Acetic Acid Enables Molecular Enumeration of Mycobacterium tuberculosis from Sputum and Eliminates the Need for a Biosafety Level 3 Laboratory.

Background: Improved monitoring of Mycobacterium tuberculosis response to treatment is urgently required. We previously developed the molecular bacterial load assay (MBLA), but it is challenging to integrate into the clinical diagnostic laboratory due to a labor-intensive protocol required at biosafety level 3 (BSL-3). A modified assay was needed.

Multiple drug-resistant Mycobacterium tuberculosis: evidence for changing fitness following passage through human hosts.

Recent studies have shown a difference in the genotype of resistant bacteria following passage in animals compared to those passaged in vitro. This suggests that organisms rapidly adapt to their environment of growth. We sought to investigate whether this phenomenon occurred in human infection and whether changes could be detected in the fitness (growth velocity) of isolates transmitted between human hosts.