Susceptibility of Mycobacterium tuberculosis to sulfamethoxazole, trimethoprim and their combination over a 12 year period in Taiwan
Journal
Journal of Antimicrobial Chemotherapy
Journal Volume
67
Journal Issue
3
Pages
633-637
Date Issued
2012
Author(s)
Abstract
Objectives: This study was designed to determine the susceptibility of clinical isolates of multidrug-resistant (MDR) and non-MDR Mycobacterium tuberculosis to sulfamethoxazole, trimethoprim and trimethoprim/sulfamethoxazole over a 12 year period in Taiwan. Patients and methods: We examined a total of 117 clinical isolates of M. tuberculosis collected from Southern Taiwan, 116 from 1995 to 2006 and an extensively drug-resistant (XDR) isolate in 2009. These included 28 isolates susceptible to all four first-line agents, 52 MDR isolates and 36 isolates with a mixed combination of drug resistance patterns other than MDR and 1 XDR isolate. Results: Sulfamethoxazole inhibited 80% growth of all 117 isolates regardless of their susceptibility to the firstline agents at an MIC 90 of 9.5 mg/L. The concentration required to inhibit 99% growth was 38 mg/L. There were no significant changes in the MIC 50 or MIC 90 of sulfamethoxazole over a 12 year period. All 117 isolates were resistant to trimethoprim at >8 mg/L. The combination of trimethoprim/sulfamethoxazole at a ratio of 1:19 had no additive or synergistic effects. Conclusions: Sulfamethoxazole inhibited the growth of clinical isolates of M. tuberculosis at achievable concentrations in plasma after oral administration. Susceptibility to sulfamethoxazole remained constant over a 12 year period. Trimethoprim was inactive against M. tuberculosis and trimethoprim/sulfamethoxazole provided no additional activity. Although the current and prior studies demonstrate that sulfamethoxazole is active against M. tuberculosis the search needs to continue for more active, lipid-soluble sulphonamides that are better absorbed into tissues and have improved therapeutic efficacy. ? The Author 2011. Published by Oxford University Press on behalf of the British Society for Antimicrobial Chemotherapy. All rights reserved.
Subjects
Sulphonamides; Sulphones; Treatment
SDGs
Other Subjects
cotrimoxazole; sulfamethoxazole; trimethoprim; antibiotic sensitivity; antibiotic therapy; antimicrobial activity; article; bacterial growth; bacterial strain; bacterium isolate; controlled study; minimum inhibitory concentration; multidrug resistant tuberculosis; Mycobacterium tuberculosis; nonhuman; Taiwan; Antitubercular Agents; Drug Interactions; Humans; Microbial Sensitivity Tests; Mycobacterium tuberculosis; Sulfamethoxazole; Taiwan; Trimethoprim; Tuberculosis
Type
journal article