Novel glycolipids of Mycobacterium avium and related M. paratuberculosis strains of relevance to AIDS and Crohn's disease.

The polar glycolipid fractions of several mycobacterial strains of the closely related species M. avium and M. paratuberculosis have been analysed by thin layer chromatography (TLC), high pH anion exchange chromatography (HPAEC), gas-liquid chromatography (GC) and nuclear magnetic resonance (NMR) spectroscopy. The upper phase of a Folch partitioning (rather than the lower phase analysed by others) was subjected to TLC in solvent system chloroform-methanol-water 50:40:10 v/v/v. A major band was purified from each mycobacterial strain. Monosaccharide analysis of that from M. avium A14 (from an AIDS patient) contained Glc, Ara, Man, Gal in ratios 7:4:3:2. whereas one strain of M. paratuberculosis (316F) had low levels of Ara, Gal and Man with major monosaccharides being Glc and two unidentified monosaccharides. A second M. paratuberculosis strain (J10) had a single TLC band containing only Glc. These known strains were compared to two slow growing mycobacterial isolates, one from a Crohn's patient and one isolated from armadillo. These were similar to J10 in only having Glc present: the former also had a similar NMR spectrum to J10, whereas the latter had a different NMR spectrum from any of the other strains analysed. The results therefore indicate that M. paratuberculosis strain 316F is more closely related to M. avium (from an AIDS patient) than it is to the classical M. paratuberculosis strain J10 and a Crohn's isolate.