Incidence, Phenotypic and Genotypic Antimicrobial Resistance of Zoonotic Salmonella spp. Isolated from Broiler chicken and Human in Egypt

This study investigated incidence, phenotypic-genotypic antimicrobial resistance in zoonotic salmonellae from broiler chicken and human in Egypt. Two hundred and forty samples were randomly collected from broilers including (liver, gizzard, intestine, n=60 of each) and from workers (hand swabs, n=60) at poultry outlets. Isolation, biochemical and serological identifications of Salmonella spp. were performed. Antimicrobial susceptibility testing of Salmonella serotypes was done using disc diffusion method. The multiple antibiotic resistance (MAR) index of Salmonella serotypes was calculated. Genotypic detection of antimicrobial resistance genes [blaTEM, floR and tetA(A)] was identified in phenotypically resistant salmonellae using PCR. The incidence of Salmonella spp. was 5% in each of liver and intestine of broilers, and 1.66% in gizzard of broilers; and 3.33% in hand swabs of workers. The serotypes of S. Typhimurium were distributed into liver of broilers (3 out of 4, 75%) and into intestine of broilers (1 out of 4, 25%). The distribution of S. Enteritidis was 33.3% (1 out of 3) in gizzard and )66.7%, 2 out of 3) was distributed in intestine of broiler. Two isolates of S. Kentucky (100%) were distributed in hand swabs from workers. The peak resistance (100%) of 9 Salmonella isolates was found to each of chloramphenicol and ampicillin followed by a highest resistance (88.8%) to doxycycline The profile of each S. Typhimurium and S. Enteritidis isolates from broiler chicken reached the peak resistance (100%) for ampicillin, chloramphenicol and doxycycline The multiple antibiotic resistance (MAR) index of Salmonella isolates was ranged from 0.23 to 0.54 with an average of 0.34. The blaTEM, tetA(A) and floR genes were identified with similar distribution percentage of 66.7% in S. Typhimurium isolates from liver. all isolates of S. Enteritidis from gizzard, S. Typhimurium from intestine, S. Enteritidis from intestine and S. Kentucky from hand swabs harbored similar distribution percentage (100%) for each blaTEM, tetA(A) and floR gene. Further studies are required to predict biological tools such as bacteriophages during poultry production to minimize entry of multidrug resistant (MDR) salmonellae from broiler chicken to human food chain.