during chronic respiratory infection in CF. Additional studies will be needed to illuminate the exact mechanisms by which implicated mutations affect their phenotypes.

Efficacy of a Pain Self-Management Intervention Tailored to People With HIV: A Randomized Clinical Trial.

Importance: Chronic pain is a common condition for which efficacious interventions tailored to highly affected populations are urgently needed. People with HIV have a high prevalence of chronic pain and share phenotypic similarities with other highly affected populations. Objective: To evaluate the efficacy of a behavioral pain self-management intervention called Skills to Manage Pain (STOMP) compared to enhanced usual care (EUC). Design, Setting, and Participants: This randomized clinical trial included adults with HIV who experienced at least moderate chronic pain for 3 months or more. The study was set at the University of Alabama at Birmingham and the University of North Carolina-Chapel Hill large medical centers from August 2019 to September 2022. Intervention: STOMP combined 1-on-1 skill-building sessions delivered by staff interventionists with group sessions co-led by peer interventionists. The EUC control group received the STOMP manual without any 1-on-1 or group instructional sessions. Main Outcomes and Measures: The primary outcome was pain severity and the impact of pain on function, measured by the Brief Pain Inventory (BPI) summary score. The primary a priori hypothesis was that STOMP would be associated with a decreased BPI in people with HIV compared to EUC. Results: Among 407 individuals screened, 278 were randomized to STOMP intervention (n = 139) or EUC control group (n = 139). Among the 278 people with HIV who were randomized, the mean (SD) age was 53.5 (10.0) years; 126 (45.0%) identified as female, 146 (53.0%) identified as male, 6 (2.0%) identified as transgender female. Of the 6 possible 1-on-1 sessions, participants attended a mean (SD) of 2.9 (2.5) sessions. Of the 6 possible group sessions, participants attended a mean (SD) of 2.4 (2.1) sessions. Immediately after the intervention compared to EUC, STOMP was associated with a statistically significant mean difference for the primary outcome, BPI total score: -1.25 points (95% CI, -1.71 to -0.78 points; P < .001). Three months after the intervention, the mean difference in BPI total score remained statistically significant, favoring the STOMP intervention -0.62 points (95% CI, -1.09 to -0.14 points; P = .01). Conclusion and Relevance: The findings of this randomized clinical trial support the efficaciousness of STOMP as an intervention for chronic pain in people with HIV. Future research will include implementation studies and work to understand the optimal delivery of the intervention. Trial Registration: ClinicalTrials.gov Identifier: NCT03692611.

HIV and intersectional stigma among people living with HIV and healthcare workers and antiretroviral therapy adherence in the Dominican Republic.

BACKGROUND: HIV-related stigma, discrimination, and social marginalization undermines optimal HIV care outcomes. More research examining the impact of HIV-related stigma, discrimination, other interlocking forms of oppression, and antiretroviral therapy (ART) adherence is needed to optimize HIV treatment programming. This study uses data from two clinics in the Dominican Republic to examine client and healthcare worker (HCW) perceptions of HIV and intersectional stigmas among people living with HIV. METHODS: Surveys exploring demographics, HIV-related stigma, various dimensions of discrimination (race/ethnicity, HIV status, sexual orientation), healthcare engagement, and medication adherence were collected from 148 clients and 131 HCWs. Analysis of variance was conducted to examine differences in stigma by clinic and logistic regressions were used to determine predictors of optimal client medication adherence. RESULTS: Perceived discrimination in healthcare facilities due to clients' sexual orientation retained significance in crude and multivariable logistic regression models and was negatively associated with ART adherence (aOR:0.79; 95% CI:0.66, 0.95). DISCUSSION: Findings highlight the importance of implementing strategies to address stigma, discrimination, and social marginalization, particularly within healthcare facilities.

Preventing Surgical Site Infections in the Era of Escalating Antibiotic Resistance and Antibiotic Stewardship.

