Evidence that host-recycling of Mycobacterium avium preserves its ability to hinder macrophage killing functions.
The opportunistic pathogen Mycobacterium avium was selected as a model for the study of the bacterial cell envelope and resistance to macrophage killing functions. We hereby demonstrate that characteristic features of M. avium, e.g. existence of a polysaccharide-rich outer layer (POL), presence of a protective capsule also called electron-transparent zone (ETZ) around phagocytized bacteria, and inhibition of phagosome-lysosome fusions (PLF), were better expressed by bacteria recently isolated from infected rabbits than by bacteria subcultured in laboratory media. Our data appeared to confirm previous suggestions that M. avium regulatory mechanisms are such that during laboratory growth of these bacteria, synthesis of surface components which may be important concerning their virulence properties, is effectively diminished.
Fréhel
C
C
Unité de Microscopie Electronique, Institut Pasteur, Paris.
Thorel
M F
MF
Rastogi
N
N
D000818:Animals; D002478:Cells, Cultured; D008264:Macrophages / Q000276:immunology / Q000382:microbiology; D008854:Microscopy, Electron; D009162:Mycobacterium avium / Q000254:growth & development* / Q000276:immunology / Q000472:pathogenicity; D014774:Virulence