Antibiotic resistance profile of Enterococcus faecium and Enterococcus faecalis isolated from broiler cloacal samples

Abstract

The present study was performed to isolate and identifyEnterococcusspp. from broiler cloacal samples to species level,to determine their resistance patterns to various antibiotics, and to detect vancomycin resistance genes. Cloacal samples of broilerscollected from slaughterhouses were inoculated in Slanetz and Bartley agars with and without vancomycin (6 μg/mL). Antibioticresistance/susceptibility testing of the isolated and identified enterococci was performed by using the disk diffusion test. Multiplex PCRwas used to identify the species and to detect vancomycin resistance genes. The majority of the isolated enterococci wasEnterococcusfaecium(60.43%, n = 142) andEnterococcus faecalis(33.62%, n = 79). E. casseliflavusandE. gallinarumwere identified from 8 (3.42%)and 6 (2.56%) isolates, respectively. It was found that 88.9% of the enterococci were resistant to tetracycline and 83.4% of them wereresistant to erythromycin. As a result, none of the strains isolated from cloacal samples of broilers carried thevan A andvan B genes. Itwas observed that 54.9% ofE. faeciumisolates and 78.4% ofE. faecalisisolates were multidrug resistant (resistant to 3 or more antibioticgroups). The lack of vancomycin-resistantEnterococcusamong the enterococci isolates was important for public health.