Does repeated exposure to hydrogen peroxide induce Candida auris resistance?

BACKGROUND: To minimize environmental colonization by microorganisms that may persist and thrive in healthcare settings, thus reducing healthcare-associated infections (HAIs), new insights over already known biocides are certainly of relevance. Although the efficacy of hydrogen peroxide (H2O2) against the emergent yeast Candida auris is moderately documented, concerns over the potential induction of resistance after repeated exposure do persist. The main objective of the present study was to evaluate the hypothetical induction of Candida auris resistance following 30 days of consecutive exposure to lethal and sublethal concentrations of H2O2. Furthermore, the authors aimed to elucidate about the rank of efficacy of H2O2 against C. auris comparing to other Candida species and whether different strains of C. auris may display different susceptibilities to H2O2. METHODS: During the induction of resistance assays, both type strains and clinical isolates of Candida auris, Candida albicans and Candida parapsilosis were exposed repeatedly to defined concentrations of H2O2, for 30 days. RESULTS: After that period, no significant differences were found when comparing the minimal inhibitory concentration values of H2O2 in case of the induced strains versus each respective positive control. Moreover, H2O2 displayed similar effectiveness against all the tested Candida species and no differences were demonstrated among the distinct strains of C. auris. CONCLUSIONS: The adoption of H2O2 solutions in routine protocols in order to promote disinfection standards against Candida auris, improving patient safety and reducing healthcare costs, is certainly welcomed.

Impact of Human Papillomavirus Vaccination on Male Disease: A Systematic Review.

Human papillomavirus (HPV)-related diseases are highly prevalent in men worldwide, comprising external anogenital condyloma, anal intraepithelial neoplasia (AIN), penile intraepithelial neoplasia (PIN), and anogenital and oropharyngeal cancers. There is exceptionally low vaccine coverage in the male population. Only 4% of men were fully vaccinated, worldwide, as of 2019. The aim of this review is to assess the impact of HPV vaccination on male disease. Three databases (MEDLINE, Web of Science, Scopus) and Clinical Trials.gov were searched. We included thirteen studies, eight randomized controlled trials (RCTs), and five cohorts, comprising a total of 14,239 participants. Regarding anal disease, seven studies reported HPV vaccine efficacy ranging from 91.1% to 93.1% against AIN1, and ranging from 89.6% to 91.7% against AIN2|3 and anal cancer. Five studies showed an efficacy against genital condyloma of 89.9% in HPV-naïve males, varying between 66.7% and 67.2% in intention-to-treat populations. Studies reporting no efficacy have included older participants. These results support vaccination of young men previously infected, beyond HPV-naïve males. The evidence quality was moderate to low for most outcomes, namely genital diseases. RCTs are needed to assess the efficacy of HPV vaccination on male oropharyngeal cancer.

Microbiota of Urine, Glans and Prostate Biopsies in Patients with Prostate Cancer Reveals a Dysbiosis in the Genitourinary System.

Prostate cancer (PCa) is the most common malignant neoplasm with the highest worldwide incidence in men aged 50 years and older. Emerging evidence suggests that the microbial dysbiosis may promote chronic inflammation linked to the development of PCa. Therefore, this study aims to compare the microbiota composition and diversity in urine, glans swabs, and prostate biopsies between men with PCa and non-PCa men. Microbial communities profiling was assessed through 16S rRNA sequencing. The results indicated that α-diversity (number and abundance of genera) was lower in prostate and glans, and higher in urine from patients with PCa, compared to non-PCa patients. The different genera of the bacterial community found in urine was significantly different in PCa patients compared to non-PCa patients, but they did not differ in glans and prostate. Moreover, comparing the bacterial communities present in the three different samples, urine and glans show a similar genus composition. Linear discriminant analysis (LDA) effect size (LEfSe) analysis revealed significantly higher levels of the genera Streptococcus, Prevotella, Peptoniphilus, Negativicoccus, Actinomyces, Propionimicrobium, and Facklamia in urine of PCa patients, whereas Methylobacterium/Methylorubrum, Faecalibacterium, and Blautia were more abundant in the non-PCa patients. In glans, the genus Stenotrophomonas was enriched in PCa subjects, while Peptococcus was more abundant in non-PCa subjects. In prostate, Alishewanella, Paracoccus, Klebsiella, and Rothia were the overrepresented genera in the PCa group, while Actinomyces, Parabacteroides, Muribaculaceae sp., and Prevotella were overrepresented in the non-PCa group. These findings provide a strong background for the development of potential biomarkers with clinical interest.

Microbiome in Male Genital Mucosa (Prepuce, Glans, and Coronal Sulcus): A Systematic Review.

The human body represents a complex and diverse reservoir of microorganisms. Although the human microbiome remains poorly characterized and understood, it should not be underestimated, since recent studies have highlighted its importance in health. This is especially evident when considering microbiota in the male reproductive system, responsible for men's fertility and sexual behavior. Therefore, the aim of this systematic review is to provide an overview of the microbial communities of the healthy male genital mucosa and its role in disease. This study was performed according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. The search was limited to the English language and studies published until August 2022 that included culture-independent techniques for microbiome characterization in male genital mucosa. Ten articles were included. The bacterial composition of the male genital mucosa consists of several genera including Prevotella, Finegoldia, Peptoniphilus, Staphylococcus, Corynebacterium, and Anaerococcus, suggesting that the male genital microbiome composition shows similarities with the adjacent anatomical sites and is related with sexual intercourse. Moreover, male circumcision appears to influence the penile microbiome. Despite the lack of knowledge on the male genital mucosa microbiome in disease, it was reported that Staphylococcus warneri and Prevotella bivia were associated with balanoposthitis, whereas Enterobacteriaceae, Prevotella, and Fusobacterium were more abundant in male genital lichen sclerosus. The limited data and paucity of prospective controlled studies highlight the need for additional studies and established criteria for sampling methods and the microbiome assay procedure. Such a consensus would foster the knowledge about the composition of the genital microbiome of healthy males and its role in disease.