Evaluation of a safe sputum processing method for detecting tuberculosis. (33/36)

AIMS: To evaluate a safe sputum processing method for detection of tuberculosis in developing countries. METHODS: A sample processing method was developed in which acid fast bacilli were killed with 1% sodium hypochlorite and concentrated by flotation on a layer of xylene before staining by the Ziehl Neelsen or auramine O methods. RESULTS: Best results were obtained by auramine O staining after flotation. Staining by the Ziehl Neelsen method after flotation gave better results than direct Ziehl Neelsen staining without flotation. CONCLUSIONS: The flotation method with Ziehl Neelsen staining offers advantages for smear preparation in the tuberculosis control programmes of developing countries.  (+info)

Detection of acid-fast bacilli in concentrated primary specimen smears stained with rhodamine-auramine at room temperature and at 37 degrees C. (34/36)

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.  (+info)

Use of UV ParaLens adapter for detection of acid-fast organisms. (35/36)

Auramine-stained mycobacterial smears from 136 clinical specimens were interpreted by using the UV ParaLens adapter (Beckton Dickinson), and results were compared with smear interpretations using a traditional fluorescent microscope and culture. The sensitivity and specificity of the ParaLens were 84 and 93%, respectively. Smears yielding discrepant results were overstained by the Kinyoun method. Overall, the sensitivity of auramine-stained smears interpreted with the UV ParaLens was comparable to that of Kinyoun-stained smears.  (+info)

Phenolic acridine orange fluorescent stain for mycobacteria. (36/36)

A new fluorescence acid-fast staining method with acridine orange as the specific stain is presented. Only two reagents are required: the acridine orange-specific stain and a destaining-counterstaining reagent. Compared with auramine fluorescence acid-fast staining, there was less nonspecific staining of non-acid-fast debris which fluoresced a pale green contrasting color to provide a background in which to search for the red-to-orange fluorescing acid-fast bacilli. The results of the study indicate that the acridine orange method is superior to the auramine method in detecting acid-fast bacilli in specimen smears.  (+info)