Annals of Agricultural and Environmental Medicine (Sep 2015)
Extended spectrum beta-lactamases in Escherichia coli from municipal wastewater
Abstract
Introduction and objective. Over the past decades, awareness of the environmental load of resistant organisms has increased. The presented paper focuses on antibiotic resistance and detection of resistance genes in environmental [i]E. coli[/i] and on the evaluation of biofilm formation in ESBLs (extended spectrum beta-lactamase) producing [i]E. coli[/i] isolated from an urban wastewater treatment plant. Materials and method. Wastewater samples and artificially added polystyrene pellets were used as the source for [i]E. col[/i]i isolation. Minimal inhibitory concentrations of 19 antibiotics were determined according to CLSI (2013). Biofilm formation was investigated by crystal violet or resazurin methods. CTX-M, carbapenemases, [i]qnrS[/i], mobile elements and virulence factors were determined by PCR. Clonal relatedness of strains was detected by principal component analysis by a Maldi biotyper. Results. ESBL phenotype was detected in 26% of environmental strains. CTX-M, CMY-2 and [i]qnrS[/i] genes of antibiotic resistance were detected. IMP gene together with integron 1 in one ertapenem resistant [i]E. coli[/i] was also recorded. There was no evident correlation between antibiotic resistance, virulence and biofilm production. Conclusions. The results showed that the wastewater is a source of ESBLs, carbapenemases and plasmid fluoroquinolone resistance. Strains with biofilm production, antibiotic resistance of CTX-M group, CMY-2, [i]qnrS[/i] genes and virulence factors present a potential environmental health risk.
