%0 Journal Article %A Draper, P. %A Rees, R. J. W. %T The Nature of the Electron-transparent Zone that Surrounds Mycobacterium lepraemurium inside Host Cells %D 1973 %J Microbiology, %V 77 %N 1 %P 79-87 %@ 1465-2080 %R https://doi.org/10.1099/00221287-77-1-79 %I Microbiology Society, %X SUMMARY: Liver and spleen tissue from mice infected 4 to 5 months previously with Mycobacterium lepraemurium has been examined in the electron microscope by negative staining, freeze-etching and ultrathin sectioning. Part or all of the electron-transparent zone seen around sectioned bacteria is composed of parallel fibrils wrapped longitudinally around the bacteria. It was isolated from homogenates of infected livers and spleens using urea density gradients and contained a mycoside of type C, a peptidoglycolipid known to occur in some other species of mycobacteria. The mycoside therefore forms a capsule around the bacterium to protect and insulate it from the host cell and its lysosomes. %U https://www.microbiologyresearch.org/content/journal/micro/10.1099/00221287-77-1-79