Expression of recombinant outer membrane protein 48 (OMP48) developing vaccine against aeromonas hydrophila infection

Abstract

Aeromonas hydrophila is one of the most common pathogen in aquaculture causing hemorrhagic septicemia. This Gram-negative bacterium can infect a wide variety of animals resulted in high economic losses. In this study, the gene omp48 coding for outer membrane protein (omp) was amplified from the A. hydrophila B66 strain. This sequence was then cloned into pET28a vector and expressed in Rosetta E. coli expression strain under the IPTG induction. The multiple alignment results showed that rOmp48 proteins had higher identities with ML09-119 strain isolated from disease outbreak than ATCC 7966.The expression of recombinant protein showed the best results in the induction of 0.75 mM IPTG concentration at 37C for 4 hours. The rOmp48 was produced mostly in insoluble state at varying temperatures from 16C to 37C. Later, the recombinant protein was purified by affinity chromatography with Nickle beads and injected to catfish. Fish immunized with rOmp48 showed significant difference of survival percentage compared to control fish. In conclusion, rOmp48 in the present study has shown its ability to protect striped catfish from A. hydrophila infection. Keywords: Aeromonas hydrophila; expression; Outer membrane protein; striped catfish; vaccine