Prevalence and Resistance of Linezolid Resistance Genes (poxtA and optrA) Detected in Enterococcus spp. Isolates from Meat Products in Iran: A Groundbreaking Report

BACKGROUND AND OBJECTIVESEnterococcus faecalis and Enterococcus faecium can cause hospital-acquired infections and have the potential to develop resistance to critical antibiotics like linezolid. Understanding the prevalence of resistance genes in non-clinical sources like food products is crucial for monitoring and preventing the spread of multidrug-resistant bacteria.MATERIALS AND METHODSIn Isfahan, Iran, ۱۳۵ meat food samples (chicken, lamb, beef, and ostrich meat) were gathered from various stores. The samples were taken to the Microbiology Laboratory and treated with saline, filtered, and placed on Bile Esculin Agar plates with vancomycin. The colonies suspected to be Enterococcus were subjected to identification tests, including biochemical and molecular methods. Antibiotic sensitivity tests were performed according to CLSI ۲۰۲۱ guidelines, and strains resistant to multiple drugs (MDR) were examined for the presence of cfr, opxtA, and optrA genes using multiplex-PCR.RESULTS AND DISCUSSIONIn study of ۱۳۵ meat samples, Enterococci strains were detected in ۵۹ samples. Among these samples, ۶۹.۴% contained Enterococcus faecalis (Efa), ۱۵.۲% contained Enterococcus faecium (Efm), ۵.۰% contained both Efa and Efm strains, and ۱۰.۱% contained other Enterococcus strains.In an antibiotic sensitivity test, tetracycline showed the highest resistance (۸۱.۷%), while linezolid had the lowest resistance (۹.۷%). Two strains of MDR Enterococci had the poxtA gene, with one strain having only poxtA and another strain having both poxtA and optrA genes. Three strains of MDR Enterococci had the optrA gene, with two strains having only optrA and one strain having both optrA and poxtA genes. Notably, none of the tested strains had the cfr gene.The statistical analysis revealed a significant correlation (P < ۰.۰۵) between the presence of poxtA and optrA genes and resistance to linezolid in multi-drug resistant Enterococci.CONCLUSIONIncreasing the utilization of antibiotics in animal farming and the poultry sector may lead to the proliferation of antibiotic resistance and the transmission of resistance genes to strains found in medical settings. It is crucial to restrict and continuously supervise the usage of antibiotics in non-clinical environments.

کلیدواژه ها:

Enterococcus ، linezolid ، Food ، poxtA ، optrA