Journal Article

Mycolactone Diffuses into the Peripheral Blood of Buruli Ulcer Patients - Implications for Diagnosis and Disease Monitoring

Demangel, Caroline, Le Chevalier, Fabien, Phillips, Richard O., Lenormand, Pascal, Veyron-Churlet, Romain, Dosso, Mireille, Wansbrough-Jones, Mark, Boneca, Ivo G., Sarfo, Fred S., Amoako, Yaw, Aka, N'Guetta, Guenin-Macé, Laure

2011

Overview

Mycobacterium ulcerans, the causative agent of Buruli ulcer (BU), is unique among human pathogens in its capacity to produce a polyketide-derived macrolide called mycolactone, making this molecule an attractive candidate target for diagnosis and disease monitoring. Whether mycolactone diffuses from ulcerated lesions in clinically accessible samples and is modulated by antibiotic therapy remained to be established. Peripheral blood and ulcer exudates were sampled from patients at various stages of antibiotic therapy in Ghana and Ivory Coast. Total lipids were extracted from serum, white cell pellets and ulcer exudates with organic solvents. The presence of mycolactone in these extracts was then analyzed by a recently published, field-friendly method using thin layer chromatography and fluorescence detection. This approach did not allow us to detect mycolactone accurately, because of a high background due to co-extracted human lipids. We thus used a previously established approach based on high performance liquid chromatography coupled to mass spectrometry. By this means, we could identify structurally intact mycolactone in ulcer exudates and serum of patients, and evaluate the impact of antibiotic treatment on the concentration of mycolactone. Our study provides the proof of concept that assays based on mycolactone detection in serum and ulcer exudates can form the basis of BU diagnostic tests. However, the identification of mycolactone required a technology that is not compatible with field conditions and point-of-care assays for mycolactone detection remain to be worked out. Notably, we found mycolactone in ulcer exudates harvested at the end of antibiotic therapy, suggesting that the toxin is eliminated by BU patients at a slow rate. Our results also indicated that mycolactone titres in the serum may reflect a positive response to antibiotics, a possibility that it will be interesting to examine further through longitudinal studies.

• Publisher: Public Library of Science,Public Library of Science (PLoS)
• Subject: Adolescent / Adult / Analysis / Anti-Bacterial Agents / Anti-Bacterial Agents - therapeutic use / Antibiotics / Bacterial Toxins / Bacterial Toxins - analysis / Bacterial Toxins - blood / Biological Markers / Biomarkers - analysis / Biomarkers - blood / Buruli Ulcer / Buruli Ulcer - blood / Buruli Ulcer - diagnosis / Buruli Ulcer - drug therapy / Buruli Ulcer - microbiology / Care and treatment / Chromatography / Chromatography, High Pressure Liquid / Chromatography, Thin Layer / Diagnosis / Disease / Exudates and Transudates / Exudates and Transudates - chemistry / Exudates and Transudates - microbiology / Female / Human health and pathology / Humans / Infectious diseases / Leukocytes, Mononuclear / Leukocytes, Mononuclear - chemistry / Leukocytes, Mononuclear - microbiology / Life Sciences / Lipids / Liquid chromatography / Longitudinal studies / Macrolides / Male / Mass Spectrometry / Medical diagnosis / Medicine / Mycobacterium ulcerans / Mycobacterium ulcerans - chemistry / Mycobacterium ulcerans - isolation & purification / Organic solvents / Pathogens / Physiological aspects / Scientific imaging / Thin layer chromatography / Toxins / Tropical diseases / Tuberculosis / Ulcers / Wounds and Injuries / Wounds and Injuries - microbiology