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Implementation factors shaping British Columbia's drug decriminalization pilot: A systematic review with narrative synthesis.

BACKGROUND: In January 2023, British Columbia (BC) became the first Canadian province to implement a legally sanctioned drug decriminalization policy, removing criminal penalties for adults possessing 2.5 g or less of opioids, cocaine, methamphetamine, and MDMA. Introduced as a three-year pilot, it aimed to reframe substance use as a public health issue, reduce stigma, and improve health and social service engagement. Criminal penalties were reintroduced for drug possession in most public spaces in May 2024, and the pilot ended in January 2026. Its termination has been interpreted as policy failure; this review aimed to examine how the pilot was implemented in practice and to identify factors that shaped its operationalization and early implementation-relevant outcomes. METHODS: We conducted a systematic review with narrative synthesis of peer-reviewed literature examining implementation-relevant aspects of BC's decriminalization pilot. Six databases were searched (January-February 2026) for studies published May 31, 2022-February 1, 2026. The protocol was registered in PROSPERO (CRD420251271694). RESULTS: Twenty-seven studies were included. Four cross-cutting implementation barriers were identified: pilot design features, public and cross-sector communication gaps, limited frontline training, and insufficient funding and infrastructure. Design features included the 2.5 g possession threshold, misalignment with real-world drug use patterns; the three-year timeframe, which constrained system-level effects; and the May 2024 amendment, which introduced additional instability. The pilot was implemented without commensurate investment in harm reduction, treatment, or housing infrastructure, within already constrained systems. CONCLUSION: BC's decriminalization pilot suggests the effects of legal reform are shaped by implementation context. Early outcomes may reflect design features, institutional readiness, and system capacity rather than legal change alone; longer-term impacts remain uncertain. Future reforms should align legal change with coordinated implementation, operational guidance, public communication, and adequate service infrastructure.

British Columbia

Relationships between cannabis and cocaine use in a randomized trial of combined buprenorphine and naltrexone for DSM-IV cocaine dependence.

BACKGROUND: Cannabis is the most commonly used drug in the United States, and among people who use cannabis, polysubstance use is common and understudied. We aimed to examine the association of tetrahydrocannabinol (THC) positive urine drug screen (+UDS) with the odds of submitting a cocaine + UDS during cocaine use disorder treatment. METHODS: We conducted a secondary data analysis of a previously reported double-blind, placebo-controlled clinical trial, CTN0048. Participants meeting criteria for opioid abuse/dependence were assigned to receive extended-release naltrexone and one of three conditions of buprenorphine (placebo, 4 mg/day, 16 mg/day) for 8 weeks. Generalized estimating equations (GEE) were used to analyze urine samples (Liu et al., 2018) collected over time, examining the association between THC + UDS and cocaine + UDS during treatment. RESULTS: Participants (n = 301) averaged 46 (SD = 8.64) years of age, were majority male (78.41 %), non-Hispanic (89.70 %), and African American (66.45 %). GEE results indicated that patients who submitted THC + UDS had significantly higher odds of submitting cocaine + UDS compared to participants who submitted THC-negative UDS across the 25 time points examined (OR = 1.47, 95 % CI = 1.21-1.79, p = 0.00). Time (OR = 0.9998, 95 % CI: 0.9997, 0.9999, p = 0.018) and the covariate of sex assigned at birth (OR = 1.77, 95 % CI = 1.13-2.77, p = 0.013) were also significant in the model, indicating very small decreases in the odds of submitting a cocaine + UDS over time for all patients and 77 % higher odds of submitting cocaine + UDS for females. CONCLUSION: THC + UDS was associated with increased odds of submitting a cocaine + UDS during treatment. Further investigation is needed to discern whether decreasing THC use will result in reduced cocaine use; however, these results suggest that it may be beneficial to counsel patients on cannabis use cessation both before and during treatment for cocaine use, as it is related to cocaine use treatment outcomes. TRIAL REGISTRATION: Secondary data analysis of ClinicalTrials.gov, TRN: NCT01402492 ("A randomized study to test the safety and effectiveness of buprenorphine in the presence of naltrexone for the treatment of cocaine dependence"; National Drug Abuse Treatment Clinical Trials Network (CTN) clinical trial: CTN0048), Registration date: 27 July 2011.

