Viruses (Jan 2023)

Growth, Pathogenesis, and Serological Characteristics of the Japanese Encephalitis Virus Genotype IV Recent Strain 19CxBa-83-Cv

  • Shigeru Tajima,
  • Takahiro Maeki,
  • Eri Nakayama,
  • Astri Nur Faizah,
  • Daisuke Kobayashi,
  • Haruhiko Isawa,
  • Yoshihide Maekawa,
  • Sri Subekti Bendryman,
  • Kris Cahyo Mulyatno,
  • Etik Ainun Rohmah,
  • Yasuko Mori,
  • Kyoko Sawabe,
  • Hideki Ebihara,
  • Chang-Kweng Lim

DOI
https://doi.org/10.3390/v15010239
Journal volume & issue
Vol. 15, no. 1
p. 239

Abstract

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Genotype IV Japanese encephalitis (JE) virus (GIV JEV) is the least common and most neglected genotype in JEV. We evaluated the growth and pathogenic potential of the GIV strain 19CxBa-83-Cv, which was isolated from a mosquito pool in Bali, Indonesia, in 2019, and serological analyses were also conducted. The growth ability of 19CxBa-83-Cv in Vero cells was intermediate between that of the genotype I (GI) strain Mie/41/2002 and the genotype V (GV) strain Muar, whereas 19CxBa-83-Cv and Mie/41/2002 grew faster than Muar in mouse neuroblastoma cells. The neuroinvasiveness of 19CxBa-83-Cv in mice was higher than that of Mie/41/2002 but lower than that of Muar; however, there were no significant differences in neurovirulence in mice among the three strains. The neutralizing titers of sera from 19CxBa-83-Cv- and Mie/41/2002-inoculated mice against 19CxBa-83-Cv and Mie/41/2002 were similar, whereas the titers against Muar were lower than those of the other two viruses. The neutralizing titers of JE vaccine-inoculated mouse pool serum against 19CxBa-83-Cv and Muar were significantly lower than those against Mie/41/2002. The neutralizing titers against the three viruses were similar in three out of the five serum samples from GI-infected JE patients, although the titers against Mie/41/2002 were higher than those against 19CxBa-83-Cv and Muar in the remaining two sera samples. In summary, we identified the basic characteristics of 19CxBa-83-Cv, but further studies are needed to better understand GIV JEV.

Keywords