GENETIC-ANALYSIS OF CLASSICAL SWINE FEVER VIRUS ISOLATES FROM A SMALLGEOGRAPHIC AREA

Twenty-eight field CSFV samples were isolated from outbreaks of CSF wh ich have occurred in three small geographic areas in Slovakia in the p eriod of December 1993 - November 1994. All the organ homogenates were positive by virus isolation and RT-PCR assay using general pestivirus virus 324/326 primers selected from 5'-noncoding (5'-NC) genomic regi on. Specific discrimination of CSFV was confirmed by the cleavage of a mplicons using Bgl I and Ava I. Four viral isolates (A, B, C, E) were selected for a comparative sequencing study. Sequencing of amplicons i n the 5'-NC, gp55 (E2), p54 (NS2) and NS5B genomic regions revealed th at A, B isolates (orginated from SR geographic area) were the same but different from identical C (NR geographic area) and E (ER geographic area) isolates. Results of molecular-genetic study were very well supp orted with epi zootological data. All CSFV isolates from Slovakia phyl ogenetically fell into the group of recent European isolates clearly s eparated from old European and American strains.