Radiometric method for testing susceptibility of mycobacteria to pyrazinamide in 7H12 broth

Heifets, L B; Iseman, M D

Title: Radiometric method for testing susceptibility of mycobacteria to pyrazinamide in 7H12 broth

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Abstract

The test of susceptibility to pyrazinamide requires an acid environment (pH less than or equal to 5.5). This, however, is not favorable to the growth of Mycobacterium tuberculosis, especially in solid agar media. To obviate this difficulty, we developed a testing method with 7H12 broth medium and based on radiometric readings of the growth. The radiometric method employed in this study (BACTEC system) provides an opportunity to detect the dynamics of growth by daily recording of the growth index, which reflects the metabolic activity of the multiplying bacteria. In our technique, M. tuberculosis isolates were initially cultivated at pH 6.8. After logarithmic growth had begun, phosphoric acid solution was added to obtain pH 5.5. When pyrazinamide was added simultaneously with the acid, the growth index of susceptible cultures decreased, whereas it continued to increase in pH 5.5 control vials and in tests with pyrazinamide-resistant strains.

Authors:: Heifets, L B; Iseman, M D

Publication Date:: Fri Feb 01 00:00:00 EST 1985

Research Org.:: National Jewish Hospital and Research Center/National Asthma Center, Denver, CO

OSTI Identifier:: 5676150

Resource Type:: Journal Article

Journal Name:: J. Clin. Microbiol.; (United States)

Additional Journal Information:: Journal Volume: 21:2

Country of Publication:: United States

Language:: English

Subject:: 59 BASIC BIOLOGICAL SCIENCES; MYCOBACTERIUM TUBERCULOSIS; GROWTH; AMIDASES; CARBON 14 COMPOUNDS; CULTURE MEDIA; INHIBITION; PH VALUE; PYRAZINES; SENSITIVITY; AZINES; BACTERIA; ENZYMES; HETEROCYCLIC COMPOUNDS; HYDROLASES; LABELLED COMPOUNDS; MICROORGANISMS; MYCOBACTERIUM; NON-PEPTIDE C-N HYDROLASES; ORGANIC COMPOUNDS; ORGANIC NITROGEN COMPOUNDS; 550701* - Microbiology- Tracer Techniques

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                    Heifets, L B, and Iseman, M D. Radiometric method for testing susceptibility of mycobacteria to pyrazinamide in 7H12 broth.  United States: N. p., 1985. 
        Web.

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                    Heifets, L B, & Iseman, M D. Radiometric method for testing susceptibility of mycobacteria to pyrazinamide in 7H12 broth.  United States.

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                    Heifets, L B, and Iseman, M D. 1985.  
        "Radiometric method for testing susceptibility of mycobacteria to pyrazinamide in 7H12 broth".  United States.

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@article{osti_5676150,

  title        = {Radiometric method for testing susceptibility of mycobacteria to pyrazinamide in 7H12 broth},

  author       = {Heifets, L B and Iseman, M D},

  abstractNote = {The test of susceptibility to pyrazinamide requires an acid environment (pH less than or equal to 5.5). This, however, is not favorable to the growth of Mycobacterium tuberculosis, especially in solid agar media. To obviate this difficulty, we developed a testing method with 7H12 broth medium and based on radiometric readings of the growth. The radiometric method employed in this study (BACTEC system) provides an opportunity to detect the dynamics of growth by daily recording of the growth index, which reflects the metabolic activity of the multiplying bacteria. In our technique, M. tuberculosis isolates were initially cultivated at pH 6.8. After logarithmic growth had begun, phosphoric acid solution was added to obtain pH 5.5. When pyrazinamide was added simultaneously with the acid, the growth index of susceptible cultures decreased, whereas it continued to increase in pH 5.5 control vials and in tests with pyrazinamide-resistant strains.},

  doi          = {},

  url          = {https://www.osti.gov/biblio/5676150},
  journal      = {J. Clin. Microbiol.; (United States)},
number       = ,

  volume       = 21:2,

  place        = {United States},

  year         = {Fri Feb 01 00:00:00 EST 1985},

  month        = {Fri Feb 01 00:00:00 EST 1985}

}

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