Abstracts summarizing recent research overseen by the WHO Advisory Committee on Variola Virus Research - 2003
Viability estimation of variola virus isolates from the Russian collection
S.N. Shchelkunov, A.A. Guskov, E.B. Sokunova, and L.S. Sandakhchiev
State Research Center of Virology and Biotechnology Vector, Koltsovo, Novosibirsk oblast, 630559 Russia
Please direct all queries to the authors at the addresses given.
Viabilities of 55 variola virus isolates stored in the Russian Collection were estimated.
Variola virus was isolated from the cultures deposited using cultivation on chorioallantoic membranes (CAM) of 12-day-old developing chick embryos and in Vero cell monolayer.
The frozen material, stored as CAMs or scabs of human cases, was ground in porcelain mortars cooled to –20°C to use the homogenate obtained for infecting 12-day-old developing chick embryos and Vero cell monolayer.
The infected embryos and cell cultures were incubated at a temperature of 34.5 ± 0.5C and cultivated for 3 days in the case of embryos; in the case of the cell cultures, until manifestation of cytopathic effect, i.e., 3 to 7 days. On completion of incubation, the embryos were opened to sample the material for further work and to count the number of pocks on CAMs for determining the biological concentration of the initial material.
The viable isolated were cultivated in Vero cell culture; DNA was isolated from virus preparations and tested in LPCR.
Of the 55 isolates tested, 32 appeared viable. The DNA suitable for LPCR was isolated from 29 variola virus isolates.