Shrestha Sanjaya Kumar, Shrestha Jasmin, Andreassen Ashild K, Strand Tor A, Dudman Susanne, Dembinski Jennifer L
Center for International Health, University of Bergen, Bergen, Norway.
Walter Reed/Armed Forces Research Institute of Medical Sciences Research Unit Nepal, Kathmandu, Nepal.
Front Microbiol. 2021 Feb 5;11:588707. doi: 10.3389/fmicb.2020.588707. eCollection 2020.
This study describes the types of Human astroviruses detected in stool samples collected from a birth cohort of children in Nepal. Using a commercial kit (ProSpecT), a total of 5,224 diarrheal and non-diarrheal stool samples were screened for Human astrovirus by ELISA. RT-PCR was performed on ELISA positive samples (2.8%) for further confirmation. The primary RT-PCR assay used targets the ORF2 region and detects human astrovirus type 1-8. Samples that were negative in this assay were further analyzed using primers that target the ORF1b region of human astrovirus which detect both classical type (HAstV 1-8) and novel types (MLB1-5, VA 1-5). PCR positive samples were analyzed by Sanger sequencing to determine the genotype. A total of 148 available ELISA positive stool samples were analyzed by RT-PCR and further genotyped. RT-PCR analysis of these samples using the ORF2 and ORF1b assay revealed that 124 (84%) were positive for classical human types (HAstV 1-8). Seven different classical HAstV genotypes based on ORF2 and ORF1a were identified (HAstV 1- HAstV 8) with the greatest prevalence of HAstV 5 genotype (42.2%), followed by HAstV 1 (34.7%), HAstV 2 and HAstV 8 (7.4%), HAstV 4 (4.1%), HAstV 3 (3.3%), and HAstV 6 (0.8%). Non-classical types were not detected in our study. A high diversity of circulating Astrovirus strains were detected in young children, both with and without symptoms of gastroenteritis. HAstV 5 and HAstV 1 were the most common genotypes in young children in Nepal.
本研究描述了在尼泊尔一个儿童出生队列采集的粪便样本中检测到的人类星状病毒类型。使用商用试剂盒（ProSpecT），通过酶联免疫吸附测定（ELISA）对总共5224份腹泻和非腹泻粪便样本进行了人类星状病毒筛查。对ELISA阳性样本（2.8%）进行逆转录聚合酶链反应（RT-PCR）以进一步确认。最初的RT-PCR检测针对开放阅读框2（ORF2）区域，可检测1 - 8型人类星状病毒。该检测呈阴性的样本使用针对人类星状病毒ORF1b区域的引物进一步分析，该引物可检测经典型（HAstV 1 - 8）和新型（MLB1 - 5、VA 1 - 5）。PCR阳性样本通过桑格测序进行分析以确定基因型。总共148份可用的ELISA阳性粪便样本通过RT-PCR进行分析并进一步基因分型。使用ORF2和ORF1b检测对这些样本进行RT-PCR分析显示，124份（84%）为经典人类类型（HAstV 1 - 8）阳性。基于ORF2和ORF1a鉴定出七种不同的经典HAstV基因型（HAstV 1 - HAstV 8），其中HAstV 5基因型的流行率最高（42.2%），其次是HAstV 1（34.7%）、HAstV 2和HAstV 8（7.4%）、HAstV 4（4.1%）、HAstV 3（3.3%）以及HAstV 6（0.8%）。在我们的研究中未检测到非经典类型。在有和没有肠胃炎症状的幼儿中均检测到了多种流行的星状病毒株。HAstV 5和HAstV 1是尼泊尔幼儿中最常见的基因型。
