Friday, July 25, 2014

(LML) Staining of M. leprae vs. M. tuberculosis and decolorizing with hydrochloric acid

Leprosy Mailing List – July 25, 2014 

Ref.: (LML)    Staining of M. leprae vs. M. tuberculosis and decolorizing with hydrochloric acid  

From:  David M. Scollard, Baton Rouge, Louisiana, USA


Dear Pieter,

The two images (see attached file) illustrate our experience with the issue of Fite vs ZN staining for M. leprae. 

The ZN stain was performed by a very good laboratory, and no AFB were seen in this section sent to us.  They also sent a positive control slide (M. tuberculosis) in which AFB were clearly stained.

The Fite stain was performed in the NHDP laboratory on another section from the same block. Many AFB are seen.

This is an extreme example, but illustrates the point. The exact details of ZN staining and decolorization vary between laboratories.  We often see fewer bacilli with a ZN stain than with a Fite stain, but it is unusual to see the total lack of staining of M. leprae with the ZN stain as in this case. 

These images are in a review that has been submitted for publication.

 

David M. Scollard, M.D., Ph.D.

Director

National Hansen’s Disease Programs

Tel:  225-756-3713 (Clinical) or 756-3776 (Administration)

Fax:  225-756-3819 or 756-3806

E-mail:  dscollard@hrsa.gov

Web:  www.hrsa.gov/hansensdisease  


LML - S Deepak, B Naafs, S Noto and P Schreuder

LML blog link: http://leprosymailinglist.blogspot.it/

Contact: Dr Pieter Schreuder << editorlml@gmail.com

 




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