Molecular Detection of Salmonella Serovars in Retailed Raw Meat Samples Using 16SrRNA, SitC and FliC Virulence Genes in Lagos, Nigeria.

Abstract

Introduction: The presence of virulence genes such assit C and fli C are known among Salmonella serovars of clinical interest. The common sources of Salmonella include dairy products, beef, poultry, eggs and vegetables. This study was aimed at identifying salmonella using 16S ribosomal RNA gene (16SrRNA), andsitCandfliCvirulence genes in raw meat samples commonly sold in open market place genotypically with PCR methods. Methods: The study observed the presence of Salmonella isolated from 124 raw meat samples using conventional phenotypic methods and analysing for presence of sitCandfliCvirulence genes. For molecular analysis, the 16S rRNAs of strains of Salmonella were used to confirm the result of the conventional method. DNA extraction and quantification was carried out followed by Polymerase Chain Reaction. The PCR products were subjected to agarose gel electrophoresis. Result: A total of 124 isolates were collected from animal sources. Of the 124 samples, 30 Salmonella isolates were positive after repeated sub culturing, biochemical and serological tests. Nineteen (63%) of the 30 isolates were positive for16SrRNAs, five (17%) for sitC while thefliC was negative. Conclusion: The PCR assay has proven to an efficient method for the identification of virulence genes in Salmonellaserovars. The presence of 16SrRNAs andsitC genes showed availability of the virulence genes in retailed raw meat samples commonly sold in Nigeria. More studies are required to track virulence factors among Salmonella isolates in Nigeria.