新生儿晚期黄疸人巨细胞病毒gB基因分型研究

目的了解引起新生儿晚期黄疸患者人巨细胞病毒（HCMV）gB基因型的分布,探讨HCMVgB基因多态性与黄疸之间的关系。结论采用荧光定量PCR法检测本院新生儿科98例晚期黄疸新生儿标本HCMV-DNA含量,巢式聚合酶链反应扩增阳性标本HCMVgB基因,并进行DNA测序,绘制种系进化树。利用HinfⅠ和RsaⅠ对gB基因进行限制性片段长度多态性（RFLP）分析。结果 30例晚期黄疸新生儿HCMV荧光定量PCR检测阳性,阳性率为30.6%。种系进化树分析结果显示gB基因分为4个基因型,gB1型15株（50%）,gB2型5株（16.7%）,gB3型9株（30.0%）,gB1/3混合型1株（3.3%）。以HCMV实验室标准株AD169作为参考,将序列进行同源性比较,gB1型同源性为94.7%～95.0%,gB2型同源性93.1%～93.4%,gB3型同源性94.7%,gB1/3型同源性93.7%。RFLP分析将gB基因分为4个基因型,分型结果与种系进化树分型一致。结论 HCMV感染是导致新生儿晚期黄疸的原因之一;gB基因的DNA序列比较保守,但仍存在一定的多态性,晚期黄疸新生儿中HCMV感染以gB1、gB3型为主。

Genetic variations in the gB genes of human cytomegalovirus strains collected from late jaundice infants

Objective To investigate the genetic variations of cytomegalovirus gB gene and to explore the relationship between the gB genotype and specimens in late jaundice cases. Methods Nested PCR was used to amplify the entire HCMV- gB gene region of clinical isolates.The samples used in this study were proven to have detectable HCMV-DNA by FQ-PCR. The PCR products were sequenced and analyzed by restriction fragment length polymorphism（RFLP）. Results 30 infants with late jaundice were confirmed to have HCMV infection and the positive rate of infection was 30.6%.According to the phylogenetic analysis,the nucleotide sequences could be divided into four major groups：group1（50%）,group2（16.7%）, group3 （30.0%） and group4 （3.3%）. Alignment comparison of the gB sequences with AD169 revealed that the nucleic acid variability rate was 94.7%-95.0% in group1,93.1%-93.4% in group2,94.7% in group3 and 93.7% in group1/3.Results obtained from RFLP analysis were also similar to the results in phylogenetic analysis. Conclusion HCMV infection may be etiologically associated with late jaundice in some infants.The DNA sequence of gB gene shared similarity among HCMV clinical isolates. The group 1 and group 3 genotype were more prevalent in the late jaundice cases than the other genotypes.