Detection of Salmonella spp. in Gastrointestinal Tract of Broiler Chickens by Polymerase Chain Reaction

Salmonella spp. cause a number of diseases in broiler, ultimately leading to death or to a decrease in production or condemning of carcasses. Thus, there are needed to rapid, sensitive, and reliable methods for detection of Salmonella to reduce the occurrence of salmonellosis. The objective of the present study was to establish a specific, sensitive and rapid PCR protocol for the detection of Salmonella at the genus level in Iran poultry industries. Salmonella spp. in the duodenum, jejunum, ileum and cecum of broiler chickens were compared by molecular analysis of 16S rRNA genes. Among 96 samples of gastrointestinal segments, a total of 56.25, 12.5 and 6.25% samples were positive for naturally occurring Salmonella spp. by PCR method at 4, 14 and 30d of ages respectively. For cecum, a total of 87.5, 12.5 and 12.5% samples were positive for naturally occurring Salmonella spp. by PCR method at 4, 14 and 30d of ages respectively. Analysis of the microbial contents of the different small intestine segments examined indicated that Salmonella spp. was not consistently detected in all intestinal segments. The results indicated that at 14 and 30 d of ages, Salmonella spp. was not detectable in the most of studied segments. In fact, posterior segments exhibited higher levels of Salmonella spp. compared with the anterior segments especially cecum. As demonstrated here, the development of new tools for high-throughput analyses will be of key importance for these studies. This technique is simple and rapid and can be used on different chicken samples for routine detection of a large number of samples on a daily basis.