Detection of Mycobacterium avium subsp paratuberculosis in milk from clinically affected cows by PCR and culture

Milk and faeces samples from cows with clinical symptoms of paratuberculosi s were examined for the presence of Mycobacterium avium subsp. paratubercul osis (M. paratuberculosis) by culture and PCR. M. paratuberculosis was cult ivated in variable numbers from faeces or intestinal mucosa in eight of 11 animals. In milk from five cows (all faeces culture positive), we cultivate d a few colonies of M. paratuberculosis (<100 CFU per ml). Milk samples fro m two cows were PCR positive (both animals were faeces culture positive, an d one cow was milk culture positive). One cow was culture negative on intes tinal mucosa, but culture positive in milk, and two cows were negative in c ulture and PCR from both faeces and milk. In conclusion, the presence of M. paratuberculosis could be detected in raw milk by PCR, but cultivation of milk was more sensitive. (C) 2000 Elsevier Science B.V. All rights reserved .