Emergence of multi-drug-resistant, vancomycin-resistant, and multi-virulent Enterococcus species from chicken, dairy,...

The present study aimed to detect the frequency of vancomycin resistance and virulence genes' profiles of multi-drug-resistant (MDR) enterococcal isolates from different sources and to investigate the sequence heterogeneity between the esp genes of MDR and vancomycin-resistant Enterococcus faecalis isolates from chicken and human sources.

Conventional phenotypic methods identified 91 isolates (60.7%) as Enterococcus species, and these isolates were retrieved from dairy (37/52), chicken (35/54), and human (19/44) origins. Enterococcal isolates were frequently resistant to rifampin (67%), and 38.5% of the isolates were MDR. Of the 22 vancomycin-resistant enterococci (VRE) detected isolates, 11 (50%), 9 (41%), 1 (4.5%), and 1 (4.5%) isolate were identified as E. faecium, E. faecalis, E. casseliflavus, and un-specified Enterococcus spp., respectively. Moreover, 22 (100%) and 19 (86.4%) isolates harbored vanA and vanB genes, respectively. Of note, gelE and asa1 genes were more prevalent among the tested isolates (95.5% each), and the multi-virulence criteria were detected among 68.2% of the examined isolates. The sequences of esp genes of E. faecalis from the chicken breast meat and human urine samples were 100% identical with other esp genes and pathogenicity islands on GeneBank, which is undesirable.

Our findings require strict hygienic measures during the processing of chickens and their by-products to minimize the possibility of transmission of virulent enterococcal strains. Furthermore, the use of antimicrobials in poultry and animal production in developing countries should be controlled to minimize the prevalence of MDR and VRE isolates in humans.