Importance: According to the Centers for Disease Control and Prevention and governing bodies within the American College of Surgeons, the administration of antibiotics as prophylaxis against infection prior to a planned elective procedure is, with rare exception, routinely recommended. The goal of "getting to zero" infections remains a high priority for policymakers, practitioners, and certainly for patients. Observations: Despite the many advances in surgical technique, skin decontamination, sterile procedure, and enhanced recovery programs, surgical site infections continue to adversely affect procedures as diverse as dental implant surgery, joint arthroplasty, and major abdominal surgery. Although surgical site infection rates are at historically low levels, progress has stalled in recent reporting periods and such infections remain disabling, costly, and occasionally lethal. Stakeholders in the field, including surgeons, infectious diseases specialists, and industry, advocate for strategies emphasizing greater levels of intraoperative sterility or broader-spectrum antibiotic coverage as the most appropriate path forward. Conclusions and Relevance: The current emphasis on ever-increasing levels of intraoperative sterility and extended-spectrum antibiotic use are not sustainable long-term solutions. Continuing to escalate these approaches may contribute to unintended consequences including antimicrobial resistance. Principles of antimicrobial stewardship and microbiome sciences can be applied to inform a more effective and sustainable approach to infection prevention in the field of surgery.

A Moderated Mediation Analysis of HIV and Intersectional Stigmas and Antiretroviral Adherence in People Living with HIV in the Dominican Republic.

Experiencing HIV and intersectional stigmas in healthcare settings may affect antiretroviral treatment (ART) adherence among people with HIV (PWH), given their need for frequent interactions with clinical settings and healthcare providers. Considering the importance of reducing stigmas to promote well-being and the need to elucidate how stigma influences health across various settings, we examined how experienced HIV stigma in Dominican Republic healthcare settings impacts ART adherence through internalized HIV stigma and whether race or sexual orientation stigma moderates this relationship. Participants were 471 PWH (aged 17-71) who were recruited from two HIV clinics in the Dominican Republic in 2021-2022. Results revealed a significant mediation effect (B=-0.10, SE = 0.05, CI [-0.234, - 0.014]) after adjusting for effect of age and time since HIV diagnosis, suggesting that experienced HIV stigma in healthcare settings was associated with more internalized HIV stigma (B = 0.39, SE = 0.11, p = .001), subsequently linked to lower ART adherence (B=-0.26, SE = 0.11, p = .016). The indirect effect was significant at low levels of race stigma (B=-0.16, SE = 0.09, CI [-0.369, - 0.001]) but not at high levels of race stigma (B=-0.06, SE = 0.05, CI [-0.175, 0.038]). This indirect effect was also significant at low levels of sexual orientation stigma (B=-0.19, SE = 0.10, CI [-0.401, - 0.023]) but not at high levels of sexual orientation stigma (B=-0.04, SE = 0.06, CI [-0.160, 0.074]). These findings suggest that addressing experienced HIV stigma in Dominican Republic healthcare settings, along with various dimensions of HIV-related stigma (e.g., internalized stigma) and intersecting stigmas (e.g., race, sexual orientation), is vital for improving health outcomes, such as optimal ART adherence.

