Advancing, promoting and sharing knowledge of health through excellence in teaching, clinical practice and research into the prevention and treatment of illness

Rapid detection of Mycobacterium ulcerans with isothermal recombinase polymerase amplification assay.

Frimpong, M; Ahor, HS; Wahed, AAE; Agbavor, B; Sarpong, FN; Laing, K; Wansbrough-Jones, M; Phillips, RO (2019) Rapid detection of Mycobacterium ulcerans with isothermal recombinase polymerase amplification assay. PLoS Negl Trop Dis, 13 (2). e0007155. ISSN 1935-2735
SGUL Authors: Laing, Kenneth Wansbrough-Jones, Mark Harding

PDF Published Version
Available under License Creative Commons Attribution.

Download (1MB) | Preview


Background Access to an accurate diagnostic test for Buruli ulcer (BU) is a research priority according to the World Health Organization. Nucleic acid amplification of insertion sequence IS2404 by polymerase chain reaction (PCR) is the most sensitive and specific method to detect Mycobacterium ulcerans (M. ulcerans), the causative agent of BU. However, PCR is not always available in endemic communities in Africa due to its cost and technological sophistication. Isothermal DNA amplification systems such as the recombinase polymerase amplification (RPA) have emerged as a molecular diagnostic tool with similar accuracy to PCR but having the advantage of amplifying a template DNA at a constant lower temperature in a shorter time. The aim of this study was to develop RPA for the detection of M. ulcerans and evaluate its use in Buruli ulcer disease. Methodology and principal findings A specific fragment of IS2404 of M. ulcerans was amplified within 15 minutes at a constant 42°C using RPA method. The detection limit was 45 copies of IS2404 molecular DNA standard per reaction. The assay was highly specific as all 7 strains of M. ulcerans tested were detected, and no cross reactivity was observed to other mycobacteria or clinically relevant bacteria species. The clinical performance of the M. ulcerans (Mu-RPA) assay was evaluated using DNA extracted from fine needle aspirates or swabs taken from 67 patients in whom BU was suspected and 12 patients with clinically confirmed non-BU lesions. All results were compared to a highly sensitive real-time PCR. The clinical specificity of the Mu-RPA assay was 100% (95% CI, 84–100), whiles the sensitivity was 88% (95% CI, 77–95). Conclusion The Mu-RPA assay represents an alternative to PCR, especially in areas with limited infrastructure. Author summary Current diagnostic methods to detect M. ulcerans suffer from delayed time-to-results in most endemic countries by the prolonged period of time for the shipment and storage of samples to a distant, centralized laboratory. The M. ulcerans recombinase polymerase amplification assay (Mu-RPA) is a new, rapid diagnostic test developed for the detection of M. ulcerans infection, known commonly as Buruli ulcer, a chronic, debilitating, necrotizing disease of the skin and soft tissues. This assay is suitable for use on a portable detection device, with the potential to be used for quick diagnosis at the point of need, providing timely results to health workers at Buruli ulcer treatment clinics.

Item Type: Article
Additional Information: © 2019 Frimpong et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Keywords: 06 Biological Sciences, 11 Medical And Health Sciences, Tropical Medicine
SGUL Research Institute / Research Centre: Academic Structure > Infection and Immunity Research Institute (INII)
Journal or Publication Title: PLoS Negl Trop Dis
ISSN: 1935-2735
Language: eng
1 February 2019Published
14 January 2019Accepted
Publisher License: Creative Commons: Attribution 4.0
Project IDFunderFunder ID
MR/J01477X/1Medical Research Council
PubMed ID: 30707706
Go to PubMed abstract
Publisher's version:

Actions (login required)

Edit Item Edit Item