Application of the Alamar blue assay to determine the susceptibility to anti-tuberculosis pharmaceuticals

Abstract

The aim of this study was to apply the Alamar Blue assay to determine the susceptibility to anti-tuberculosis
pharmaceuticals, in Mycobacterium tuberculosis isolated strains from patients with tuberculosis (TB). In this study, a
TB diagnostic was done by bacilluscope as an essential diagnostic tool for pulmonary TB using the Ziehl-Neelsen
(ZN) stain. Furthermore, a culture was prepared in Lowenstein-Jensen (L-J) solid media, Middlebrook 7H9, and
Middlebrook 7H10. For all the clinical samples investigated, five reference strains of M. tuberculosis were used to
standardize the sensibility to streptomycin (SM), isoniazid (INH), rifampicin (RIF), and ethambutol (EMB) of the ATCC.
Additionally, 97 Mycobacterium strains were analyzed from clinical isolations. The microplate Alamar Blue assay
(MABA) was standardized and applied. The resistance levels of this disease were obtained in La Comarca Region
(Lagunera). The results indicated that the MABA test is fast and easy to apply, however the most important aspect is
the reliability of the method to determine the drug sensibility to pharmaceuticals. The MABA colorimetric test can be
used in different regional as well as state TB diagnostic laboratories.