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Updated: May 10, 2026
An Automated Culture System for Use in Preclinical Testing of Host-Directed Therapies for Tuberculosis
Published on: August 16, 2021
Association between Mycobacterium tuberculosis lineage and time to sputum culture conversion
E S Click1, C A Winston, J E Oeltmann
1Epidemic Intelligence Service, Centers for Disease Control and Prevention, Atlanta, GA 30333, USA. eoc9@cdc.gov
Setting:
Mycobacterium tuberculosis comprises four principal genetic lineages: one evolutionarily ancestral (Indo-Oceanic) and three modern. Whether response to tuberculosis (TB) treatment differs among the lineages is unknown.
Objective:
To examine the association between M. tuberculosis lineage and time to sputum culture conversion in response to standard first-line drug therapy.
Design:
We conducted an exploratory retrospective cohort analysis of time to sputum culture conversion among pulmonary tuberculosis (PTB) cases reported in the United States from 2004 to 2007.
Results:
The analysis included 13,170 PTB cases with no documented resistance to first-line drugs who received a standard four-drug treatment regimen. Among cases with baseline positive sputum smear results, relative to cases with Euro-American lineage, cases with Indo-Oceanic lineage had higher adjusted hazards of sputum culture conversion (aHR 1.32, 95%CI 1.20-1.45), whereas cases with East-African-Indian or East-Asian lineage did not differ (aHR 1.05, 95%CI 0.88-1.25 and aHR 0.99, 95%CI 0.91-1.07, respectively). Among cases with baseline negative sputum smear results, time to sputum culture conversion did not differ by lineage.
Conclusion:
Although these results are exploratory, they suggest that the eradication of viable bacteria may occur sooner among cases with Indo-Oceanic lineage than among those with one of the three modern lineages. Prospective studies of time to sputum culture conversion by lineage are required.
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