Analysis of lipids reveals differences between ‘Mycobacterium habana’ and Mycobacterium simiae

Abstract

Fatty and mycolic acids and the pattern of glycolipids were studied in a collection of 34 strains of 'Mycobacterium habana' and in two strains of Mycobacterium simiae. Major glycolipids of these micro-organisms were assigned to the glycopeptidolipid (GPL) structural type, but both mycobacteria differed in the patterns obtained by TLC. The strains of 'M. habana' were separated into four groups (A-D), taking into account the presence or absence of several polar GPLs: group A contained GPL-I, GPL-ll and GPGIII; group B contained GPGI, GPGII', GPGll and GPGIII; group C contained GPGII', GPL-II and GPGIII; group D did not contain any of these compounds. Fatty acids of both bacteria were similar, and ranged from 14 to 26 carbon atoms, hexadecanoic, octadecenoic and tuberculostearic acids being predominant. Mycolic acids were also similar by TLC and HPLC, and consisted of a=, a'-and ketomycolates.Partial structural analysis by M S carried out in strains 'M. habana' TMC 5135 and M. simiae ATCC 25275l revealed that a-and ketomycolates ranged, in general, from 79 to 87 carbon atoms, and a'-mycolates from 58 to 67 carbon atoms. The a-and ketomycolates belonged to several structural series, and minor variations were found between the two strains examined. The data obtained justified the synonymy between 'M. habana' and M. simiae but indicated, in turn, that the former can be distinguished on the basis of GPL analysis. Most strains of 'M. habana' can be defined by the presence of GPGll and GPGIII, a finding that could be useful in the quality control of potential vaccine strains.

Analysis of the structure of mycolic acids of Mycobacterium simiae reveals a particular composition of α-mycolates in strain ‘habana’ TMC 5135, considered as immunogenic in tuberculosis and leprosy

“…As previously reported (Mederos et al, 1998;Minnikin et al, 1984), a-, a9-and keto-mycolates were present in the four strains studied. All mycolates could be identified without ambiguity by comparison of the 1 H-NMR spectra obtained with those reported elsewhere (Watanabe et al, 1999(Watanabe et al, , 2001.…”

“…The general pattern and structure of the mycolic acids of the different strains of M. simiae were similar, as expected (Mederos et al, 1998;Minnikin et al, 1984). The major amycolates combined two di-substituted cyclopropane rings, and the major oxygenated mycolates (keto-mycolates) contained one trans di-substituted cyclopropane ring.…”

“…Purified fractions with the same structural type of MAMEs were combined and analysed by 1 H-NMR and MS (see below). When necessary, these compounds were repurified using preparative TLC (silica-gel plates, Merck), as previously described (Mederos et al, 1998). We did not find a significant influence of acid methanolysis on cyclopropane rings or double bonds, because no artefacts were revealed by 1 H-NMR or MS. On the other hand, the recommendations of Watanabe et al (2001) in the purification of mycolates were followed, to avoid mistakes with the proportion of cis/trans isomerism.…”

“…habana' TMC 5135 has been reported (Khoo et al, 1996), as well as the general composition of lipids of several strains within the 'habana' group (Mederos et al, 1998), and this has taxonomic potential. However, the analysis of the fine structure of the mycolic acids of M. simiae is still pending.…”

Altered expression profile of mycobacterial surface glycopeptidolipids following treatment with the antifungal azole inhibitors econazole and clotrimazole

“…Pathogenic mycobacteria produce an array of unusual lipophilic compounds that are required for growth and survival of the organism in the human host (Karakousis et al, 2004). The use of refined analytical techniques coupled with structural characterization has continued to provide detailed structural knowledge on the species-and serotypespecific glycolipids of the genus Mycobacterium (Khoo et al, 1996a;Mederos et al, 1998;Nishiuchi et al, 2004). These highly diverse glycosylated surface antigens have been broadly classified into three major families: the phenolic glycolipids (PGLs), the trehalose-containing lipooligosaccharides (LOSs) and the glycopeptidolipids (GPLs) (Brennan & Nikaido, 1995;Vergne & Daffé, 1998).…”