Non-typhoidal Salmonella is a zoonotic bacterium having a worldwide risk to public health and chicken industry. Primary aim of study is to assess Salmonella prevalence in chicken and human then serotyping, antibiogram, virulence and antibiotic resistance genes identification by PCR and sequence analysis. In total, 300 samples were gathered (100 chicken liver, 150 chicken feces, 50 human stool). Bacteriological examination, serotyping, antibiogram, virulence (invA, stn) and antibiotic resistance genes (ermB, aadB) PCR screening for detection of virulence and antimicrobial resistance of strains and stn gene sequencing in S. Typhimurium of poultry (STP), S. Enteritidis of poultry (SEP) and S. Typhimurium of human (STH) were accomplished. Salmonella prevalence was 4% for both chicken (12/300) and human samples (2/50). Chicken isolates serotyped as S. Typhimurium (50%) and S. Enteritidis (50%). Human isolates typed as S. Typhimurium (100%, 2/2). All serovars were resistant to clindamycin and erythromycin (100%). Multidrug-resistance (MDR) was detected in SEP, STP, STH by 100%, 80% and 50%, respectively. invA, stn genes were detected by 100% in all serovars. ermB was detected in SEP, STH and STP by 100%, 100% and 80% respectively. aadB gene was detected in SEP, STP and STH by 100%, 80% and 50%, respectively. stn sequencing revealed similarity between S. Typhimurium of human and S. Typhimurium and S. Enteritidis of chicken origin was 98.4% and 99.3%, respectively. It could be concluded that S. Typhimurium, S. Enteritidis of chicken and S. Typhimurium of human were MDR and share high stn gene similarity suggesting a public health alarm.
Keywords: Salmonella, Chicken, Serotyping, Antibiogram, virulence, Antibiotic resistance genes, Sequencing