PCR technique as an alternative method for diagnosis and molecular epidemiology of rabies virus.

We have investigated the PCR amplification technique of viral nucleic acids as an alternative protocol for diagnosis and epidemiological studies of rabies virus. A primer set mapping in the nucleoprotein cistron allowed a specific and sensitive amplification of infected brain material, fulfilling the diagnosis requirements. One hundred samples checked by Southern or dot-blot analysis using both radioactive and non-radioactive probes showed identical results in parallel with routine techniques. For molecular epidemiological studies we selected another set of conserved primers flanking the highly evolutive pseudogene (psi gene) region. This set was found to be efficient for all tested fixed rabies virus strains or wild rabies virus isolates as well as the rabies-related Mokola virus. We describe a progressive characterization of the strain that could be extended from rapid typing by a limited panel of restriction enzymes, to the ultimate identification of the nucleotide sequence by an original direct sequencing technique of amplified segments.