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

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)。

Genetic characterization of poliovirus isolates from environmental sewage surveillance in Shandong, 2010

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.