The present study was Conducted to determinate the existence and distribution of some virulence genes among Salmonella serovars isolated from broiler flocks in Egypt. A total of 55 Salmonella isolates were recovered from different samples (liver, yolk sacc, gall bladder and caecum) collected from apparently healthy and diseased broilers suffered from whitish diarrhea, dehydration and respiratory distress. Thirty isolates were serotyped into S. Enteritidis, S. Infantis, S. Kentucky, S.Maloma, S.Bardo ,S.Gdansk, S.Typhimurium and S. Blegdame. Molecular detections of invA, ompA and stn virulence genes in 15 Salmonella isolates were applied using specific primer sets. The results reported detection of the screening genes in all 15 examined isolates. In conclusion, these genes appear to have a critical role in pathogenicity of Salmonella infection in poultry. So as to understand the process of pathogenicity and design of control and therapy treatment strategies for salmonellosis in broiler chickens.
Key words: Salmonella, virulence genes, broiler, diarrhea.