Humans

A risk-need-responsivity (RNR)-informed systematic review of needs during the pretrial period.

OBJECTIVE: Pretrial risk assessments are becoming increasingly popular in the United States. Despite the importance of assessing and intervening around "needs" in the risk-need-responsivity model, few pretrial risk assessments include comprehensive assessment of needs. We aim to provide a systematic review of the prevalence of and predictive utility of needs within the pretrial population. HYPOTHESES: There were no hypotheses given the nature of the study. METHOD: We conducted searches for articles in the EBSCO, ProQuest, and Google Scholar databases using key words related to 11 needs domains: antisocial personality, procriminal attitudes, procriminal associates, substance use, family/marital relationships, school/work, prosocial recreational activities, self-esteem, housing, mental health, and physical health. We identified 215 articles that reported on the prevalence of needs or explored their predictive associations with pretrial misconduct outcomes in adult populations. RESULTS: Overall, we find few comprehensive investigations of needs in the pretrial domain, apart from substance use. Variation in methodology and operationalization contributes to wide variability in prevalence estimates. We found only 15 articles that examined predictive associations between pretrial needs and outcomes, which were limited to investigations of behavioral health, employment, and housing needs. Substance use and housing needs emerged as the only consistent predictors of pretrial misconduct. CONCLUSIONS: Researchers should more directly assess the prevalence and predictive utility of needs within the pretrial period to bolster the evidence base for including these factors in pretrial risk assessments. (PsycInfo Database Record (c) 2026 APA, all rights reserved).

Humans

Frequent readmissions after hospitalization for alcohol withdrawal: a systematic review and meta-analysis.

BACKGROUND: Alcohol use disorder and alcohol withdrawal syndrome impose substantial clinical and economic burdens, with repeated hospitalizations being common. We aimed to systematically review readmission rates following inpatient detoxification, assess variation across study designs and hospital settings, and identify key risk and protective factors. METHODS: We performed a literature search in Embase and Pubmed on 10/04/2026 focusing on studies assessing in hospital alcohol detoxification. Exclusion criteria included studies on substance use other than alcohol and outpatient or residential treatment. Main outcome was rehospitalization, and meta-analysis was performed to estimate pooled readmission proportions. Secondary outcomes were risk factors and protective factors influencing the rate of rehospitalization. RESULTS: Twenty-five studies were included. The pooled proportion of readmissions following alcohol detoxification was estimated at 17% (95% CI: 14%-21%; 13 studies, n = 287,896) within 1 month, increasing to 44% (95% CI: 36%-52%; 8 studies, n = 2,877) at 1 year. Substantial between-study heterogeneity was observed. Subgroup analyses found no significant differences by hospital setting or time period. Findings for study aim and study design were mixed and based on limited data A small number of studies suggested associations with housing stability, employment, and treatment engagement. CONCLUSIONS: This meta-analysis suggests that approximately one in six patients are readmitted within 1 month and nearly half within 1 year after inpatient alcohol detoxification. However, readmission rates varied considerably across settings and populations. Future research should evaluate targeted interventions to reduce readmissions among high-risk patient groups.

Humans

Care Navigation for Methamphetamine Use Disorder: A Randomized Clinical Trial.

