Comparison of nucleic acid hybridization, polymerase chain reaction, and virus isolation for detection of bovine herpesvirus 1 (BHV-1) in bovine semen

Bovine Herpesvirus 1 (BHV-1) is an economically important viral agent causing infectious bovine rhinotracheitis (IBR), infectious pustular vulvovaginitis (IPV), infectious pustular balanoposthitis, encephalitis, conjunctivitis, enteritis, abortion and immunosuppression in cattle. The virus which is frequently found in bovine semen can be transmitted by artificial insemination internationally, and is correlated with reduced fertility and abnormal fetal development. Therefore, the detection of BHV-1 in artificial insemination centres and semen banks is of prime importance to the cattle industry. The objective of this study was to optimize virus isolation, dot blot hybridization and the polymerase chain reaction (PCR) for detection of BHV-1 in bovine semen and to compare the sensitivity of these three methods for detection of BHV-1 in bovine semen.

Two 18 month-old, BHV-1 seronegative bulls were experimentally infected with 2 mL of 10$\sp5$ TCID$\sb{50}$/50 $\mu$L of BHV-1 via their prepuces. The semen samples, nasal swabs, prepucial swabs and serum samples were collected 7 days before infection and on days 0, 4, 10, 20, 30, and 40 after infection. Only the semen sample of Bull 1 collected at day 4 was positive by dot blot hybridization, and semen samples from both bulls at day 4 were positive by either virus isolation or PCR with ethidium bromide staining. On the other hand, semen samples which were collected from both bulls on days 4, 10, 20, and 30, and from Bull 1 at day 40 after infection, were positive by PCR with Southern blot hybridization. (Abstract shortened by UMI.).