Determination of minimum bactericidal concentration, in single or combination drugs, against Mycobacterium tuberculosis

To evaluate an assay to detect minimum bactericidal concentration (MBC) in , using as single model rifampicin, isoniazid, levofloxacin (LVX) and linezolid (LNZ) and in combination. MBCs were carried out directly from resazurin microtiter assay plate and 3D checkerboard in H Rv and five resistant clinical isolates. The proposed MBC assay showed similar values to those determined by MGIT™, used as control. LVX and LNZ's MBC values were close to their MIC values. LNZ or LVX combined with isoniazid and rifampicin showed MBC value reduced in 63.7% of the assays. The proposed assay to determine MBCs of drugs can be applied to the study of new compounds with anti- activity to detect their bactericidal effect and also in laboratory routine for clinical dose adjustment of drugs according to the patient's profile.