title: Lack of mycobactin dependence of mycobacteria isolated on Middlebrook 7H11 from clinical cases of ovine paratuberculosis.
abstract: 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.
authors.affiliation: Servicio de Investigación y Mejora Agraria (SIMA), Dpto. de Agricultura y Pesca, Derio, Vizcaya, Spain.
authors.forename: J J
authors.initials: JJ
authors.lastname: Adúriz
authors.forename: R A
authors.initials: RA
authors.lastname: Juste
authors.forename: N
authors.initials: N
authors.lastname: Cortabarria
mesh_terms: D000818:Animals; D003470:Culture Media / Q000737:chemistry; D016927:Mycobacterium avium subsp. paratuberculosis / Q000302:isolation & purification*; D010080:Oxazoles; D010283:Paratuberculosis / Q000382:microbiology*; D016133:Polymerase Chain Reaction / Q000662:veterinary; D012756:Sheep; D012757:Sheep Diseases / Q000382:microbiology*
chemical_list: D003470:Culture Media; D010080:Oxazoles; C018608:mycobactins