Identification and phylogenic analysis of Coxsackie-virus B5 during an outbreak of aseptic meningitis in Shandong

Abstract

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. 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. 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. 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.