Sensitivity of Acid-Fast Staining for Mycobacterium tuberculosis in Formalin-fixed Tissue
- 1 October 2002
- journal article
- research article
- Published by American Thoracic Society in American Journal of Respiratory and Critical Care Medicine
- Vol. 166 (7) , 994-997
- https://doi.org/10.1164/rccm.2111028
Abstract
Microscopic examination of tissue sections of mycobacterial lesions frequently results in few or no bacilli seen, even if the lesions appear active histologically. This might be due to the effects of the fixative fluid and/or organic solvent, both of which are conventionally used to make tissue sections for histopathology, on the acid-fast staining of bacteria. The present study was performed to examine how formalin and xylene lower the sensitivity of acid-fast staining for Mycobacterium tuberculosis and to clarify the meaning of the staining result in tissue sections. Microscopic observation of mycobacteria smeared on glass slides revealed that both of these agents greatly reduced the sensitivity of acid-fast staining. Moreover, the number of bacilli was calculated in 30 samples of paraffin-embedded granulomatous lesions using acid-fast microscopy and real-time polymerase chain reaction. The numbers of bacilli present that were estimated by real-time polymerase chain reaction were considerably higher than those counted with a microscope. These results suggest that the bacilli are frequently missed or underestimated with acid-fast microscopy on formalin-fixed, paraffin-embedded tissue.Keywords
This publication has 34 references indexed in Scilit:
- Development of Conventional and Real-Time PCR Assays for Detection of Legionella DNA in Respiratory SpecimensJournal of Clinical Microbiology, 2001
- Utilization of the rpoB Gene as a Specific Chromosomal Marker for Real-Time PCR Detection of Bacillus anthracisApplied and Environmental Microbiology, 2001
- Direct Detection of Legionella Species from Bronchoalveolar Lavage and Open Lung Biopsy Specimens: Comparison of LightCycler PCR, In Situ Hybridization, Direct Fluorescence Antigen Detection, and CultureJournal of Clinical Microbiology, 2001
- Evaluation of real-time quantitative PCR for identification and quantification of Chlamydia pneumoniae by comparison with immunohistochemistryJournal of Microbiological Methods, 2001
- Development and evaluation of a real-time quantitative PCR for the detection of human cytomegalovirusJournal of Virological Methods, 2001
- Use of real-time PCR and the LightCycler system for the rapid detection of Pneumocystis carinii in respiratory specimensDiagnostic Microbiology and Infectious Disease, 2001
- Sensitive Identification of Mycobacterial Species Using PCR-RFLP on Bronchial WashingsAmerican Journal of Respiratory and Critical Care Medicine, 2000
- Transcontinental Spread of Multidrug-resistantMycobacterium bovisAmerican Journal of Respiratory and Critical Care Medicine, 1999
- Auramine Fluorescence for Acid-Fast Bacilli in Formalin-fixed Paraffin-embedded TissuesAmerican Journal of Clinical Pathology, 1995
- Mycolic acid patterns of some species of MycobacteriumArchiv für Mikrobiologie, 1984