Comparison of methods for Identification of Mycobacterium abscessus and M. chelonae isolates.
Mycobacterium abscessus and Mycobacterium chelonae are two closely related species that are often not distinguished by clinical laboratories despite the fact they cause diseases requiring different treatment regimens. Multilocus enzyme electrophoresis, PCR-restriction fragment length polymorphism analysis of the 65-kDa heat shock protein gene, biochemical tests, and high-performance liquid chromatography of mycolic acids were used to identify 75 isolates as either M. abscessus or M. chelonae that were originally submitted for drug susceptibility testing. Only 36 of these isolates were submitted with an identification at the species level. Using the above methods, 46 of the isolates were found to be M. abscessus and 29 were identified as M. chelonae. Eight isolates originally submitted as M. chelonae were identified as M. abscessus, and one isolate submitted as M. abscessus was found to be M. chelonae. The four identification methods were in agreement in identifying 74 of the 75 isolates. In drug susceptibility testing, all isolates of M. abscessus exhibited resistance to tobramycin (MIC of 8 to > or =16 microg/ml), while all isolates of M. chelonae were susceptible to this drug (MIC of < or = 4 microg/ml). The results suggest that once an identification method is selected, clinical laboratories should be able to easily identify isolates of M. abscessus and M. chelonae.
Yakrus
M A
MA
Tuberculosis/Mycobacteriology Branch, Division of AIDS, STD, and TB Laboratory Research, National Center for Infectious Diseases, Centers for Disease Control and Prevention, Atlanta, Georgia 30333, USA. may2@cdc.gov
Hernandez
S M
SM
Floyd
M M
MM
Sikes
D
D
Butler
W R
WR
Metchock
B
B
D000900:Anti-Bacterial Agents / Q000494:pharmacology; D001426:Bacterial Proteins; D015373:Bacterial Typing Techniques; D018834:Chaperonin 60; D018833:Chaperonins / Q000235:genetics; D002851:Chromatography, High Pressure Liquid; D004587:Electrophoresis, Agar Gel / Q000379:methods; D004798:Enzymes / Q000032:analysis; D006801:Humans; D008826:Microbial Sensitivity Tests / Q000379:methods; D009165:Mycobacterium Infections, Nontuberculous / Q000175:diagnosis* / Q000382:microbiology*; D016926:Mycobacterium chelonae / Q000145:classification* / Q000187:drug effects / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism; D009171:Mycolic Acids / Q000032:analysis; D009170:Nontuberculous Mycobacteria / Q000145:classification* / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism; D016133:Polymerase Chain Reaction; D012150:Polymorphism, Restriction Fragment Length
D000900:Anti-Bacterial Agents; D001426:Bacterial Proteins; D018834:Chaperonin 60; D004798:Enzymes; D009171:Mycolic Acids; C074119:heat-shock protein 65, Mycobacterium; D018833:Chaperonins