Diagnosis of bovine herpesvirus-1 in semen by PCR and antibodies by ELISA
Abstract
IBR is a highly infectious viral disease in dairy animals. Seroprevalance of IBR has been reported by many workers. Seronegative bulls should be used for A.I. programme. BHV-1 is also secreted in the semen of infected bulls. In the present study 99 semen samples were collected from cattle and buffalo bulls which were exclusively used for A.I. programme. A total of 92 serum sample from the same bulls were collected. Serum samples were screened for presence of IBR specific antibodies using a commercial Indirect ELISA kit. The seroprevalence was found to be 15.21%. The seropositivity in murrah bulls was found to be 2.59% and in cattle bulls was 80%. It was concluded that cross bred cattle bulls were more prone to IBR infection than indigenous breeds and murrah buffalo bulls were quite resistant to IBR infection. PCR was standardized for screening semen samples for presence of BHV-1.Out of 99 semen samples none was found positive. PCR sensitivity limit was found to be 1.25 TCID50, 12.5 TCID50 and 50 TCID50 by chelax –100 extraction method, standard phenol chloroform method and Triazol reagent method respectively. PCR sensitivity limit was found to be DNA equivalent 1.5 fg (1x10-15g). It was concluded that chelax-100 extraction method was less time consuming and more sensitive, can be applied for routine field diagnosis.