Quantification of genes encoding resistance to aminoglycosides, β-lactams and tetracyclines in wastewater environments by real-time PCR

Abstract

In this study real-time PCR assays, based on the LUX™-technique, were developed for quantification of genes mediating resistance to aminoglycosides [aac(6´′)-Ie + aph(2´′´′)], β-lactams (mecA), and tetracyclines (tetA and tetB), for use in wastewater environments. The developed assays were applied on DNA extracted from three wastewater-associated environments: soil from an overland flow area treating landfill leachates, biofilm from a municipal wastewater treatment plant, and sludge from a hospital wastewater pipeline. The highest concentration of all genes was observed in the hospital pipeline and the lowest in the overland flow system. TetA and aac(6´′)-Ie + aph(2´′´′) could be detected in all environments. The tetB gene was detected in the overland flow area and the hospital wastewater pipeline and mecA was detected in the wastewater treatment plant and the hospital pipeline. The developed LUX™ real-time PCR assays were shown to be fast and reproducible tools for detection and quantification of the four genes encoding antibiotic resistance in wastewater.