IMPORTANCE: Stimulant-involved deaths continue to increase in the US, and methamphetamine use remains a weighty public health concern. Treating methamphetamine use disorders is complicated. Contingency management has demonstrated the best effectiveness but is not widely implemented. OBJECTIVE: To examine the effectiveness of dedicated care navigation in linking patients to treatment. DESIGN, SETTING, AND PARTICIPANTS: This prospective randomized clinical trial was conducted at an integrated safety-net health system in Denver, Colorado, between April 10, 2023, and December 31, 2024. Eligible participants were 18 years or older who had a methamphetamine-related encounter in an acute care setting; those with involuntary treatment holds, substance treatment in past 90 days or actively seeking treatment, and inability to provide consent were excluded. Participants completed baseline, 30-day, and 90-day study visits. INTERVENTION: Dedicated care navigation, incorporating contingency management principles, with a focus on addressing health-related social needs. MAIN OUTCOMES AND MEASURES: Linkage to treatment within 30 and 90 days of enrollment defined as a composite measure of at least 1 of the following: electronic health record data indicating a visit at the health system's substance treatment clinic, a behavioral health encounter at an outpatient clinic, temporary residential treatment, or self-reported treatment on the 30- and/or 90-day follow-up survey. RESULTS: Of 192 participants enrolled in the Beginning Early and Assertive Treatment for Methamphetamine Use trial, 156 (81.3%) were male, and the median age was 39 (IQR, 31-47) years. Most participants were unstably housed (163 [84.9%]), not currently employed (158 [82.3%]), and without regular access to a working phone (94 [49.0%]). Of the 96 participants randomized to the intervention, 60 (62.5%) engaged in 2 or more navigation sessions, 45 (46.9%) completed the 30-day study visit, and 47 (49.0%) completed the 90-day study visit compared with 44 (46.3%) and 37 (38.5%), respectively, of the 96 randomized to the control arm. No statistically significant differences in treatment linkage were observed at 30 days (24 participants [25.0%] in both arms; risk ratio, 1.00 [95% CI, 0.61-1.63]) or 90 days post enrollment, (32 [33.3%] in intervention vs 24 [25.0%] in control arms; risk ratio, 1.33 [95% CI, 0.85-2.09]). CONCLUSIONS AND RELEVANCE: In this randomized clinical trial, integrating principles of contingency management into the intervention may have increased engagement with a dedicated care navigator but did not increase likelihood of linkage to treatment for methamphetamine use disorder. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT06033365.

Humans

Relationships Between Risky Substance Use and Irritable Bowel Syndrome (IBS) Severity, Mental Health, and Smoking-Related Processes in Adults with IBS Who Smoke.

Objective: Irritable Bowel Syndrome (IBS) is a debilitating chronic pain condition that presents a major and growing public health burden. Combustible cigarette smoking plays a role in the maintenance of IBS, and the co-occurrence of these conditions warrants greater focus. Moreover, given that smoking co-occurs with other substance use behaviors, the impact of these comorbid behaviors on physical and mental health-related outcomes among individuals with IBS who smoke is warranted. The goal of the present cross-sectional study was to assess relationships of risky alcohol, cannabis, and opioid use with IBS severity, anxiety and depression, and smoking-related processes among adults with IBS who smoke. Methods: In total, 263 adults who met Rome IV criteria for IBS and who smoked combustible cigarettes were included in the study. Hierarchical regression analyses were conducted to examine the influence of risky substance uses on IBS symptom severity, IBS-related quality of life, anxiety, depression, perceived barriers for smoking cessation, and cigarette dependence. Results: Results indicated that opioid use was statistically related to all criterion variables, whereas alcohol use was specifically associated with depression and anxiety. Cannabis use showed a statistically significant association only with anxiety symptoms. Conclusions: The present investigation is among the first to explore the role of risky substance use in terms of a wide array of IBS, mental health, and smoking processes among adults with IBS who smoke. The findings suggest that substance use should be a focal point of screening and intervention for the IBS population to optimize outcomes beyond the reach of medical therapies.

Irritable bowel syndrome

Determination of 13 per- and polyfluoroalkyl substances in human plasma samples using LC-MS/MS: application to capillary microsamples.

