Markus Schauer

Hotels contain diverse functional environments, yet longitudinal evidence on viable bacterial contamination and its response to COVID-associated hygiene changes remains limited. This retrospective serial cross-sectional study analyzed 544 environmental samples from five audits of a German hotel conducted in 2016, 2018, 2019, 2022, and 2023. Pre-pandemic audits (2016, 2018–2019) were compared with 2022–2023 audits across four functional environments: guest rooms, child-oriented areas, wellness/water facilities, and food-service operations. Outcomes included culture positivity, contamination severity, polymicrobial and priority-microorganism detection, persistent hotspots, and organism distributions. Modified Poisson models adjusted for functional environment and used cluster-robust inference. All statistical analyses were performed in R (version 4.5.1). High contamination declined from 54.2% pre-COVID to 19.3% in 2022–2023 (aPR, 0.36; 95% CI, 0.25–0.54; p < 0.001), an adjusted reduction of 34.1 percentage points (95% CI, 21.5–46.6). Culture positivity remained unchanged (63.4% vs. 60.1%; aPR, 0.96; 95% CI, 0.83–1.12; p = 0.634), whereas polymicrobial contamination decreased (aPR, 0.61; 95% CI, 0.39–0.96; p = 0.032; adjusted reduction, 8.3 percentage points; 95% CI, 1.0–15.7). Priority-microorganism detection was unchanged (aPR, 1.06; 95% CI, 0.67–1.67; p = 0.804), despite a shift toward S. aureus and P. aeruginosa. Culture positivity remained approximately 90% in child-oriented and food-service areas. Eight of 15 recurring surface categories remained persistent hotspots, including wet-room floors, frequently touched controls, paddling-pool features, and food-service machinery. The Bacillus cereus group decreased from 12.6% to 2.5%, whereas Staphylococcus aureus and Pseudomonas aeruginosa were each detected in 0% versus 5.8% of samples (q < 0.001). Audits in 2022–2023 showed lower contamination intensity without corresponding reductions in overall culture positivity or priority-microorganism prevalence. Complementary burden-, complexity-, and organism-based indicators are needed for environmental-hygiene evaluation.

Fitness centers represent high-contact environments where microorganisms can accumulate and persist on shared surfaces. This study aimed to investigate bacterial contamination dynamics on gym equipment and evaluate the effects of hydrogen peroxide (H₂O₂) nebulization combined with preceding professional manual cleaning on the recovery of viable surface-associated microorganisms. A two-phase investigation was conducted in a commercial fitness facility. Repeated environmental sampling was performed on 12 gym devices over five consecutive days at three daily timepoints (morning, midday, evening), followed by a pre–post assessment of the combined terminal decontamination procedure. All isolates were recovered using culture-based methods and identified by MALDI TOF MS. Species were classified by ecological origin, and persistence, diversity, and intervention effects were quantified using ecological metrics. Statistical analyses were performed in R. Across all samples, 248 isolates representing 61 species were detected, with the recovered isolates predominantly belonging to skin-associated families including Micrococcaceae (25.4%), Staphylococcaceae (24.2%), and Moraxellaceae (22.2%). Routine cleaning with an alcohol-based cleaner produced only modest reductions in recovered bacterial isolate counts (p = 0.173), with 68% of environmental species no longer recovered after routine cleaning, whereas 93% of skin-associated species remained detectable following routine cleaning. In contrast, the terminal decontamination procedure consisting of professional manual cleaning followed by H₂O₂ nebulization resulted in 88% of detected species no longer being recovered after treatment, with no Gram-negative species recovered in post-treatment cultures, while only three Gram-positive species (Staphylococcus epidermidis, Staphylococcus hominis, and Dietzia cinnamea) continued to be recovered after treatment. Contamination levels and persistence patterns varied markedly across devices. Gym equipment surfaces repeatedly yielded predominantly human-derived communities of recoverable viable bacteria despite routine cleaning. The combined terminal decontamination procedure produced greater reductions in recoverable bacterial species than routine overnight cleaning under the conditions evaluated, supporting further investigation of this combined intervention as a supplemental terminal decontamination strategy for high-traffic fitness environments.

