Cloning and expression of the fusion protein FimH/FliC from Uropathogenic Escherichia coli (UPEC) isolate from Iran

Urinary tract infection (UTI) is one of the most common infections in the world. The majority of UTI caused by Uropathogenic Escherichia coli (UPEC) strains. FimH and FliC are the most important virulence factors of UPEC. To date, any ideal vaccine against UTI has not been approved for human use and we need to test new target to develop an ideal vaccine against UTI. In this study, we constructed fusion FimH/FliC of UPEC as a novel vaccine candidate against UTI. PCR amplification of fimH and fliC genes of the UPEC isolates was performed by specific primers designed for this purpose. Construction of fimH/fliC hybrid gene was performed by overlap PCR. The fimH, fliC and fimH/fliC were cloned in pET28a vector. The confirmation of expression of the proteins was done by SDS-PAGE and Western blot. The fliC and fimH genes were amplified in all of the UPEC isolates tested. The fimH showed significant homology with the sequences in GenBank. We generated a fusion consisting of the fimH gene linked to the N-terminal end of fliC. Sequencing of the fusion fimH/fliC showed that fusion was constructed precisely. SDS-PAGE and western blot confirmed the expression of the proteins in optimized condition. Urinary tract infection is a huge burden on healthcare system in many of the countries. UPEC isolated in around 80% of UTI cases. Antibiotic therapy resulted in the emergence of antibiotic resistance in UPEC strains. This is the major cause for an increasing requirement to vaccine to prevent UTI. This work describes for the first time the construction of a novel fusion protein from Iranian UPEC isolate. Further immunological studies are required for evaluation of this protein as a novel and safe vaccine candidate against UTI caused by UPEC.