Cloning and sequencing of ompf Salmonella typhi Salmonella ompf gene in Escherichia coli Origami

Background and Aim: Salmonella Typhi belongs to the family Enterobacteriaceae, gram-negative bacilli and causes gastrointestinal diseases such as typhoid. This bacterium has a special structure and various genes, including the ompf gene (outer membrane protein). Recent studies have shown the possibility of using ompf in the development of a diagnostic tuberculosis vaccine. Therefore, the aim of this study was to clone and sequence the ompf gene of Salmonella typhi, the causative agent of typhoid in Escherichia coli Oragami, in order to obtain a vaccine. Methods: Sampling of people with salmonellosis was performed during 4 months from the infectious ward of medical centers in Tehran province. After identifying and performing specific biochemical tests, Salmonella typhi was isolated and DNA was extracted. Salmonella typhi strains with ompf gene were then extracted by PCR. The ompf gene of the positive strains was transfected into the Escherichia coli bacterium by vector and cloned by TA technique. Finally, the expression of genes in Escherichia coli Oregami was measured by Real time PCR technique. ClustalX and Mega5 software were used to draw the phylogenetic tree.   Results: A total of 12 Salmonella typhi isolates were isolated from the screening of clinical specimens sent to the laboratory, which were identified based on morphological characteristics, microscopy and biochemical tests. Of these, only one wasolate had the ompf gene. After cloning, ompf genes, cloned selection colony strains (blue / white) were isolated. In order to confirm the results of DNA cloning, it was extracted from suspicious colonies and analyzed by Real time PCR. Sequence, m13 and proliferation curves confirmed gene expression in Escherichia coli origami. Conclusion: In this study, by genomic evaluation of Salmonella typhimurium isolated from patients with tuberculosis, ompf gene with immunization potential was extracted from this bacterium in order to make a vaccine and cloning was successful. Finally, by examining the phylogenetic tree drawn in this study, the degree of similarity and kinship of Salmonella typhi with other species was shown.