Correlation between bacterial microbiome and species in water from public bath facilities by 16S rRNA gene amplicon sequencing.

UNLABELLED

Public bath facilities are a major source of infections in Japan. In this study, we performed 16S rRNA gene amplicon sequencing to characterize the bacterial community in bath and shower water from public bath facilities, along with chemical parameters, and investigated the effect of the bacterial microbiome on the presence of species. Although no significant difference in bacterial community richness was observed between bath and shower water samples, there was a remarkable difference in the bacterial community structure between them. Distance-based redundancy analysis revealed that several factors (free residual chlorine, pH, and conductivity) were correlated with the bacterial community in bath water. The most abundant bacterial genera in the samples were (13.7%) in bath water and (13.6%) in shower water, as indicated by the taxonomic composition, and the dominant bacteria differed between these environmental samples. was the most frequently detected species, with additional 15 other species detected in water samples. In positive water samples, several unassigned and uncultured bacteria were enriched together. In addition, the co-occurrence network showed that was strongly interconnected with two uncultured bacteria. and negatively correlated with species. The present study reveals the ecology of species, especially their interactions with other bacteria that are poorly understood to date.

IMPORTANCE

Public bath facilities are major sources of sporadic cases and outbreaks of infections. Recently, 16S rRNA gene amplicon sequencing has been used to analyze bacterial characteristics in various water samples from both artificial and natural environments, with a particular focus on bacterial species. However, the relationship between the bacterial community and species in the water from public bath facilities remains unclear. In terms of hygiene management, it is important to reduce the growth of species by disinfecting the water in public bath facilities. Our findings contribute to the establishment of appropriate hygiene management practices and provide a basis for understanding the potential health effects of using bath and shower water available in public bath facilities.