Characterization of virulence, colony morphotype and the glycopeptidolipid of Mycobacterium avium strain 104.
METHODS
Members of the Mycobacterium avium complex (MAC) are responsible for mycobacterial disease in children, the aged and in immunocompromised individuals. The complex consists of different species, serovars and morphologic forms that vary in virulence. One isolate of the MAC is currently being sequenced (MAC 104) and was chosen based on its derivation from an AIDS patient and the fact that it could be genetically manipulated.


OBJECTIVE
MAC 104 was therefore analyzed for virulence, colony morphotype and expression of the glycopeptidolipid (GPL) responsible for serotying differences and the rough to smooth morphological switch.


RESULTS
The isolate was found to be virulent in the murine model of low-dose aerosol infection in that it could colonize the lung, proliferate within the tissue and disseminate to other organs. MAC 104 expressed a variety of colony morphotypes, the most prevalent of which were smooth opaque, smooth transparent and rough. All three morphotypes could persist in the lung; however, the transparent and rough morphotypes grew more rapidlyinvivo. The rough morphotype was unusual in that it expressed an atypical form of the GPL usually absent from rough morphotypes.


CONCLUSIONS
This characterization complements the genome data and confirms that MAC 104 behaves similarly to other MAC isolates.
Torrelles
J B
JB
Mycobacteria Research Laboratories, Department of Microbiology, Colorado State University, Fort Collins, CO 80523, USA.
Ellis
D
D
Osborne
T
T
Hoefer
A
A
Orme
I M
IM
Chatterjee
D
D
Brennan
P J
PJ
Cooper
A M
AM
D000818:Animals; D000942:Antigens, Bacterial / Q000032:analysis*; D000954:Antigens, Surface / Q000032:analysis*; D015373:Bacterial Typing Techniques; D002849:Chromatography, Gas; D008171:Lung Diseases / Q000382:microbiology; D013058:Mass Spectrometry; D051379:Mice; D008810:Mice, Inbred C57BL; D009162:Mycobacterium avium / Q000472:pathogenicity*; D015270:Mycobacterium avium-intracellulare Infection / Q000382:microbiology; D010641:Phenotype
D000942:Antigens, Bacterial; D000954:Antigens, Surface