ABSTRACT
A comparative analysis of biological properties of A(H1N1) influenza virus strains isolated in 1977 and the prototypic strain isolated in 1947 was performed. The strains showed marked differences in the vivo and in vitro replication as well as in the sensitivity to inhibitors of normal animal sera and to interferon. Also, their neuraminidases displayed different sensitivity to detergents. On the other hand, the strains did not differ significantly with respect to ability for interferon induction in vivo and hemagglutinin sensitivity to detergents.
Subject(s)
Influenza A Virus, H1N1 Subtype , Influenza A virus/physiology , Virus Replication , Disease Outbreaks , Influenza A virus/enzymology , Interferons/pharmacology , Neuraminidase/metabolism , Species Specificity , Virus Replication/drug effectsABSTRACT
Antigenic analysis of strains isolated in the USSR during the epidemic in 1974/1975 showed differences in the hemagglutination inhibition test and in neuramidase activity with antisera against three reference strains. Strains isolated in a later period of the epidemic were classified into subgroup A/Port Chalmers/1/73. Nearly all strains were effective inducers of interferon and were susceptible to this inhibitor of virus replication.
Subject(s)
Antigens, Viral/analysis , Disease Outbreaks/epidemiology , Influenza, Human/epidemiology , Orthomyxoviridae/isolation & purification , Antigens, Surface/analysis , Epitopes , Hemagglutination, Viral , Humans , Orthomyxoviridae/classification , Orthomyxoviridae/immunology , Serotyping , USSRABSTRACT
Slab polyacrylamide gel electrophoresis of Influenza-virus A strains varying in antigenic composition of the envelope and in the natural host species showed the nucleprotein and membrane proteins to have a standard molecular weight of 58,000 and 24,000 daltons, respectively. The electrophoretic mobility and molecular weights of the light and heavy chains of haemagglutinin varied in the strains under study. The differences observed persisted on passaging and were transferred upon genome recombination.
Subject(s)
Influenza A virus/analysis , Peptides/analysis , Viral Proteins/analysis , Electrophoresis, Polyacrylamide Gel , Hemagglutinins, Viral/analysis , Molecular WeightABSTRACT
Limited outbreaks of influenza were reported in the far east of the U.S.S.R. early in November, 1977, and a week or two later in cities in Siberia and the European parts of the U.S.S.R. The majority of influenza-virus isolates belonged to the H1N1 subtype of influenza-A virus, though strains of the current H3N2 subtype were also isolated. A moderate epidemic of H1N1 influenza spread throughout the country in the middle of December. Mainly children over 5 years and young adults were infected.
Subject(s)
Influenza A Virus, H1N1 Subtype , Influenza A virus/isolation & purification , Influenza, Human/microbiology , Adolescent , Adult , Antigens, Viral/analysis , Child , Disease Outbreaks , Hemagglutination Inhibition Tests , Hemagglutinins/analysis , Humans , Immune Sera , Influenza A virus/enzymology , Influenza A virus/immunology , Influenza, Human/epidemiology , Neuraminidase/analysis , USSRABSTRACT
A continuous line of guinea pig kidney cells (CGPK/H) and a continuous line of mouse fibroblasts (L/H) spontaneously infected with parainfluenza virus SV5 were found. These cultures showed no enhanced cell degeneration or symplast formation, nor was haemagglutinin accumulation or infectious virus demonstrated in them. However, regular reproduction of ribonucleoprotein (RNP) characteristic of parainfluenza viruses, morphologically complete virions and antigens producing antibody to SV5 virus were found in the cells. Focal haemadsorption neutralized by antiserum to SV5 virus was also demonstrated. The infection persisted in the cell populations for over 2 years (the observation period) under standard conditions of cell dispersion and subcultivation.
