Research and Diagnostic Center, Centers for Disease Control, Department of Health, Taipei, Taiwan, ROC.
Research and Diagnostic Center, Centers for Disease Control, Department of Health, Taipei, Taiwan, ROC; School of Medical Laboratory Science and Biotechnology, Taipei Medical University, Taipei, Taiwan, ROC.
J Microbiol Immunol Infect. 2014 Dec;47(6):447-54. doi: 10.1016/j.jmii.2013.07.003. Epub 2013 Aug 29.
BACKGROUND/PURPOSE: In recent years, coxsackievirus B3 (CV-B3) has been determined as a dominant enterovirus serotype that may cause severe complications in patients. Since 2008 in Taiwan, some enterovirus isolates have been regarded as untypeable [by employing commercial immunofluorescence assay (IFA) kits]. In 2012, the number of isolates increased. Genetic sequence analysis further confirmed that CV-B3 was present in most of the untypeable viruses.
Isolates of CV-B3 were collected for basic local alignment search tool (BLAST) analysis and for phylogenetic analyses, based on VP1 gene sequences. In addition, the Taiwan Centers for Disease Control (Taiwan CDC) developed an in-house indirect IFA using polyclonal antibodies (e.g., rabbit antisera) for diagnosis. The sensitivity and specificity were both evaluated by testing 61 reference enteroviruses and 307 local enteroviruses that were isolated between 1998 and 2010.
Based on the results of the BLAST and phylogenetic analyses, five main genogroups (i.e., GI-GV) were classified and the reference strains in Taiwan in previous years were primarily clustered in the GV-A subgenogroup. However, the 15 CV-B3 isolates recently analyzed in this study were classified in four different groups: GIII, GIV, GV-A, and GV-B. Among these 15 isolates, all 10 isolates in the GV-B group were initially reported as untypeable nonpolio enteroviruses when using commercial kits. The conditions of the in-house indirect IFA were optimized by checkerboard titration, thereby resulting in a sensitivity of 100% and a specificity of 98.5%.
This is the first report describing the phylogenetic relatedness of recent CV-B3 strains in Taiwan. An indirect IFA kit was developed by the Taiwan CDC for detecting CV-B3 viruses that are untypeable by commercial IFA kits.
背景/目的：近年来，柯萨奇病毒 B3（CV-B3）已被确定为一种主要的肠病毒血清型，可能导致患者出现严重并发症。自 2008 年以来，在台湾，一些肠病毒分离株被认为无法分型[通过使用商业免疫荧光检测试剂盒（IFA）]。2012 年，分离株数量增加。遗传序列分析进一步证实，CV-B3 存在于大多数无法分型的病毒中。
基于 VP1 基因序列，对 CV-B3 分离株进行基本局部比对搜索工具（BLAST）分析和系统发育分析。此外，台湾疾病管制署（Taiwan CDC）开发了一种内部间接 IFA，使用多克隆抗体（如兔抗血清）进行诊断。通过测试 61 种参考肠病毒和 1998 年至 2010 年间分离的 307 种本地肠病毒，评估了敏感性和特异性。
基于 BLAST 和系统发育分析的结果，将五个主要基因群（即 GI-GV）进行了分类，台湾近年来的参考株主要聚集在 GV-A 亚基因群中。然而，本研究最近分析的 15 株 CV-B3 分离株被分为四个不同的组：GIII、GIV、GV-A 和 GV-B。在这 15 个分离株中，GV-B 组的所有 10 个分离株最初使用商业试剂盒报告为无法分型的非脊髓灰质炎肠病毒。通过棋盘滴定优化了内部间接 IFA 的条件，从而使灵敏度达到 100%，特异性达到 98.5%。
这是台湾最近 CV-B3 株系进化关系的首次报告。台湾疾病管制署开发了一种间接 IFA 试剂盒，用于检测商业 IFA 试剂盒无法分型的 CV-B3 病毒。