RESUMEN: Experimentar estigmas relacionados con el VIH e interseccionales en entornos de atención médica puede afectar la adherencia al tratamiento antirretroviral (TAR) entre las personas que viven con VIH (PVVIH), dado que necesitan interacciones frecuentes con entornos clínicos y proveedores de atención médica. Considerando la importancia de reducir los estigmas para promover el bienestar y la necesidad de esclarecer cómo el estigma influye en la salud en diversos contextos, examinamos cómo el estigma del VIH experimentado en entornos de atención médica en la República Dominicana impacta la adherencia al TAR a través del estigma internalizado del VIH y si el estigma racial o de orientación sexual modera esta relación. Los participantes fueron 471 PVVIH (de 17 a 71 años) que fueron reclutados de dos clínicas de VIH en la República Dominicana en 2021­2022. Los resultados revelaron un efecto de mediación significativo (B=-0.10, SE = 0.05, CI [-0.234, − 0.014]) después de ajustar por el efecto de la edad y el tiempo desde el diagnóstico de VIH, sugiriendo que el estigma del VIH experimentado en entornos de atención médica estaba asociado con un mayor estigma internalizado del VIH (B = 0.39, SE = 0.11, p = .001), vinculado posteriormente a una menor adherencia al TAR (B=-0.26, SE = 0.11, p = .016). El efecto indirecto fue significativo en niveles bajos de estigma racial (B=-0.16, SE = 0.09, CI [-0.369, − 0.001]) pero no en niveles altos de estigma racial (B=-0.06, SE = 0.05, CI [-0.175, 0.038]). Este efecto indirecto también fue significativo en niveles bajos de estigma por orientación sexual (B=-0.19, SE = 0.10, CI [-0.401, − 0.023]) pero no en niveles altos de estigma por orientación sexual (B=-0.04, SE = 0.06, CI [-0.160, 0.074]). Estos hallazgos sugieren que abordar el estigma del VIH experimentado en entornos de atención médica en la República Dominicana, junto con diversas dimensiones del estigma relacionado con el VIH (por ejemplo, estigma internalizado) y estigmas interseccionales (por ejemplo, raza, orientación sexual), es vital para mejorar los resultados de salud, como la adherencia óptima al TAR.

Implementation of a safer conception programme for HIV-affected men and women in rural Uganda.

We integrated safer conception care into a Ugandan HIV clinic. People with HIV (PWH), or partnered with a PWH, and desiring children were eligible for the Healthy Families Clinic Program. Clients completed quarterly safer conception counselling visits and questionnaires to provide information around method preferences and outcomes (partner pregnancy, partner seroconversion). We used clinic level data to evaluate longitudinal viral suppression among PWH. Between November 2016 and January 2020, 361 clients (53% men) accessed services. 75% were PWH (51% women, 96% men): 99% were on antiretroviral therapy (ART) and most reported HIV-sero-different partnerships (97%). Frequently selected safer conception methods included ART (86%), timed condomless sex (74%), and PrEP (40%) with important differences by HIV-serostatus and gender. 22.5% reported pregnancy. Most (97%) PWH were virally suppressed at enrolment and 81% of non-virally suppressed PWH were virally suppressed at 15 months. Two HIV-negative clients (2%) had HIV seroconversion. There is demand for safer conception care in a public sector HIV-clinic in Uganda. Men and women have unique safer conception care preferences. The majority of clients engaged in safer conception care had viral suppression at follow up.

Trimethoprim-Sulfamethoxazole Plus Azithromycin to Prevent Malaria and Sexually Transmitted Infections in Pregnant Women With HIV (PREMISE): A Randomized, Double-Masked, Placebo-Controlled, Phase IIB Clinical Trial.

