鸭群中REV感染的流行病学调查  

Reticuloendotheliosis Virus infection in ducks–an epidemiological Studies

作　　者：倪楠[1] 崔治中[1] 

机构地区：[1]山东农业大学动物医学院,泰安271018

出　　处：《微生物学报》2008年第4期514-519,共6页Acta Microbiologica Sinica

基　　金："十一五"国家科技支撑计划(2006BAD06A08)~~

摘　　要：【目的】了解网状内皮组织增生病病毒(REV)在鸭群中的感染状态。【方法】从山东省不同地区送检的病(死)鸭中,随机采集法氏囊、脾脏和肝脏等220份样品。细胞培养分离病毒,以提取的组织DNA为模板进行特异性斑点杂交、PCR和nest-PCR检测。从不同地区阳性样品中任选一个进行克隆测序、同源性比较和进化树分析。【结果】从35/39份法氏囊、54/84份脾脏和32/97份肝脏DNA样品中检出REV(121/220)。其中法氏囊的检出率最高,显著高于肝脏、脾脏(P<0.01),但用细胞培养分离病毒、常规PCR、组织DNA直接点杂交检测时,均未检出REV。YN-1和BZ-1株env基因片段与美国分离的鸭源SNV株同源性高达99.8%,LQ-1株env基因片段与美国鸡源分离株的同源性为100%,均高于近几年中国鸡源分离株。【结论】在检测REV感染时,应加强对法氏囊的检测,但由于REV在感染鸭的组织中含量很低,应采用更为敏感的nest-PCR。同源性和进化树分析表明,我国鸭源REV很可能是在引进未经对REV检疫的种鸭时引入的。[Objective] To study the epidemiological status of reticuloendotheliosis virus （REV） infection in ducks. [Methods] Two hundred and twenty tissue samples of the Bursa, spleens and livers were randomly collected from 97 sick or dead ducks from 3 areas in Shandong Province, China. REV infections were tested by virus isolation in cell cultures, direct dot blot hybridization, regular PCR and nest-PCR with tissue-extracted DNA as the templates. PCR products of env gene fragments were cloned and sequenced, sequences of env gene fragments were compared and analyzed. [Results] REV infections were detected in 35/39 （90%） bursal samples, 54/84 （64%） spleens and 32/97 （33%） livers by Nest-PCR. The positive rate of bursal samples was significantly higher than spleen and liver samples （P〈0.01）. No positive sample was detected by virus isolation, direct dot blot hybridization or regular PCR from the same Bursa, spleen and liver samples. In sequence comparisons of amplified env gene fragments, Yinan-1 and Binzhou-1 had 99.8% of identity with reference SNV strain isolated from ducks in USA, and Linqu-1 had 100% identity with two other reference strains isolated from chickens in USA. However, they had lower homology with strains isolated from chickens in China. [Conclusion] More attention should be given to bursal samples in detection of REV. Since REV was existing only at a very low level in infected samples and difficult to be detected, nest-PCR should be conducted as the more sensitive assay. Sequence homology comparisons and phylogenetic tree analysis suggested that REV infections in these ducks may originally come from imported breeder ducklines without insoection for REV.

关 键 词：网状内皮增生病病毒 巢式PCR 病原分离 序列分析 

分 类 号：S858.32[农业科学—临床兽医学]