Molecular detection of virulence and resistance genes of Enterococcus species isolated from milk and milk products

Abstract

Enterococcus species are one of the most serious pathogens that could pose risk to animal and human also a reservoir of genes encoding antibiotic resistance which can be transferred to other microorganisms. In the last decade, Enterococci become the most frequently reported cause of an abdominal or pelvic infection, septicemia, and enterococcal meningitis in humans. So, this study aimed to focus alight on virulence of these microbes and to show the linkage between antimicrobial resistance and biofilm formation in Enterococcus spp . A total of 120 samples of raw milk and cheese were collected from different markets in Qena province, Egypt. These samples were suspected for microbial analysis as culture, biochemical method, VITEK2 system and PCR technique for detection of resistance and virulence genes. The conventional identification showed that 30 isolates were suspected to be Enterococcus spp., VITEK 2 system confirmed the isolates as Enterococcus and classified them into 15 isolates as Enterococcus faecalis ( E. faecalis ),10 isolates as Enterococcus faecium ( E. faecium ) whereas the least species were 5 isolates were Enterococcus gallinarum ( E. gallinarum ). also, our isolates showed their ability to form moderate and weak of biofilm with percentage%66.67% and 16.67% respectively. Also, the results of antimicrobial susceptibility showed high resistance against penicillin, Erythromycin, Amoxicillin, Nitrofurantoin and Cefotaxime. Our study is fueling the concern on a significant relationship between biofilm formation and specific types of antimicrobial resistance in Enterococcus spp. as Cefotaxime, Penicillin, Ampicillin and Erythromycin. Ten isolates were selected and tested by PCR for detection antimicrobial resistance and biofilm genes. The isolates obtained in this study harbored different antimicrobial resistance genes included erm B (80%), bla Z (100%) and van A (30%) and biofilm formation genes included hyl and ef3 314 (100%), esp (90%). Finally, we included, the deterrence of the contamination by Enterococcus spp. in milk and its products becomes necessary by applying strict hygienic measure.