Genetic Correlation of Virulent Salmonella Serovars (Extended Spectrum β-Lactamases) Isolated from Broiler Chickens...

This study aimed to detect the virulent Salmonella serovars (including ESBLs producing) isolated from broiler chickens and humans. Three hundred broilers and sixty human fecal samples were bacteriologically examined. Thirty (10%) and fourteen (23.4%) Salmonella isolates were recovered from broiler and human samples, respectively. The most predominant serovar was S. enteritidis and S. typhimurium. All Salmonella isolates were confirmed by conventional PCR-based invA and ompA genes. Multidrug resistant (MDR) isolates were screened for the detection of adrA and csgD biofilm-associated genes, which were found in all isolated serovars except one S. typhimurium and 2 S. infantis of chicken isolates that were devoid of the adrA gene. Moreover, MDR isolates were screened for detection of seven resistance genes including ESBLs and other classes of resistance genes. Chicken isolates harbored bla_TEM, int1, bla_CTX and qnrS genes as 100, 27.8, 11.1 and 11.1%, respectively, while all human isolates harbored bla_TEM, int1 and int3 genes. The genetic correlations between virulent Salmonella serovars (including antimicrobial resistance) avian and human origins were compared. In conclusion, the high prevalence of virulent ESBL producing Salmonella serovars in broilers and humans with genetic correlations between them might be zoonotic and public health hazards.