Legionella relative abundance in shower hose biofilms is associated with specific microbiome members

Abstract

Legionella are natural inhabitants of building plumbing biofilms, where interactions with other microorganisms influence their sur- vi v al, pr oliferation, and death. Her e, we inv estigated the associations of Legionella with bacterial and eukar yotic micr obiomes in biofilm samples extracted from 85 shower hoses of a multiunit residential building. Legionella spp. relative abundance in the biofilms ranged betw een 0-7.8%, of whic h onl y 0-0.46% w as L. pneumophila . Our data suggest that some microbiome members were associated with high (e.g. Chthonomonas , Vrihiamoeba ) or low (e.g. Aquabacterium , Vannella ) Legionella r elati v e a bundance. The corr elations of the differ- ent Legionella variants (30 Zero-Radius OTUs detected) showed distinct patterns, suggesting separate ecological niches occupied by different Legionella species. This study provides insights into the ecology of Legionella with respect to: (i) the colonization of a high n umber of r eal shower hoses biofilm samples; (ii) the ecological meaning of associations between Legionella and co-occurring bacte- rial/eukaryotic organisms; (iii) critical points and future directions of microbial-interaction-based-ecological-investigations.