USE OF THE POLYMERASE CHAIN-REACTION (PCR) TO DIFFERENTIATE SEROLOGICALLY SIMILAR VIRAL HEMORRHAGIC SEPTICEMIA (VHS) VIRUS ISOLATES FROM EUROPE AND AMERICA

Since 1988, VHSV (viral haemorrhagic septicaemia virus) has occasional ly been isolated from salmonids and marine fish in USA. The isolates a re so far serologically indistinguishable from the European VHSV refer ence strain F1. However, the nucleotide sequence of an American isolat e (Makah) revealed a unique 20 nucleotide sequence in close proximity to the N gene. This sequence is not present in the European VHSV isola tes. Through the use of PCR (polymerase chain reaction) and specific p rimer sets for the amplification of N gene fragments it is now possibl e to distinguish between the European and American isolates within hal f a day.