[A susceptibility study of Mycobacterium avium-intracellulare strains using the broth macrodilution method]

The macrobroth dilution method was used for determining the resistance and/or sensitivity of 10 nontuberculous mycobacteria strains from Mycobacterium avium-intracellulare (MAI) complex isolated from patients presenting with respiratory symptoms. Drugs employed were as follows: isoniazid, ethambutol, rifampicin, streptomycin, gentamicin and amikacin. With respect to susceptibility of the strains studied, the greater sensitivity was found to be against ethambutol, amikacin, and gentamicin. The possibility of replacing the Middlebrook 7H9 liquid culture medium by the UIT-L liquid culture medium was analyzed. Normalization of the method was attained and a shortening of the reading time when using the UIT-L culture medium was also obtained.