IDENTIFICATION OF VIRULENCE GENES, β-LACTAMS AND QUINOLONES RESISTANCE-ASSOCIATED GENES AND INTEGRONS IN SALMONELLA ISOLATED FROM RETAIL CHICKEN MEAT AND GIBLETS IN EGYPT

The study investigated the prevalence of virulent and antibiotic resistant Salmonella (S) in retail chicken meat (CM) and pooled giblets (PG) in Egypt. Seventy-two and 64 % of examined CM and PG samples harbored Salmonellae, respectively. When S. Infantis was the most predominant serovar, followed by S. Kentucky, and then S. Virchow. The antibiotic resistance experiment showed a high rate of multiple drug resistant (MDR) Salmonellae. Remarkably, 64.7% of the isolates were resistant to ciprofloxacin (the drug of choice for Salmonella infection). Molecularly, a noteworthy correlation between the MDR and the presence of integrons class 1 and 3. When, integrons 1 and 3 were detected in 100 and 92 % of identified MDR isolates, respectively, while class 2 integrons were not found. Surprisingly, 53.8 and 100% of the molecularly identified isolates were resistant to ciprofloxacin and nalidixic acid, despite the absence of plasmid-mediated quinolone resistance (PMQR)-associated genes (qnrA, qnrB and qnrS, aac(6')-Ib-cr and qepA) from all MDR isolates. This indicates that other genetic factors could be incriminated in this pattern. Beta-lactam resistance was explored by the existence of bla(TEM), bla(CTX), and bla(CMY-2) genes in most MDR isolates. Additionally, 4 virulence genes were detected in almost all serovars. Concerning virulence genes, invA, hilA, sopB, and stn were detected in 100, 100, 100 and 94.7 % of MDR serovars, respectively. While, spvC was detected in only 7.6 %, and pef was absent. The high prevalence of MDR virulent Salmonella strains in retail chicken meat and giblets in Egypt should be faced with a great worry, as consumers could be under a great public health risk.