Microbial contamination in hospitality settings remains understudied despite the high density of human contact and diverse operational activities that characterize hotel environments. This study aimed to characterize microbial contamination patterns and environmental hygiene risks across multiple functional areas of family-oriented hotels. A cross-sectional environmental microbiological investigation was conducted in family hotels in Bavaria, Germany. A total of 225 environmental surface samples were collected from guest rooms, child areas, food-related areas, service environments, and water-exposed locations. Bacterial isolates were identified using culture-based microbiology and MALDI-TOF mass spectrometry. Microbial prevalence, contamination severity, microbial richness, and pathogen prevalence were assessed using mixed-effects ordinal logistic regression, generalized additive model (GAM), and integrated hygiene profile, all performed in R (version 4.5.1). Microbial occurrence patterns differed markedly across functional areas. Contamination category distributions differed significantly among areas, with food-related environments showing the strongest enrichment in the highest contamination category (72.7%). Food-related areas showed significantly greater odds of severe contamination than guest rooms (OR = 8.37, 95% CI: 1.89–37.00), child areas (OR = 6.16, 95% CI: 1.20–31.46), and water-exposed environments (OR = 12.34, 95% CI: 2.45–62.10). Microbial richness differed across operational zones (p = 0.048) and was positively associated with contamination severity (β = 0.141, p < 0.001). GAM revealed a significant non-linear richness–contamination relationship (p < 0.001). Integrated hygiene profile consistently identified food-related and service areas as the highest risk environments. Environmental hygiene risks in hospitality settings display functional-area heterogeneity, highlighting the need for targeted, area-specific hygiene management strategies.

Background: Public fitness facilities are high-contact environments that facilitate microbial transfer via shared surfaces; however, temporal dynamics and device-specific contamination patterns remain insufficiently characterized. Methods: A repeated-measures observational study was conducted in a fitness facility over five consecutive weekdays (Monday to Friday). A total of 180 surface samples were collected from 12 gym devices, each sampled three times daily (morning, noon, and evening). Surface-associated cultivable bacteria were recovered using culture-based methods followed by MALDI-TOF MS identification. Ecological metrics, including species richness and Shannon diversity, were calculated, and taxa were classified by origin (skin-associated versus environmental). Device-specific contamination profiles were developed using a composite index incorporating pathogen presence, contamination frequency, and persistence. Temporal trends and predictors of contamination were analyzed using mixed-effects regression models. All statistical analyses were performed in R. Results: A total of 248 bacterial isolates were identified, representing 61 species across 32 families, with a predominance of skin-associated taxa (72.2%). Sampling time point was a strong independent predictor of contamination (adjusted OR for noon vs. morning: 7.19; p < 0.001). While overall microbial diversity remained stable across devices (Shannon index, p = 0.44), substantial heterogeneity was observed in pathogen prevalence, multispecies burden, and persistence. The functional trainer and leg extension showed the highest composite risk scores (42.3%), while the ab crunch machine and upper body ergometer demonstrated significantly increasing contamination trends over the sampling period (p < 0.05). Co-occurrence analysis showed nonrandom microbial associations, with the strongest positive links between Micrococcus luteus and Staphylococcus saprophyticus (Φ = 0.76) and Staphylococcus aureus (Φ = 0.61). Conclusions: Gym equipment surfaces harbor predominantly human-associated microbial communities exhibiting dynamic temporal contamination patterns, and on selected devices, increasing the baseline contamination across consecutive cleaning cycles. The findings indicate that contamination patterns on shared fitness equipment are dominated by taxa commonly associated with human skin and support targeted hygiene interventions focused on frequently contacted devices and periods of elevated contamination.

Despite its clinical importance, Staphylococcus aureus colonization in community populations remains insufficiently understood. This study aimed to determine the prevalence, anatomical distribution (nasal versus throat), and antimicrobial resistance patterns of Staphylococcus aureus colonization in healthy community-dwelling adults and to identify demographic and clinical factors associated with carriage. A cross-sectional study was conducted among 100 community-dwelling adults in Germany, yielding 200 nasal/throat samples. Staphylococcal isolates were identified using MALDI-TOF MS, and antimicrobial susceptibility was determined according to EUCAST guidelines. MRSA and PVL genes were assessed using molecular assays, and genetic relatedness was evaluated by rep-PCR. Associations with demographic and clinical variables were analyzed using multivariable logistic regression in R. Staphylococcus aureus carriage prevalence was 39%, higher in the nose (33%) than the throat (19%), with rare MRSA (3%) and no PVL detection. Significant nasal–throat discordance was observed (p < 0.01), with a fair agreement between sites (κ = 0.34). Resistance patterns among Staphylococcus aureus isolates were dominated by penicillin G resistance (47%), while 35% remained fully susceptible, and multidrug resistance was rare (6%). Multivariable analyses indicated no strong associations between overall, nasal, or throat carriage and age, sex, recent antibiotic use, or other clinical exposures (p > 0.05), with wide confidence intervals, potentially reflecting limited statistical power and only modest model discrimination (AUC 0.65–0.68). These findings indicate that community Staphylococcus aureus colonization is potentially marked by modest prevalence, substantial anatomical discordance, and a low-risk resistance profile, while common demographic and clinical factors contributed little to explaining carriage patterns.