Per- and polyfluoroalkyl substances (PFAS) are chemicals widely applied in industrial processes and highly persistent in the environment, whose extensive use has been linked to adverse health effects. Venous plasma is the conventional matrix for PFAS assessment in blood, and LC-MS/MS is the most used quantification technique. Despite the relevance of this topic, biomonitoring data on human exposure to PFAS in Brazil remain limited. This study validated an LC-MS/MS method for determination of 13 PFAS in human plasma. Blood samples were collected from volunteers by phlebotomy, followed by protein precipitation with acetonitrile containing 1% formic acid (v/v) and solid-phase extraction. Chromatographic separation was achieved on an Acquity UPLC HSS T3 column. The assay was linear over a calibration range of 0.2-20 ng/mL. Intra- and inter-assay precision (CV%) were within the ranges of 2.06-12.0% and 0.25-10.7%, respectively. As for accuracy, results were 89.0-112.9%. Matrix effect ranged from -1.31 to 0.05%. Stability after four freeze/thaw cycles and under autosampler conditions were also confirmed for all analytes. The method was applied to 40 paired venous and capillary plasma samples. Both measures exhibited high correlation (r = 0.926). PFOS was the only compound detected at concentrations ≥0.2 ng/mL (LLOQ) in all samples, with capillary plasma concentrations of 0.85-13.50 ng/mL. In summary, the method showed good validation performance and demonstrated the suitability of capillary plasma samples as an alternative matrix for PFAS quantification.

Humans

Yoga MAT: A factorial randomized study using the Multiphase Optimization Strategy to develop a multicomponent yoga intervention for people with chronic pain taking medications for opioid use disorder.

BACKGROUND: People taking medications for opioid use disorder (MOUD) commonly experience chronic pain. Yoga interventions show promise for decreasing pain-related disability in other populations. More time spent in yoga practice may improve pain-related outcomes. METHODS: The Multiphase Optimization Strategy (MOST) provided the framework for developing an optimized yoga intervention package. In a 2x2x2x2 factorial experiment, we evaluated four candidate intervention components which, when added to a weekly yoga class, might increase yoga engagement. The primary outcome was minutes per week of yoga practice (classes and other yoga practice) over the 12-week intervention period. We sought to determine which combination of intervention components was associated with the most yoga practice for people with chronic pain taking buprenorphine or methadone as MOUD. RESULTS: We enrolled 192 adults. There was a significant main effect for Component "B" (having two private sessions with a yoga teachers; IRR = 1.10, 90%CI 1.02; 1.18), and a synergistic interaction between Components "B" and "D" (D was financial incentives for attending class; IRR = 1.11, 90%CI 1.02; 1.19). This combination of these two components (without other potential components) was associated with the second highest model-predicted mean minutes of yoga per week (157.1min; 90% CI = 120.1-194.0) which was only 4min less than the combination including all four components. CONCLUSIONS: We identified a combination of intervention components as the optimized intervention. A next step will be to test the effect of this optimized intervention on pain and substance use outcomes in a randomized controlled clinical trial.

Humans

Blinding integrity in psychedelic research: Evidence from a comparative randomized controlled trial of psilocybin, MDMA, and methylphenidate in healthy volunteers.

Maintaining effective blinding is a major methodological challenge in psychedelic research. This study provides a comprehensive evaluation of blinding integrity in 120 healthy volunteers who received either psilocybin, MDMA, or methylphenidate (active placebo) in a double-blind, randomized controlled trial. Using a multi-level assessment incorporating forced-choice substance guesses, certainty ratings, decision factors, and subjective substance effects, the analyses characterize blinding integrity and its relation to the substance experience. Results indicate that overall blinding was insufficient, with psilocybin showing the highest rates of functional unblinding, MDMA moderate levels, and methylphenidate the lowest. As an active placebo, methylphenidate provided more effective blinding for MDMA than for psilocybin. Incorporating certainty levels of substance guesses revealed a more differentiated pattern, with lower functional unblinding rates. Decision factors and subjective substance experiences were associated with phenomenological substance effects. Prior substance experiences did not influence accuracy of forced-choice substance guesses. These findings provide empirical guidance for the design and reporting of blinding procedures in psychedelic trials and underscore the value of systematic, multi-level assessment of blinding integrity.

Humans

Psychedelic-induced hypomania and mania: a systematic review and meta-analysis.

