In vitro amplification of BVDV field strains isolated in Argentina: effect of cell line and culture conditions

A. C. ODEÓN; M. R. LEUNDA; C. FAVERÍN; N. BOYNAK; M. M. VENA; O. ZABAL

REVISTA ARGENTINA DE MICROBIOLOGíA

Año: 2009 vol. 41 p. 79 - 85

0325-7541

The aim of this work was to study the in vitro amplification of BVDV (Pestivirus, Flaviridae) field isolates from Argentinain MDBK, BoTur and BHK-21 continuous cell lines. Field isolates 99/134 (mucosal disease), 00/693 (mucosal disease),04P7016 (respiratory disease) and 04/89 (mucosal disease), genotype 1b, were used and compared with theSinger and NADL reference strains, genotype 1a. Additionally, cell lines derived from explants of bovine testis (RD-420), bovine uterus (NCL-1) and porcine kidney (PKZ) were tested as alternative substrates for BVDV propagation invitro. The effect of cell line, harvest time and infection protocol was evaluated. The viral titers observed depended onthe virus and harvest time but not on the infection protocol. We found that MDBK and BoTur cell lines were susceptibleto the infection whereas BHK-21 and PKZ were not. NADL viral titers, 00/693 and 04/89, increased from 24 to 48 h p.i.in BoTur cells and then reached a plateau, whereas those of 99/134 and 04P7016 remained constant between 24 and72 h p.i. BVDV Singer, on the other hand, presented a maximum titer at 24 h p.i. and then decreased. BVDV-NADLtiters increased in MDBK and NCL-1 but not in RD-420 between 24 and 48 h p.i., and then decreased at 72 h p.i.These facts lead us to conclude that neither the subgenotypes (1a, 1b) nor the clinical symptoms of the animal fromthe virus had been isolated seem to affect the virus cell line kinetics of viral replication in vitro. On the other hand, themost homogenous behavior, the most similar replication curves, and highest titers observed in MDBK and NCL-1seem to indicate that these lines are generally more susceptible to BVDV replication.