Background: This trial tested the effectiveness of a novel regimen to prevent malaria and sexually transmitted infections (STIs) among pregnant women with HIV in Cameroon. Our hypothesis was that the addition of azithromycin (AZ) to standard daily trimethoprim-sulfamethoxazole (TMP-SMX) prophylaxis would reduce malaria and STI infection rates at delivery. Methods: Pregnant women with HIV at gestational age <28 weeks were randomized to adjunctive monthly oral AZ 1 g daily or placebo for 3 days and both groups received daily standard oral TMP-SMX through delivery. Primary outcomes were (1) positive peripheral malaria infection by microscopy or polymerase chain reaction and (2) composite bacterial genital STI (Chlamydia trachomatis, Neisseria gonorrhoeae, or syphilis) at delivery. Relative risk and 95% confidence intervals were estimated using 2 × 2 tables with significance as P < .05. Results: Pregnant women with HIV (n = 308) were enrolled between March 2018 and August 2020: 155 women were randomized to TMP-SMX-AZ and 153 women to TMP-SMX-placebo. Groups were similar at baseline and loss to follow up was 3.2%. There was no difference in the proportion with malaria (16.3% in TMP-SMX-AZ vs 13.2% in TMP-SMX; relative risk, 1.24 [95% confidence interval, .71-2.16]) or STI at delivery (4.2% in TMP-SMX-AZ vs 5.8% in TMP-SMX; relative risk, 0.72 [95% confidence interval, .26-2.03]). Adverse birth outcomes were not significantly different, albeit lower in the TMP-SMX-AZ arm (preterm delivery 6.7% vs 10.7% [P = .3]; low birthweight 3.4% vs 5.4% [P = .6]). Conclusions: The addition of monthly azithromycin to daily TMP-SMX prophylaxis in pregnant women living with HIV in Cameroon did not reduce the risk of malaria or bacterial STI at delivery.

2023 Neer Award for Basic Science: Genetics of Cutibacterium acnes in revision shoulder arthroplasty: a large-scale bacterial whole-genome sequencing study.

BACKGROUND: Cutibacterium acnes is the bacterium most commonly responsible for shoulder periprosthetic joint infection (PJI) and is often cultured from samples obtained at the time of revision for failed shoulder arthroplasty. We sought to determine whether these bacteria originate from the patient or from exogenous sources. We also sought to identify which C. acnes genetic traits were associated with the development of shoulder PJI. METHODS: We performed bacterial whole-genome sequencing of C. acnes from a single-institution repository of cultures obtained before or during primary and revision shoulder arthroplasty and correlated the molecular epidemiology and genetic content of strains with clinical features of infection. RESULTS: A total of 341 isolates collected over a 4-year period from 88 patients were sequenced. C. acnes cultured from surgical specimens demonstrated significant similarity to the strains colonizing the skin of the same patient (P < .001). Infrequently, there was evidence of strains shared across unrelated patients, suggesting that exogenous sources of C. acnes culture-positivity were uncommon. Phylotypes IB and II were modestly associated with clinical features of PJI, but all phylotypes appeared inherently capable of causing disease. Chronic shoulder PJI was associated with the absence of common C. acnes genes involved in bacterial quorum-sensing (luxS, tqsA). CONCLUSION: C. acnes strains cultured from deep intraoperative sources during revision shoulder arthroplasty demonstrate strong genetic similarity to the strains colonizing a patient's skin. Some phylotypes of C. acnes commonly colonizing human skin are modestly more virulent than others, but all phylotypes have a capacity for PJI. C. acnes cultured from cases of PJI commonly demonstrated genetic hallmarks associated with adaptation from acute to chronic phases of infection. This is the strongest evidence to date supporting the role of the patient's own, cutaneous C. acnes strains in the pathogenesis of shoulder arthroplasty infection. Our findings support the importance of further research focused on perioperative decolonization and management of endogenous bacteria that are likely to be introduced into the arthroplasty wound at the time of skin incision.

Population-average mediation analysis for zero-inflated count outcomes.

Mediation analysis is an increasingly popular statistical method for explaining causal pathways to inform intervention. While methods have increased, there is still a dearth of robust mediation methods for count outcomes with excess zeroes. Current mediation methods addressing this issue are computationally intensive, biased, or challenging to interpret. To overcome these limitations, we propose a new mediation methodology for zero-inflated count outcomes using the marginalized zero-inflated Poisson (MZIP) model and the counterfactual approach to mediation. This novel work gives population-average mediation effects whose variance can be estimated rapidly via delta method. This methodology is extended to cases with exposure-mediator interactions. We apply this novel methodology to explore if diabetes diagnosis can explain BMI differences in healthcare utilization and test model performance via simulations comparing the proposed MZIP method to existing zero-inflated and Poisson methods. We find that our proposed method minimizes bias and computation time compared to alternative approaches while allowing for straight-forward interpretations.

