cell surface-exposed glycopeptidolipids confer a selective advantage to the smooth variants of Mycobacterium smegmatis in vitro

• Published in: FEMS microbiology letters Vol. 290; no. 1; pp. 39 - 44
• Main Authors: Kocíncová, Dana, Winter, Nathalie, Euphrasie, Daniel, Daffé, Mamadou, Reyrat, Jean-Marc, Etienne, Gilles
• Format: Journal Article
• Language: English
• Published: Oxford, UK Oxford, UK : Blackwell Publishing Ltd 2009; Blackwell Publishing Ltd; Wiley-Blackwell; Oxford University Press
• Subjects: Animals; Bacteriology; Biological and medical sciences; Cell Line; Cell Membrane - chemistry; Cell Membrane - metabolism; Cell surface; Epithelial Cells - immunology; Epithelial Cells - microbiology; evolution; Fundamental and applied biological sciences. Psychology; Glycolipids - chemistry; Glycolipids - metabolism; Glycopeptides - chemistry; Glycopeptides - metabolism; glycopeptidolipid; Glycopeptidolipids; Internalization; Laboratories; Life Sciences; Lipids; Macrophages; Macrophages - immunology; Macrophages - microbiology; Mice; Microbiology; Microbiology and Parasitology; Morphology, structure, chemical composition; Mycobacterium smegmatis; Mycobacterium smegmatis - growth & development; Mycobacterium smegmatis - metabolism; Mycobacterium smegmatis - physiology; Phagocytosis - immunology; smooth morphotype; glycopeptidolipid; smooth morphotype; evolution; Smooth form; Statistical analysis; Typing; Mycobacterium smegmatis; Lipids; Mycobacteriales; Selective advantage; Morphology; Mycobacteriaceae; Bacteria; Evolution; Actinomycetes; Fitness; MYCOBACTERIUM SMEGMATIS; GLYCOPEPTIDOLIPID; SMOOTH MORPHOTYPE; EVOLUTION
• ISSN: 0378-1097; 1574-6968
• DOI: 10.1111/j.1574-6968.2008.01396.x

The cell surface of mycobacteria is quite rich in lipids. Glycopeptidolipids, surface-exposed lipids that typify some mycobacterial species, have been associated with a phenotypic switch between rough and smooth colony morphotypes. This conversion in Mycobacterium smegmatis is correlated with the absence/presence of glycopeptidolipids on the cell surface and is due to insertion sequence mobility. Here, we show that the occurrence of a high amount of glycopeptidolipids in the smooth variant leads to lower invasion abilities and lower internalization by macrophages. We further show that the high production of glycopeptidolipids on the cell surface can confer a selective advantage to the smooth variant when grown in vitro. This higher fitness under the laboratory condition might explain the selection of smooth variants in several independent laboratories. The implications of these findings are discussed.