Intracellular lipophilic inclusions of mycobacteria in vitro and in sputum

摘要: Although most mycobacterial lipids are thought to be associated with the cell envelope, authors previously observed substantial deposits of intracellular lipophilic material. A Nile-red-based cytological assay was used determine factors which affect presence and natural history inclusions (ILIs) in Mycobacterium smegmatis. Development ILIs stationary-phase cultures broth aged (6 days) colonies on agar. Using variants Youmans’ defined medium, frequency size minimal carbon-poor medium. were form within 15 min after provision fatty acids medium a period several days nitrogen-poor Analysis non-polar lipid extracts ILI-rich -poor preparations indicated that triacylglycerols (TAGs) major component inclusions. The acyl substituents TAGs varied according whether they formed Middlebrook 7H9 broth, low-nitrogen or rapidly oleic acid supplementation broth. These studies support storage function for mycobacteria addition their suggested occurrence as components envelope. To assess possible role tuberculosis, combined acid-fast (Auramine)/Nile red applied heavily positive sputum samples from patients tuberculosis. Strong Nile signals obtained cells, indicating ILI occur M. tuberculosis vivo. This may reflect distinct physiological state these it has not been reproduce vitro. findings indicate uptake long-chain TAG biosynthetic degradative pathways important aspects metabolism, meriting further investigation.