Serotonergic psychedelics are increasingly investigated as treatments for affective disorders. Concerns persist regarding their potential to induce hypomania or mania, particularly in individuals with bipolar spectrum vulnerability. Whether these substances precipitate transient mood switches or contribute to persistent bipolar illness or diagnostic transition remains unclear. We conducted a systematic review of human studies examining manic or hypomanic symptoms following exposure to serotonergic psychedelics (psilocybin, LSD, mescaline, DMT/ayahuasca) or MDMA (CRD420251160656). Databases and trial registries were searched through January 26, 2026. Eligible designs included randomized and non-randomized clinical studies, registry-based cohorts, cross-sectional surveys, and longitudinal observational studies. Outcomes included dysphoria/euphoria, manic or hypomanic symptoms and transition to bipolar disorder. Risk of bias was assessed using ROBINS-I, ROB2 or NIH tools. Twenty-three studies met inclusion criteria, four contributing to meta-analysis. Rates of psychedelic-associated dysphoria/euphoria, hypomania or mania ranged from 5.8% in controlled trials of psilocybin-assisted psychotherapy for major depressive disorders to 30% in naturalistic studies of individuals with bipolar disorder. When present, manic symptoms were typically acute and self-limited. Observational studies identified higher risks among individuals with bipolar I disorder, familial vulnerability, polysubstance use, and unsupervised or illegal use. Registry-based cohorts examining diagnostic transitions showed a prevalence of subsequent transition to bipolar disorder of 4% (95% CI 2-8%; N = 7478; I² = 32.1%), with little evidence for a hallucinogen-specific signal. Overall, serotonergic psychedelics appear to pose a low but clinically meaningful relative risk of transient mood-related symptoms in susceptible individuals while remaining relatively safe in controlled clinical settings. Long-term outcomes and repeated exposure remain insufficiently studied, underscoring the need for rigorous longitudinal research.

Humans

Contact tracing for hepatitis C: perspectives of people with experience of substance use and hepatitis C on intervention acceptability.

INTRODUCTION: Chronic hepatitis C (HCV) is a major cause of cirrhosis and hepatocellular carcinoma. In the UK, the principal risk factor for HCV is injecting drug use. The introduction of direct acting anti-virals (DAA's) have transformed HCV care, with cure rates of over 95%. However, HCV is often asymptomatic, and reinfection is a concern. Modelling and real-life studies demonstrate the potential effectiveness of a contact tracing approach for finding people who have acquired HCV through injecting drug use. However, it is not used routinely in the UK. This qualitative study was undertaken to assess the acceptability of a contact tracing approach to identify people who have injected drugs with an index patient recently diagnosed with HCV. METHODS: Twelve people with lived or living experience of injecting drug use and an HCV diagnosis were interviewed using semi-structured interview topic guides. Participants were purposefully selected according to the inclusion criteria and to ensure there was an even spread of male and female participants. Sekhon's Theoretical Framework of Acceptability, incorporating seven components (affective attitude, burden, ethicality, intervention coherence, opportunity cost, perceived effectiveness, and self-efficacy) was used to analyse data from interview transcripts. RESULTS: A sample of 12 people who inject drugs in the UK indicated that a contact tracing approach was acceptable across two components of Sekhon's acceptability framework: affective attitude and ethicality. Participants broadly found the idea of tracing people who may be at risk of contracting HCV acceptable, and the approach aligned with their value systems. A contact tracing approach would help alleviate concerns about putting other people's lives at risk through HCV transmission and was seen as a 'sensible' way of finding people at risk. However, there were caveats to this acceptability. Contact tracing approaches delivered by mainstream health, or governmental organisations increased burden, opportunity costs and perceived effectiveness of a contact tracing approach for HCV, particularly within contexts of exclusion and criminalisation of people who inject drugs. Burden and opportunity costs were also affected by individual experiences and risks of violence, sexual violence and abuse. There was a lack of knowledge of contact tracing approaches amongst respondents, leading to a lack of intervention coherence and misunderstandings of what contact tracing was and how it would work. Trusted relationships with NGOs and HCV specialist nurses reduced burden and increased confidence and ability (self-efficacy) to engage with a contact tracing approach. CONCLUSION: People who inject drugs broadly perceive contact tracing as an acceptable method of finding people who are at risk of HCV. However, this acceptability is based on specific modes of delivery through trusted organisations. Findings further highlight the importance of naming and describing contact tracing approaches appropriately, as well as assessing and mitigating against potential risk to index patients, to increase self-efficacy and capacity to engage. Considering these findings, the potential for expanding existing contact tracing approaches should be explored to ensure the UK reaches and maintains its elimination targets.

