Rapidly-growing Mycobacterium Susceptibility−Broth Dilution

Rapidly-growing mycobacteria isolated from a primary clinical specimen, on a submitted AFB conventional solid medium, or an AFB broth medium

Pure culture isolate on an AFB conventional solid medium or a minimum of 1 mL of AFB broth medium

Conventional or broth medium, tightly sealed, in etiologic agent packaging

Determine the susceptibility of rapidly-growing mycobacterial isolates to a profile of antimycobacterial agents. If cultures remain positive after 6 months of treatment, repeat susceptibility testing is recommended.

Susceptibilities cannot be reported if the organism fails to grow in the test medium. Susceptibilities cannot be performed on mixed cultures. An organism identification is required prior to reporting susceptibility results.

This test was developed and its performance characteristics determined by Labcorp. It has not been cleared or approved by the Food and Drug Administration.

Sensititre® broth microdilution (MIC)

There is no interpretive criteria for tigecycline and clofazimine as there is insufficient clinical data available. Tobramycin is primarily used for M. chelonae treatment. Other rapid growers are generally resistant to this drug. Inducible resistance for clarithromycin is achieved through an extended incubation of up to 14 days. The following organisms do not have a functional erm gene and do not undergo extended incubation: M. chelonae, M. immunogenum, M. mucogenicum, M. peregrinum, and M. senegalense. Clarithromycin is the class representative drug for macrolides. Imipenem results do not predict results for meropenem or ertapenem, as imipenem activity against rapidly growing mycobacteria is greater than meropenem or ertapenem.