Fusion Expression Of OmpTS Gene With Hly Gene Of Aeromonas Hydrophila Strain BYKAH2008AC

Extracellular protease, S layer protein and the membrane protein are important virulencegenes of Aeromonas hydrophila. Hemolysin decrease toxicity vaccine has high efficiency inlaboratory protective test. The outer membrane protein gene is a important adhesion factor andprotective antigen, not only can effectively arouse humoral immunity and cellular immunity, butalso can have immune cross response to other strains with different serum type. These twogenes have been proved to be protective antigens against Aeromonas hydrophila.In this study primers were designed in accordance with the gene OmpTS and Hlysequence of A.hydrophila published in GenBank.（1）With the specific primers, their codingregions encoding335amino acid and461amino acid respectively were amplified by PCRmethod and cloned in to pET32a vector linking by flexible clips.（2）Homology analysisshowed that the protein encoded by BYKAH2008AC OmpTS gene has95.9%homology andthe protein encoded by BYKAH2008AC Hly gene has99%homology with other serum typeAeromonas hydrophila.（3）After transformed into E.coli DH5a and induced with IPTG，thel08kD fusion engineered protein was expressed as expected.（4）After purified by Ni2+afinitychromatography, the protein was used to immunize the rabbit to produce antiserum. TheELISA result showed that the titer of antiserum was above1:40000. Western blot analysisshowed that rabbit antiserum to OmpTS and Hly all reacted with this fusion engineered protein，which indicated the fusion protein may have similar epitopes to these natural proteins．All thesefindings suggest that this recombinant OmpTS-Hly has the potential to be candidatecomponents of an effective vaccine in fish against the infection of A.hydrophila.