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目的 研究丙型肝炎病人系列血清标本的丙型肝炎病毒 (HCV)基因型变化及HCV膜区基因变异和“准种”现象。方法 对 4例因献血感染HCV病人的系列血标本 ,用特异性引物PCR扩增检测 ,5′ NCR和核心区测序确定HCV基因型 ,并对标本膜区基因进行克隆 ,每个标本随机选择 5～9个克隆进行测序分析。结果 发现随着时间推移 ,存在HCV基因型的转换现象。在 2种HCV基因型转换期存在混合感染。所有测定序列均为 1b或 2a或 1b +2a基因型。对从部分血样中获得的 5～9个克隆测序表明 ,在不同克隆间虽然存在一定的核苷酸差异 ,但在 5 70nt长度的序列中 ,仅有 0 8～4 5 6个核苷酸差异。结论 HCV基因变化是多层次的。同一病人可混合感染不同基因型HCV ,HCV膜区基因有随时间而发生变异现象。但在本研究的标本中 ,通过对同一标本基因多个克隆的序列测定 ,未见明显的“准种”现象。
Objective To study the changes of hepatitis C virus (HCV) genotypes and gene mutation and “quasispecies” of HCV membrane in serum samples from patients with hepatitis C virus. Methods A total of 4 blood samples from patients with HCV infection by blood donation were detected by PCR with specific primers. The HCV genotypes were determined by 5 ’NCR and core sequencing and cloned into the membrane regions of the specimens. Each sample was randomly selected 5 ~ 9 clones for sequencing analysis. As a result, it was found that over time, there was a conversion phenomenon of the HCV genotype. There were mixed infections in the two HCV genotype transition periods. All assay sequences are 1b or 2a or 1b + 2a genotypes. Sequencing of 5 to 9 clones obtained from partial blood samples showed that although there were some nucleotide differences among different clones, only 58 to 546 nucleotide differences . Conclusion The changes of HCV gene are multi-level. The same patient can be mixed infection of different genotypes HCV, HCV membrane gene mutations over time. However, no significant “quasispecies” phenomenon was observed in the specimens of this study by sequencing multiple clones of the same specimen.