Some Molecular Studies on Salmonella on Chickens

The objective of these study to observe the distribution of three such genes, namely, Salmonella enterotoxin (stn) (14, 12,) (, Salmonella Enteritidis fimbrial (sef) and plasmid encoded fimbrial (pef) genes (15), among different serovars of Salmonella enterica isolated chicken. The work included Isolation of salmonellae from broiler breeder chicken farms. Phenotypic characterization of Salmonella isolates using (Morphological, cultural and biochemical identification. Serological identification. ) Molecular identification of the isolates using polymerase chain reaction (PCR). Dead birds were collected from broiler chicken farms from 3 distinct governorates, Giza, Monofia and Qaluobia suspected to be salmonellae infected. Specimens for salmonellae isolation included liver, spleen, and intestine that were collected under aseptic condition. A total isolate belonging to S. Typhimurium, S. Enteritidis, S. Blockley, and S. Kentucky serovars were subjected to polymerase chain reaction (PCR) assay for the detection of stn, sef and pef genes using their specific primers and the PCR products were analyzed by 1 per cent agarose gel electrophoresis for the presence of the respective genes. Results Varying distribution pattern of these genes was observed amongst the isolates. While, stn was found in all the strain we isolated, sef was found only among the S. Enteritidis isolates. The pef gene was found to be absent in some isolates. Conclusion Findings indicated that the stn gene is widely distributed among Salmonella irrespective of the serovars and source of isolation. However, the sef gene appears to be serovar specific. Since the stn gene is found in all the isolates, it can be a viable target gene to explore the possibility of direct detection of Salmonella from samples from biological sources.