[Monitoring of infectious diseases among wild boars].

Sixty-seven serum samples and 43 pathological material samples from wild boars, taken in 5 regions of Russia and in the Kharkov Region of the Ukraine in 2002 to 2005 were studied. Wild boars in some regions of Russia were shown to be carriers of Aujeszky's disease virus, porcine parvovirus, porcine circovirus type 2, lymphotropic herpesvirus-1, porcine cytomegalovirus, Mycoplasma hyopneumoniae and Pasteurella multocida. The classical swine fever (CSF) virus genome was detected by polymerase chain reaction in the samples from 10 wild boars from 2 Russian regions (the Tver and Moscow Regions). Sequencing of the E2 gene 5'-terminal region of detected CSF virus isolates showed that they were closely related to two field virus isolates early found in domestic pigs in the Moscow and Vladimir Regions, which suggests that there is an epizootic relation between the SCF outbreaks among wild boars and domestic pigs in these regions. Tests for porcine reproductive and respiratory syndrome, transmissible porcine gastroenteritis, porcine influenza, enteroviruses, and actinobacillus-induced pleuropneumonia were negative in all the regions under study.

[Recombinant non-structural 3A, 3B and 3AB proteins of foot-and-mouth disease virus: use for differentiation of vaccinated and infected cattle].

Recombinant proteins 3A, 3B and 3AB were obtained by expression in Escherichia coli and purified by metal-chelate chromatography. The proteins were used as antigens in indirect ELISA to differentiate vaccinated and infected cattle. While testing 200 sera from cattle 3A-ELISA was more sensitive and specific than 3B- and 3AB-ELISA. Compared with "Chekit FMD-3ABC", 3A-ELISA showed the same level of specificity and higher level of sensitivity.

Use of the recombinant nonstructural 3A, 3B, and 3AB proteins of foot-and-mouth disease virus in indirect ELISA for differentiation of vaccinated and infected cattle.

Recombinant foot-and-mouth disease virus (FMDV) proteins 3A, 3B, and 3AB were produced by expressing the corresponding genes in Escherichia coli and purified by metal-chelate affinity chromatography. The recombinant proteins were used as antigens in indirect enzyme-linked immunosorbent assay (ELISA) to differentiate between vaccinated and FMD-infected animals. The following parameters were determined: working concentrations of antigens and peroxidase conjugate of cattle anti-IgG, the optimum composition of blocking buffer, and the positive-negative threshold of the reaction. Tests performed with approximately 200 serum samples taken from animals of different immunity states showed that the protocol with protein 3A as the antigen (3A-ELISA) provided the most reliable differentiation. All the newly developed systems proved to outperform the commercial Chekit FMD-3ABC kit in sensitivity, and 3A-ELISA was no less specific.

[Immunological and biological characteristics of viral isolates of porcine reproductive and respiratory syndrome]. / Immunobiologicheskiie svoistva izoliatov virusa reproduktivnogo i respiratornogo sindroma svinei.

Described in the paper are study results of some immunobiological properties of 5 field isolates of the porcine reproductive and respiratory syndrome virus (PRRSV), obtained in Russia and Byelorussia in 1998-2001. According to the research work, the PRRSV isolates with different immunobiological properties have been circulating in the territories of Russia and Byelorussia. Three of the 4 examined virus isolates were found to be pathogenic and 1 avirulent to pigs.