牙鲆鱼肠道弧菌感染症及病原特性研究

对一起养殖牙鲆Paralichthys olivaceus病害进行了发病情况、临床表现、病理变化及病原学方面的检验,结果表明为细菌性败血感染症。经过对10尾病(死)牙鲆做病变肝组织及腹水中细菌的染色检查,取其中6尾的肝、肾、腹水为材料做细菌分离与纯培养后进行形态及理化特性测定,选择代表菌株进行16S rRNA基因序列测定及系统发育学分析,结果表明分离做纯培养的12株菌(HQ010223-1至HQ010223-12)为同种细菌———弧菌属Vibrio的鱼肠道弧菌V.ichthyoenteri。经以代表菌株(HQ010223-1)对健康牙鲆做人工感染试验,表明该菌在所检牙鲆病例的相应病原学意义;用37种抗菌类药物对6株菌所做的药敏试验,结果显示在不同菌株间无明显的敏感与耐药性差异。

Infection and characterization of Vibrio ichthyoenteri isolated from flounder (Paralichthys olivaceus)

A disease of farmed flounder was examined,including conditions of disease,clinical signs,pathological changes and pathogens.The results showed that the disease belonged to bacterial septicaemia.The bacteria from liver and ascitic fluid of 10 diseased or dead flounder were dyed and examined,isolation and pure culturing of pathogenic bacteria from kidney,liver,spleen and ascitic fluid of 6 examined moribund fish were conducted,and the morphological characteristics and physiological and biochemical characteristics of isolates were detected.In addition,the 16S rRNA genes of representative strain were sequenced and a molecular phylogenetic tree was constructed.The results showed that the examined 12 strains(HQ010223-1 to HQ010223-12) were identified as V.ichthyoenteri(Ishmaru et al,1996) of Vibrio(Pacini 1854).Artificial infection experiments of representative strain(HQ010223-1) to healthy flounder were conducted,the results showed corresponding pathogenicity of the strain.The tests of antibiotic sensitivity of 6 strains to used thirty-seven antimicrobial agents showed that there was no difference in sensitivity and resistance between strains.