柯萨奇B5病毒引起山东省一起无菌性脑膜炎暴发的鉴定及其亲缘进化分析

摘要

Objective To identify the pathogen that caused an outbreak of aseptic meningitis in Shandong province in 2005. Phylogenic analysis was carried out on Coxsackie-virus B5 (CVB5) which was isolated during this outbreak. Methods 78 stool and 58 cerebrospinal fluids (CSF) specimens were collected from some inpatients during this outbreak. Virus isolation and reverse transcription-polymerase chain reaction (RT-PCR) was then performed. Phylo-genetic trees based on entire and partial VP1 sequences were constructed among CVB5 isolates and others published in GenBank. Results The isolation rates of stool and CSF specimens were 38.5% (30/78) and 48.3% (28/58) respectively. Among the results of serotype identification and molecular typing of 58 positive isolates, 54 were identified as CVB5, 2 as ECHO24, 1 as CVB3 and 1 as CVA9. Results from viral investigation showed that CVB5 was the main pathogen causing this outbreak. Data from homological comparisons indicated that Shandong strains had the highest nucleotide acid identity with the Zhejiang/ 12/02 strain (97.5%-97.8%), and lower identity (78.3%-78.6%) with the prototype strain (Faulkner strain). Phylogenic tree in VP1 region showed that CVB5 could be separated into four genotypes. Isolates of this outbreak belonged to genotype D. Conclusion CVB5 was the major etiological agent correlated with this outbreak. The shift of predominant genotype might serve as one of the causes that associated with the outbreaks of aseptic meningitis.%目的 鉴定引起2005年山东省兖州市一起无菌性脑膜炎暴发的病原体,并对分离的柯萨奇B5病毒(CVB5)进行基因特征分析.方法 从兖州市无菌性脑膜炎暴发期间部分住院患者中采集78份粪便标本和58份脑脊液标本进行病毒分离和血清型鉴定;同时对其阳性分离物采用反转录-聚合酶链反应进行分子定型,对其中的CVB5进行全长VP1区核苷酸序列测定和亲缘进化分析.结果 78份粪便标本和58份脑脊液标本的病毒分离率分别为38.5%(30/78)和48.3%(28/58).58株阳性分离物的血清型鉴定和分子定型结果显示,其中54株为CVB5,2株为ECHO24,CVB3和CVA9各1株.病原学结果显示引起此次无菌性脑膜炎暴发的病原体主要为CVB5.同源性分析显示,CVB5分离株与2002年浙江分离株(Zhejiang/12/02株)在核苷酸水平上同源性最近,为97.5%～97.8%;与CVB5原型株(Faulkner株)相比核苷酸同源性为78.3%～78.6%.VP1区亲缘进化树显示CVB5可以分为A、B、C、D 4个基因型,引起本次暴发的CVB5属于基因型D.结论 CVB5是引起兖州市无菌性脑膜炎暴发的病原体.优势基因型的变迁可能是造成无菌性脑膜炎反复暴发的因素之一.