2017年福建省1起2B基因型风疹暴发的病原学分析

Etiology of an outbreak caused by 2B genotype rubella virus in Fujian province, 2017

目的分析2017年福建省一所学校风疹暴发的风疹病毒基因特征。方法采用Vero/hSLAM细胞对患者咽拭子标本进行风疹病毒分离,通过逆转录-聚合酶链式反应(RT-PCR)方法扩增风疹病毒E1蛋白基因的739个核苷酸片段,对扩增产物进行测序和遗传变异分析。结果 10份患者咽拭子标本中分离到5株风疹病毒,均为2B基因型。5株分离株核苷酸和氨基酸同源性均为100%;与中国其他地区流行株核苷酸和氨基酸遗传距离分别为0.017-0.025和0.002-0.006;与疫苗株BRDII相比,分离株在E1蛋白第333氨基酸位点存在丙氨酸→缬氨酸的突变。结论本起暴发由本地流行的2B基因型风疹病毒引起。

Objective To analyze genetic characteristics of rubella viruses isolated from a school-based rubella outbreak in Fujian province in 2017. Methods We used Vero/hSLAM cells to isolate rubella viruses from throat swabs of patients. We used reverse transcription-polymerase chain reaction(RT-PCR) to amplify 739 nucleotide fragments of the E1 protein gene of rubella virus and sequence the amplified products for a genetic variation analysis. Results Five rubella virus strains were isolated from 10 patients and identified as 2 B genotype. The homologies of nucleotides and amino acids within 5 isolated strains were both 100%. The genetic distances of nucleotides and amino acids between the isolated strains and other Chinese strains were 0.017-0.025 and 0.002-0.006, respectively. Compared with the BRDII vaccine strain, the strains isolated in this outbreak had a mutation from alanine to valine at amino acid site 333 of the E1 protein. Conclusions The outbreak was caused by a 2 B genotype rubella virus that was circulating locally.