中文摘要：

为分析嗜水气单胞菌现今流行菌株与20世纪80年代末分离的国内疫苗生产株J-1在生物学特性上的差异,对2009-2010年分离的5株嗜水气单胞菌进行了溶血性、溶蛋白性、外膜蛋白图谱、ERIC-PCR图谱分析及斑马鱼致病性试验,并与J-1株作对比。结果显示：5株菌均溶血、溶蛋白,且来自发病鱼的4株菌（NJ-35、XX-52、XY-16、CS-43）胞外产物的活性与J-1株相似,但高于来自健康鱼的菌株（JH-17）。斑马鱼致病性试验表明,来自发病鱼的4株菌毒力较强,LD50为1.2×10^2～6.9×10^3 CFU/mL,均属强毒株;来自健康鱼的菌株和J-1株毒力较弱,LD50高于1.0×10^6 CFU/mL。外膜蛋白及ERIC-PCR图谱分析显示,来自发病鱼的4株菌相似,而与来自健康鱼的菌株明显不同;同疫苗菌株J-1相比,4株来自发病鱼菌株的ERIC-PCR图谱与之相似,但外膜蛋白图谱与之有较大差别。说明疫苗菌株J-1在外膜蛋白表达上与现今流行菌株有一定差别。

英文摘要：

To investigate the discrepancy in biological characteristics between epidemic strains and Chi- nese vaccine strain J-1 of Aeromonas hydrophila ,five strains of A. hydrophila isolated in 2009-2010 were selected for detection of hemolytic and proteolytic activities, outer membrane protein（OMP） and ERIC- PCR profiles,and virulence in zebrafish. The Chinese vaccine strain J-1 was used as control. The results showed that the five strains of bacteria had hemolytic and proteolytic activities, and the activities of 4 strains（NJ-35, XX-52,XY-16 ,CS-43） from diseased fish were similar to that of J-1 ,but higher than that of bacterial strain（JH-17） from healthy fish. The virulence assay in zebrafish showed that the 4 strains were more virulent and their LD~0 were between 1.2×10^2 and 6.9×10^3 CFU/mL,but JH-17 and J-1 were weak, and their LD50 were higher than 1.0×10^6 CFU/mL. OMP and ERIC-PCR profiles analysis showed that the 4 strains were similar,but significantly different from JH-17. In comparison with the vaccine strain J-1 ,the 4 strains were similar in ERIC-PCR profile, but different in the OMP profile. It suggests that there exists a difference in the expression of OMP between the epidemic strains and Chinese vaccine strain J-1.