IDENTIFICATION OF NOVEL OUTER MEMBRANE PROTEINS OF SALMONELLA TYPHI AS VACCINE CANDIDATE BY REVERSE VACCINOLOGY APPROACH

Background and Aim:Salmonella enterica serovar Typhi (S. Typhi) cause enteric fever, which is very common in the developing world. The recent emergence of antimicrobial resistant isolates of S. Typhi makes typhoid fever, a global public health risk. Vaccination is an important strategy to control new isolates of S. Typhi and to interrupt transmission during outbreaks. Outer Membrane Proteins (OMPs) of S. Typhi are potent immunogens, which could serve as vaccine candidates. Reverse vaccinology as a revolutionary genome-based approaches, can be used to identify novel vaccine candidates. In this study a collection of bioinformatic tools based on the principle of reverse vaccinology were employed to identify novel OMPs as potential vaccine candidates for future vaccine development.Methods:In silico prediction of vaccine candidates among 7 complete genomes of S. Typhi including subcellular localization, human protein homology, antigenicity, solubility, transmembrane helices, BLASTp and virulence factors were performed. Proteins failing to comply with the set parameters were filtered at each step.Results:Among all OMPs of S. Typhi analyzed in this study, outer membrane fimbrial user protein (tsaC), Vi polysaccharide export protein (vexA) and outer membrane usher protein (steB) were identified as potential candidates qualifying all the set criteria.Conclusion:These predicted vaccine antigen candidates can be used in a basis for development of different vaccine types such as subunit protein vaccines and epitope peptide vaccines against S. Typhi.

کلیدواژه ها:

enteric fever ، Salmonella Typhi ، vaccine ، vaccine candidate ، reverse vaccinology ، outer membrane proteins