We studied the outermost constituents of the cell envelopes, which are involved in the interaction between the bacilli and the host cells, of five pathogenic and non-pathogenic mycobacterial species for comparison with those we have previously characterized from M. tuberculosis. The extracellular materials (ECMs) were isolated by ethanol precipitation and compared to the surface-exposed materials (SXMs) extracted by mechanical means. The materials from both sources were composed almost exclusively of polysaccharides and proteins. Two groups of mycobacteria were clearly distinguishable. The first group comprised the pathogenic species M. kansasii which produced large amounts of ECM, the glycosyl composition of which was similar to that of the SXM. The second group comprised M. avium and the non-pathogenic strains of M. gastri, M. phlei and M. smegmatis which produced small amounts of ECM. This latter group could be subdivided into those which produced carbohydrate-rich ECM (M. avium and M. gastri) and those forming protein-rich ECM (M. phlei and M. smegmatis), a classification that correlated with the difference in the growth rate of the two subgroups. The glycosyl composition of the ECM of a given species was qualitatively similar to that of the SXM, except for M. avium and M. phlei whose SXM were devoid of arabinose. In addition to glucose, mannose and arabinose, xylose was detected in the hydrolysis products of the ECM and SXM of M. smegmatis, the SXM of M. phlei and the ECM of some batches of M. avium. The polysaccharide constituents of the ECM and SXM of the different mycobacteria were purified by anion-exchange and gel-filtration chromatography; all were found to be neutral compounds devoid of acyl substituents. The extracellular polysaccharides consisted of high-molecular-mass glycogen-like glucans, arabinomannans and mannans, structurally similar to the corresponding substances previously characterized from the capsule of M. tuberculosis. The same types of polysaccharides were characterized from the SXM of all the strains, except M. avium and M. phlei which were devoid of arabinomannans. This study questions the unique and universal representation of the mycobacterial cell envelope and the existence of the so-called acidic polysaccharide-rich outer layer.
AndersenA.B.,
BrennanP.J. Proteins and antigens of Mycobacterium tuberculosis. In Tuberculosis. Pathogenesis1994 Edited by
BloomB.R.
Washington, DC: American Society for Microbiology; Protection and Control, pp 307–332
BermudezL.E.,
YoungL.S.,
EnkelH. Interaction of Mycobacterium avium complex with human macrophages: roles of membrane receptors and serum proteins. Infect Immun1991; 59:1697–1702
ChatterjeeD.,
BozicC.M.,
McNeilM.,
BrennanP.J. Structural features of the arabinan component of the lipoara-binomannan of Mycobacterium tuberculosis. J Biol Chem1991; 266:9652–9660
ChatterjeeD.,
LowellK.,
RivoireB.,
McNeilM.R.,
BrennanP.J. Lipoarabinomannan of Mycobacterium tuberculosis: capping with mannosyl residues in some strains. J Biol Chem1992; 267:6234–6239
DafféM.,
BrennanP.J.,
McNeilM. Predominant structural features of the cell wall arabinogalactan of Mycobacterium tuberculosis as revealed through characterization of oligoglycosyl alditol fragments by gas chromatography/mass spectrometry and by 1H- and 13C-NMR analyses. J Biol Chem1990; 265:6734–6743
DafféM.,
BrennanP.J.,
McNeilM. Major structural features of the cell wall arabinogalactans of Mycobacterium, Rhodococcus and Nocardia spp. Carbohydr Res1993; 249:383–398
DanielT.M. Soluble mycobacterial antigens. In The Mycobacteria. A Sourcebook1984 Edited by
KubicaG.P.,
WayneL.G.
New York: Marcel Dekker, Inc; Part A, pp 417–465
FattoriniL.,
XiaoY.,
LiB.,
IppolitiF.,
OreficiG. Induction of IL-1β, IL-6, TNF-a, GM-CSF and G-CSF in human macrophages by smooth transparent and smooth opaque colonial variants of Mycobacterium avium. J Med Microbiol1994; 40:129–133
HarboeM. The significance of proteins actively secreted by Mycobacterium tuberculosis in relation to immunity and complications of mycobacterial diseases. Int J Lepr1992; 60:470–476
HenningsonP.J.,
GudmestadN.C. Comparison of exopolysaccharides from mucoid and nonmucoid strains of Clavib-acter michiganensis subspecies sepedonicus. Can J Microbiol1992; 39:291–296
KhooK.-H.,
DellA.,
MorrisH.R.,
BrennanP.J.,
ChatterjeeD. Inositol phosphate capping of the nonreducing termini of lipoarabinomannan from rapidly growing strains of Mycobacterium. J Biol Chem1995; 270:12380–12389
LemassuA.,
L£vy-Fr£baultV.V.,
LanäelleM.-A.,
DaffeM. Lack of correlation between colony morphology and lipooligosaccharide content in the Mycobacterium tuberculosis complex. J Gen Microbiol1992; 138:1535–1541
McNeilM.R.,
BrennanP.J. Structure, function and biogenesis of the cell envelope of mycobacteria in relation to bacterial physiology, pathogenesis and drug resistance; some thoughts and possibilities arising from recent structural information. Res Microbiol1991; 142:451–463
MisakiA.,
AzumaI.,
YamamuraY. Structural and immunochemical studies on D-arabino-D-mannans and D-mannans of Mycobacterium tuberculosis and other Mycobacterium species. J Biochem1977; 82:1759–1770
Ortalo-MagnéA.,
DupontM.A.,
LemassuA.,
AndersenA.B.,
GounonP.,
DafféM. Molecular composition of the outermost capsular material of the tubercle bacillus. Microbiology1995; 141:1609–1620
Ortalo-MagnéA.,
AndersenA.B.,
DafféM. The outermost capsular arabinomannans and other mannoconjugates of virulent and avirulent tubercle bacilli. Microbiology1996a; 142:927–935
Ortalo-MagnéA.,
LemassuA.,
LanéelleM.A.,
BardouF.,
SilveG.,
GounonP.,
MarchaiG.,
DafféM. Identification of the surface-exposed lipids on the cell envelopes of Mycobacterium tuberculosis and other mycobacterial species. J Bacteriol1996b; 178:456–461
PaulT.R.,
BeveridgeT.J. Preservation of surface lipids and determination of ultrastructure of Mycobacterium kansasii by freeze-substitution. Infect Immun1994; 62:1542–1550
RastogiN.,
FréhelC.,
DavidH.L. Triple-layered structure of mycobacterial cell wall: evidence for the existence of a polysaccharide-rich outer layer in 18 mycobacterial species. Curr Microbiol1986; 13:237–242
SchlesingerL.S.,
HullS.R.,
KaufmanT.M. Binding of the terminal mannosyl units of lipoarabinomannan from a virulent strain of Mycobacterium tuberculosis to human macrophages. J Immunol1994; 152:4070–4079
SeibertF.B. The isolation of three different proteins and two polysaccharides from tuberculin by alcohol fractionation Their chemical and biological properties. Am Rev Tuberc Pulm Dis1949; 59:86–101
WayneL.G.,
KubicaG.P. Genus Mycobacterium Lehmann and Neumann 1896, 363th. In Bergey's Manual of Systematic Bacteriology1986 Edited by
SneathP.H.A.,
MairN.S.,
SharpeM.E.,
HoltJ.G.
Baltimore: Williams & Wilkins; 2 pp 1436–1457