杂交鲟源鲁氏耶尔森菌的分离鉴定及致病性和药敏特性分析  

Isolation,Identification and Pathogenicity Observation of Yersinia ruckeri from Hybrid Sturgeon(Acipenser.baerii ♀ × Acipenser.schrenckii ♂)

作　　者：任朝颖 高宣 贺蝶 李杨[1] 李芳[1] 薛洋 翟旭亮 吕光俊[1] 朱成科[1] REN Chaoying;GAO Xuan;HE Die;LI Yang;LI Fang;XUE Yang;ZHAI Xuliang;LYU Guangjun;ZHU Chengke(College of Fisheries,Southwest University/Key Laboratory of Freshwater Fish Reproduction and Development(Ministry of Education),Rongchang Chongqing 402460,China;Chongqing Fisheries Technical Extension Center,Chongqing 401120,China)

机构地区：[1]西南大学水产学院/淡水鱼类资源与生殖发育教育部重点实验室,重庆荣昌402460 [2]重庆市水产技术推广总站,重庆401120

出　　处：《西南大学学报（自然科学版）》2024年第11期54-66,共13页Journal of Southwest University(Natural Science Edition)

基　　金：重庆市水产科技创新重点攻关项目(4322200160);重庆市技术创新与应用发展项目(cstc2020jscx-lyjsAX0011);重庆市生态渔产业体系资助项目(4322190028).

摘　　要：为鉴定重庆彭水某养殖场杂交鲟(西伯利亚鲟Acipenser.baerii♀×史氏鲟Acipenser.schrenckii♂)大量死亡的病原体,从病症明显的杂交鲟肝脏中分离获得1株优势菌株PSHS.通过对分离菌株的形态学特征、生理生化特征及16S rRNA,gyrB,rpoB和cpn60基因序列进行鉴定,PCR检测毒力基因携带情况,人工回归感染实验确定其致病性,K-B纸片法对菌株进行耐药性测定,并通过组织切片观察病理变化.结果表明:优势菌株PSHS为鲁氏耶尔森菌(Yersinia ruckeri),该菌含有yhlA,yrp1,yrpA,OmpF,ampC 5种毒力基因,对杂交鲟的半数致死量(LD_(50))为1.8×10^(6) CFU/mL,且发病症状与自然患病相似.药敏结果显示:菌株PSHS对左氧氟沙星、氟苯尼考等6种药物表现出高度敏感;对阿莫西林、杆菌肽等21种抗生素表现耐药.组织病理学观察表明:杂交鲟肝、脾、肾、肠、鳃均有不同程度的损伤,其中以肝细胞变性空泡化和肝血窦充血扩张、肾小球萎缩且炎性细胞浸润、肠绒毛坏死脱落及肌肉层充血表现最为明显.In order to identify the pathogenic bacteria causing massive death of hybrid sturgeon in a breeding farm in Pengshui,Chongqing,a dominant strain named PSHS was obtained from the liver of diseased hybrid sturgeon.The isolated strains were identified by morphological observation,physiological and biochemical characteristics,16S rRNA,gyrB,rpoB and cpn60 gene sequence analysis.The virulence gene was detected by PCR,pathogenicity was determined by recursive infection test,drug resistance was determined by K-B disk method,and pathological changes were observed by biopsy.The identification results showed that the dominant strain PSHS was Yersinia ruckeri based on morphological characteristics,physiological and biochemical characteristics and molecular biological identification results.Virulence gene detection results show that the bacteria containing yhlA,yrp1,yrpA,OmpF and ampC 5 kinds of virulence genes by PCR assay.The recursive infection test showed that the LD_(50) of strain PSHS to hybrid sturgeon was 1.8×10^(6) CFU/mL,and the symptoms were similar to those of natural disease.The results of antibiotic resistance test showed that strain PSHS was highly sensitive to levofloxacin,florfenicol and other six drugs.It was resistant to 21 kinds of antibiotics such as penicillin and erythromycin.Histopathological analysis showed that liver,spleen,kidney,intestine and gill of hybrid sturgeon had varying degrees of lesions,among which the most obvious lesions were hepatocyte degeneration and vacuolation,hepatic sinus congestion and dilatation,glomerular atrophy and inflammatory cell infiltration,intestinal villus necrosis and loss,and intestinal muscle layer congestion.This study reported that the strain of Y.ruckeri PSHS has strong pathogenicity to hybrid sturgeon,which provides a new reference for effective treatment of the disease caused by this strain and safe drug use in breeding and production.

关 键 词：杂交鲟 鲁氏耶尔森菌 分离鉴定 致病性 药敏特性 

分 类 号：S941.42[农业科学—水产养殖]