Molecular Analysis of Some Virulence Genes of Salmonellae Isolated from Chicken at Sharkia Governorate

Abstract

Poultry is one of the most reservoirs of Salmonella that can be transmitted to humans through the food chain causing high risk bacterial food poisoning. In the present study, bacteriological examination of 200 samples from broiler internal organs (liver,2ceci, un absorbed yolk sac) from1 day old chicks suffering from omphalitis and respiratory disorders after hatching, revealed 26 Salmonella isolates 13%. Serotyping of 26 Salmonella isolates by slide agglutination test using specific monovalent and polyvalent O and H Salmonella sera revealed eleven different Salmonella serotypes, with S. Enteritidis as the most prevalent serotype (38.5%) followed by S.Tamale (23.07%). ,S. Typhymurium (19.2%), S. Kentucky (15.4%)and ,S.Heldberg (3.8%).most Salmonella isolates were sensitive to Ciprofloxacin ,sulfa methoxasole – trimethoprime , Chlorumphenicol and gentamycin .while they were resistant to Erythromycin ,Rifamycin , Amoxycillin /clavulinic acid ,colistin sulfate and cefotaxime . PCR detection of 6verulant genes of 5 strains of Salmonella isolates which proved to play an important role in the virulence of Salmonella in chicken. In this study detection of (invA gene, hilA gene, stn gene, spvc gene, fmH gene and pefA gene) is with percentages of (100%, 80%, 100%, 0%, 100% and 40%)respectively. From examined 5MDR Salmonella isolates, Integron class1were detected in all of them (100%) but no strain was found to harbor Integron class2.