南宁市腹泻患儿人星状病毒检测及基因特征分析

Detection of human astrovirus and its genetic characteristics among infants with diarrhea in Nanning City

目的了解南宁市腹泻患儿人星状病毒的基因特征。方法收集2013年南宁市某医院儿科门诊腹泻患儿粪便标本201份,采用实时荧光PCR法进行人星状病毒检测,阳性标本再用PCR方法扩增开放读码框2(open reading frame2,ORF2)部分片段并送测序,通过Blast比对和系统进化树分析序列的基因特征。结果 201份粪便标本中检出6份星状病毒阳性,检出率3.0%(6/201);其中5株测序成功,经Blast比对显示2株为1型,其余3株分别为2、4和5型,系统进化树分析发现1型均为lineage 1a,2型为lineage 2c,4型为lineage 4a,5型毒株与参考株的同源性为94.0%~99.0%,不进行lineage划分。结论南宁市腹泻患儿存在人星状病毒感染,其基因型呈多样性分布。

Objective To investigate the genetic characteristics of human astrovirus （HAstV） among infants with diarrhea in Nanning City. Methods Two hundred and one stool samples were collected from diarrhea infants visiting pediatric department of a hospital in Nanning City in 2013, and then real-time polymerase chain reaction （PCR） was used to detect HAstV. The open reading frame 2（ORF2） fragments of positive samples were amplified by PCR and delivered for sequencing. The genetic characteristics of the sequences were analyzed by Blast alignment and phylogenetic tree. Results HAstV was detected in 6 stool samples, with the detection rate of 3.0% （6/201）. 5 strains were sequenced successfully. The Blast alignment revealed that 2 of the 5 strains were HAstV-1, and the other 3 strains were HAstV-2, HAstV-4 and HAstV-5 respectively. Phylogenetic analysis indicated that both HAstV-1 strains belonged to lineage 1a, the HAstV-2 strain to lineage 2c and the HAstV-4 strain to lineage 4a. The HAstV-5 strain shared 94.0%-99.0% nucleotide sequence identity with the reference strains, so lineage mapping was not performed. Conclusions HAstV infection is found in infants with diarrhea in Nanning City, and its genotypes show diversity.