Abstract
The MICs of pyrazinamide (PZA) were determined for Mycobacterium tuberculosis cultivated under different pH conditions in 7H12 liquid medium. Mycobacterial growth was monitored by the radiometric method (BACTEC system; Johnston Laboratories, Inc., Towson, Md.). We observed a predictable eightfold difference between the MICs determined at pH 5.5 and those determined at pH 5.95. The highest MICs for 21 susceptible strains were 50.0 micrograms/ml at pH 5.5 and 400 micrograms/ml at pH 5.95. This eightfold difference enabled us to predict MICs at pH 5.5 from the values observed at pH 5.95. The use of 7H12 broth at pH 5.95 simplified the radiometric PZA susceptibility test by avoiding the addition of acid solutions in the course of cultivation, which was required when the test was performed at pH 5.5. An additional benefit of using pH 5.95 instead of pH 5.5 was that all tested strains grew at pH 5.95, while some of them, especially PZA-resistant strains, did not grow at pH 5.5.
Full text
PDF
Selected References
These references are in PubMed. This may not be the complete list of references from this article.
- Brander E. A simple way of detecting pyrazinamide resistance. Tubercle. 1972 Jun;53(2):128–131. doi: 10.1016/0041-3879(72)90029-3. [DOI] [PubMed] [Google Scholar]
- Butler W. R., Kilburn J. O. Improved method for testing susceptibility of Mycobacterium tuberculosis to pyrazinamide. J Clin Microbiol. 1982 Dec;16(6):1106–1109. doi: 10.1128/jcm.16.6.1106-1109.1982. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Butler W. R., Kilburn J. O. Susceptibility of Mycobacterium tuberculosis to pyrazinamide and its relationship to pyrazinamidase activity. Antimicrob Agents Chemother. 1983 Oct;24(4):600–601. doi: 10.1128/aac.24.4.600. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Dickinson J. M., Aber V. R., Mitchison D. A. Bactericidal activity of streptomycin, isoniazid, rifampin, ethambutol, and pyrazinamide alone and in combination against Mycobacterium Tuberculosis. Am Rev Respir Dis. 1977 Oct;116(4):627–635. doi: 10.1164/arrd.1977.116.4.627. [DOI] [PubMed] [Google Scholar]
- Heifets L. B., Iseman M. D. Radiometric method for testing susceptibility of mycobacteria to pyrazinamide in 7H12 broth. J Clin Microbiol. 1985 Feb;21(2):200–204. doi: 10.1128/jcm.21.2.200-204.1985. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Konno K., Feldmann F. M., McDermott W. Pyrazinamide susceptibility and amidase activity of tubercle bacilli. Am Rev Respir Dis. 1967 Mar;95(3):461–469. doi: 10.1164/arrd.1967.95.3.461. [DOI] [PubMed] [Google Scholar]
- MACKANESS G. B. The intracellular activation of pyrazinamide and nicotinamide. Am Rev Tuberc. 1956 Nov;74(5):718–728. doi: 10.1164/artpd.1956.74.5.718. [DOI] [PubMed] [Google Scholar]
- McClatchy J. K., Tsang A. Y., Cernich M. S. Use of pyrazinamidase activity on Mycobacterium tuberculosis as a rapid method for determination of pyrazinamide susceptibility. Antimicrob Agents Chemother. 1981 Oct;20(4):556–557. doi: 10.1128/aac.20.4.556. [DOI] [PMC free article] [PubMed] [Google Scholar]
- McDERMOTT W., TOMPSETT R. Activation of pyrazinamide and nicotinamide in acidic environments in vitro. Am Rev Tuberc. 1954 Oct;70(4):748–754. doi: 10.1164/art.1954.70.4.748. [DOI] [PubMed] [Google Scholar]
- Salfinger M., Kafader F. M. Susceptibility testing of Mycobacterium tuberculosis to pyrazinamide. Zentralbl Bakteriol Mikrobiol Hyg A. 1987 Jul;265(3-4):404–407. [PubMed] [Google Scholar]
- Siddiqi S. H., Libonati J. P., Middlebrook G. Evaluation of rapid radiometric method for drug susceptibility testing of Mycobacterium tuberculosis. J Clin Microbiol. 1981 May;13(5):908–912. doi: 10.1128/jcm.13.5.908-912.1981. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Snider D. E., Jr, Good R. C., Kilburn J. O., Laskowski L. F., Jr, Lusk R. H., Marr J. J., Reggiardo Z., Middlebrook G. Rapid drug-susceptibility testing of Mycobacterium tuberculosis. Am Rev Respir Dis. 1981 Apr;123(4 Pt 1):402–406. doi: 10.1164/arrd.1981.123.4.402. [DOI] [PubMed] [Google Scholar]
- Stottmeier K. D., Beam R. E., Kubica G. P. Determination of drug susceptibility of mycobacteria to pyrazinamide in 7H10 agar. Am Rev Respir Dis. 1967 Nov;96(5):1072–1075. doi: 10.1164/arrd.1967.96.5.1072. [DOI] [PubMed] [Google Scholar]
- Tarrand J. J., Spicer A. D., Gröschel D. H. Evaluation of a radiometric method for pyrazinamide susceptibility testing of Mycobacterium tuberculosis. Antimicrob Agents Chemother. 1986 Dec;30(6):852–855. doi: 10.1128/aac.30.6.852. [DOI] [PMC free article] [PubMed] [Google Scholar]