Microbial communities of biofilms developed in a chlorinated drinking water distribution system: A field study of antibiotic resistance and biodiversity

Antibiotic resistance and biodiversity were investigated in microbial communities attached to inner surfaces of water supply fittings in a chlorinated drinking water distribution system (DWDS) supplied by two independent water treatment plants (WTPs) drawing the same source water. The investigation of the effect of the season, the applied water treatment technology, and type, material, and age of water supply fittings on both antibiotic resistance and biodiversity in biofilms involved collection of tubercles during summer and winter seasons throughout the DWDS. A total of 16 samples were collected (8 per season) from areas supplied by two independent WTPs. Culturable aerobic antibiotic resistant bacteria (ARB) proved more prevalent in summer. Various antibiotic resistance genes (ARGs) were detected, confirming the role of biofilms as ARGs reservoirs, but the abundances of quantified genes (sulI, ermB, qacE.1, intI1) were low (a range of

Automated summary

The study investigated antibiotic resistance and biodiversity in microbial communities attached to inner surfaces of water supply fittings in a chlorinated drinking water distribution system supplied by two independent water treatment plants. Results showed that culturable aerobic antibiotic resistant bacteria (ARB) were more prevalent in summer, with various antibiotic resistance genes (ARGs) detected in biofilms but at low abundances.