Genetic differences of E gene of a Thai strain of Japanese encephalitis virus that determine small plaque size phenotype but not neurovirulence in suckling mice
Lorroengsil, S.; Chen, A.; Sällberg, M.; Pantuwatana, S.
Southeast Asian Journal of Tropical Medicine and Public Health 39(3): 387-393
2008
ISSN/ISBN: 0125-1562 PMID: 18564676 Document Number: 619492
Two small plaque variants of Japanese encephalitis virus (JEV), S4P9 and S9P10, were recovered from the wild type of JEV strain KE-093 using plaque purification in combination with the temperature-shift induction technique. Growth patterns of the S4P9 and S9P10 in BHK-21 cells as well as neurovirulence in suckling mice were similar to that of KE-093. An amino acid substitution, lysine for glutamic acid, was present in envelope protein at residue E-83 in the small plaque variants. This study shows that small plaque phenotype is not always associated with attenuation in vivo.