Comparison of ubiquitous antibiotic-resistant Enterobacteriaceae populations isolated from wastewaters, surface waters and drinking waters

摘要

This study aimed at assessing the role of ubiquitous (non-Escherichia coli) Enterobacteriaceae in thedissemination of antimicrobial resistance through the urban water cycle. Enterobacteriaceae isolatedfrom a municipal wastewater treatment plant (111 isolates), urban water streams (33 isolates) anddrinking water (123 isolates) were compared in terms of: (i) genera distribution, (ii) resistance to 12antibiotics, and (iii) class 1 and class 2 integrons. The predominant bacterial genera were the same inthe different types of water, although with a distinct pattern of species. The most prevalentresistance phenotypes were observed for amoxicillin, ticarcillin, cephalothin and sulphamethoxazole(24–59% in the three types of water). No resistance against ceftazidime or meropenem wasobserved. Resistance to cephalothin, amoxicillin and sulphamethoxazole was significantly moreprevalent in drinking water, water streams and wastewater, respectively, than in the other types ofwater. It was possible to recognize antibiotic-resistance associations, namely for the pairsstreptomycin–tetracycline (positive) and ticarcillin–cephalotin (negative). Class 1 and/or class 2integrons with similar gene cassettes were detected in the three types of water. This studydemonstrated that Enterobacteriaceae are important vehicles of antibiotic resistance, namely indrinking water.