Humans

Public health, public protest: The role of health burdens and healthcare access in protest mobilisation.

Health and politics are intertwined, yet few studies have examined the association between health and protest. This study examined whether population health burdens were associated with protest incidence and whether healthcare access modified these associations. Analysis was based on an unbalanced 2004-2023 country-year panel, combining protest counts from ACLED with rates for 22 GBD causes. Mixed-effects negative-binomial models estimated incidence-rate ratios (IRRs) with interactions for healthcare access (±1 SD). Two-way fixed-effects Poisson models were estimated as a benchmark to distinguish cross-national associations from within-country dynamics. Health burdens were systematically, but heterogeneously, associated with protest. Rates for several non-communicable burdens were associated with protest, notably musculoskeletal disorders (IRR 1.72, 95% CI 1.37-2.15), neoplasms (1.24, 1.06-1.44), substance-use disorders (1.32, 1.12-1.56) and HIV/AIDS and other STIs (1.24, 1.12-1.38). Higher healthcare access generally attenuated health-protest associations. Fixed-effects models confirmed several associations (e.g. HIV/AIDS, neoplasms) but revealed that others (e.g. maternal/neonatal disorders, enteric infections) were driven primarily by cross-national differences. Population health burdens were associated with cross-national variation in protest mobilisation. Chronic, non-communicable burdens were associated with heightened protest, whereas poverty-linked and early-life burdens were associated with lower mobilisation. Healthcare access was associated with attenuation of these relationships.

Humans

Stable chloroform emissions in southeastern China: insights from recent observations.

Chloroform (CHCl3) is a short-lived ozone-depleting substance not currently regulated under the Montreal Protocol. Due to the unique meteorological conditions in East Asia, CHCl3 emitted in this region has a greater potential to reach the stratosphere and contribute to ozone depletion. As an essential component of national CHCl3 emissions, southeastern China has attracted increasing attention. However, long-term observational data in this region remain relatively scarce, with no updates since 2020. In this study, we continuously measured atmospheric CHCl3 concentrations at a remote monitoring station in southeastern China from 1 June 2023 to 31 May 2025. Frequent concentration enhancements were observed during the monitoring period, with mixing ratios ranging from 9.3 to 134.1 ppt and an average value of 36.8 ± 19.7 ppt. Back-trajectory analysis indicated that air masses associated with elevated CHCl3 levels primarily originated from coastal industrial provinces in eastern China. Using the Potential Source Contribution Function and Concentration Weighted Trajectory methods, we identified the Yangtze River Delta (Jiangsu, Anhui, and Zhejiang Provinces) and Jiangxi Province as dominant source regions. Emissions of CHCl3 in southeastern China were estimated using the Tracer Ratio Method to be approximately 30.1 ± 5.3 Gg/yr from 2023-06-01 to 2025-05-31, indicating overall stability relative to earlier estimates and no apparent upward trend. These findings provide updated insights into the current status of CHCl3 emissions in southeastern China and highlight the need for continued monitoring and emission assessment of CHCl3 in East Asia, given its unregulated status and implications for ozone layer recovery.

Air Pollutants

How the Social Context and Peer Helping Contribute to Better Alcohol Outcomes Among Sober Living House Residents: Mediation Analyses.

