Abstract
Many laboratory workers prefer the rhodamine-auramine method of staining acid-fast bacilli (AFB) in primary specimen smears rather than carbol fuchsin stains because the stain is more readily interpreted and yields greater sensitivity. The increasing incidence of AFB infections serves as an impetus to optimize the rhodamine-auramine stain. A total of 782 primary smears were evaluated blindly by the rhodamine-auramine method at both room temperature and 37 degrees C. Thirty-five smears (4.5%) were positive for AFB, 30 were positive by both methods, and 5 were positive at 37 degrees C only. Room temperature staining detected only 85.7% of the positive primary smears. Of the 30 smears positive by both methods, 13 (43.3%) had equal numbers of AFB on both smears, 13 (43.3%) had more AFB on the smear stained at 37 degrees C, and 4 (13.3%) had greater numbers of AFB on the smear stained at room temperature. No smears were positive only when stained at room temperature. The increasing diagnostic emphasis placed on the primary smear underscores the importance of optimizing AFB smear methods, and rhodamine-auramine staining at 37 degrees C enhances the detection of AFB compared with conventional staining at room temperature.
Full text
PDF
Selected References
These references are in PubMed. This may not be the complete list of references from this article.
- Dooley S. W., Villarino M. E., Lawrence M., Salinas L., Amil S., Rullan J. V., Jarvis W. R., Bloch A. B., Cauthen G. M. Nosocomial transmission of tuberculosis in a hospital unit for HIV-infected patients. JAMA. 1992 May 20;267(19):2632–2634. [PubMed] [Google Scholar]
- Edlin B. R., Tokars J. I., Grieco M. H., Crawford J. T., Williams J., Sordillo E. M., Ong K. R., Kilburn J. O., Dooley S. W., Castro K. G. An outbreak of multidrug-resistant tuberculosis among hospitalized patients with the acquired immunodeficiency syndrome. N Engl J Med. 1992 Jun 4;326(23):1514–1521. doi: 10.1056/NEJM199206043262302. [DOI] [PubMed] [Google Scholar]
- Ellner J. J., Hinman A. R., Dooley S. W., Fischl M. A., Sepkowitz K. A., Goldberger M. J., Shinnick T. M., Iseman M. D., Jacobs W. R., Jr Tuberculosis symposium: emerging problems and promise. J Infect Dis. 1993 Sep;168(3):537–551. doi: 10.1093/infdis/168.3.537. [DOI] [PubMed] [Google Scholar]
- Fischl M. A., Uttamchandani R. B., Daikos G. L., Poblete R. B., Moreno J. N., Reyes R. R., Boota A. M., Thompson L. M., Cleary T. J., Lai S. An outbreak of tuberculosis caused by multiple-drug-resistant tubercle bacilli among patients with HIV infection. Ann Intern Med. 1992 Aug 1;117(3):177–183. doi: 10.7326/0003-4819-117-3-177. [DOI] [PubMed] [Google Scholar]
- Huebner R. E., Good R. C., Tokars J. I. Current practices in mycobacteriology: results of a survey of state public health laboratories. J Clin Microbiol. 1993 Apr;31(4):771–775. doi: 10.1128/jcm.31.4.771-775.1993. [DOI] [PMC free article] [PubMed] [Google Scholar]
- TRUANT J. P., BRETT W. A., THOMAS W., Jr Fluorescence microscopy of tubercle bacilli stained with auramine and rhodamine. Henry Ford Hosp Med Bull. 1962 Jun;10:287–296. [PubMed] [Google Scholar]
- Tenover F. C., Crawford J. T., Huebner R. E., Geiter L. J., Horsburgh C. R., Jr, Good R. C. The resurgence of tuberculosis: is your laboratory ready? J Clin Microbiol. 1993 Apr;31(4):767–770. doi: 10.1128/jcm.31.4.767-770.1993. [DOI] [PMC free article] [PubMed] [Google Scholar]