2011年秋，福建和广东地区养殖的皱纹盘鲍(Haliotis discus hannai)相继暴发死亡。同年12月，我们从广东汕头病区取样分离得到2株弧菌，其中bb3为溶藻弧菌(Vibrio alginolyticus)， bb4为哈氏弧菌(V. harveyi)。本研究以bb3、bb4作为供试菌株对1龄皱纹盘鲍进行侵染实验，获得如下结果：20℃条件下，供试菌及其胞外产物粗提液注射处理均可致受试鲍死亡，浓度2.5×107 cfu/mL 的 bb3与2.0×107cfu/mL的bb4悬液注射可分别引发43.33%和78.02%的受试鲍死亡；供试菌株的致死毒性与注射弧菌的总量正相关，与受试幼鲍的壳长、全湿重负相关；注射或浸泡-创伤两种处理方式均可导致受试鲍死亡，并且因注射供试弧菌而死亡的幼鲍软体部组织被健康鲍取食后也可引发取食者死亡；从侵染实验死亡的受试鲍软体部组织中可重新分离得到这2种供试弧菌。上述结果表明，溶藻弧菌 bb3和哈氏弧菌bb4是皱纹盘鲍的病原菌。药敏试验表明， bb3、bb4均已对抗生素具有一定程度的耐药性，在测试的20种抗生素中，仅有头孢曲松和丁胺卡那霉素是这2株弧菌同时高度敏感的抗生素，但bb3和bb4却对8种抗生素同时表现出抗性。%An incidence of massive mortality of the Pacific abalone, Haliotis discus hannai broke out in Fujian and Guangdong Provinces in the fall of 2011.Two vibrio strains were isolated from moribund juvenile abalones col-lected from a local aquaculture farm in Shantou of Guangdong Province. The strains were identified as Vibrio alginolyticus (Va) and Vibrio harveyi (Vh) in genotype and their toxicities were evaluated through a series of infec-tion experiments. The results indicated that both strains and their extracellular products were lethal to one-year-old Pacific abalone juveniles. Two-week cumulative mortality was 43.33%and 78.02%for animals intramuscle-injected with Va at 2.5×107 cfu/mLand Vh at 2.0×107 cfu/mL, respectively. The abalone mortality was found to be positively related to the concentration of vibrio but negatively related to the size of the abalones. In addition, soaking-wound treatment induced the death of tested abalone. Moreover, healthy abalones were infected by taking soft tissues of dead ones and died ultimately. Both Vibrio strains were isolated again from infected abalone. Antibiotic susceptibil-ity tests indicated drug-resistance in both strains. The Va strain was highly sensitive to six while Vh strain was sen-sitive to only four out of 20 antibiotics tested. Both strains were sensitive to only ceftriaxone and amikacin but were resistant to at least 8 antibiotics among 20 antibiotics tested.
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