Chemical basis of rough and smooth variation in mycobacteria

Abstract

Rough and smooth colony variants of Mycobacterium kansasii were compared with respect to surface glycolipid composition. Thin-layer chromatography of the native glycolipid antigens, gas chromatography of the constituent sugars, and in situ probing with an appropriate monoclonal antibody by colony dot blot enzyme-linked immunosorbent assay and immunogold labeling demonstrated that all M. kansasii strains of smooth colony morphology contain on their surfaces the recently described trehalose-containing lipooligosaccharides, whereas all rough variants were devoid of such surface antigens. Yet all strains, rough and smooth, contained another glycolipid, the M. kansasii-specific phenolic glycolipid. Previous studies by others had shown that the rough forms of M. kansasii persist longer than smooth variants in experimentally infected mice. Therefore, this study may provide some insight into the question of the chemical basis of pathogenesis in certain mycobacteria.

Unexpected Link between Lipooligosaccharide Biosynthesis and Surface Protein Release in Mycobacterium marinum

“…This rough-dry phenotype is also strongly associated with LOS deficiency in M. kansasii (35) but less clearly in Mycobacterium gastri (44) and M. canettii (45). In M. marinum, two mutants with rough-dry colony morphology, A1/A7 (mmar_2353) and A9 (whiB4), were still producing LOS.…”

“…These studies showed that smooth strains producing LOS were rapidly cleared from the animal organs, whereas the rough LOS-deficient strains showed greater persistence (35,50). It has been proposed that the presence of LOS might act as a mask for other surface-associated factors, such as lipoarabinomannan and phenolic glycolipids (35); enhanced exposure of these glycolipids might result in a more virulent infection. The fact that LOS production is absent in most species of the M. tuberculosis complex, except for the ancient M. canettii, also fits with this hypothesis.…”

“…For instance, M. kansasii strains devoid of LOS have a rough colony morphology, whereas all tested strains with LOS were smooth (35). In M. marinum defects in higher order LOS biosynthesis have also been correlated with altered colony morphology, described as a smooth-wrinkled phenotype (15,16).…”

Synthesis of an unusual polar glycopeptidolipid in glucose-limited culture of Mycobacterium smegmatis

“…As the nomenclature suggests, GPLs contain a tripeptide-amino alcohol core, -Phe--allo-Thr--Ala--alaninol, which is linked with hydroxylated fatty acyl chain at the N-terminal -Phe through amide linkage (Brennan & Goren, 1979). The -allo-Thr and the terminal -alaninol are further linked with 6-deoxytalose (6-dTal) and O-methyl rhamnose, respectively, to form serovar non-specific GPL (nsGPL) that are found in all species of M. avium complex (Brennan & Goren, 1979 ;Belisle & Brennan, 1989 ;Aspinall et al, 1995). The nsGPL, also called core GPL, is further glycosylated at 6-dTal to produce serovarspecific polar GPL (Brennan & Nikaido, 1995) (Fig.…”

A New Glycosylated Lipopeptide Incorporated into the Cell Wall of a Smooth Variant of Gordona hydrophobica

“…However, Barrow and Brennan (6) pointed out that mycoside D is likely to be a mixture of polar and apolar C mycoside glycopeptidolipids (GPLs). 1 Belisle and Brennan (7) showed that the smooth variants of Mycobacterium kansasii possess trehalose-containing lipooligosaccharides, whereas the rough variants were devoid of such surface components.…”