2013—2020年重庆市急性弛缓性麻痹病例非脊灰肠道病毒分离株分型鉴定分析

Genotyping and identification of non-polio enterovirus isolates from acute flaccid paralysis cases in Chongqing in 2013-2020

摘要:

目的 对2013-2020年期间从重庆市急性弛缓性麻痹病例（acute flaccid paralysis, AFP）中分离到的53株（non‐polio enterovirus, NPEV）进行分型鉴定，了解NPEV型别分布特点。方法 使用商品化荧光定量PCR (real-time fluorescence quantitative polymerase chain reaction, real-time PCR)试剂对NPEV快速鉴定，结合VP1区和VP4区核苷酸序列特征进行分型。结果 鉴定出50株肠道病毒, A组33株（66.00%），B组17株（34.00%）,不包含C、D组肠道病毒，3株不能分型。EV-A71为优势型别，11株（22.00%），2016年及以后未分离到EV-A71。本研究中，VP4区和VP1区序列在NPEV分组上完全一致。结论 使用商品化荧光定量PCR试剂对肠道病毒分型时，高CT值的鉴定结果有可能不准确。NPEV分型中，先使用VP4区序列进行分组，然后在使用VP1区进行基因分型，可简化实验流程。重庆市AFP病例NPEV分离株的型别多样性较差，为丰富和完善重庆市肠道病毒基因数据库，有必要开展呼吸道传播的肠道病毒相关研究。

Abstract:

Objective To classify and identify the 53 strains of non-polio enterovirus (NPEV) isolated from acute flaccid paralysis (AFP) cases in Chongqing from 2013 to 2020, and to investigate the genotype distribution of the strains. Methods Commercial real-time fluorescence quantitative polymerase chain reaction (real-time PCR) reagents were used for rapid identification of the strains. The nucleotide sequences of VP1 and VP4 regions were used for genotyping. Results Fifty enteroviruses were identified, 33 (66%) in group A and 17 (34%) in group B. Group C and D enteroviruses were not found in these strains，and 3 strains could not be identified. In this study, EV-A71 was the dominant type, with 11 strains (22%), but EV-A71 strain was not isolated since 2016. The sequences of VP4 region and VP1 region were completely consistent in enterovirus grouping. Conclusion When using commercial real-time PCR reagents for enterovirus typing, the identification results of high CT values may be inaccurate. In the genotyping of enterovirus, the nucleotide sequence of VP4 region is first used for grouping, and then the nucleotide sequence of VP1 region is used for genotyping, which could simplify the experimental process. NPEV isolates from AFP cases in Chongqing showed poor genotype diversity. In order to enrich and improve the enterovirus gene database in Chongqing, it is necessary to carry out research on enterovirus transmitted by respiratory tract.