[Phenotyte of epidemic influenza B virus strains isolated in different years].
The reproducing ability at elevated temperatures (non-ts phenotype) was examined for 38 influenza B virus strains isolated in different years in different countries. Out of the 7 strains isolated in 1940 to 1973, only one showed temperature-sensitivity of reproduction (a ts phenotype). In 1984 to 1988, the proportion of temperature-sensitive strains increased up to 55% (6 of 11). Since the late 1990s, the majority (90%) of the study influenza B viruses demonstrated a pronounced ts phenotype. Influenza B virus strains were also examined for their resistance to serum inhibitors. Prior to the divergence of influenza B viruses into two lines: B/Jamagata and B/Victoria, the epidemic viruses exhibited a high resistance to nonspecific inhibitors of normal equine serum. This property was also preserved in all study B/Victoria strains; however, 83% of the B/Jamagata viruses were inhibitor-sensitive. The present study has demonstrated the heterogenicity of epidemic influenza B viruses in temperature- and inhibitor-sensitivity.
Larionova
N V
NV
Kiseleva
I V
IV
Isakova
I N
IN
Litvinova
O M
OM
Rudenko
L G
LG
D000818:Animals; D004196:Disease Outbreaks; D014943:Global Health; D006385:Hemagglutination Inhibition Tests; D006736:Horses; D006801:Humans; D009981:Influenza B virus / Q000502:physiology*; D007251:Influenza, Human / Q000821:virology*; D044967:Serum; D013696:Temperature; D014779:Virus Replication