Characteristics of influenza virus depending on temperature of replication
Brydak, L.
Medycyna Doswiadczalna i Mikrobiologia 31(4): 245-250
1979
ISSN/ISBN: 0025-8601 PMID: 544982 Document Number: 150654
Influenza virus A Port Chalmers 1/73 (H3N2) was passaged in 11-day chick embryos at 37, 35, 33 and 30.degree. C. For each of the lowered temperatures, a modified temperature optimum of neuraminidase activity was established after 12-15 passages. The modification was most significant for virus passaged at 30.degree. C and its maximum neuraminidase activity was only slightly lower compared with the control (37.degree. C). Virus lines from the individual passage temperatures were given intranasally to mice, which were then tested for the presence of virus antigen in lungs (by immunofluorescence), and for serum HI antibodies. In mice given virus passaged at 37, 35 and 33.degree. C only trace amounts or a lack of virus antigen lungs were observed after 48 h and 7 days. The animals given virus passaged at 30.degree. C, showed the antigen after both 48 h and 7 days, thus indicating virus replication in the lungs. HI antibodies determined 7 and 14 days after infection showed no differences depending on virus passage temperatures. In animals infected with virus passaged at 30.degree. C, NI antibody levels were significantly higher compared with controls.