Contribution of the patient microbiome to surgical site infection and antibiotic prophylaxis failure in spine surgery.

Despite modern antiseptic techniques, surgical site infection (SSI) remains a leading complication of surgery. However, the origins of SSI and the high rates of antimicrobial resistance observed in these infections are poorly understood. Using instrumented spine surgery as a model of clean (class I) skin incision, we prospectively sampled preoperative microbiomes and postoperative SSI isolates in a cohort of 204 patients. Combining multiple forms of genomic analysis, we correlated the identity, anatomic distribution, and antimicrobial resistance profiles of SSI pathogens with those of preoperative strains obtained from the patient skin microbiome. We found that 86% of SSIs, comprising a broad range of bacterial species, originated endogenously from preoperative strains, with no evidence of common source infection among a superset of 1610 patients. Most SSI isolates (59%) were resistant to the prophylactic antibiotic administered during surgery, and their resistance phenotypes correlated with the patient's preoperative resistome (P = 0.0002). These findings indicate the need for SSI prevention strategies tailored to the preoperative microbiome and resistome present in individual patients.

Re-evaluating the relationship between youth with HIV and BMI in an age of increasing rates of overweight and obese youth.

BACKGROUND: Newer antiretrivirals (ART) have shifted the metabolic experiences of people with HIV (PWH) from those of wasting syndrome to increases in body mass index (BMI). This study sought to examine the relationship between BMI and ART use among youth with HIV (YWH). METHODS: Charts from YWH ages 10-24 with at least two documented BMIs at least 6 months apart between 2017 and 2020 were included (N = 44). Statistical analyses were conducted in SAS 9.4. RESULTS: Clients were predominately African American (66%) males (73%) aged 19-24 years (64%), with men having sex with men (48%) being the most common mode of transmission. YWH on non-integrase inhibitor (INSTI) regimens had greater absolute increases in BMI compared to those on INSTI regimens (p = 0.03). Fourteen percent of clients using INSTI experienced an increase in BMI class from normal to overweight or overweight to obese; no non-INSTI users changed BMI class. Time since diagnosis and BMI change due to weight gain were positively associated (p = 0.03) among behaviorally-acquired YWH. CONCLUSIONS: Increasing BMI and changing BMI classes may be more likely among YWH using INSTI. More longitudinal studies inclusive of diet and exercise profiles are needed to understand the relationship between INSTI and YWH BMI.

The Characteristics of Youth With Missed HIV Visits in Alabama.

Gaps in knowledge remain related to understanding missed human immunodeficiency virus (HIV) visits and youth with HIV (YWH). This study examined data from an Alabama academic HIV clinic with clients aged 16 to 24 years old and found that non virally suppressed and older YWH were associated with missed visits among YWH.

Microbial interactions among Gardnerella, Prevotella and Fannyhessea prior to incident bacterial vaginosis: protocol for a prospective, observational study.

