title: Mycolic acid index susceptibility method for Mycobacterium tuberculosis.
abstract: A rapid drug susceptibility test to measure the susceptibility of Mycobacterium tuberculosis to isoniazid (INH) and rifampin (RIF) using clinical isolates and a newly defined mycolic acid index (MAI) was evaluated. A total of 200 clinical isolates of M. tuberculosis were tested for susceptibility or resistance to INH and RIF by the MAI susceptibility and indirect-proportion methods. Overall, there was agreement between the two methods for 398 (99.5%) of the 400 total tests. Specifically, the sensitivity of the MAI susceptibility method for INH and RIF was 97.6 and 100%, respectively. The specificity and positive predictive value were 100% for both drugs, and the negative predictive value for INH and RIF was 98.3 and 100%, respectively. In conclusion, the MAI susceptibility method described here can be used for rapid drug susceptibility testing of M. tuberculosis clinical isolates within 5 days after clinical isolates are incubated in the presence or absence of an antituberculosis drug.
authors: Departamento de Microbiología, Facultad de Medicina, Universidad Autónoma de Nuevo León, Monterrey, México. jviader@ccr.dsi.uanl.mx
authors: J M
authors: JM
authors: Viader-Salvadó
authors: E
authors: E
authors: Garza-González
authors: R
authors: R
authors: Valdez-Leal
authors: M A
authors: MA
authors: del Bosque-Moncayo
authors: R
authors: R
authors: Tijerina-Menchaca
authors: M
authors: M
authors: Guerrero-Olazarán
mesh_terms: D000995:Antitubercular Agents / Q000494:pharmacology*; D004352:Drug Resistance, Microbial; D006801:Humans; D007538:Isoniazid / Q000494:pharmacology*; D008826:Microbial Sensitivity Tests / Q000379:methods / Q000592:standards; D009169:Mycobacterium tuberculosis / Q000737:chemistry* / Q000187:drug effects*; D009171:Mycolic Acids / Q000032:analysis*; D011237:Predictive Value of Tests; D012293:Rifampin / Q000494:pharmacology*; D012680:Sensitivity and Specificity; D013997:Time Factors; D014397:Tuberculosis, Pulmonary / Q000382:microbiology
chemical_list: D000995:Antitubercular Agents; D009171:Mycolic Acids; D007538:Isoniazid; D012293:Rifampin