Micronutrient status is strongly influenced by dietary patterns; however, the extent to which plant-forward dietary patterns versus omnivorous diets shape micronutrient profiles and their associations with blood pressure, body composition, and cardiovascular health remains unclear. This cross-sectional study aimed to comprehensively assess associations between blood micronutrient profiles, blood pressure, and body composition in adults, with analyses stratified by dietary patterns to compare omnivorous and plant-forward dieters. Secondary cross-sectional analyses were conducted using data from an exploratory study of 488 Austrian adults (median age: 38 y [IQR 21]; 48% female, 52% male). Participants were classified as omnivores (n = 260) or plant-forward dieters (including 194 flexitarians, 25 vegetarians, and 9 vegans; n = 228). Blood pressure and anthropometric measurements were obtained alongside fasting venous blood sample analysis to quantify a comprehensive panel of micronutrient, hematological, lipid, and inflammatory biomarkers. Micronutrient concentrations were standardized (scaled −1 to +1, truncated ±3) and evaluated for deficiency or excess according to sex-specific reference ranges. Linear regression was used to analyze the association of micronutrients with BMI, including age and sex as covariates. Vitamin D showed the highest micronutrient deficiency, observed in 96% of omnivores and 93% of plant-forward dieters. Across both dietary subgroups, multiple micronutrients, together with age and sex, were significant correlates of body weight, body mass index, and blood pressure (p < 0.05). Significant differences between omnivores and plant-forward dieters were observed for blood pressure, lipid, hematological, and inflammatory markers, with participants adhering to plant-forward dietary habits exhibiting lower blood pressure and more favorable lipid profiles (p < 0.05). The findings highlight the potential of diet-type-specific strategies for personalized cardiometabolic risk management.

With billions of users worldwide, social media has become a powerful force in shaping lifestyle behaviors, including physical activity (PA), particularly among young adults. This narrative review examined the growing role of social media–driven interventions in promoting PA among young adults at risk of obesity. We analyzed the application of behavior change theories, including Social Cognitive Theory, the Theory of Planned Behavior, the COM-B, and specific behavior change techniques, alongside the role of intersectionality in shaping intervention effectiveness. Platform-specific strategies across Instagram, TikTok, YouTube, and Facebook were summarized, highlighting engagement mechanisms, personalized content delivery, and behavior change approaches that influence behavioral, physiological, and motivational outcomes. Despite these opportunities, challenges such as ethical concerns, misinformation, accessibility barriers, and quality control issues remained significant. Finally, future directions were outlined, including integration with wearables, AI-driven multi-platform strategies, co-designed interventions, and policy frameworks to optimize digital health promotion. In conclusion, social media offers considerable potential as a cost-effective, accessible tool for promoting PA and preventing obesity in young adults, though effectiveness is limited by misinformation, unregulated content, and poor quality control.

Genetic polymorphisms contribute to inter-individual variation in liver detoxification, influencing susceptibility to exposures and responses to interventions. While urinary biomarkers reflect Phase II activity, the impact of genotype on supplementation response remains unclear. In a pilot, prospective, open-label cohort study, 30 Austrian adults completed an 8-week multi-ingredient liver support supplementation regimen (e.g., glutathione, N-acetylcysteine, α-lipoic acid). First-morning urine was collected at baseline and follow-up for measurement of D-glucaric acid, mercapturic acids, and creatinine. Dried blood spots were genotyped for polymorphisms in detoxification genes (CYP1A1, GSTM1, GSTP1, GSTT1, and NQO1), and participants were stratified into normal (NDC) or limited (LDC) detoxification capacity groups. Adherence was monitored through logs, mid-study interviews, and product counts. The intervention led to modest reductions in body weight (−0.87 kg, p < 0.05) and BMI (−0.31 kg/m², p < 0.05), and significant increases in urinary D-glucaric acid (p < 0.05) and mercapturic acids (p < 0.01), with consistent responses across detoxification genotype groups (p > 0.05). The pattern of biomarker responses based on clinically defined categories did not differ significantly between the study groups (adjusted odds ratio = 2.88, p > 0.05). The observed increases in urinary biomarkers and reductions in weight and BMI are consistent with potential modulation of detoxification pathways following liver support supplementation, independent of genetic polymorphisms influencing detoxification capacity.