Medically Important Mycobacteriacontinued Clinical Microbiology Review 214
ORGANISM PATHOGENICITY KEY POINTS
M. fortuitum
M. leprae
Common in environment. Rapid grower. Weakly gram
pos. Weakly acid fast. Stains with carbolfuchsin, but
may not with fluorescent stain.
Endemic in Southern hemisphere. <100 cases per year
in U.S. Most in TX, CA, LA, HI, PR. Armadillos may be
reservoir. Doesn’t grow on artificial media. Can be
grown in footpads of mice & armadillos. Dx by acid-fast
stain of tissue. Less acid fast than M. tuberculosis.
Infections of skin, soft tissues, IV & injection sites,
surgical wounds
Leprosy (Hansen’s disease)
