Open AccessImmunoproteomics of extracellular proteins of the Aeromonas hydrophila China vaccine strain J‐1 reveal a highly immunoreactive outer membrane protein
Author(s) -
Ni Xiaodan,
Wang Na,
Liu Yongjie,
Lu Chengping
Publication year - 2010
Publication title -
fems immunology & medical microbiology
Language(s) - English
Resource type - Journals
eISSN - 1574-695X
pISSN - 0928-8244
DOI - 10.1111/j.1574-695x.2009.00646.x
Subject(s) - aeromonas hydrophila , biology , microbiology and biotechnology , polyclonal antibodies , bacterial outer membrane , recombinant dna , antiserum , antigen , immunogenicity , pathogen , antibody , virology , serotype , bacteria , gene , escherichia coli , immunology , biochemistry , genetics
Aeromonas hydrophila is a gram‐negative bacterium that can infect a variety of aquatic and terrestrial animals. It is essential to develop a vaccine to reduce the economic losses caused by this bacterium in aquaculture worldwide. Here, an immunoproteomic assay was used to identify the immunogenic extracellular proteins of the Chinese vaccine strain J‐1. Ten unique immunogenic proteins were identified from the two‐dimensional electrophoresis immunoblot profiles by matrix‐assisted laser desorption ionization time‐of‐flight mass spectrometry (MALDI‐TOF‐MS) or MALDI‐TOF‐TOF‐MS. One protein of interest, Omp38, was detected by antisera on two‐dimensional immunoblots, suggesting that it might be located both extracellularly and in the membrane. In exploring the potential of Omp38 as a vaccine candidate in fish, we found the omp38 gene to be prevalent by PCR among different (36/48) A. hydrophila isolates. The recombinant Omp38 induced a strong antibody response in rabbits, and the polyclonal antibody could recognize a band of approximately 38 kDa in the immunoblots of outer membrane protein extracts from most (24/40) of the A. hydrophila strains, including different predominant serotypes in China. These results indicated that the outer membrane antigen identified in this study could be developed as a vaccine candidate to induce protective immunity against A. hydrophila infection.