Comparative genomic analyses of β-lactamase (blaCMY-42)-encoding plasmids isolated from wastewater treatment plants in Canada

Canadian Journal of Microbiology, Ahead of Print. Wastewater treatment plants (WWTPs) are useful environments for investigating the occurrence, diversity, and evolution of plasmids encoding clinically relevant antibiotic resistance genes (ARGs). Our objective was to isolate and sequence plasmids encoding meropenem resistance from bacterial hosts within Canadian WWTPs. We used two enrichment culture approaches for primary plasmid isolation, followed by screening for antibiotic resistance, conjugative mobility, and stability in enteric bacteria. Isolated plasmids were sequenced using Illumina MiSeq and Sanger sequencing methods. Bioinformatics analyses resolved a multi-resistance IncF/MOBF12 plasmid, pFEMG (209  357 bp), harbouring resistance genes to β-lactam (blaCMY-42, blaTEM-1β, and blaNDM-5), macrolide (mphA-mrx-mphR), tetracycline (tetR-tetB-tetC-tetD), trimethoprim (dfrA12), aminoglycoside (aadA2), and sulfonamide (sul1) antibiotic classes. We also isolated an IncI1/MOBP12 plasmid pPIMR (172 2 80 bp) carrying similar β-lactamase and a small multi-drug efflux resistance gene cluster (blaCMY-42-blc-sugE) to pFEMG. The co-occurrence of different ARGs within a single 24 552 bp cluster in pFEMG — interspersed with transposons, insertion sequence elements, and a class 1 integron — may be of significant interest to human and veterinary medicine. Additionally, the presence of conjugative and plasmid maintenance genes in the studied plasmids corresponded to observed ...
Source: Canadian Journal of Microbiology - Category: Microbiology Authors: Source Type: research