2010年山东省环境污水中脊髓灰质炎病毒的监测及其基因特征分析

Genetic Characterization of Poliovirus Isolates from Environmental Sewage Surveillance in Shandong,2010

本研究在山东省开展了脊髓灰质炎病毒（Poliovirus,PV）的外环境监测,从济南、临沂两地采集污水标本,浓缩处理后进行病毒分离,对分离到的PV采用中和试验进行血清定型,并对其VP1及3D区进行序列测定,分析其基因突变和重组情况。2010年,共采集污水标本32份,PV阳性10份,阳性率31.3%;分离到18株PV（PV1型3株,PV2型9株,PV3型6株）,均为疫苗相关株,VP1完整编码区核苷酸变异数在0~4个之间,在3株PV2型病毒和4株PV3型病毒的基因组中发现重组;对VP1区影响神经毒力的减毒位点分析发现,PV1型病毒中有1株在nt 2 749发生突变（A→G）,PV2型病毒中有1株在nt2 908发生A→G突变,3株在nt2 909发生U→C突变,6株PV3型病毒全部在nt2 493发生C→U突变。环境污水中可以分离到PV,其基因重组率和主要减毒位点的回复突变率较高,未发现脊灰野毒株和疫苗衍生株脊灰病毒（Vaccine-derived poliovirus,VDPV）。

To investigate the genetic characteristics of poliovirus isolates from environmental sewage surveillance in Shandong province,we collected sewage samples in Jinan and Linyi City.Serotyping and VP1/3D sequencing were performed on polioviruses isolated from the concentrated sewage samples,and VP1 mutation and recombination were analyzed.Thirty-two of sewage samples were collected,and polioviruses were detected in 10 of the samples with a positive rate of 31.3%.Eighteen Sabin strains were isolated including three type 1,nine type 2,and six type 3 polioviruses,and the number of nucleotide substitutions in VP1 coding region varied from 0 to 4.Recombination was found in three Sabin 2 and four Sabin 3 polioviruses.Analysis of neurovirulence sites of VP1 revealed that one Sabin 1 vaccine strain had a nucleotide change of A to G at nt 2749,one Sabin 2 strain had a nucleotide change of A to G at nt 2908,three Sabin 2 strains had a nucleotide change of U to C at nt 2909,and all six Sabin 3 strains had a nucleotide change of C to U at nt 2493.Poliovirus vaccine strains could be isolated from environmental sewage with a high rate of gene recombination and back mutation of neuvirulence-associated sites.None of wild-type poliovirus or vaccine-derived poliovirus was detected.