Lack of mycobactin dependence of mycobacteria isolated on Middlebrook 7H11 from clinical cases of ovine paratuberculosis

Vet Microbiol. 1995 Jul;45(2-3):211-7. doi: 10.1016/0378-1135(95)00037-b.


Mycobacterium avium subsp. paratuberculosis is distinguished from other mycobacterial species by its dependence on the iron-chelator factor mycobactin and its prolonged incubation period when grown in vitro. Traditionally, a very low rate of isolation has been considered characteristic of sheep strains of this mycobacterium species. In the present study, a comparison was made of the performance of two media, Löwenstein-Jensen and Middlebrook 7H11/OADC both with and without mycobactin, on the isolation of M. a. paratuberculosis from ovine cases of the disease. A high isolation rate in both media was observed. Moreover, our results indicated that mycobactin dependence of sheep strains of M. a. paratuberculosis is medium related, being dependent on Löwenstein-Jensen and independent on Middlebrook 7H11/OADC.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Culture Media / chemistry
  • Mycobacterium avium subsp. paratuberculosis / isolation & purification*
  • Oxazoles
  • Paratuberculosis / microbiology*
  • Polymerase Chain Reaction / veterinary
  • Sheep
  • Sheep Diseases / microbiology*


  • Culture Media
  • Oxazoles
  • mycobactins