[Genetic variability of the nucleocapsid protein of the virus of the porcine reproductive and respiratory syndrome]. / Variabel'nost' gena belka nukleokapsida virusa reproduktivnogo i respiratornogo sindroma svinei (RRSS).

The porcine reproductive and respiratory syndrome (PRRS) is a contagious viral pathology caused by PRRS virus. There are 2 types of the above virus--the European and American ones. Distribution patterns of the PRRS virus were studied for Russia and Byelorussia. Above 700 porcine sera obtained from 32 households of 21 Russia's administrative regions and from 19 households of 6 Byelorussia's administrative regions were tested for presence of antibodies to the PRRS virus. Simultaneously, the samples were tested for virus presence by polymerase chain reaction (PCR). It was proven serologically that the PRRS virus is widespread in the territories of Russia and Byelorussia. Noteworthily, all field isolates found in Russia and Byelorussia belong to the European type. Not a single viral isolate of the American PRRS type was found. The nucleocapsid (N) recombinant protein was obtained on the basis of the Russian field isolate of the PRRS virus by using the E. coli. expression system. Finally, it was shown as possible to use the recombinant protein in indirect immune enzyme assay for the sake of detecting the antibodies to the PRRS virus.

[Synthesis of recombinant proteins from the American and European viruses of the porcine reproductive and respiratory syndrome in baculovirus expression system and their antigenic properties]. / Sintez v bakulovirusnoi sisteme rekombinantnykh belkov amerikanskogo i evropeiskogo tipov virusa reproduktivnogo i respiratornogo sindroma svinei i ikh antigennye svoistva.

The baculovirus expression system was made use of to derive the recombinant nucleocapsid (N) proteins of the American and European virus types and of the porcine reproductive and respiratory syndrome (PRRS). The obtained products were purified by metal-affine chromatography and their specificity was confirmed in immunechemical reactions with reference monoclonal antibodies. The antigenic activity of recombinant proteins was studied by indirect immune enzyme assay (IEA) with porcine serum, which had been in advance characterized by the "HerdCheck" kit (IDEXX Co.). It was shown as possible to apply the derived recombinant antigens in determining, by indirect IEA, antibodies to the PRRS virus.