Detection of bovine herpesvirus-1 in bovine semen by a nested PCR assay

A nested PCR assay targeting a portion of the glycoprotein IV gene has been developed for the detection of Bovine Herpesvirus-1 (BHV-1). Rapid and sensitive detection of the PCR products was achieved using a nonisotopic reverse dot-blot format with a visible color readout. Cross-reactivity of this PCR assay was not observed with the closely related BHV-3. The sensitivity of this assay when tested on a supernatant from a BHV-1 cell culture was approximately 4.5 TCID50 (50% tissue culture infectious dose). A procedure using the chelating resin Chelex 100 was used to prepare viral DNA from artificially inoculated samples of extended and raw semen for use in the PCR assay. In combination with nested PCR and reverse dot blot, this method allowed the detection of 5 x 10(3) TCID per 0.5 ml of semen, which is comparable to the detection in the Cornell Semen Test. The whole procedure can be completed in approximately 8 h. This assay has therefore the potential of replacing the currently available yet time consuming and costly detection methods for BHV-1 in bovine semen.