Ethambutol resistance as determined by broth dilution method correlates better than sequencing results with embB
Zhijian Zhang1, Yufeng Wang, Yu Pang
1Respiratory Diseases Department of Nanlou, Chinese People's Liberation Army General Hospital, Beijing, China.
Abstract:
We evaluated the correlation of phenotypic ethambutol (EMB) susceptibility as determined by two drug susceptibility methods with embB mutations in multidrug-resistant (MDR) Mycobacterium tuberculosis strains. The concordance rate for EMB resistance between broth dilution method and sequencing results (83.6%) was significantly higher than between the proportion method and sequencing results (61.7%) (P = 0.004). Of the embB mutants, 75.4% (46/61) possessed a mutation at embB306. Our results demonstrated that ethambutol resistance determined by broth dilution method reveals better correlation with embB mutations than the proportion method in MDR isolates.
