Standard chemotherapy with excluding isoniazid in a murine model of tuberculosis

Sun Shim Tae, Gae Lee Eun, Min Choi Chang, Sang Bum Hong, Yeon Mok Oh, Chae Man Lim, Do Lee Sang, Younsuck Koh, Sung Kim Woo, Soon Kim Dong, Sang Nae Cho, Dong Kim Won

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Abstract

Background: Isoniazid (INH, H) is a key drug of the standard first-line regimen for the treatment of tuberculosis (TB), yet some reports have suggested that treatment efficacy was maintained even though INH was omitted from the treatment regimen. Methods: One hundred forty C57BL/6 mice were infected with the H37Rv strain of M. tuberculosis with using a Glas-Col aerosol generation device, and this resulted in depositing about 100 bacilli in the lung. Four weeks after infection, anti-TB treatment was initiated with varying regimens for 4-8 weeks; Group 1: no treatment (control), Group 2 (4HREZ): 4 weeks of INH, rifampicin (R), pyrazinamide (Z) and ethambutol (E), Group 3: 1HREZ/3REZ, Group 4: 4REZ, Group 5- 4HREZ/4HRE, Group 6: 1HREZ/3REZ/4RE, and Group 7: 4REZ/4RE. The lungs and spleens were harvested at several time points until 28 weeks after infection, and the colony-forming unit (CFU) counts were determined. Results: The CFU counts increased steadily after infection in the control group. In the 4-week treatment groups (Group 2-4), even though the culture was negative at treatment completion, the bacilli grew again at the 12-week and 20-week time points after completion of treatment. In the 8-week treatment groups (Groups 5-7), the bacilli did not grow in the lung at 4 weeks after treatment initiation and thereafter. In the spleens of Group 7 in which INH was omitted from the treatment regimen, the culture was negative at 4-weeks after treatment initiation and thereafter. However, in Groups 5 and 6 in which INH was taken continuously or intermittently, the bacilli grew in the spleen at some time points after completion of treatment. Conclusion: TThe exclusion of INH from the standard first-line regimen did not affect the treatment outcome in a murine model of TB in the early stage of disease. Further studies using a murine model of chronic TB are necessary to clarify the role of INH in the standard first-line regimen for treating TB.

Original languageEnglish
Pages (from-to)177-182
Number of pages6
JournalTuberculosis and Respiratory Diseases
Volume65
Issue number3
DOIs
Publication statusPublished - 2008 Sep 1

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All Science Journal Classification (ASJC) codes

  • Pulmonary and Respiratory Medicine
  • Infectious Diseases

Cite this

Tae, S. S., Eun, G. L., Chang, M. C., Hong, S. B., Oh, Y. M., Lim, C. M., Sang, D. L., Koh, Y., Woo, S. K., Dong, S. K., Cho, S. N., & Won, D. K. (2008). Standard chemotherapy with excluding isoniazid in a murine model of tuberculosis. Tuberculosis and Respiratory Diseases, 65(3), 177-182. https://doi.org/10.4046/trd.2008.65.3.177