致病性嗜水气单胞菌保护性抗原的研究

本试验采用SDS－PAGE对10株嗜水气单胞菌（Ah）的外膜蛋白（OMP）和脂多糖（LPS）进行分析，结果显示大多数菌株具有相似的OMP图谱，而LPS则有较大的差异，用鲫鱼抗AhJ-1株全菌血清进行免疫转印，发现S蛋白（S－layerProtein）是70％Ah菌株的共同抗原，而LPS则有明显的抗原多样性，AhJ－1株抗血清仅能与同源菌株起反应。用AhJ－1株HEC毒素（Hemolvticactivity，Enterotoxicity，Cytotoxicity，HEC）的单克隆抗体检测此10株Ah，8株细菌可产生抗原性相同的HEC毒素。用纯化的AhJ－1株的S蛋白、LPS及HEC毒素（预先天活）分别免疫小鼠，强化免疫后，对同源菌株的攻击均能完全保护；S蛋白免疫组和HEC毒素免疫组对异源菌株TPS－30的攻击均能保护，而LPS免疫组则不能完全保护。上述结果表明，S蛋白和HEC毒素是Ah的主要共同保护抗原。AhJ-1株有望成为预防嗜水气单胞菌败血症的疫苗生产菌株。

Analysis of the Protective Antigens of Phthogenic Aeromonas hedrophila

Outer membrane protein(OMP) and lipopolysaccharide(LPS) of Aeromona hydrophila were analyzed by SDS -PAGE. The results showed that different strains of Aeromonas hydrophila had different LPS patterns but similar OMP profiles.Immunoblotting with antibodies against whose cell antigen of A. hydrophila strain J-1(Ah J-1)revealed that S-layer protein was a common surface antigen among A. hydrophila. Antigenicity of S-layer proteins of A. hydrophila(7/10) was the same as that of Ah J-1,but LPS presented divergent antigenicity.Most strains of A.hydrophila(8/10) produced HEC toxin with the same antigenicity, as indicated by DoT-ELISA with monoclonal antibodies against HEC toxin of Ah J-1. Not only HEC toxin but also S-layer protein and LPS of Ah J-1 induced strong protective immune response against challenge with homogeneous virulent bacterial strain.It could be concluded that S-layer protein and HEC toxin are common protective antigens of A. hydrophila and Ah J-1 may be used as vaccine-producing strain.