Multi-aspect molecular and stractural bioinformatic study of outer membrane protein (OmpTS) of Aeromonas hydrophila common cause of infectious septicemia in fish for immunization goals

Aeromonas hydrophila, a mobile gram-negative bacteria, is widely considered as an opportunistic and zoonotic bacteria of warm-water fish pathogens. The high incidence of fish mortalities, economic losses, and bacterial resistance have highlighted the need to develop new strategies such as vaccination for prevention and treatment against A.hydrophila. In regards to recent studies, OmpTS a virulence factor located in outer membrane of A.hydrophila. Due to importance of bacterial septicemia, molecular and stractural bioinformatic study of OmpTS to immunization of fish is neccessary. In this study, A.hydrophila isolated from the kidney of infectious Acipenser persicus were examined by biochemical tests e.g. Oxidase, Catalase, TSI, SIM, Asculin, Nitrate and Sugar tests. Dedicated primers were designed based on OmpTS gene, then PCR products were used for DNA sequencing. Finally, the phylogenetic tree and protein structures (first, second and third) were prepared for further information about structure and characteristic of OmpTS. Biochemical tests and DNA sequencing confirmed A.hydrophila isolated from the kidney of infectious Acipenser persicus. Based on phylogenetic tree reports, OmpTS of A.hydrophilasis more similar to A.aquariorumand lessto A.diversa. Structural analysis of OmpTS indicated its stability under laboratory handling conditions. In addition, active sites of OmpTS was attributed to the sequence between 102-340 amino acids. Adequate preventive measures in order to avoid the serious consequences of water infections especially with gram-negative bacteria should be employed in Aquaculture industry. On the other hand there are no bioinformatic data on the OmpTS. Our results demonstrated that OmpTS gene can be potentiated to immunization of fish against A.hydrophila infection.