BACKGROUND: Sober Living Houses (SLHs) adopt a social model approach, which emphasizes peer helping. Although SLHs appear to be effective, little is known regarding why. This longitudinal study examined whether higher SLH social model adherence produces better resident outcomes by increasing resident helping. METHODS: Baselines were conducted with 205 residents entering 28 SLHs, with follow-ups through 6 months. Measures included 1-month perceived SLH social model adherence; 2-month help given to and received from SLH residents; and 6-month alcohol use and severity. Analyses were lagged, multivariate mediation models accounting for clustering within SLH. Separate models examined help given and received for each outcome, yielding four model tests. RESULTS: The hypothesized model was unsupported, with all four tests showing nonsignificant indirect effects. However, exploratory post-hoc tests showed significant indirect effects between higher 1-month resident helping and better 6-month alcohol outcomes via higher 1-month SLH social model adherence. Effects held across three of four model tests. CONCLUSIONS: Results suggest that residences adhering to social model principles do not achieve better outcomes by stimulating helping, but rather that more resident helping may foster a supportive SLH social environment, which itself drives better outcomes. Thus, residences might emphasize both resident helping and social model principles.

Sober living

Interface-dependent V. parahaemolyticus biofilm under varying temperatures, media, and oxygen conditions: implications for seafood safety.

Vibrio parahaemolyticus biofilms play a critical role in pathogen persistence in marine and seafood-processing environments, where oxygen availability, temperature, and surface interfaces vary widely. This study investigated biofilm development by three strains on partially submerged stainless-steel coupons under gas-liquid-wall (GLW) and fully submerged (SM) interfaces. Viable cell counts (log&#x2081;&#x2080;CFU/cm2) along with normalized protein concentration per viable cell (nProt) and normalized polysaccharide concentration per viable cell (nPol) were measured, under aerobic and anaerobic conditions across a temperature range of 15-30&#xa0;&#xb0;C, using tryptic soy broth with 3% NaCl (TSB) and seawater-based medium (SW). GLW biofilms consistently exhibited higher cell counts (6.4-7.3 log&#x2081;&#x2080;CFU/cm2) compared to SM biofilms (5.9-6.3 log&#x2081;&#x2080;CFU/cm2), suggesting that enhanced oxygen diffusion promotes bacterial proliferation. Conversely, SM biofilms exhibited significantly higher nProt and nPol levels (p&#xa0;<&#xa0;0.001), indicating increased production of the extracellular polymeric substance (EPS) matrix under low-oxygen, high-nutrient conditions. Microscopy and three-dimensional surface plot analyses revealed relatively uniform biofilm layers at the GLW interface, whereas SM biofilms formed heterogeneous, tower-like structures. EPS production was further influenced by medium composition, oxygen, and temperature. SM biofilms grown in SW exhibited significantly higher nProt and nPol than those in TSB under aerobic conditions (p&#xa0;<&#xa0;0.001), indicating enhanced matrix stabilization. Under anaerobic conditions at 15&#xa0;&#xb0;C, nProt and nPol were higher, whereas under aerobic conditions, peak nProt and nPol occurred at elevated temperatures. These findings highlight a trade-off between bacterial growth and matrix production and provide insight into biofilm adaptation and persistence in seafood-processing environments. These insights may help develop improved biofilm control and seafood safety management.

Biofilms

"Everybody thinks that it won't happen to them": A mixed-methods study of HIV prevention strategies among people experiencing homelessness who use drugs.

