Cell envelope architectures of leprosy-derived corynebacteria,Mycobacterium leprae, and related organisms: a comparative study

Rastogi, Nalin; Fréhel, Claude; David, Hugo L.

doi:10.1007/bf01567571

Cited by 15 publications

(10 citation statements)

References 17 publications

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“…Ultrathin sections were stained with ruthenium red, a stain that strongly reacts with the surface of mycobacteria Rastogi et al, 1984). Examination of thin sections revealed for both strains a cell envelope structure (Fig.…”

Section: Ultrastuctural Features Of the M Smegmatis Strainsmentioning

confidence: 99%

The cell envelope structure and properties of Mycobacterium smegmatis mc2155: is there a clue for the unique transformability of the strain?

et al. 2005

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The cell envelope structure and properties of Mycobacterium smegmatis mc 2 155: is there a clue for the unique transformability of the strain? Mycobacterium smegmatis is often used as a surrogate host for pathogenic mycobacteria, especially since the isolation of the transformable smooth morphotype strain mc 2 155 from the isogenic rough wild-type strain ATCC 607. Biochemical analysis of the cell envelope components revealed a lack of polar glycolipids, namely the lipooligosaccharides and the polar subfamilies of glycopeptidolipids, in the mc 2 155 strain. In addition, the latter strain differs from its parent by the distribution of various species of glycolipids and phospholipids between the outermost and deeper layers of the cell envelope. The presence of filamentous and rope-like structures at the cell surface of mc 2 155 cells grown in complex media further supported an ultrastructural change in the cell envelope of the mutant. Importantly, a significantly more rapid uptake of the hydrophobic chenodeoxycholate was observed for the mutant compared to wild-type cells. Taken together, these data indicate that the nature of the surface-exposed and envelope constituents is crucial for the surface properties, cell wall permeability and bacterial phenotype, and suggest that the transformable character of the mc 2 155 strain may be in part explained by these profound modifications of its cell envelope.

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Section: Ultrastuctural Features Of the M Smegmatis Strainsmentioning

confidence: 99%

The cell envelope structure and properties of Mycobacterium smegmatis mc2155: is there a clue for the unique transformability of the strain?

et al. 2005

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“…In addition to LAM or armadillo-derived mycobacteria, leprosy lesions are associated with large numbers of coryneform bacteria, termed leprosy-derived corynebacteria (LDC) (58,135,232,234). Although it was once thought that these organisms were non-acid-fast forms of M. leprae, it is now known that they are not related to mycobacteria and probably play a role similar to that played by LAM (74,232).…”

Section: The Search For a Mycobacterial Etiologymentioning

confidence: 99%

“…Although it was once thought that these organisms were non-acid-fast forms of M. leprae, it is now known that they are not related to mycobacteria and probably play a role similar to that played by LAM (74,232). Unlike the LAM, LDC are primarily associated with the lesions and are rarely isolated from noninfected tissues.…”

Section: The Search For a Mycobacterial Etiologymentioning

confidence: 99%

Crohn's disease and the mycobacterioses: a review and comparison of two disease entities

1989

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Crohn's disease is a chronic granulomatous ileocolitis, of unknown etiology, which generally affects the patient during the prime of life. Medical treatment is supportive at best, and patients afflicted with this disorder generally live with chronic pain, in and out of hospitals, throughout their lives. The disease bears the name of the investigator who convincingly distinguished this disease from intestinal tuberculosis in 1932. This distinction was not universally accepted, and the notion of a mycobacterial etiology has never been fully dismissed. Nevertheless, it was 46 years after the distinction of Crohn's disease and intestinal tuberculosis before research attempting to reassociate mycobacteria and Crohn's disease was published. Recently, there has been a surge of interest in the possible association of mycobacteria and Crohn's disease due largely to the isolation of genetically identical pathogenic Mycobacterium paratuberculosis from several patients with Crohn's disease in the United States, the Netherlands, Australia, and France. These pathogenic organisms have been isolated from only a few patients, and direct evidence for their involvement in the disease process is not clear; however, M. paratuberculosis is an obligate intracellular organism and strict pathogen, which strongly suggests some etiologic role. Immunologic evidence of a mycobacterial etiology, as assessed by humoral immune determinations, has been conflicting, but evaluation of the more relevant cellular immunity has not been performed. Data from histochemical searches for mycobacteria in Crohn's disease tissues have been equally conflicting, with acid-fast bacilli detected in 0 to 35% of patients. Animal model studies have demonstrated the pathogenic potential of isolates as well as elucidated the complexity of mycobacterial-intestinal interactions. Treatment of Crohn's disease patients with antimycobacterial agent has not been fully assessed, although case reports suggest efficacy. The similarities in the pathology, epidemiology, and chemotherapy of Crohn's disease and the mycobacterioses are discussed. The issue is fraught with controversy, and the data generated on the association of mycobacteria and Crohn's disease are in their infantile stages so that a general conclusion on the legitimacy of this association cannot be made. While no firm evidence clearly implicates mycobacteria as an etiologic agent of Crohn's disease, the notion is supported by suggestive and circumstantial evidence and a remarkable similarity of Crohn's disease to known mycobacterial diseases.

