RITM's innovative method on detecting Mycobacterium tuberculosis gets published in Philippine Jo

Congratulations to the staff of RITM Histopathology Laboratory, led by Ms. Ester Cabic, for publishing their innovative method on detecting Mycobacteria in tissue samples.

Kudos also to Dan Louie Renz Tating (Coordinator), Hannah Mugol(Research Associate) and Ericka Gilo for assisting our clients, from study conduct, analysis and publication.

ABSTRACT:

Introduction. Mycobacterium tuberculosis and Mycobacterium leprae are acid-fast organisms with lipid-rich cell walls that resist decolorization with acidified alcohol after application of a dye with heat. The Ziehl-Neelsen and Fite Faraco staining technique, which are diagnostic tools for identification of acid-fast bacilli (AFB) found in histopathologic samples, are based on this principle. A modification of the Ziehl-Neelsen technique is described as an alternative rapid and reliable method of diagnosis for prompt detection and treatment.

Methodology. One hundred and seven (107) archived tissue specimens from autopsy and dermatology cases interpreted as positive for M. tuberculosis and M. leprae were stained using the proposed modified acid-fast (MAF) technique compared with Fite Faraco (FF) staining method as reference standard. Each specimen was read by two independent evaluators.

Results. The degree of diagnostic agreement of the MAF with FF was calculated. For autopsy (n=16) and dermatology (n=91) samples, the Cohen’s kappas are 0.765 (substantial) and 0.397 (fair), respectively. Overall, the Cohen’s kappa is 0.458 (moderate).

Conclusion. The proposed modified Acid-Fast staining method may be considered as an alternative to the conventional Ziehl-Neelsen method and the Fite Faraco method in identifying positive acid-fast bacilli in tissue samples taken from clinical cases of M. tuberculosis and M. leprae.