Recombinant Flagellin Protein Can Efficiently Protect Mice Against Salmonella Typhi

Abstract

Introduction: Globally, Salmonella enterica serotype Typhi is responsible for more than 10 million enteric fever cases, annually. Because of the emergence of multidrug-resistant strains of many bacteria, including Salmonella Typhi, vaccination may be a preferred strategy to combat infectious diseases. In the present study, the efficiency of flagellin protein as a recombinant vaccine candidate was evaluated in BALB/c mice. Materials and Methods: For this aim, flagellin protein was expressed in E. coli BL21 (DE3). Mice were grouped into two groups: test and control. The test group was immunized by the intraperitoneal administration of recombinant protein in combination with Freund's adjuvant. Following the completion of the immunization period, the mice were challenged by IP injection of 10 LD50 of live Salmonella Typhi and subsequent culture of their spleens and livers. Results: Flagellin protein expression was confirmed by SDS-PAGE and Western blotting. ELISA showed the proper stimulation of the humoral immunity of the immunized mice. The bacterial count decreased significantly in the spleens and livers of the immunized animals in comparison to the control ones. Conclusions: Findings of this study show the efficiency of flagellin recombinant protein in protecting mice against Salmonella Typhi.