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“…The POL of M. aurum treated with 100 ,ig of colistin per ml was also observed by the RR staining procedure (15). All the procedures for fixation, dehydration, embedding, and specific stainings were carried out as described earlier for mycobacteria (12)(13)(14)(15)(16). Thin sections were cut on a LKB ultratome III, mounted on copper grids, and observed with a Siemens 101 electron microscope.…”

Section: Methodsmentioning

confidence: 99%

“…Like that of other mycobacteria (12)(13)(14)(15)(16)19), the cytoplasmic membrane of M. aurum has an asymmetrical profile, only the outer layer of which is specifically stained with the Thidry cytochemical method for electron microscopy (13,19). This observation facilitated the direct examination of the cytoplasmic membrane as a possible site of action of colistin.…”

mentioning

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Antibacterial action of colistin (polymyxin E) against Mycobacterium aurum

David¹,

Rastogi²

1985

Antimicrob Agents Chemother

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Mycobacterium aurum was susceptible to the antibiotic colistin (polymyxin E), which had an MIC of 5 ,ug/ml and an apparent bactericidal effect at concentrations above 50 ,ug/ml. Treatment of actively growing cells with sublethal concentrations of colistin (15 ,Ig/ml) resulted in synchronized cell division once the antibiotic was removed. Under conditions of synchronized cell growth, one cycle of DNA replication lasted 120 min and one cycle of cell division lasted about 180 min. Although the antibiotic treatment during synchronization experiments did not produce apparent changes in the bacterial envelope, it was accompanied by the accumulation of a polysaccharide-like substance in the bacterial cytoplasm which gradually decreased after the removal of antibiotic and by an increase in the number of mesosomes at 3 h after antibiotic removal. This step was closely linked to the doubling time of bacteria. Lethal concentrations of colistin of 50 and 100 ,ug/ml, which caused about 90 and 99% cell death, respectively, produced significant cytoplasmic membrane injuries, patchy appearance of the cell wall outer polysaccharide layer, and little cell lysis. These data indicate that the cytoplasmic membrane is a site of action of colistin and raise a question as to whether an outer bilayer exists in mycobacteria, at least functionally.The antibiotic colistin (polymyxin E) exerts its antibacterial action by interacting with membrane bilayers (la, 11, 21, 23). In gram-negative bacteria, which are surrounded by an outer membrane bilayer, the antibiotic causes characteristic deformities in the outer membrane, probably binding to lipopolysaccharides (7,8). Direct evidence of its interaction with the cytoplasmic membrane, however, has been more difficult to obtain (20). As condensation of the bacterial genome is an early event during the action of the antibiotic (20) and, moreover, the bacterial genome is attached to the plasma membrane (3, 18), which is probably necessary for its replication (6), we wondered whether treatment of cells with sublethal concentrations of colistin would result in a reversible detachment from the membrane. If this is the case, the removal of colistin would permit a simultaneous reattachment of the genome in all the cells, leading to synchronized cell division.To examine the mode of action of colistin and to test the above hypothesis about synchronized cell division, we selected Mycobacterium aurum, as it is susceptible to low concentrations of colistin (2). Like that of other mycobacteria (12)(13)(14)(15)(16)19), the cytoplasmic membrane of M. aurum has an asymmetrical profile, only the outer layer of which is specifically stained with the Thidry cytochemical method for electron microscopy (13,19). This observation facilitated the direct examination of the cytoplasmic membrane as a possible site of action of colistin. Moreover, M. aurum forms a polysaccharide outer layer (POL) which is homogenously distributed on the bacterial cell surface and can be revealed by ruthenium red (RR) staining (lla). Recen...

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Cell envelope architectures of leprosy-derived corynebacteria,Mycobacterium leprae, and related organisms: a comparative study

Cited by 15 publications

References 17 publications

The cell envelope structure and properties of Mycobacterium smegmatis mc2155: is there a clue for the unique transformability of the strain?

The cell envelope structure and properties of Mycobacterium smegmatis mc2155: is there a clue for the unique transformability of the strain?

Crohn's disease and the mycobacterioses: a review and comparison of two disease entities

Antibacterial action of colistin (polymyxin E) against Mycobacterium aurum

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