2009年我国部分地区禽白血病分子流行病学调查

Molecular epidemiology of avian leukosis virus isolates from some regions of China in 2009

为了解自2009年年初以来国内一些地区禽白血病流行情况及流行毒株的分子特征,我们从湖北、黑龙江、山东、辽宁、吉林、广东、宁夏、安徽8个省区39个鸡场采集疑似禽白血病病料样品178份,用ALV-A、ALV-B和ALV-J特异性引物,通过PCR方法进行检测。结果表明,8个省的35个鸡场的124份病料中检出了ALV-J(69.7%);25份病料中检出了ALV-A(13.9%);7份病料中检出了ALV-B(3.9%)。14个分离毒株env基因氨基酸同源性为84.3%～99%;与J亚群原型毒株HPRS-103的氨基酸序列同源性为87.3%～98.2%;与其它J亚群env基因氨基酸序列同源性为83%～97.4%。遗传进化分析表明,14个ALV-J分离株分别分属于不同的分支。其中,LJL09DH02分离株与其它分离株及参考毒株的的亲缘关系最远,与HPRS-103的氨基酸同源性仅为87.3%。另外4个分离株的env基因与HPRS-103的氨基酸同源性低于93%,其余9株与HPRS-103的同源性较高(96.6%以上)。该调查结果表明,我国目前ALV的感染主要以J亚群为主,ALV-A和B同时存在。

To determine the extent of avian leukosis virus infection in China in 2009, 178 suspected ALV samples were collected from 39 chicken farms in eight provinces and examined by polymerase chain reaction （PCR） with ALV-A, ALV-B and ALV-J gene specific primers. Among these samples, 129 samples were detected positive for ALV-J （71.7 %）, 25 samples for ALV-A （13.9 %） and 7 samples for ALV-B （3.9 %）. Sequence analysis of 14 selected isolates showed that they shared 87.3 %-98.2 % amino acid sequence identities. Phylogenetic analysis indicated that all 14 isolates belonged to different branches. The LJL09DH02 isolate showed the lowest identity with HPRS-103 （87.3 %） while another isolates showed high identity from 93 % to 96.9 %. These results indicated that ALV-J as the primary pathogen was prevalent in Chinese broiler and layer flocks.