摘要
取某养殖场健康狐狸 (6 1份 )、貉 (2 4份 )粪样 ,用套式PCR(RT-nPCR)方法检测犬冠状病毒 (CCV)并进行基因型鉴定。结果显示 :狐狸粪样中有 4 3份 (70 . 5 % )为CCVⅡ型阳性 ,2 9份 (47. 5 % )为CCVⅠ型阳性 ,两型混合感染2 5份 ,占 4 1 0 % ,两型总感染率为 77 .0 %。 2 4份貉粪样中 ,2 2份为CCVⅡ型阳性 (91 .7% ) ,其中 16份为CCVⅠ型、Ⅱ型混合感染 (6 6 . 7% )。分别取狐狸和貉粪样中CCVⅠ、Ⅱ型阳性PCR产物各 2份 (共 8份 )进行测序 ,均与CCV的M基因序列相符 ,证实PCR结果非假阳性。序列及系统进化分析表明 ,CCVⅠ型与源于意大利腹泻犬的CCVⅠ型 (AF5 0 2 5 83)同源性最高 (96 . 7%～ 98. 1% ) ;CCVⅠ、Ⅱ两种基因型同源性为 88. 3%～ 89. 7% ,在进化树中处于两个大的分支上 ;同为CCVⅡ型 ,狐狸源与貉源序列也存在多个位点差异。首次在貉粪中检出CCV ,证实在健康狐狸、貉群体中存在CCV流行 ,且CCVⅠ、Ⅱ型并存。
fecal samples from healthy foxes and 24 from healthy raccoon dogs were examined by RT-nested PCR assays for the presence and genotypic identification of Canine coronaviruses (CCVs). 77.0 fox samples were recognized as CCV positive, 43 of which belonged to type Ⅱ and 29 to type Ⅰ, as well as both genotypes were simultaneously detected in 25 samples. Out of the total 24 fecal samples from raccoon dogs, 22 were CCV positive for type II and 16 for type Ⅰ. M gene fragments of 8 samples were sequenced, 4 of which were confirmed as CCV type Ⅰ and the other 4 as CCV type Ⅱ. Sequence analysis showed that the M gene of CCV type I had a high similarity of 96.7～98.1 between the fox-and raccoon dog strains and the reported Italian strain from diarrhea dogs.The two genotypes, with an identity of 88.3～89.7, formed two separate branches in phylogenetic tree. Interestingly, the sequence at several nucleic acid sites of CCV type Ⅱ differed between foxes and raccoon dogs. The co-existence and popularity of the two CCV genotypes in healthy foxes and raccoon dogs were first confirmed in this article.
出处
《微生物学报》
CAS
CSCD
北大核心
2005年第2期305-308,共4页
Acta Microbiologica Sinica
基金
上海科技兴农重点公关项目〔农科攻字 (2 0 0 3 )第D 1号〕~~
