What is the most reliable solid culture medium for tuberculosis treatment trials?
We conducted a prospective study to determine which solid medium is the most reliable overall and after two months of therapy to detect Mycobacterium tuberculosis complex (MTB). MTB isolation and contamination rates on LJ and Middlebrook 7H10 and 7H11 agar with and without selective antibiotics were examined in a single laboratory and compared against a constructed reference standard and MGIT 960 results. Of 50 smear positive adults with pulmonary TB enrolled, 45 successfully completed standard treatment. Two spot sputum specimens were collected before treatment and at week 8 and one spot specimen each at weeks 2, 4, 6, and 12. The MTB recovery rate among all solid media for pre-treatment specimens was similar. After 8 weeks, selective (S) 7H11 had the highest positivity rate. Latent class analysis was used to construct the primary reference standard. The 98.7% sensitivity of 7H11S (95% Wilson confidence interval 96.4%-99.6%) was highest among the 5 solid media (P = 0.003 by bootstrap); the 82.6% specificity of 7H10S (95% CI 75.7%-87.8%) was highest (P = 0.098). Our results support 7H11S as the medium of choice. Further studies in different areas where recovery and contamination are likely to vary, are recommended.
Department of Medical Microbiology, College of Health Sciences, Makerere University, Kampala, Uganda; Uganda-Case Western Reserve University Research Collaboration, Kampala, Uganda. Electronic address: moses.joloba@case.edu.
Moses L
ML
Joloba
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. Electronic address: jlj@case.edu.
John L
JL
Johnson
Division of Tuberculosis Elimination, Centers for Disease Control and Prevention, National Center for HIV/AIDS, Viral Hepatitis and TB Prevention, Atlanta, GA, USA. Electronic address: ewc6@cdc.org.
Pei-Jean I
PJ
Feng
Division of Tuberculosis Elimination, Centers for Disease Control and Prevention, National Center for HIV/AIDS, Viral Hepatitis and TB Prevention, Atlanta, GA, USA. Electronic address: llb1@cdc.gov.
Lorna
L
Bozeman
Division of Tuberculosis Elimination, Centers for Disease Control and Prevention, National Center for HIV/AIDS, Viral Hepatitis and TB Prevention, Atlanta, GA, USA. Electronic address: ssg3@cdc.gov.
Stefan V
SV
Goldberg
Uganda-Case Western Reserve University Research Collaboration, Kampala, Uganda. Electronic address: kammorg@gmail.com.
Karen
K
Morgan
Uganda-Case Western Reserve University Research Collaboration, Kampala, Uganda. Electronic address: pgitta@mucwru.or.ug.
Phineas
P
Gitta
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. Electronic address: whb@case.edu.
Henry W
HW
Boom
Division of Tuberculosis Elimination, Centers for Disease Control and Prevention, National Center for HIV/AIDS, Viral Hepatitis and TB Prevention, Atlanta, GA, USA. Electronic address: cqh9@cdc.gov.
Charles M
CM
Heilig
Uganda-Case Western Reserve University Research Collaboration, Kampala, Uganda. Electronic address: hmk@chs.mak.ac.ug.
Harriet
H
Mayanja-Kizza
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. Electronic address: EisenachKathleenD@uams.edu.
Kathleen D
KD
Eisenach
D000293:Adolescent; D000328:Adult; D000995:Antitubercular Agents / Q000627:therapeutic use*; D003470:Culture Media / Q000592:standards*; D004353:Drug Evaluation, Preclinical; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009169:Mycobacterium tuberculosis / Q000302:isolation & purification; D011446:Prospective Studies; D012015:Reference Standards; D012680:Sensitivity and Specificity; D014397:Tuberculosis, Pulmonary / Q000188:drug therapy* / Q000382:microbiology; D055815:Young Adult
D000995:Antitubercular Agents; D003470:Culture Media
Drug trials; LCA; Mycobacterium tuberculosis; Solid media