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.

Prospective evaluation of BDProbeTec strand displacement amplification (SDA) system for diagnosis of tuberculosis in non-respiratory and respiratory samples.

Nucleic acid amplification techniques (NAATs) have been demonstrated to make significant improvements in the diagnosis of tuberculosis (TB), particularly in the time to diagnosis and the diagnosis of smear-negative TB. The BD ProbeTec strand displacement amplification (SDA) system for the diagnosis of pulmonary and non-pulmonary tuberculosis was evaluated. A total of 689 samples were analysed from patients with clinically suspected TB.

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.

Estimation of mutation rates in antibiotic research.

Luria and Delbruck identified that the frequency of mutation was subject to considerable fluctuation. They argued that the large fluctuation in the number of organism surviving exposure to bacteriophage meant that resistance was acquired through mutation rather than a physiological adaptation to the bacteriophage. Mutations that arose early in the broth culture would give rise to a "Jackpot culture" (1).

Comparison of fitness of two isolates of Mycobacterium tuberculosis, one of which had developed multi-drug resistance during the course of treatment.

Objectives: We report the cases of two patients, brother and sister, both with pulmonary tuberculosis. Both patients complied poorly with treatment. One developed multi-drug resistant disease, whilst the other did not.