Department of Microbiology, Faculty of Medicine, Chiang Mai Universitygrid.7132.7, Chiang Mai, Thailand.
Center of Excellence in Emerging and Re-emerging Diarrheal Viruses, Chiang Mai Universitygrid.7132.7, Chiang Mai, Thailand.
Microbiol Spectr. 2022 Jun 29;10(3):e0044822. doi: 10.1128/spectrum.00448-22. Epub 2022 May 12.
Human norovirus is a major virus that causes acute gastroenteritis in all age groups. Recently, norovirus recombinant strains have been reported as the cause of norovirus outbreaks. This study has investigated the distribution of norovirus genotypes and recombinant strains circulating in children hospitalized with diarrhea in Chiang Mai, Thailand from 2017 to 2018. A total of 882 stool specimens were tested for the presence of norovirus GI and GII by reverse transcription-PCR (RT-PCR) assay. Genotypes of the viruses were assessed by partial VP1 nucleotide sequencing and the representative strains were further characterized for norovirus recombinant strains by amplification of ORF1 (RdRp)/ORF2 (VP1 capsid) junction region. From a total of 882 stool samples, 131 (14.9%) were positive for norovirus, of which the majority of norovirus genogroups were norovirus GII, and only one was identified as norovirus GI. A wide variety of norovirus genotypes were detected in this study, including GI.5, GII.2, GII.3, GII.4, GII.6, GII.7, GII.13, GII.14, and GII.17 with the predominance of GII.2 (62.5%) in 2017 and GII.4 (57.0%) in 2018. Nevertheless, it should be noted that GII.4 remained the most predominant genotype (50.4%) in overall prevalence. Analysis of norovirus recombination revealed that several norovirus recombinant strains (GII.2[P16], GII.3[P16], GII.4[P16], GII.4[P31], GII.6[P7], GII.13[P16], and GII.14[P7]) had been identified with the predominance of GII.2[P16] in 2017 and changed to GII.4[P16] and GII.4[P31] in 2018. In conclusion, this study reported the detection of a wide variety of norovirus genotypes and several norovirus recombinant strains in Chiang Mai, Thailand from 2017 to 2018. In the present study, the prevalence of norovirus infection in children with acute gastroenteritis in Chiang Mai, Thailand between 2017 and 2018 was 14.9%. A variety of norovirus genotypes were detected, including GI.5, GII.2, GII.3, GII.4, GII.6, GII.7, GII.13, GII.14, and GII.17 with the predominance of GII.4 genotype. In addition, several norovirus recombinant strains (GII.2[P16], GII.3[P16], GII.4[P16], GII.4[P31], GII.6[P7], GII.13[P16], and GII.14[P7]) had been identified. Our results revealed that GII.2[P16] was a predominant strain till the end of 2017 and then was replaced by GII.4[P16] and GII.4[P31] in 2018. The findings imply that norovirus recombinant strains emerged in Chiang Mai, Thailand and that circulating strains changes over time.
人类诺如病毒是引起所有年龄段急性胃肠炎的主要病毒。最近，已报道诺如病毒重组株是诺如病毒暴发的原因。本研究调查了 2017 年至 2018 年在泰国清迈因腹泻住院的儿童中循环的诺如病毒基因型和重组株的分布。共检测了 882 份粪便标本，采用逆转录-聚合酶链反应（RT-PCR）检测诺如病毒 GI 和 GII。通过部分 VP1 核苷酸测序评估病毒基因型，并通过扩增 ORF1（RdRp）/ORF2（VP1 衣壳）连接区对代表性菌株进行进一步鉴定诺如病毒重组株。在总共 882 份粪便样本中，有 131 份（14.9%）为诺如病毒阳性，其中大多数诺如病毒基因群为诺如病毒 GII，只有 1 份被鉴定为诺如病毒 GI。本研究检测到多种诺如病毒基因型，包括 GI.5、GII.2、GII.3、GII.4、GII.6、GII.7、GII.13、GII.14 和 GII.17，其中 2017 年以 GII.2（62.5%）为主，2018 年以 GII.4（57.0%）为主。然而，值得注意的是，总体流行率中 GII.4 仍然是最主要的基因型（50.4%）。诺如病毒重组分析表明，已鉴定出几种诺如病毒重组株（GII.2[P16]、GII.3[P16]、GII.4[P16]、GII.4[P31]、GII.6[P7]、GII.13[P16]和 GII.14[P7]），2017 年以 GII.2[P16]为主，2018 年则变为 GII.4[P16]和 GII.4[P31]。总之，本研究报道了 2017 年至 2018 年在泰国清迈检测到多种诺如病毒基因型和几种诺如病毒重组株。本研究在 2017 年至 2018 年期间，泰国清迈急性胃肠炎患儿诺如病毒感染的患病率为 14.9%。检测到多种诺如病毒基因型，包括 GI.5、GII.2、GII.3、GII.4、GII.6、GII.7、GII.13、GII.14 和 GII.17，以 GII.4 基因型为主。此外，还鉴定出几种诺如病毒重组株（GII.2[P16]、GII.3[P16]、GII.4[P16]、GII.4[P31]、GII.6[P7]、GII.13[P16]和 GII.14[P7]）。我们的研究结果表明，GII.2[P16]是 2017 年底的主要菌株，随后在 2018 年被 GII.4[P16]和 GII.4[P31]取代。这表明诺如病毒重组株在泰国清迈出现，流行株随时间发生变化。
