Characterization of β-Lactamases and Multidrug Resistance Mechanisms in Enterobacterales from Hospital Effluents and Wastewater Treatment Plant.

Antimicrobials in wastewater promote the emergence of antibiotic resistance, facilitated by selective pressure and transfer of resistant genes. Enteric bacteria belonging to , , , and species ( = 126) from hospital effluents and proximate wastewater treatment plant were assayed for susceptibility to four antimicrobial classes. The β-lactamase encoding genes harbored in plasmids were genotyped and the plasmids were sequenced. A multidrug resistance phenotype was found in 72% ( = 58) of isolates, 70% ( = 43) of species isolates, and 40% ( = 25) of and species. Moreover, 86% ( = 50) of , 77% ( = 33) of species, and 25% ( = 4) of species isolates phenotypically expressed extended spectrum β-lactamase. Regarding ESBL genes, and were found in while species harbored , , or . Genes coding for aminoglycoside modifying enzymes, adenylyltransferases (, phosphotransferases (, acetyltransferases (, (), sulfonamide/trimethoprim resistant dihydropteroate synthase (), dihydrofolate reductase (), and quinolone resistance protein () were also identified. Monitoring wastewater from human sources for acquired resistance in clinically important bacteria may provide a cheaper alternative in regions facing challenges that limit clinical surveillance.