Differentiation between Cyprinid herpesvirus type-3 lineages using duplex PCR

• Published in: Journal of virological methods 2009, Vol.158, p.1-2
• Main Authors: Bigarre, L, Baud, M, Cabon, J, Antychowicz, J, Bergmann, S.M, Engelsma, M.Y, Pozet, F, Reichert, M, Castric, J
• Format: Article
• Subjects: common carp; disease; dna; infected fish; koi herpesvirus; mortality; polymerase-chain-reaction; simplex-virus type-1; thymidine kinase; tissues
• ISSN: 0166-0934; 1879-0984

To date, all the isolates of Cyprinid herpesvirus type-3 (CyHV3) responsible for serious outbreaks in carps Cyprinus carpio have been found to be very similar or identical on the basis of DNA sequences of a few reference genes. However, two genetic lineages (U/I and J) are distinguished by full-length genome sequencing. Two molecular markers presenting genetic variations were targeted for developing a duplex PCR assay able to distinguish CyHV3-U/I from CyHV3-J while avoiding DNA sequencing. The method was validated on a series of 42 samples of infected carps from France, The Netherlands and Poland collected from 2001 to 2008. Among these samples, both the U/I and J genotypes were identified, but also a third genotype representing a genetic intermediate between U/I and J for one of the two molecular markers. A classification of CyHV3 genotypes, based on the alleles of the two molecular markers, is proposed. The assay is easy to perform and provides a genotype information with samples moderately or highly concentrated. This tool should improve our knowledge regarding the present distribution and future diversification of this emerging virus.