The Japanese isolates of Palyam serogroup viruses isolated from 1985 to 2001 were investigated for the genome sequence of segments 2 and 7 and were phylogenetically analyzed in comparison with Australian and African isolates of the same serogroup. In the phylogenetic analysis of segment 7, these viruses were divided into three clusters according to geographical origin. Phylogenetic analysis based on segment 2, which encodes a serotype-specific antigen, revealed 2 clusters, the cluster containing Chuzan virus and the cluster containing the Australian and African Palyam serogroup viruses. To examine the antigenic relationship among viruses categorized in different clusters, we conducted a cross-neutralization test. KSB-29/E/01 isolated in 2001 in Japan was neutralized by antiserum not only to D’Aguilar virus (Australian isolate) but also to Chuzan virus. These results indicated that genetically and antigenically unique characteristics of KSB-29/E/01 could be attributed to the genetic reassortment of segment 2 between Chuzan virus and D’Aguilar virus.
(Clinical Virology Section, Kyushu Res. ST., TEL +81-99-268-2078)
Ohashi et al. (2004) J. Clin. Microbiol. 42: 3684-3688.