摘要
对一株鱼源致病菌L1进行了16SrDNA的鉴定、6种毒力基因的PCR检测、溶血素和4种胞外酶的定性分析以及半数致死密度测定和药敏试验。试验结果表明,菌株L1为蜡样芽孢杆菌,携带与腹泻毒素相关的溶血素BL基因、肠毒素T基因、细胞毒素K基因、多效调控因子、非溶血性肠毒素5种毒力基因,不含呕吐基因;并且该菌分泌溶血素、蛋白酶、淀粉酶、脂肪酶、尿素酶;其对斑马鱼96h半数致死密度为3.26×10~8cfu/mL。药敏试验结果表明,该菌对庆大霉素等15种药物敏感。本试验旨在从毒力基因和外毒素角度评估该菌对水产养殖动物的潜在致病性;通过药物敏感性试验,为蜡样芽孢杆菌引起的水产动物疾病防治提供用药参考。
A strain of pathogenic bacterium from diseased half-smooth tongue-sole Cynoglossus semilaevis was identified by 16SrDNA,and 6 kinds of virulence gene were detected by RT-PCR as well as extracellulase activity,and hemolytic activity.The median lethal dosage were determined and drug susceptibility was tested by Kirby-Bauer method.The results showed that the strain was identified as Bacillus cereus with virulence genes of hemolysin（hblC）,enterotoxin（bceT）,cytotoxin（CytK）,and pleiotropic regulator（plcR）,and non hemolytic toxin（nheA）and without cereulide（ces）.The extracellulase activity（hemolysin,proteinase,diastase,lipase and urease）was detected,and the zebrafish was challenged with the pathogenic strain,with 96 hLD50 of 3.26×10^8 cfu/mL.Drug susceptibility testing showed that the strain of bacterium was sensitive to 15 kinds of drugs.The findings evaluate the potential pathogenicity of B.cereus by virulence genes and exotoxin,and provide reference for control of the aquatic animal diseases.
出处
《水产科学》
CAS
CSCD
北大核心
2018年第1期59-65,共7页
Fisheries Science
基金
天津市科技计划项目(15ZXBFNC00290)
关键词
蜡样芽孢杆菌
毒力基因
胞外酶
药敏试验
Bacillus cereus
virulence genel extracellulase
drug susceptibility
作者简介
王琰（1991-），女，硕士研究生；研究方向：水产动物疾病与免疫．E-mail：wangyan．333@qq．com．;通讯作者：刘金兰（1966-），女，教授；研究方向：水产动物疾病与免疫．E-mail：ljlan1115@163．com．
