[Infectional and molecular-genetical properties of cryopreserved strains of adeno- and rotaviruses].

Influence of cryopreservation and long-term storage in conditions of moderate-low temperatures on infectious activity and molecular-genetic properties of monkey rotavirus, human family rotavirus and human adenovirus of serotype 3 has been studied. Preservation of initial antigenic structure and biological properties of the given viruses is necessary both in biotechnology for manufacture of means of specific preventive maintenance and diagnostics of human adeno- and rotavirus infection and for preservation of collection strains. The conducted researches have shown, that cryopreservation monkey rotavirus standard strain SA-11 in conditions of moderately low temperature at -20 degrees C with the subsequent storage during 18 years resulted in significant degradation of virus RNA and loss of infectious properties of the virus. Cryopreservation of human adenovirus of serotype 3 at -20 degrees C with the subsequent storage in these conditions during 12 years also leads to the loss of its infectious properties, despite high resistance of the virus described in literature to physical and chemical influences of the environment. Therefore it is expedient to perform cryopreservation and storage of even nonpurified strains of these viruses at temperatures of liquid nitrogen (-196 degrees C).

[Amplification of proviral DNA of bovine immunodeficiency virus in experimentally infected animals].

The primer set for detection of bovine immunodeficiency virus (BIV) proviral DNA, retrovirus of unknown pathology, by standard polymerase chain reaction was developed. Amplicon of the expected size was detected in DNA from peripheral blood mononuclear cells of seropositive experimentally BIV infected sheep and cattle. Primers targeted the short fragment of BIV pol gene. Sequences of BIV proviral DNA extracted from BIV infected cell culture as well as from experimentally infected cows were taken for targeted pol BI BPX gene locus. Problems of BIV detection from the clinical material of the experimentally and naturally infected animals are discussed.