Abstract:

Objective To evaluate BAC spreader for minimum inhibitory concentration（MIC） determination in Mycobacterium tuberculosis（MTB）. Methods BAC spreader and glass bead grinding were used respectively to prepare bacterial suspensions of MTB ATCC 27294 standard strain H37Rv and 28 clinical MTB strains,and these bacterial suspensions were inoculated into TREK Sensititre MYCOTB well for drug susceptibility test. The performance of BAC spreader on MTB MIC was assessed by visual observation,acid-fast staining,colonial morphology in MYCOTB well and drug susceptibility test results. The role of BAC spreader for MIC determination in MTB was evaluated. Results The results of visual observation and acid-fast staining showed that the bacterial suspensions of BAC spreader were dispersed. The drug susceptibility test results showed that the consistency rate of the 2 methods was 100%. Conclusions The BAC spreader can improve the automation of MTB bacterial suspension preparation,particular in quantitative test as MIC drug susceptibility test,reducing the quantitative error caused by human factors,which is beneficial to the determination standardization and reproducibility.

Key words: Mycobacterium tuberculosis, BAC spreader, Minimum inhibitory concentration, Drug susceptibility test