Rapidly growing mycobacteria: testing of susceptibility to 34 antimicrobial agents by broth microdilution.
A total of 18 strains of Mycobacterium fortuitum, 15 strains of M. chelonei, and 31 strains of M. chelonei-like organisms were tested by both broth microdilution and agar dilution to determine their susceptibility to 34 antimicrobial agents. All strains grew well enough in cation-supplemented Mueller-Hinton broth for endpoints to be read after 72 h of incubation. Some strains of M. chelonei did not grow on Mueller-Hinton agar. A few discrepancies were noted between the broth and agar procedures. For M. fortuitum, doxycycline, minocycline, amikacin, sulfamethoxazole, and sulfamethoxazole-trimethoprim were the most active agents. For M. chelonei, amikacin, sisomicin, tobramycin, and erythromycin were the most active agents. The M. chelonei-like organisms were most susceptible to ampicillin, doxycycline, minocycline, amikacin, erythromycin, sulfamethoxazole, and sulfamethoxazole-trimethoprim. Broth microdilution appears to be a reliable method for susceptibility testing of rapidly growing mycobacteria, although clinical studies are needed to determine how well in vitro results correlate with therapeutic in vivo outcome.
D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D002455:Cell Division; D004353:Drug Evaluation, Preclinical; D004352:Drug Resistance, Microbial; D008826:Microbial Sensitivity Tests / Q000379:methods*; D009161:Mycobacterium / Q000187:drug effects* / Q000254:growth & development; D013045:Species Specificity
D000900:Anti-Bacterial Agents