YAMAZAKI T, SATO N, HAGA S, KASHIWABARA Y, TAMURA T, YAMASHITA K, OKAZAWA Y, TANNO K; Interscience Conference on Antimicrobial Agents and Chemotherapy.
Abstr Intersci Conf Antimicrob Agents Chemother Intersci Conf Antimicrob Agents Chemother. 2000 Sep 17-20; 40: 155.
Natl. Inst. of Infectious Diseases, Tokyo, Japan
BACKGROUND: The number of living organisms can be estimated from the quantification of adenosine triphosphate (ATP) content in them. We applied ATP-measuring method to the antimicrobial susceptibility testing of M. tuberculosis. The aim of this study was to assess the availability of mycobacterial ATP measurement for the drug susceptibility testing of M. tuberculosis.METHODS: Each tube containing 5.0 ml of Middlebrook 7H9 broth and drugs at various concentrations was inoculated with 0.1 ml of bacterial suspension. The drug concentrations were 0.1 microg/ml of isoniazid, 2.0 microg/ml of rifampin, 2.5 microg/ml of ethambutol (EMB), 2.0 microg/ml of streptomycin, and 5.0 microg/ml of kanamycin. These tubes were incubated at 37 degrees C for 0 to 7 days. After incubation, 0.1 ml of each sample was used for extraction of mycobacterial ATP, and the ATP content was measured by the bioluminescent assay. The results were expressed as RLU ratio (RLU in test/RLU in control). The RLU ratio less then 0.5 was decided as susceptible to drugs.RESULTS: Reduction of ATP content was observed in susceptible strains but not in resistant ones within 3 to 5 days of cultivation. Highly reproducible results were obtained with six ATCC reference strains. The correlations between ATP method and reference methods such as 7H10 agar proportion, MGIT and MICs methods in 65 clinical isolates of M. tuberculosis were 92.3%, 96.9%, and 96.9%, respectively. False resistance to EMB could be removed by treating samples with the FCT reagent. Conclusion: This method is simple, rapid (results are obtained within 5 days), highly reproducible and nonradiometric. It can be used for the assessment of drug susceptibility testing for M. tuberculosis.KEYWORDS: Antimicrobial susceptibility; Bioluminescent assay; Mycobacterium tuberculosis
Publication Types:
Keywords:
- Adenosine Triphosphate
- Agar
- Bacteriological Techniques
- Ethambutol
- Evaluation Studies
- Isoniazid
- Kanamycin
- Microbial Sensitivity Tests
- Mycobacterium
- Mycobacterium tuberculosis
- Research Design
- Rifampin
- Streptomycin
- Tuberculosis
- methods
Other ID:
UI: 102248064
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