Seasonality Determines the Variations of Biofilm Microbiome and Antibiotic Resistome in a Pilot-Scale Chlorinated Drinking Water Distribution System Deciphered by Metagenome Assembly

Abstract

Understanding the biofilm microbiome and antibiotic resistome evolution in drinking water distribution systems (DWDSs) is crucial to ensure the safety of drinking water. We explored the 10 month evolution of the microbial community, antibiotic resistance genes (ARGs), mobile gene elements (MGEs) co-existing with ARGs and pathogenic ARG hosts, and the ARG driving factors in DWDS biofilms using metagenomics assembly. Sampling season was critical in determining the microbial community and antibiotic resistome shift. Pseudomonas was the primary biofilm colonizer, and biofilms diversified more as the formation time increased. Most genera tended to cooperate to adapt to an oligotrophic environment with disinfectant stress. Biofilm microbial community and antibiotic resistome assembly were mainly determined by stochastic processes and changed with season. Metagenome assembly provided the occurrence and fates of MGEs co-existing with ARGs and ARG hosts in DWDS biofilms. The abundance of ARG- and MGE-carrying pathogen Stenotrophomonas maltophilia was high in summer. It primarily harbored the aph(3)-IIb, multidrug transporter, smeD, and metallo-beta-lactamase ARGs, which were transferred via recombination. The microbial community was the most crucial factor driving the antibiotic resistance shift. We provide novel insights about the evolution of pathogens and ARGs and their correlations in DWDS biofilms to ensure the safety of drinking water.

Sewage Sludge Promotes the Accumulation of Antibiotic Resistance Genes in Tomato Xylem

“…Bacterial community composition is usually regarded as the most important factor in driving shifts of ARG composition in plant–soil continuums. − However, we found that fungi can also influence the composition of ARGs in the xylem (Figure S11). Fungi can indirectly influence antibiotic resistome by affecting ARG bacterial hosts, such as providing nutrients to feed bacteria, secreting antibiotics to antagonize bacteria, or competing for resources with bacteria. , For example, Talaromyces and Penicillium , belonging to Ascomycota, can produce a variety of secondary metabolites with antibacterial activities, thus likely playing a role in shaping the antibiotic resistome. , …”