金定鸭神经症状相关致病菌分离和鉴定  

Isolation and Identification of Pathogenic Bacteria Associated with Neurological Signs of Jinding Ducks

作　　者：刘贺[1,2] 李琼 黄晶晶 胡晓阳 王笑言 赵辉[3] LIU He;LI Qiong;HUANG Jingjing;HU Xiaoyang;WANG Xiaoyan;ZHAO Hui(Centre for Animal Disease Prevention and Control in Fushun City,Fushun 113006,China;College of Veterinary Medicine,China Agricultural University,Key Laboratory of Animal Epidemiology and Zoonoses of Ministry of Agriculture and Rural Affairs,Beijing 100193,China;Liaoning Academy of Agricultural Sciences,Shenyang 110161,China)

机构地区：[1]辽宁省抚顺市动物疫病预防控制中心,抚顺113006 [2]中国农业大学动物医学院,农业农村部动物流行病学与人兽共患病重点实验室,北京100193 [3]辽宁省农业科学院,沈阳110161

出　　处：《中国畜牧兽医》2023年第12期5114-5122,共9页China Animal Husbandry & Veterinary Medicine

基　　金：国家现代农业产业技术体系(CARS-42-16、CARS-42-32)。

摘　　要：【目的】探究导致金定鸭神经症状的病原菌。【方法】从辽宁金定鸭主产区4个24~48日龄的发病群中选择有神经症状以及纤维素性心包炎、肝周炎和气囊炎病变的病例共22例,用胰酶大豆琼脂(tryptic soy agar,TSA)和麦康凯琼脂(MacConkey’s agar,MCA)从脑组织分离细菌,通过革兰染色和瑞氏染色、生化试验和16S rDNA基因序列分析法对细菌分离株进行鉴定。【结果】从金定鸭脑组织中分离出的19株细菌均为革兰阴性杆菌,其中17株细菌(命名为H1株~H17株)在MCA培养基不生长,在生化试验中呈阴性结果,另外2株细菌(命名为H18株和H19株)在MCA形成红色菌落,能发酵葡萄糖、乳糖和麦芽糖,甲基红与吲哚试验均为阳性。以H1株为代表的17株分离株与血清1~19型的鸭疫里默氏菌(Riemerella anatipestifer,RA)参考菌株之间16S rDNA基因序列相似性为99.1%~100%。分离株H18株和H19株与所选8株大肠杆菌(Escherichia coli,E.coli)参考菌株之间16S rDNA基因序列相似性为99.2%~99.9%。用16S rDNA扩增产物序列进行遗传演化分析的结果显示,以H1株为代表的17株分离株属于RA,分离株H18株和H19株属于大肠杆菌。【结论】在观察的病例中,RA是导致金定鸭表现神经症状的主要致病菌,大肠杆菌亦可导致金定鸭出现神经症状。【Objective】The aim of the present study was to determine the pathogenic bacteria responsible for neurologic signs of Jinding ducks.【Method】Twenty-two sick ducks,which displayed neurologic signs and lesions of fibrinous pericarditis,perihepatitis and airsacculitis,were randomly selected from four 24-to 48-day-old flocks of Jinding ducks from a region with intensive egg-laying duck production in Liaoning province.Brain tissues were sampled and bacterial isolation were performed by using tryptic soy agar(TSA)and MacConkey’s agar(MCA),and identified by Gram and Wright’s staining,biochemical testing,and 16S rDNA gene sequencing.【Result】The 19 strains of bacteria isolated from the brain tissue of Jinding duck were all Gram-negative bacteria.Among them,17(named H1-H17)failed to grow in MCA and tested negative in the biochemical assays,whereas other 2 isolates(named H18 and H19)formed red colonies in MCA,fermented glucose,lactose,and maltose,and were methyl red and indole positive.On the basis of comparative analyses of the 16S rDNA amplicon sequences,the 17 isolates represented by H1 shared 99.1%-100%identities with reference strains of RA serotypes 1 to 19.The H18 and H19 isolates were 99.2%-99.9%identical to the selected eight reference Escherichia coli strains.Phylogenetic analysis based on the amplified 16S rDNA amplicon sequences further demonstrated that the 17 isolates represented by H1 belonged to RA and that isolates H18 and H19 belonged to Escherichia coli.【Conclusion】In the studied cases,RA was responsible for neurologic signs in Jinding ducks,and that Escherichia coli could also cause neurologic signs in Jinding ducks.

关 键 词：金定鸭 鸭疫里默氏菌 大肠杆菌 神经症状 

分 类 号：S855.1[农业科学—临床兽医学]