Phenotypic and molecular detection of CTX-M β-lactamases in Salmonella enterica local isolates from different origins in Mosul

Abstract

Aims: Multiple drug-resistant Salmonella has become a worldwide threat in human and veterinary medicine, especially with the increasing emergence of extended-spectrum β-lactamases (ESBLs) producing strains. The present study was aimed to investigate the occurrence and prevalence of ESBLs and CTX-M enzymes as a potential antimicrobial resistance mechanism in Salmonella enterica from different origins in Mosul city, Iraq. Methodology and results: Forty-six S. enterica local isolates were detected for the occurrence of multiple drug resistance (MDR) and extended-spectrum β-lactamases (ESBLs) using CLSI methodology. Phenotypically positive isolates for ESBLs detection test were molecularly investigated for the presence of blaCTX-M gene using PCR technique. The results showed that 41.3% of the isolates were phenotypically ESBLs-producers and 57.9% of them harbored blaCTX-M gene, which encodes for the enzyme CTX-M. The results indicated the occurrence of ESBLs and blaCTX-M gene in S. enterica strains from clinical, veterinary and environmental origins. Conclusion, significance and impact of study: Research findings from this study shed light on the possible medical threat that ESBLs producing S. enterica could represent to human health as they could transmit through the food chain. The awareness level of antimicrobials utilization in all sectors should be elevated to reduce the global dissemination of multidrug resistance and blaCTX-M harboring Salmonella stains.