INTRODUCTION: The aetiology of bacterial vaginosis (BV), a biofilm-associated vaginal infection, remains unknown. Epidemiologic data suggest that it is sexually transmitted. BV is characterised by loss of lactic acid-producing lactobacilli and an increase in facultative and strict anaerobic bacteria. Gardnerella spp are present in 95%-100% of cases; Gardnerella vaginalis has been found to be more virulent than other BV-associated bacteria (BVAB) in vitro. However, G. vaginalis is found in women with normal vaginal microbiota and colonisation is not sufficient for BV development. We hypothesise that Gardnerella spp initiate BV biofilm formation, but incident BV (iBV) requires incorporation of other key BVAB (ie, Prevotella bivia, Fannyhessea vaginae) into the biofilm that alter the transcriptome of the polymicrobial consortium. This study will investigate the sequence of microbiologic events preceding iBV. METHODS AND ANALYSIS: This study will enrol 150 women aged 18-45 years with normal vaginal microbiota and no sexually transmitted infections at a sexual health research clinic in Birmingham, Alabama. Women will self-collect twice daily vaginal specimens up to 60 days. A combination of 16S rRNA gene sequencing, qPCR for Gardnerella spp, P. bivia and F. vaginae, and broad range 16S rRNA gene qPCR will be performed on twice daily vaginal specimens from women with iBV (Nugent score 7-10 on at least 2 consecutive days) and controls (with comparable age, race, contraceptive method and menstrual cycle days) maintaining normal vaginal microbiota to investigate changes in the vaginal microbiota over time for women with iBV. Participants will complete daily diaries on multiple factors including sexual activity. ETHICS AND DISSEMINATION: This protocol is approved by the University of Alabama at Birmingham Institutional Review Board (IRB-300004547) and written informed consent will be obtained from all participants. Findings will be presented at scientific conferences and published in peer-reviewed journals as well as disseminated to providers and patients in communities of interest.

Viral load and sexually transmitted infection testing among youth with HIV in a southern United States clinic.

Background: As compared to their older peers, youth with HIV (YWH) are less likely to attain viral suppression and have higher rates of sexually transmitted infections (STI). In this exploratory study, we examine the relationship between HIV viral suppression, STI testing, and STI diagnosis among YWH receiving care at a clinic in the southern United States.Methods: Data from 933 clinical visits (2017-2020) were aggregated into singular patient records for YWH aged 10-24 years in Alabama (N = 139). Analyses included univariate generalized linear mixed models performed with the PROC GLIMMIX procedure approximating the marginal likelihood by using Laplace's method.Results: Sample median age was 22 years at the index visit. Most YWH were 20-24 years old (69.1%), male (67.6%), and identified as Black (77%); 58.3% were virally unsuppressed at index visit. YWH who identified as White or of other races had 4.79 times higher odds of being virally suppressed as compared to Black YWH (p < .01); STI testing behavior and STI positive diagnosis were associated with lower odds of being virally suppression.Conclusions: Findings suggest that among YWH, receiving STI testing and having an STI diagnosis is associated with a lack of viral suppression, suggesting that extra efforts may be necessary to support YWH who have an STI to attain suppression. Research is needed to examine individual behaviors, structural forces, and clinic features that could impact STI care engagement, specifically among unsuppressed YWH.

Acceptability, feasibility and potential of an intervention using secret Facebook groups to complement existing HIV prevention strategies among female sex workers in Cameroon, a randomized pilot study.

This randomized pilot project evaluated an intervention promoting health care literacy around HIV, pre-exposure prophylaxis (PrEP), and stigma reduction using private social media groups that complemented existing HIV prevention services among female sex workers (FSWs) in Cameroon. The intervention was 12 HIV and sexual health videos tailored to FSWs that were released over 8 weeks through a secret Facebook group platform. In-person surveys were administered before, after the intervention, and three months later. No HIV seroconversions were detected; all participants completed follow-up and agreed to recommend the intervention to a coworker. Although the intervention was assessed to be acceptable and feasible to implement, poor internet connectivity was a key barrier. In time-series analysis, the intervention group participants reported improved PrEP interest, PrEP knowledge, and condom use along with reduced PrEP and HIV-related stigma, but no impact on sex-work related stigma or social cohesion. Similar results occurred in the control group. Cross-contamination and small pilot study size might have hindered the ability to detect the differential impact of this intervention. As communications technology increases in Cameroon, it is essential to learn more about FSWs preferences on the use of social media platforms for HIV prevention strategies.

Application of marginalized zero-inflated models when mediators have excess zeroes.

