Paratuberculosis caused by Mycobacterium paratuberculosis is a chronic enteritis of ruminants which is characterized by intractable diarrhea and emaciation. Diagnosis is made by the direct detection of M. paratuberculosis in bovine faeces by the polymerase chain reaction (PCR) using primers specific for the IS900 sequence of this organism. PCR tests use relatively complicated and laborious sample preparation procedures. In order to facilitate this test, the commercial DNA purification matrix, InstaGene (Bio-Rad, USA), was used in the present study for the PCR sample preparation. It was consequently easily and quickly possible to prepare PCR amplifiable DNA of M. paratuberculosis. This PCR test using InstaGene was applicable to faecal specimens from experimentally infected calves with M. paratuberculosis. PCR was positive for all samples which were positive in faecal culture. The sensitivity of this PCR using InstaGene was exceeded that of the commercial PCR test conducted on same faecal samples.
(Lab. of Physiologically Active Substances, Biological Products Research Division)