BACKGROUND: HIV disproportionately affects people experiencing homelessness, particularly those who use drugs. Although effective prevention strategies exist, uptake remains suboptimal in high-risk populations. Limited research has examined how this population engages with HIV prevention strategies and the contextual factors shaping behaviors. METHODS: We conducted a mixed-methods study of adults (&#x2265;18 years) experiencing homelessness with recent drug use, recruited from three Boston sites (Feb 2024-Jan 2025). Participants completed a survey assessing HIV prevention strategy uptake. A subsample completed in-depth interviews on factors influencing behavior. Guided by the Theoretical Domains Framework, we coded qualitative data and identified themes to help contextualize uptake. RESULTS: Among 196 participants, mean age was 48; 61% identified as male and 44% as non-Hispanic White. Forty-two percent reported condomless sex, and among those who had ever injected drugs (n = 123), 24% reported syringe sharing in the prior three months. Only 9% reported current PrEP use, and 12% had ever used HIV self-tests. Qualitative findings highlighted perceived control as a key facilitator, while low perceived HIV risk hindered uptake across strategies. Additional barriers varied by strategy and included partner dynamics and substance use affecting condom use, structural constraints affecting syringe use, and knowledge, stigma, and cost concerns affecting PrEP and self-testing. CONCLUSION: In this cohort of people experiencing homelessness who use drugs, HIV prevention strategy uptake was suboptimal, with particularly low PrEP and HIV self-testing use. Qualitative findings suggest that interventions to promote HIV prevention strategy uptake in this population should leverage perceived control, address perceived risk, and target strategy-specific interpersonal and structural barriers.

Humans

Optimizing eco-engineering pedogenesis of bauxite residues: Synergistic effects of humus and FeSO4/sulfur on microbial community and function.

Eco-engineered pedogenesis represents a promising approach for soil amelioration of bauxite residues (BRs) through exogenous organic matter. However, the role of humus in mediating this process remains poorly understood, significantly impeding the eco-engineering rehabilitation of BRs. In this study, we conducted pot experiments and subsequent microbial analysis to evaluate the individual improvement of humic acid (HA), fulvic acid (FA), and corn straw (SWZ) on the BRs' pedogenesis. High-throughput sequencing analysis revealed that both FA and SWZ were more effective than HA in steering microbial community assembly, as community diversity, dominant taxa enrichment, and species' interaction were all significantly higher (p < 0.05) in the FA/SWZ treatments than in HA treatments. Notably, the combination of FA with FeSO4 specifically enriched halophilic taxa, while FA coupled with sulfur (S) significantly improved the connectivity and complexity of the microbial network, as the average connection degree increasing from 1.008 to 1.113. Hydrolytic enzyme activity assays further indicated that FA, especially when combined with S, was the most effective treatment in restoring microbial function during BR pedogenesis. These findings highlight FA as a critical driver of microbial restructuring and functional recovery in BRs. Moreover, its efficacy can be enhanced by co-amendment with FeSO4 or S. This study provides important theoretical and practical insights for optimizing organic-inorganic amendment strategies to accelerate the eco-engineering pedogenesis of bauxite residues.

Humic Substances

New insights into soil amendment: Impact of humic acid on typical antibiotic resistance in agricultural soil.

Humic acid (HA) addition can improve agricultural soil, but little is known about how it affects the soil resistome. In this study, we used selective agar plate combined with quantitative PCR (qPCR) and 16S rRNA gene sequencing to investigate how HA influences antibiotic resistant bacteria (ARB) and antibiotic resistant genes (ARGs) in soil contaminated with erythromycin and kanamycin. 0.1 % HA reduced the abundance of culturable erythromycin-resistant bacteria (ERB), while promoting the growth of kanamycin-resistant bacteria (KRB). Lysinibacillus and Paenibacillus were the dominant genera in ERB and KRB, respectively, governing the changes in their abundances. At this concentration, the Lysinibacillus abundance in ERB decreased from 96.74 % to 70.57 %. Meanwhile, that of Paenibacillus in KRB increased from 33.40 % to 77.44 %. The copy number of ermF decreased after HA addition, while that of ermB increased. Furthermore, 0.1 % HA significantly reduced the copy number and relative abundance of aadA1 and aac(6')-Ib (aka aacA4)-03 in the soil. Changes in these two types of ARB and ARGs were primarily driven by shifts in the microbial community structure. Soil physicochemical properties, particularly increased organic matter (OM), altered the absolute abundance of ermB. Meanwhile, changes in intI1 abundance determined the risk associated with aadA1 and aac(6')-Ib (aka aacA4)-03. These findings emphasize the dual role of HA in the dissemination of antibiotic resistance in agricultural soils and highlight the necessity of considering dose-dependent effects when applying HA as a soil amendment.

Soil Microbiology