Initial experiences with consensus primer PCR for detection of animal herpesviruses

Abstract

Consensus primer polymerase chain reaction (CP-PCR) is a useful technique for the detection and partial characterisation of novel viruses of veterinary importance. CP-PCR differs from conventional PCR, in that the upstream and downstream primers each consist of a mixture of slightly different oligonucleotides, rather than a single, defined sequence. As used in virus discovery, CP-PCR amplifies a segment of the genome of all members of a particular virus group. Conserved virus genes, e.g. those encoding enzymes, are the most suitable targets when designing these strategies. We used a previously validated CP-PCR method to amplify herpesviral DNA from the left conjunctival sac of a farmed red deer (Cervus elaphus) with keratitis. Sequencing of the CP-PCR product revealed 97% homology to a 174-base pair segment of a novel rhadinovirus of elk (Alces alces) (GenBank AY237365.1). An attempt to isolate a herpesvirus from the deer's conjunctival sac in tissue culture was unsuccessful, as was PCR using conventional primers specific for Cervid herpesvirus 1. This case exemplifies the potential value of CP-PCR for detection of novel herpesviruses.