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从急性弛缓性麻痹（ＡＦＰ）病例分离的３２株脊髓灰质炎（脊灰）病毒，在ＷＰ１编码区，经ＰＣＲ－ＲＦＬＰ方法鉴定，并经核酸测序进一步证实为疫苗株。其中５株为Ⅰ型疫苗株，１６株Ⅱ型疫苗株，１１株Ⅲ型疫苗株。以同样的分析方法检测这些毒株基因组的３Ｄ聚合酶编码区，发现２株Ⅰ型疫苗株在３Ｄ区的４３１个核苷酸序列为野毒序列，即这２株为Ｓａｂｕｎｌ因型（ＶＰ１）与野毒基因型（３Ｄ）重组株；其余３株Ⅰ型疫苗株未发现基因重组，１６株Ⅱ型疫苗株中１１株为Ｓａｂｉｎ２基因型（ＶＰ１）与Ｓａｂｉｎ３基因型（３Ｄ）重组株，３株为Ｓａｉｂｎ２基因型（ＶＰ１）与（Ｓａｂｉｎ１＋Ｓａｂｉｎ２）基因型（３Ｄ）重组株，其余２株未发现基因重组。１１株Ⅲ型疫苗株中只有１株发生重组，为Ｓａｂｉｎ３基因型（ＶＰ１）与Ｎｏｎ－Ｓａｂｉｎ基因型（３Ｄ）重组株。另外，对５＇末端非编码区与神经毒力相关的关键位点（Ⅰ型的４８０－Ｇ和５２５－Ｕ，Ⅱ型的４８１－Ａ及Ⅲ型的４２２－Ｕ）基因的检测发现，５株Ⅰ型疫苗株中，１株在位点５２５－Ｕ突变，碱基Ｃ置换Ｕ；３株在位点４８０－Ｇ突变，碱基Ａ置换Ｇ；另１株未发现突变。１６株Ⅱ型疫苗株均在位点４８１－Ａ突变，碱基Ｇ置换Ａ。
Thirty-two poliomyelitis (poliovirus) isolates from acute flaccid paralysis (AFP) cases were identified by PCR-RFLP in the WP1 coding region and further confirmed as vaccine strains by nucleic acid sequencing. Among them, 5 were Type I vaccine strains, 16 Type II vaccine strains and 11 Type III vaccine strains. The 3D polymerase coding region of these strains was detected by the same analysis method. The 431 nucleotide sequences of the two strains of type I strain in the 3D region were wild-type sequences, that is, the two strains were the Sabunl type (VP1) And wild type genotype (3D) recombinant strains. The remaining three strains of type I vaccine strains found no gene recombination. Among the 16 strains of type II vaccine strains, 11 strains were Sabin2 genotype (VP1) and Sabin3 genotype (3D) For Saibn2 genotype (VP1) and (Sabin1 + Sabin2) genotype (3D) recombinant strains, the remaining two strains found no genetic recombination. Only one of the 11 Type III vaccine strains was recombinant, which was a Sabin3 genotype (VP1) and Non-Sabin genotype (3D) recombinant strain. In addition, the detection of neurotoxicity-related key sites (type I 480-G and type 525-U, type II 481-A and type III 422-U) genes in the 5 ’ One strain of strain I strain 525-U mutated at site 525-U and the base C replaced U; three had 480-G mutation at site A and G replaced at base A; and no mutation was found in the other strain. The 16 strains of type Ⅱ vaccine were all mutated at site 481-A and the base G was replaced by A.