The problem of the universality of biological models for in vitro replication of virulent and attenuated strains of African swine fever virus (Asfarviridae: Asfivirus), classical swine fever virus (Flaviviridae: Pestivirus), and porcine reproductive and respiratory syndrome virus (Arteriviridae: Bet

INTRODUCTION The current state of pig industry in Russia is characterized by the dominance of pig farms of III-IV compartments and a reduction in livestock in private subsidiary and peasant farms against the background of the spread of infectious diseases, mainly caused by viruses of African and classical swine fever (ASFV and CSFV), and porcine reproductive and respiratory syndrome (PRRSV). The classical method of virus cultivation in vitro is still relevant for the diagnosis of diseases, isolation of relevant strains, studying their properties, attenuation, and obtaining vaccine raw materials. The aim of the study is to select of a universal biological model for in vitro replication of ASFV, CSFV, and PRRSV based on the analysis of permissiveness levels of various cell cultures (primary cell cultures, subcultures, and continuous cell lines).

Materials And Methods

The study utilized known virulent, vaccine, and attenuated strains of ASFV, CSFV, and PRRSV. Five primary cell cultures, two subcultures and eleven transferable cell lines / sublines were tested. The degree of tolerance was calculated based on the results of semi-quantitative estimates using the real-time PCR method for five consecutive passages.

Results

For in vitro replication of both virulent and attenuated strains of ASFV, the optimal biological models were primary cell cultures of pBMC, PAM, PL, PS, ST, and PK. For the virulent strain of CSFV, the following were optimal: PAM, PL, ST, PK, PS, RRC, and PK-15 (ATCC). For the vaccine strain of CSFV, the optimal models were synovial membrane subcultures of lamb (MSO/ARRIAH) and kid (MSC/ARRIAH), as well as ST, PAM, PL, and PS. For virulent strains of PRRSV, both American and European types, the optimal model was the primary cell culture PAM. For the attenuated strain of American-type PRRSV, PAM, PL, and MA-104 were suitable, while for the attenuated strain of European-type PRRSV, PAM, PL, and Marc-145 were optimal.

Conclusion

It has been established that some primary cell cultures, such as PAM and PL, with a predominance of mononuclear cells are universal biological models for the in vitro reproduction of virulent and attenuated strains of ASFV, CSFV, and PRRSV.