Austria-wide survey on resistant, potentially pathogenic bacteria at Austrian bathing sites, 2017

There is growing concern about human-induced antibiotic resistance and on the occurrence of antibiotic-resistant, potentially pathogenic bacteria in the environment. The aim of this study was to investigate the incidence of resistant, clinically relevant bacteria at bathing sites. In total, 27 of 263 bathing sites authorized under the EU Bathing Water Directive (3 per Austrian state) were sampled during the summer of 2017. Samples were tested for antibiotic-resistant bacteria by enrichment in thioglycollate broth and cultivation on chromogenic media. The screening for potentially pathogenic antibiotic-resistant bacteria was negative in 23 of the 27 samples. Antibiotic-resistant bacteria were detected from 4 of the 27 bathing sites: one Pseudomonas aeruginosa and three resistant Enterobacteriaceae (piperacillin/tazobactam-resistant Enterobacter cloacae with high-level expression of AmpC beta-lactamase, carbapenem-resistant Enterobacter mori, extended-spectrum beta-lactamase-producing Escherichia coli). Despite the occurrence of resistant bacteria, we consider the public health risk at Austrian bathing sites as low.