title: How we determined the most reliable solid medium for studying treatment of tuberculosis.
abstract: Phase 2 clinical trials for tuberculosis (TB) treatment require reliable culture methods to determine presence or absence of Mycobacterium tuberculosis (Mtb) over the course of therapy, as these trials are based primarily on bacteriological endpoints. We evaluate which of 5 solid media is most reliable: Lowenstein-Jensen (LJ) egg-base medium and 4 Middlebrook agar media (nonselective 7H10 and 7H11 and selective 7H10 and 7H11). We analyze 393 specimens from 50 HIV-negative Ugandan adults with newly-diagnosed, pulmonary TB and high acid-fast bacillus smear grade. Specimens were collected every 2-4 weeks during the first 12 weeks of therapy. We compare the results for each culture to 2 composite reference standards--one that was deemed positive if any solid culture was positive for Mtb and another based on latent-class analysis. Both reference standards established that the 2 selective Middlebrook media most reliably determine the presence or absence of Mtb (P < 0.003), largely because of their lower contamination rates. We also showed that results on Middlebrook media were similar to each other, while LJ was most frequently discordant. Contaminated results appeared more likely to be truly negative than to harbor undetected Mtb.
authors.affiliation: Division of Tuberculosis Elimination, Centers for Disease Control and Prevention, National Center for HIV/AIDS, Viral Hepatitis, STD, and TB Prevention, Atlanta, GA, USA. Electronic address: cqh9@cdc.gov.
authors.forename: Charles M
authors.initials: CM
authors.lastname: Heilig
authors.affiliation: Division of Tuberculosis Elimination, Centers for Disease Control and Prevention, National Center for HIV/AIDS, Viral Hepatitis, STD, and TB Prevention, Atlanta, GA, USA.
authors.forename: Pei-Jean I
authors.initials: PJ
authors.lastname: Feng
authors.affiliation: Department of Medical Microbiology, College of Health Sciences, Makerere University, Kampala, Uganda; Uganda-Case Western Reserve University Research Collaboration, Kampala, Uganda.
authors.forename: Moses L
authors.initials: ML
authors.lastname: Joloba
authors.affiliation: Uganda-Case Western Reserve University Research Collaboration, Kampala, Uganda; Tuberculosis Research Unit, Department of Medicine, Case Western Reserve University School of Medicine, Cleveland, OH, USA.
authors.forename: John L
authors.initials: JL
authors.lastname: Johnson
authors.affiliation: Uganda-Case Western Reserve University Research Collaboration, Kampala, Uganda.
authors.forename: Karen
authors.initials: K
authors.lastname: Morgan
authors.affiliation: Uganda-Case Western Reserve University Research Collaboration, Kampala, Uganda.
authors.forename: Phineas
authors.initials: P
authors.lastname: Gitta
authors.affiliation: Uganda-Case Western Reserve University Research Collaboration, Kampala, Uganda; Tuberculosis Research Unit, Department of Medicine, Case Western Reserve University School of Medicine, Cleveland, OH, USA.
authors.forename: W Henry
authors.initials: WH
authors.lastname: Boom
authors.affiliation: Uganda-Case Western Reserve University Research Collaboration, Kampala, Uganda.
authors.forename: Harriet
authors.initials: H
authors.lastname: Mayanja-Kizza
authors.affiliation: Tuberculosis Research Unit, Department of Medicine, Case Western Reserve University School of Medicine, Cleveland, OH, USA; Department of Pathology, University of Arkansas for Medical Sciences, Little Rock, AR, USA.
authors.forename: Kathleen D
authors.initials: KD
authors.lastname: Eisenach
authors.affiliation: Division of Tuberculosis Elimination, Centers for Disease Control and Prevention, National Center for HIV/AIDS, Viral Hepatitis, STD, and TB Prevention, Atlanta, GA, USA.
authors.forename: Lorna
authors.initials: L
authors.lastname: Bozeman
authors.affiliation: Division of Tuberculosis Elimination, Centers for Disease Control and Prevention, National Center for HIV/AIDS, Viral Hepatitis, STD, and TB Prevention, Atlanta, GA, USA.
authors.forename: Stefan V
authors.initials: SV
authors.lastname: Goldberg
mesh_terms: D000293:Adolescent; D000328:Adult; D000995:Antitubercular Agents / Q000627:therapeutic use*; D017322:Clinical Trials, Phase II as Topic; D003470:Culture Media / Q000592:standards*; D006801:Humans; D008875:Middle Aged; D009169:Mycobacterium tuberculosis / Q000302:isolation & purification; D011446:Prospective Studies; D012015:Reference Standards; D012680:Sensitivity and Specificity; D013183:Sputum / Q000382:microbiology; D014397:Tuberculosis, Pulmonary / Q000188:drug therapy* / Q000382:microbiology; D055815:Young Adult
chemical_list: D000995:Antitubercular Agents; D003470:Culture Media
keywords: Composite reference standard; Latent-class model; Lowenstein–Jensen culture medium; Middlebrook agar culture media; Mycobacterium tuberculosis