Sur la structure des diesters de tréhalose (“cord factors”) produits par Nocardia asteroides et Nocardia rhodochrous
TL;DR: In this paper, the free lipids of Nocardia asteroides contain a series of corynomycolic acids ranging from C28H54O3 to C36H68O3.
About: This article is published in Chemistry and Physics of Lipids.The article was published on 1970-08-01. It has received 78 citations till now. The article focuses on the topics: Nocardia & Cord factor.
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3,705 citations
TL;DR: The nocardiae are facultative intracellular pathogens that can persist within the host, probably in a cryptic form (L-form), for life and are an important part of the normal soil microflora worldwide.
Abstract: The nocardiae are bacteria belonging to the aerobic actinomycetes. They are an important part of the normal soil microflora worldwide. The type species, Nocardia asteroides, and N. brasiliensis, N. farcinica, N. otitidiscaviarum, N. nova, and N. transvalensis cause a variety of diseases in both normal and immunocompromised humans and animals. The mechanisms of pathogenesis are complex, not fully understood, and include the capacity to evade or neutralize the myriad microbicidal activities of the host. The relative virulence of N. asteroides correlates with the ability to inhibit phagosome-lysosome fusion in phagocytes; to neutralize phagosomal acidification; to detoxify the microbicidal products of oxidative metabolism; to modify phagocyte function; to grow within phagocytic cells; and to attach to, penetrate, and grow within host cells. Both activated macrophages and immunologically specific T lymphocytes constitute the major mechanisms for host resistance to nocardial infection, whereas B lymphocytes and humoral immunity do not appear to be as important in protecting the host. Thus, the nocardiae are facultative intracellular pathogens that can persist within the host, probably in a cryptic form (L-form), for life. Silent invasion of brain cells by some Nocardia strains can induce neurodegeneration in experimental animals; however, the role of nocardiae in neurodegenerative diseases in humans needs to be investigated.
739 citations
TL;DR: In this paper, the role of trehalose in the growth of Mycobacterium smegmutis under various conditions of nitrogen limitation was examined, and the results of labeling studies suggested that the free trehaloses in these cells may be utilized for purposes except as an energy reserve, whereas glycogen is probably stored mainly as a reserve.
Abstract: Publisher Summary This chapter discusses the metabolism of α,α-trehalose. The chapter outlines the various reactions that have been shown to be involved in the metabolism of trehalose. The other isomers of trehalose containing D-glucopyranose—that is, α,β-trehalose and β,β-trehalose have been synthesized chemically. However, except for a few rare cases, these isomers of trehalose do not appear to be naturally occurring. The mechanism of biosynthesis of α,α-trehalose. To determine the role of trehalose in Mycobacterium the levels of free and “bound” (that is, lipid-associated) trehalose and glycogen during growth of Mycobacterium smegmutis under various conditions of nitrogen limitation is examined. Whereas the glycogen levels increased markedly as the nitrogen content of the medium was lowered, the levels of trehalose remained fairly constant. The results of labeling studies suggested that the free trehalose in these cells may be utilized for purposes except as an energy reserve, whereas glycogen is probably stored mainly as a reserve. Synthesis and degradation of trehalose constitute a mechanism for the resorption of D-glucose in the kidney and, perhaps, also in the intestine. It has also been suggested that trehalose—like another naturally occurring, nonreducing disaccharide, sucrose—could function in the movement of carbohydrate, .i.e., as a translocate in plants or insects, or both.
504 citations
TL;DR: This review covers the types of lipids found in bacteria and actinomycetes, especially those reported in the recent literature, including fatty acids; glycerides; phospholipids; glycolipid; and amino acid-containing lipids; and discusses their potential in taxonomy.
Abstract: Written from a taxonomist's point of view and aimed primarily at other taxonomists, this review covers the types of lipids found in bacteria and actinomycetes, especially those reported in the recent literature, including fatty acids; glycerides; phospholipids; glycolipids; and amino acid-containing lipids including peptidolipids, peptidoglycolipids, sulfolipids, hydrocarbons, and waxes, and discusses their potential in taxonomy. Included are a survey of the recent findings on the stability of bacterial lipid patterns in terms of the effect of medium constituents and physical parameters of growth, age, and other factors and a short section on preferred methods of extraction, purification, and analysis.
