A New Approach for Designing a Potentially Vaccine Candidate against Urinary Tract Infection by Using Protein Display on Lactobacillus

Background: The prevalence of Urinary Tract Infection (UTI) is really high in the world. Escherichia coli is a major agent of UTI. One of the strategies for decreasing UTI infections is vaccine development. As the attachment is a really important stage in colonization and infection, at- tachment inhibition has an applied strategy. FimH protein is a major factor during bacterial colonization in urinary tract and could be used as a vaccine. Thus, it was considered in this research as a candidate anti- gen. Methods: The sequences of fimH and acmA genes were used for de- signing a synthetic gene. It was cloned to pET23a expression vector and transformed to E. coli (DE3) Origami. To confirm the expression of recombinant protein, SDS-PAGE and western blotting methods were used. Subsequently, recombinant protein was purified. On the other hand, Lactobacillus reuteri was cultured and mixed with FimH / AcmA recombinant protein. The rate of protein localization on lactobacillus surface was assessed using ELISA method. Results: It was showed that the recombinant protein was expressed in E. coli (DE3) Origami and purified by affinity chromatography. More- over, this protein could be localized on lactobacillus surface by 5 days. Conclusion: In current study, a fusion recombinant protein was pre- pared and displayed on L. reuteri surface. This strain could be used for animal experiment as a competitor against Uropathogenic E. coli (UPEC). Using manipulated probiotics strains instead of antibiotic ther- apy could decrease the antibiotic consumption and reduce multi-drug resistant strains.