Mediation analysis has become increasingly popular over the last decade as researchers are interested in assessing mechanistic pathways for intervention. Although available methods have increased, there are still limited options for mediation analysis with zero-inflated count variables where the distribution of response has a "cluster" of data at the zero value (i.e. distribution of number of cigarettes smoked per day, where nonsmokers cluster at zero cigarettes). The currently available methods do not obtain unbiased population average effects of mediation effects. In this paper, we propose an extension of the counterfactual approach to mediation with direct and indirect effects to scenarios where the mediator is a count variable with excess zeroes by utilizing the Marginalized Zero-Inflated Poisson Model (MZIP) for the mediator model. We derive direct and indirect effects for continuous, binary, and count outcomes, as well as adapt to allow mediator-exposure interactions. Our proposed work allows straightforward calculation of direct and indirect effects for the overall population mean values of the mediator, for scenarios in which researchers are interested in generalizing direct and indirect effects to the population. We apply this novel methodology to an application observing how alcohol consumption may explain sex differences in cholesterol and assess model performance via a simulation study comparing the proposed MZIP mediator framework to existing methods for marginal mediator effects.

Transposon sequencing identifies genes impacting Staphylococcus aureus invasion in a human macrophage model.

Staphylococcus aureus is a facultative intracellular pathogen in many host cell types, facilitating its persistence in chronic infections. The genes contributing to intracellular pathogenesis have not yet been fully enumerated. Here, we cataloged genes influencing S. aureus invasion and survival within human THP-1 derived macrophages using two laboratory strains (ATCC2913 and JE2). We developed an in vitro transposition method to produce highly saturated transposon mutant libraries in S. aureus and performed transposon insertion sequencing (Tn-Seq) to identify candidate genes with significantly altered abundance following macrophage invasion. While some significant genes were strain-specific, 108 were identified as common across both S. aureus strains, with most (n = 106) being required for optimal macrophage infection. We used CRISPR interference (CRISPRi) to functionally validate phenotypic contributions for a subset of genes. Of the 20 genes passing validation, seven had previously identified roles in S. aureus virulence, and 13 were newly implicated. Validated genes frequently evidenced strain-specific effects, yielding opposing phenotypes when knocked down in the alternative strain. Genomic analysis of de novo mutations occurring in groups (n = 237) of clonally related S. aureus isolates from the airways of chronically infected individuals with cystic fibrosis (CF) revealed significantly greater in vivo purifying selection in conditionally essential candidate genes than those not associated with macrophage invasion. This study implicates a core set of genes necessary to support macrophage invasion by S. aureus, highlights strain-specific differences in phenotypic effects of effector genes, and provides evidence for selection of candidate genes identified by Tn-Seq analyses during chronic airway infection in CF patients in vivo.

Social Support Assets and Needs of Underrepresented Students Participating in Health Sciences Pathways Programs in Birmingham, Alabama.

BACKGROUND: Using the Asset Bundle Model, we sought to understand the social support assets and needs of underrepresented minority (URM) high school, undergraduate, and graduate students. SETTING: Study participants were or had participated in health sciences pathway programs at Birmingham City Schools and/or the University of Alabama at Birmingham. METHODS: We took a concurrent mixed methods approach to conduct an environmental scan of health science pathway programs in the Birmingham, AL area. Four focus groups were conducted between November 2022 and January 2023, and a 225-item online survey was administered between November 4, 2022, and February 4, 2023. Both tools collected data from high school, undergraduate, and graduate students to examine key components of existing health care pathways programs for URMs and identify barriers and facilitators to successful implementation of such programs. RESULTS: Twenty-two students participated in the focus groups, and 168 individuals responded to the survey. Both focus group participants and interview respondents were primarily URMs (eg, 68.2% and 65.7% identified as Black or African American, respectively). Survey responses and focus group discussions showed that, overall, undergraduate and graduate students programs develop more robust identities as future health care professionals through friendships and institutional supports, expand their networks more broadly through mentorship, and feel more supported by family members in their academic endeavors than high school students. CONCLUSIONS: Health science pathway programs for URMs should facilitate and bolster social supports for students, especially those in high school, to enhance persistence through education and into the workforce.