贵州省2004年分离到的脊髓灰质炎病毒分子生物学特征

目的研究贵州省2004年分离到的脊髓灰质炎(脊灰)病毒分子生物学特征。方法对贵州省2004年分离到的所有脊灰病毒,用聚合酶链反应-限制性酶切片段长度多态性分析(PCR-RFLP)和酶联免疫吸附试验(ELISA)法进行了型内鉴定,并对型内鉴定异常株进行了VP1区的序列测定。结果贵州省在2004年急性弛缓性麻痹(AFP)病例及接触者、流动人口和健康儿童的粪便标本中,共有95例分离到脊灰病毒。其中Ⅰ型22例,Ⅱ型26例,Ⅲ型21例,混合型19例,脊灰病毒混合非脊灰肠道病毒7例。经用PCR-RFLP和ELISA方法进行型内鉴定,共有16株病毒与疫苗株病毒存在差异,其中3株脊灰病毒与疫苗株病毒在PCR-RFLP图谱上有差异[其中1株同时为双反应(DRV)],3株ELISA结果为DRV,11株ELISA结果为非疫苗类似株(NSL)。在这些型内鉴定异常株病毒中,Ⅰ型13株,Ⅱ型3株。对这16株脊灰病毒进行VP1区序列测定,发现9株Ⅰ型疫苗衍生脊灰病毒(VDPV)和1株Ⅱ型VDPV。结论根据对贵州省2004年从95例AFP病例及接触者、流动人口、健康儿童分离的脊灰病毒的血清定型结果和型内鉴定结果及对13株Ⅰ型和8株Ⅱ型脊灰病毒VP1区核苷酸序列测定证实,脊灰减毒活疫苗病毒在人群的循环导致疫苗病毒神经毒力恢复突变。通过AFP病例监测系统及时发现了Ⅰ型VDPV的循环和Ⅱ型VDPV。对2004年下半年脊灰病毒基因特点的分析,提示贵州省已经阻断了Ⅰ型VDPV的循环。

Molecular Biology Characterization of the Poliovirus Isolates of Guizhou in 2004

Objective Investigation the Gene characterization of the polioviruses isolated from AFP cases in Guizhou Province in 2004. Methods Both PCR-RFLP and ELISA were used to identify these isolates and the sequence of VP_1 code gene of the aberrant isolates were determined and analyzed. Results In 2004, 95 polioviruses were isolated from the stool samples of AFP cases,contactors,floating people,and healthy children in Guizhou Province.In these poliovirus isolates, 22 were type , 26 were type ,21 were type ,19 were mixer,7 were polioviruses mixed with non-poliovirus enterovirus (NPEV). Both PCR-RFLP and ELISA as routine intratypic differentiation (ITD) method to identify all the poliovirus isolates. We found that comparing with Sabin strains,3 isolates had aberrant enzyme-cut maps by PCR-RFLP method,3 isolates were double reaction virus (DRV) by ELISA method and 11 isolates were non-sabine like (NSL) by ELISA method. In these isolates,13 were type and were type , Further more,we sequenced complete VP_1 code gene for the 16 isolates. 9VDPVs and 1 VDPV were detected. ConclusionThrough both serotyping and ITD of 95 polio isolates isolated from AFP cases in Guizhou in 2004,and sequence analysis of VP_1 gene of 13 type isolates and 8 type isolates indicated that vaccine virus had (circulated) short-term among limit children in Guizhou in 2004,and thepartial neurovirulence attenuated site had reversed in some polio isolates.The VP_1 gene characterization analysis confirmed that VDPVs had limit circulated and has been interrupted after complementary immunization.This research provides a strong scientific data for finding the VDPV,cVDPVs, and certifying that the cVDPVs circulating has been interrupted.