涅斯捷连科氏菌对仿刺参的致病性初步研究

The Pathogenicity of Bacterium Nesterenkonia halotolerans to Sea Cucumber (Apostichopus japonicus)

2005-2007年在大连、营口地区室内养殖仿刺参幼参阶段发生附着基和池壁变红现象,同时伴随池内幼参体壁溃疡、死亡。对变红的附片和患病幼参进行病原菌分离,结果均分离出一株在TCBS和2216E培养基上显示绝对优势的桔红色菌株。人工回接感染试验表明,该菌株对仿刺参具有一定致病性。通过菌株培养特征观察、生理生化特性试验和16SrRNA分析,鉴定该优势菌为耐盐捏斯连科菌。该菌最适生长温度25～37℃、最适合生长pH 7.6～8.0、食盐质量分数超过6%生长最旺盛。药敏试验结果表明,对先锋V、先锋必、先锋Ⅵ、先锋孟多、头胞氯氨苄、新霉素、万古霉素、乙酰螺旋霉素、强力霉素、二甲胺四环素、呋南妥因、萘啶酸、氟嗪酸、氟罗沙星显示高度敏感,对头胞噻肟和复方新诺明不敏感。

The reddening phenomenon was found in attachments and tank walls in sea cucumber （Apostichopusjaponicus） culture in Dalian and Yingkou from 2005 to 2007, being accompanied by skin ulceration and death in the sea cucumber juveniles. A dominant bacterial strain was isolated from the red attachment substrate and the infected sea cucumber by TCBS and 2216E media, and always showed orange in color. Artificial infection assays showed that the bacterium had a degree of pathogenicity to the sea cucumber, and was Nesterenkonia halotolerans by characteristic observation of culture, biochemical characterization and direct sequencing of 16S rRNA gene. The biochemical characterization revealed that the strain had good growth at pH 7.6-8.0, temperature range of 25-37 ℃ and a salinity of over 6%. Drug sensitivity tests showed that the bacterial strain was found to be much sensitive to Cefamezin, Cefobid, Velosef, Cefamandde, Cefador, Neomycinum, Vancomycinum, Acetylspiramycinum, Vibramycin, Minocycline, Nitrofurantoin, Nalidixic Acid, Ofloxacin and Fleroxacin, and no sensitive to Claforan and TMP/SMZ, which will be helpful in the disease control and health management during sea cucumber culture.