title: Rapid direct testing of susceptibility of Mycobacterium tuberculosis to isoniazid and rifampin on nutrient and blood agar in resource-starved settings.
abstract: In this study, we evaluated the performance of blood agar (by macroscopic growth) and nutrient agar (by a microcolony detection method) for drug susceptibility testing of Mycobacterium tuberculosis against rifampin (RIF) and isoniazid (INH), using 67 smear-positive sputum specimens. The direct proportion method on Lowenstein-Jensen (LJ) medium was used as the "gold standard." Compared with LJ medium, results for both media were in 100% agreement for RIF, while for INH the agreement levels for blood agar and nutrient agar were 98% and 95%, respectively. Within 2 weeks, 100% of specimens yielded results on blood agar, while 96.8% of specimens yielded results on nutrient agar. Our study showed that blood agar and nutrient agar can be used as alternative media for direct susceptibility testing of RIF and INH, especially in resource-poor settings.
authors.affiliation: Department of Pathology, Combined Military Hospital, Dera Ismail Khan, Pakistan. luqmansatti@hotmail.com
authors.forename: Luqman
authors.initials: L
authors.lastname: Satti
authors.forename: Aamer
authors.initials: A
authors.lastname: Ikram
authors.forename: Ahmet Yilmaz
authors.initials: AY
authors.lastname: Coban
authors.forename: Anandi
authors.initials: A
authors.lastname: Martin
mesh_terms: D000362:Agar; D000995:Antitubercular Agents / Q000494:pharmacology*; D003470:Culture Media / Q000737:chemistry*; D003906:Developing Countries; D006801:Humans; D007538:Isoniazid / Q000494:pharmacology*; D008826:Microbial Sensitivity Tests / Q000379:methods; D009169:Mycobacterium tuberculosis / Q000187:drug effects*; D015203:Reproducibility of Results; D012293:Rifampin / Q000494:pharmacology*; D012680:Sensitivity and Specificity; D013997:Time Factors
chemical_list: D000995:Antitubercular Agents; D003470:Culture Media; D000362:Agar; D007538:Isoniazid; D012293:Rifampin