Mycobacteria--methods to meet the CDC guidelines
Yamane, N.
Rinsho Byori. Japanese Journal of Clinical Pathology 47(6): 539-546
1999
ISSN/ISBN: 0047-1860 PMID: 10434571 Document Number: 499316
In response to the guidelines from the Centers for Disease Control and Prevention, Atlanta, U.S.A. (1994), a considerable effort has been focused on the development and application of rapid laboratory testings for Mycobacterium tuberculosis. Concerning the first goal, "acid-fast bacillus smear results should be reported within 24 hr of specimen collection", most laboratories latently have an ability to perform unless the specimens will be processed in a lump. However, the second goal, "isolation and identification of M. tuberculosis should be within 10 to 14 days", is almost impossible for most Japanese laboratories where the radiometric Bactec 460 system is not applicable. In recent years, several nonradiometric, automated or semiautomated mycobacterial culture systems are developed and applied. To date, the evaluated results indicate that the newly developed mycobacterial culture systems with Middlebrook 7H9 broth can report positive with means of 17 to 20 day incubation, 3 to 6 days behind the CDC guidelines. Finally, regarding the third goal, "susceptibility test results should be within a total of 15 to 30 days", our developed microdilution test method can report quantitative minimum inhibitory concentrations (MICs) for M. tuberculosis after 7 day incubation. Overall, our procedures are very close to the CDC guidelines, except for isolation and identification of M. tuberculosis. The remaining key to fulfil the guidelines is a rapid detection, that is, culture media which can support rapid mycobacterial growth and advanced technology to detect attenuated growth of M. tuberculosis.