Detection of bovine group-A rotavirus by reverse transcriptase-polymerase chain reaction

Rotavirus was first discovered to be an animal pathogen in 1969 by Mebus and his colleagues. Since then it has been accepted as an important aetiological agent of diarrhoea in children and in young animals including many mammalian and avian species (Estes and Cohen, 1989). Because of difficulty in cultivation of the virus in cell culture, varicus tests like electron microscopy, complement fixation test, fluorescent antibody test, enzyme immunoassays and ribonucleic acid-polyacrylamide gel electrophoresis (RNA-PAGE) have been used for detection of rotavirus antigen or nucleic acids in faecal samples. Although the most commonly used methods in clinical laboratories, for detection of rotavirus infection are RNA-PAGE and ELISA because of their reasonable specificity and sensitivity (Steel et al., 1992), these methods have certain limitations. ELISA with polyclonal antisera have disadvantage of giving false positive results (Pedley and McCrae, 1984), thus requiring repititive testing for verification. Detection of rotavirus by RNA-PAGE followed by silver staining is specific but is not applicable for large scale sample screening. The PCR based detection assays are much more sensitive and specific than RNA-PAGE and ELISA. Thus, the present communication describes the amplification of the gene encoding the major neutralizing antigen (VP7 protein) of the virus by the reverse transcriptase-polymerase chain reaction (RTPCR) method.