The Clarithromycin Susceptibility Genotype Affects the Treatment Outcome of Patients with Mycobacterium abscessus Lung Disease.

accounts for a large proportion of lung disease cases caused by rapidly growing mycobacteria. The association between clarithromycin sensitivity and treatment outcome is clear. However, culture and antibiotic susceptibility testing are time-consuming. Clarithromycin susceptibility genotyping offers an alternate, rapid approach to predicting the efficacy of clarithromycin-based antibiotic therapy. lung disease patients were divided into two groups based upon the clarithromycin susceptibility genotype of the organism isolated. A retrospective analysis was conducted to compare the clinical features, microbiological characteristics, and treatment outcomes of the two groups. Several other potential predictors of the response to treatment were also assessed. Sixty-nine patients were enrolled in the clarithromycin-resistant genotype group, which included 5 infected with 2058-2059 mutants and 64 infected with (41)T28-type ; 31 were in the clarithromycin-sensitive group, i.e., 6 and 25 patients infected with genotypes (41)C28 and (41) M type, respectively. The results showed that lung disease patients infected with clarithromycin-sensitive and -resistant genotypes differed significantly in clarithromycin-based combination treatment outcomes. Patients infected with the clarithromycin-sensitive genotype exhibited higher initial and final sputum-negative conversion and radiological improvement rates and better therapeutic outcomes. Multivariate analysis demonstrated that genotyping was a reliable and, more importantly, rapid means of predicting the efficacy of clarithromycin-based antibiotic treatment for lung disease.