Simultaneous staining of sputum smears for acid-fast and lipid-containing Myobacterium tuberculosis can enhance the clinical evaluation of antituberculosis treatments
Division of Medical Physiology, MRC Centre for Tuberculosis Research, DST/NRF, Centre of Excellence for Biomedical Tuberculosis Research, Faculty of Medicine and Health Sciences, Stellenbosch University, Tygerberg, South Africa; Task Applied Science, Bellville, Cape Town, South Africa; Department of Statistics, Faculty of Natural Sciences, University of the Western Cape, Cape Town, South Africa; Department of Paediatrics and Child Health, Faculty of Medicine and Health Sciences, Stellenbosch University, Tygerberg, South Africa
Dormant, slow-growing, antibiotic-tolerant Mycobacterium tuberculosis undermine the shortening of tuberculosis treatment to less than 6 months and are thought to be characterised by intracellular lipid bodies. Antibiotic effects on such persisting bacilli escape evaluation as they cannot be readily cultured. We identified cells containing lipid bodies in sputum smears from 86 newly diagnosed pulmonary tuberculosis patients and monitored these cells daily in 42 patients over the first 14 days of treatment with rifampicin, the experimental compound SQ-109, or both agents combined. Counts of Nile-Red-positive lipid-body containing cells were correlated with those of Auramine-O-positive cells and colony forming units of viable Mycobacterium tuberculosis on agar plates. Rifampicin but not SQ-109 significantly reduced colony forming units but all treatments distinctively and significantly changed the proportions of lipid body-containing bacilli and viable Mycobacterium tuberculosis. Monitoring lipid-body containing bacilli in sputum during treatment with experimental antituberculosis regimens may identify putative treatment-shortening regimens. © 2015 Elsevier Ltd.
agar; auramine; lipid; n (2 adamantyl) n' geranylethylenediamine; rifampicin; acid fast bacterium; adult; Article; cell counting; clinical article; clinical evaluation; colony forming unit; confocal laser microscopy; human; lung tuberculosis; Mycobacterium tuberculosis; priority journal; sputum culture; sputum smear; treatment duration