Radioimmune assays and molecular studies that place Anopheles B and Turlock serogroup viruses in the Bunyavirus genus (Bunyaviridae).

Molecular analyses indicate that Turlock virus (TUR, Turlock serogroup) and Boraceia virus (BOR, Anopheles B serogroup) have virion RNA species and polypeptides comparable in size to those of members of the Bunyavirus genus and unlike those of members of the newly defined Phlebovirus, Nairovirus, or Uukuvirus genera (Bunyaviridae). The 11 terminal 3' end nucleotides of the three virion RNA species of both BOR and TUR viruses (HOUCAUCACAUG...) are identical in sequence to the 3' end sequences of the viral RNA species of snowshoe hare (SSH) and La Crosse bunyaviruses (LAC, California serogroup, Bunyavirus genus). Competition radioimmune assays (RIA), using iodinated LAC nucleocapsid polypeptide (N), or LAC glycoproteins (G1, G2), and LAC rabbit hyperimmune antisera, or iodinated Oriboca (ORI, Group C, Bunyavirus genus) N, or G1 and G2 polypeptides and LAC antisera, or iodinated Bunyamwera (BUN, Bunyamwera serogroup, Bunyavirus genus) N, or G1 and G2 polypeptides and BUN or LAC antisera, have indicated that the virion polypeptides of BOR virus share antigenic determinants with these other bunyaviruses. Competition RIA analyses also have shown that TUR virus shares antigenic determinants with LAC virus. The competition RIA analyses have confirmed the antigenic relationships of LAC, SSH, trivittatus, Bwamba, Aino, Simbu, Mermet, Guaroa, Lumbo, Tahyna, ORI, Anopheles A, BUN, Capim, Guama and Shark river viruses (Bunyavirus genus members), and lack of antigenic relationships between Karimabad, or Chagres, or sandfly fever, Sicilian, Viruses (Phlebovirus genus members), and the bunyaviruses, LAC, ORI, or BUN.

Genotypic varieties of La Crosse virus isolated from different geographic regions of the continental United States and evidence for a naturally occurring intertypic recombinant La Crosse virus.

The tripartite ribonucleic acid (RNA) genomes of 23 alternate isolates of La Crosse virus have been analyzed by the procedure of oligonucleotide fingerprinting. By comparison with the fingerprints of the three viral RNA species (large, medium and small) of prototype La Crosse virus, the viruses have been categorized in terms of the degree of their RNA sequence relatedness. The A type La Crosse viruses, which have been recovered from Wisconsin, Minnesota, Indiana and Ohio, have viral RNA sequences that are closely related to those of prototype La Crosse virus. The B type La Crosse viruses, which have been recovered from Minnesota, Wisconsin and Illinois, have RNA sequences which, although related, are easily distinguished from those of type A viruses. A La Crosse virus isolate obtained from Rochester, Minnesota, appears to be an intertypic type A/B recombinant, it has a small size RNA segment like those of the B type La Crosse virus isolates, but medium- and large-sized RNA species like those of the A type La Crosse virus isolates. The C type La Crosse viruses have viral RNA sequences that neither closely resemble the A or B type La Crosse viruses. They have been recovered from eastern Ohio, New York State, Texas, Georgia and North Carolina.

A comparison of La Crosse virus isolated obtained from different ecological niches and an analysis of the structural components of California encephalitis serogroup viruses and other bunyaviruses.

Analyses of the oligonucleotide fingerprints of the three genome ribonucleic acid (RNA) species of 11 isolates of La Crosse (LAC) virus, obtained from various ecological niches in the northern United States and compared to those of prototype LAC virus, showed that in each place from which these isolates were obtained LAC variants and varieties were present with related, but distinguishable, nucleotide sequences for their large, medium, or small RNA species. The RNA genomes of prototypes trivittatus (TVT), snowshoe hare (SSH), Tahyna (TAH), and Lumbo (a variety of TAH) viruses of the California encephalitis (CE) serogroup, and Guaroa of the Bunyamwera serogroup also consist of three RNA species, each with unique and distinguishable nucleotide sequences which bear little resemblance to those of the LAC virus isolates. The virions of CE group viruses (CE, Jamestown Canyon, Keystone, LAC, Melao, SSH, TVT, TAH viruses and South River, an unregistered virus) have three major viral polypeptides, designated G1, G2, and N.

La Crosse virus soluble cell culture antigen.

A virus-free soluble antigen, obtained by ammonium sulfate precipitation of the supernatant fluids of La Crosse virus-infected BHK-21 cell cultures, was more reactive and more specific than infected suckling mouse brain antigen when compared by immunodiffusion and counterelectrophoresis tests. By complement fixation tests, the antigen was cross-reactive with heterologous California group arbovirus hyperimmune mouse ascitic fluids, but to a lesser degree than was the standard sucrose-acetone-extracted infected suckling mouse brain antigen. The major virion nucleocapsid protein of La Crosse virus was found by polyacrylamide gel electrophoresis to be the soluble antigen protein responsible for precipitation in immunodiffusion and counterelectrophoresis tests.

The rapid concentration and purification of influenza virus from allantoic fluid.

Influenza virus was quantitatively recovered from infectious allantoic fluid by precipitation with 8 percent (wt/vol) polyethylene glycol 6000 (PEG-6000). Virus concentrated by PEG-6000 treatment was rapidly purified by gel permeation chromatography through controlled pore glass beads. The purity of virus preparations achieved by this method, when judged by three independent criteria, was comparable to virus preparations purified by conventional density gradient procedures.