1986--2011年广西猪瘟流行监测及遗传变异分析

Epidemic surveillance and genetic variation analysis of swine fever virus in Guangxi in the past 25 years

采用Nested-PCR方法对采自广西各地1986-2011年间,199个猪场(养殖户)的1 521份样品进行CSFV、PRRSV、PCV2、PRV、HPS等病原的检测及流行病学调查,结果发现广西猪瘟以混合感染为主,病性复杂。尽管保育猪发病仍占第1位,但近年来母猪繁殖障碍、无症状带毒感染的发病率已明显提高。通过对25年来收集的77株广西CSFV流行株E2基因的比较分析,发现广西猪瘟流行株分为基因I群和II群,目前仍未发现基因III群。起源于欧洲大陆的S2.1亚型毒株已经成为广西的优势流行株,多引起临床的急性和亚急性感染;以SHIMEN株为代表的中国经典毒株S1.1亚型是造成母猪繁殖障碍、隐性带毒感染的主要毒株。流行于20世纪80-90年代间的基因S2.2及S2.3亚型毒株已经基本消失,值得进一步研究。广西CSFV流行株E2蛋白部分关键氨基酸位点已经发生变异,可能会导致疫苗的不完全保护。

One thousand five hundred and twenty one samples from 199 farms （farmers） in Guan gxi in the last 25 years （19862011）were detected by NestedPCR method for detection and the epidemiological survey of as CSFV, PRRSV, PCV2, PRV, HPS. The results showed that mixed infec tion was dominant with the CSF in Guangxi, showing a complexity in type of the disease. Although incidence in weaned piglets still accounted for the first place,a significant boost was shown in re productive failure and asymptomatic infection with virus in sows,in the resent years. Comparative analysis of 77 CSFV Guangxi epidemic strains of E2 gene collected in the last 25 years demonstra ted that the currently popular CSFV in Guangxi contains gene group I and group II,whereas gene group III has not been perceived so far. But the S2.1 subtype originated in continental Europe has become dominant epidemic strains in Guangxi, generally causing acute and subcute clinical infec tion. The native typical gene SHIMEN strains of S1.1 subtype remains epidemic in Guangxi pigs, being the main strains in causing reproductive failure in sows and hidden infection with virus; gene S2.2 and S2.3 subtype prevailing during the 1980s and 1990s have disappeared, the causes of which de serve further study. The key E2 protein amino acid sites of CSFV Guangxi epidemic strains have mutated, which may lead to unsound protection of the vaccine.