Detection of beta-lactam antibiotic resistance in aquatic Enterobacteriaceae isolates

Abstract

Production of the beta-lactamase enzymes is the primary resistance mechanism caused by uncounscious consumption of the beta-lactam group of antibiotics in Enterobacteriaceae. Combined disc tests were performed for extended-spectrum beta-lactamase (ESBL) confirmation (n = 15) and class C beta-lactamase (AmpC) confirmation (n = 6) after the disc diffusion test was applied in total of 27 Enterobacteriaceae strains from Western Black Sea, Lake Manyas and Lake Iznik. Plasmid-mediated blaTEM, blaSHV, blaCTX-M , blaIMP genes, CIT, MOX, FOX gene groups and chromosomal bla AmpC gene of E. cloacae were investigated with polimerase chain reaction (PCR). Three E. coli strains were shown to produce ESBL while one E.coli and three E. cloacae strains were confirmed for AmpC production by disc tests. blaTEM (n = 2), blaSHV (n = 4), blaCTX-M (n = 2), blaTEM + blaSHV (n = 1), blaCTX-M + CIT (n = 1), blaSHV + CIT (n = 1) genes and/or gene groups were detected in eleven E. coli isolates; while blaSHV (n = 3) was observed in three Klebsiella strains (two K.oxytoca and one K.pneumoniae). With this study, aquatic environments of Turkey were proved to be the reservoirs of antibiotic resistance determinants of plasmid-mediated beta-lactamases in environmental wild-type bacteria transmitted by horizontal gene transfer.

Current and Future Technologies for the Detection of Antibiotic-Resistant Bacteria

“…Despite these limitations, PCR remains a valuable tool in AMR research and surveillance. These are just a few examples, as there are many different AMR genes that can be detected using PCR: mecA gene, which confers resistance to methicillin in Staphylococcus aureus [46]; blaSHV gene, which confers resistance to beta-lactam antibiotics in Enterobacteriaceae [47]; tetM gene, which confers resistance to tetracycline antibiotics in many bacterial species [48]; and vanA gene, which confers resistance to vancomycin in Enterococcus species [49].…”