Non-typhoidal Salmonella (NTS) strains are among the major foodborne pathogens with emerging multidrug-resistant phenotypes. In this study, antimicrobial susceptibilities of a collection of  Salmonella isolates (n=54) recovered from poultry and bivalve molluscs were performed. The study also investigated the virulence and resistance genes profiling as well as the phylogenetic relationships through PFGE and ERIC/PCR fingerprinting. Results revealed the presence of multiple virulence genes among Salmonella  isolates. siiA ,  sopB ,  cat2 ,  safC ,  sefB and sopE2 genes were present in most (83.32%-100%) of the isolates, while the remaining tested genes ( spvC , spvB, and sopE ) were exclusively detected within the serotype Enteritidis. The highest resistance rates were observed for oxacillin (94.4%), ampicillin (37%) and nalidixic acid (27.7%), followed by cefotaxime and amoxicillin/clavulanic acid (14.8%), trimethoprim/sulfamethoxazole (9.3%) and ciprofloxacin (5.5%). The results of the present study indicate that S.  Enteritidis serotype possessed the widest range of virulence determinants and increasing levels of resistance. Such high-risk clones should be particularly controlled in Tunisia. Overall, increased resistance and virulence confers a selective advantage for the evolution of the bacteria which represents an alarming problem for global public health. The genetic study via Pulsed-field gel electrophoresis (PFGE) and enterobacterial repetitive intergenic consensus PCR (ERIC/PCR) showed the high diversity of the clonal origins of the bacteria and the sources of contamination,and revealed the great capacity of the pathogen to diversify within food-producing animals.

This content is only available as a PDF.
You do not currently have access to this content.