title: Growth detection failures by the nonradiometric Bactec MGIT 960 mycobacterial culture system.
abstract: Mycobacterial growth in liquid culture can go undetected by automated, nonradiometric growth detection systems. In our laboratory, instrument-negative tubes from the Bactec MGIT 960 system are inspected visually for clumps suggestive of mycobacterial growth, which (if present) are examined by acid-fast smear analysis. A 3-year review demonstrated that ∼1% of instrument-negative MGIT cultures contained mycobacterial growth and that 10% of all cultures yielding mycobacteria were instrument negative. Isolates from instrument-negative MGIT cultures included both tuberculous and nontuberculous mycobacteria.
authors.affiliation: Department of Pathology, Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts, USA.
authors.forename: Jeremy A
authors.initials: JA
authors.lastname: Peña
authors.forename: Mary Jane
authors.initials: MJ
authors.lastname: Ferraro
authors.forename: Colleen G
authors.initials: CG
authors.lastname: Hoffman
authors.forename: John A
authors.initials: JA
authors.lastname: Branda
mesh_terms: D001331:Automation / Q000379:methods; D001431:Bacteriological Techniques / Q000379:methods*; D003951:Diagnostic Errors / Q000706:statistics & numerical data*; D006801:Humans; D009161:Mycobacterium / Q000254:growth & development / Q000302:isolation & purification*; D009165:Mycobacterium Infections, Nontuberculous / Q000175:diagnosis* / Q000382:microbiology*; D014376:Tuberculosis / Q000175:diagnosis* / Q000382:microbiology*