泗洪地区克氏原螯虾病原维氏气单胞菌鉴定及致病性分析  

Identification and pathogenicity analysis of Aeromonas veronii isolated from Procambarus clarkia in Sihong

作　　者：汤环宇 钱且奇 陈圳 徐静雯 朱玉洁 许文静 姬进宝 高策 张晓君[1] TANG Huan-yu;QIAN Qie-qi;CHEN Zhen;XU Jing-wen;ZHU Yu-jie;XU Wen-jing;JI Jin-bao;GAO Ce;ZHANG Xiao-jun(College of Animal Science and Technology,Yangzhou University,Yangzhou 225009,Jiangsu,China)

机构地区：[1]扬州大学动物科学与技术学院,江苏扬州225009

出　　处：《淡水渔业》2023年第4期61-71,共11页Freshwater Fisheries

基　　金：江苏省政策引导类“富民强县”项目(SZ-SQ20210567,SZ-SQ2021055)。

摘　　要：为了探究江苏省泗洪县多家养殖场克氏原螯虾(Procambarus clarkii)出现暴发性死亡的病因,本研究以濒死的克氏原螯虾进行病原检测分析,从濒死虾肝胰腺中分离到优势生长菌(菌株编号CPA2020),经对分离菌进行致病性、形态与生理生化特征及gyrB基因同源性与系统发育分析,结果表明引起克氏原螯虾暴发性死亡的病原为维氏气单胞菌(Aeromonas veronii),人工感染实验结果表明分离菌CPA2020对克氏原螯虾具有较强的致病性,LD 50为6.31×10^(5) CFU/mL。组织病理学观察发现克氏原螯虾的肝胰腺与肠道组织出现严重的病理损伤,肝细胞裂解,空泡化严重,部分肝细胞坏死,肠壁结缔组织萎缩,皱嵴减少,肠上皮细胞坏死,与自然患病虾的病理变化相同。毒力基因检测表明分离菌CPA2020携带lip、hly、flgN、ompA、flgM、flaH、aha和flgA 8种毒力基因。此外分离菌CPA2020可分泌卵磷脂酶、明胶酶和溶血素。耐药谱测定结果显示,该菌对链霉素、万古霉素、环丙沙星等12种药物耐药,对头孢唑林、克拉霉素等9种药物中介,对头孢呋辛、左氟沙星、氨曲南等13种药物敏感。A dominant strain CPA2020 was isolated from the hepatopancreas of moribund Procambarus clarkii to identify the pathogen of the outbreak of the disease in cultured Procambarus clarkii in Sihong,Jiangsu Province.It was identified as Aeromonas veronii based on morphological observation,biochemical identification,physiology characteristics and sequencing of and gyrB gene.In the challenge test,the symptoms of P.clarkii artificially infected with strain CPA2020 were similar to those of naturally infected P.clarkia.Histopathological analysis revealed that hepatopancreas and intestinal epithelial cells became necrotic and damaged,accompanied by atrophy of the intestinal connective tissue and reduced wrinkled ridges.LD 50 value of the strain CPA2020 to P.clarkii was 6.31×10^(5) CFU/mL.Detection of virulence-associated genes by PCR indicated that the isolated strain carried 8 virulence genes:lip,hly,flgN,ompA,flgM,flaH,aha and flgA.The results of extracellular enzyme detection showed that the isolated strain could secrete lecithinase,gelatinase and hemolysin.The drug resistance test results showed that the strain was resistant to 12 kinds of drugs,such as cotrimoxazole,vancomycin and streptomycin,mediated by nine kinds of drugs,such as cefazolin and clarithromycin,which was sensitive to 13 kinds of drugs such as aztreonam,cefuroxime and levofloxacin.This study aimed to explore the pathogenicity and drug resistance of CPA2020 from P.clarkia.It could provide a reference basis for preventing and controlling A.veronii in aquatic animals.

关 键 词：维氏气单胞菌(Aeromonas veronii) 克氏原螯虾(Procambarus clarkii) 致病性 耐药性 

分 类 号：S945[农业科学—水产养殖]