391 citations
TL;DR: In this paper, the authors examined lipid composition as a guide to the classification of bacteria and showed that qualitative fatty acid analyses could be used to differentiate between various organisms, such as bacteria.
Abstract: Publisher Summary This chapter examines lipid composition as a guide to the classification of bacteria. The correlation of lipid composition with taxonomic classification showed that qualitative fatty acid analyses could be used to differentiate between various organisms. Lipids are most simply defined as the natural products that may be isolated from biological materials by extraction with organic solvents and that are usually insoluble in water. The lipids commonly found in bacteria are amphiphatic molecules, that is, they consist of distinct polar and apolar regions. The chemical composition of many bacterial components, including lipids, can be affected by a variety of external factors, such as temperature of growth, substrate composition, pH of environment, and time of harvesting. The ideal chemotaxonomic method has three basic criteria: (1) it should be applicable to as large a number of organisms as possible; (2) the required information should be readily obtained; and (3) the parameters utilized should differ as widely as possible from one genus or family to the next.
268 citations
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TL;DR: Mice and guinea pigs infected with extracted bacilli may develop tuberculosis considerably slower than animals injected with comparable amounts of unextracted organisms.
Abstract: The bacillary cords characteristic for virulent tubercle bacilli are readily disrupted when wet bacilli are suspended in hydrocarbons such as paraffin oil or petroleum ether. The disruption of cords is due to the removal of a material coating the surface of the bacilli and causing them to adhere to each other. This material can be obtained from virulent bacilli by extracting them with petroleum ether. It is a lipid. Avirulent variants of tubercle bacilli do not yield a similar material after extraction in the same manner; only little of it is obtained from BCG bacilli. The following properties of the fraction obtained by petroleum ether extraction are described: (a) It inhibits the migration of leukocytes in vitro. (b) If repeatedly injected in small doses into mice, it is toxic, whereas a single high dose does not give rise to toxic manifestations. (c) The susceptibility of mice to the toxic action of repeated injections parallels to some extent their degree of susceptibility to infection with the strain of tubercle bacilli from which the fraction was obtained. (d) The injection of the extracted material into guinea pigs does not induce a state of allergic reactivity toward tuberculin. Likewise, tuberculin-positive guinea pigs do not show hypersensitivity against injections of the extracted substance. Bacilli extracted with petroleum ether do not lose their viability. They grow out normally in vitro, and they are still pathogenic. However, the removal of the petroleum ether-soluble lipid from the bacilli results in a loss of the ability of the organisms to inhibit the migration of polymorphonuclear leukocytes. Moreover, mice and guinea pigs infected with extracted bacilli may develop tuberculosis considerably slower than animals injected with comparable amounts of unextracted organisms. The significance of these findings is discussed in relation to the problem of the virulence of tubercle bacilli.
317 citations
TL;DR: The chemical structure of cord factor of Mycobacterium tuberculosis has been established as trehalose-6,6'-dimycolate (I), C186H366O17±10CH2, and methylation studies show that the two mycolic acid molecules are attached through an ester linkage to the primary hydroxyl groups oftrehalose.
275 citations
TL;DR: Intraperitoneal vaccination of mice with cord factor did not protect the mice against a challenge with virulent tubercle bacilli and the significance of the cellular response induced by cord factor is discussed.
Abstract: Amounts of trehalose-6,6-dimycolate as small as 1 to 5 μg can, after intravenous injection, induce in the lungs of mice formation of tubercles in which the cellular composition is indistinguishable from that in tubercles formed after an infection with living BCG bacilli. The strongest cellular response in mice was induced by cord factor from Mycobacterium kansasii; the weakest was induced by cord factor from the BCG strain of M. bovis. It was found that three intravenous injections of cord factor induced a more extensive cellular response than did one injection of the same total amount of cord factor. Mice treated intravenously with cord factor were protected against an intravenous challenge with the virulent H37Rv strain of M. tuberculosis. The cellular response in the lungs of mice to intraperitoneal injections of living BCG and cord factor was very weak compared with that after intravenous injections. Intraperitoneal vaccination of mice with cord factor did not protect the mice against a challenge with virulent tubercle bacilli. Mice vaccinated intraperitoneally with BCG were immunized although no granulomas, or very few, were present in the lungs at the time of the challenge. The significance of the cellular response induced by cord factor is discussed.
152 citations
133 citations