Evaluation of phenol ammonium sulfate basic fuchsin and auramine O staining by pot technique for the detection of acid-fast bacilli among patients suspected of pulmonary tuberculosis

Abstract

Introduction and Aim: Tuberculosis (TB) remains a major public health concern with its high incidence and mortality. In developing countries, smear microscopy continues to be the primary diagnostic tool for the diagnosis of TB. Sputum samples processing under resource-limited settings could be hazardous, which urges  safe and efficient smear microscopy techniques. This study aimed to evaluate the efficacy of two different pot methods: Phenol ammonium sulfate (PhAS) auramine O and PhAS basic fuchsin in comparison to the conventional Auramine O method.  Materials and Methods: A prospective cross-sectional study was conducted at the Department of Microbiology with 74 sputum samples. All sputum samples were processed using the Auramine O method PhAS auramine O and PhAS basic fuchsin staining methods. Microsoft Office Excel (Microsoft, Redmond, WA, USA) was used to maintain and analyze all the data. Results: A total of 8 (10.7%) samples were positive for AFB and 67 (89.3%) samples were negative, according to routine auramine O method and pot methods. Pot methods showed a 100% sensitivity and specificity compared to the conventional Auramine O method. In terms of sputum smear grading, the direct smear using auramine O showed better results compared to pot methods. Conclusion: Pot methods like PhAS basic fuchsin and PhAS auramine O are efficient to detect AFB in sputum smears by reducing the risk of laboratory-acquired infections.