scholarly journals Effects of Decontamination, DNA Extraction, and Amplification Procedures on the Molecular Diagnosis of Mycobacterium ulcerans Disease (Buruli Ulcer)

2012 ◽  
Vol 50 (4) ◽  
pp. 1195-1198 ◽  
Author(s):  
D. Affolabi ◽  
N. Sanoussi ◽  
K. Vandelannoote ◽  
M. Odoun ◽  
F. Faihun ◽  
...  
Keyword(s):  
Dna Extraction ◽  
Molecular Diagnosis ◽  
Buruli Ulcer ◽  
Mycobacterium Ulcerans

scholarly journals Evaluation of different DNA extraction methods and loop-mediated isothermal amplification primers for the detection of Mycobacterium ulcerans in clinical specimens

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Anthony Ablordey ◽  
Evans Ahotor ◽  
Charles A. Narh ◽  
Sandra A. King ◽  
Isra Cruz ◽  
...  
Keyword(s):  
Dna Extraction ◽  
Extraction Method ◽  
Point Of Care ◽  
Buruli Ulcer ◽  
Extraction Methods ◽  
Isothermal Amplification ◽  
Mycobacterium Ulcerans ◽  
Loop Mediated Isothermal Amplification ◽  
Dna Extraction Method ◽  
Dna Extraction Methods

Abstract Background Early diagnosis and treatment of Buruli ulcer is critical in order to avoid the debilitating effects of the disease. In this regard, the development of new diagnostic and point of care tools is encouraged. The loop-mediated isothermal amplification for the detection of Mycobacterium ulcerans represents one of the new tools with a good potential of being developed into a point of care test. There is however the need to standardize the assays, reduce sample preparation times, improve the detection/visualization system and optimize them for high-throughput screening, adaptable to low resourced laboratories. Methods In this study, we assessed two DNA extraction protocols (modified Boom and EasyNAT methods), three previously published LAMP primer sets (BURULI, MU 2404 and BU-LAMP), and compared the sensitivity and specificity of LAMP assays on three DNA amplification platforms. Results Our results show that Buruli ulcer diagnosis using primers targeting IS2404 for the LAMP method is sensitive (73.75–91.49%), depending on the DNA extraction method used. Even though the modified Boom DNA extraction method provided the best results, its instrumentation requirement prevent it from being field applicable. The EasyNAT method on the other hand is simpler and may represent the best method for DNA extraction in less resourced settings. Conclusions For further work on the development and use of LAMP tests for Buruli diagnosis, it is recommended that the BURULI sets of primers be used, as these yielded the best results in terms of sensitivity (87.50–91.49%) and specificity (89.23–100%), depending on the DNA extraction methods used.

scholarly journals Rapid Extraction Method of Mycobacterium ulcerans DNA from Clinical Samples of Suspected Buruli Ulcer Patients

Diagnostics ◽  
2019 ◽  
Vol 9 (4) ◽  
pp. 204
Author(s):  
Michael Frimpong ◽  
Hubert Senanu Ahor ◽  
Samuel Asamoah Sakyi ◽  
Bernadette Agbavor ◽  
Emmanuel Akowuah ◽  
...  
Keyword(s):  
Dna Extraction ◽  
Extraction Procedure ◽  
Buruli Ulcer ◽  
Molecular Techniques ◽  
Isothermal Amplification ◽  
Mycobacterium Ulcerans ◽  
Recombinase Polymerase Amplification ◽  
Clinical Samples ◽  
Rapid Extraction ◽  
Extraction Protocol

Isothermal amplification techniques such as recombinase polymerase amplification (RPA) and loop-mediated isothermal amplification (LAMP) for diagnosing Buruli ulcer, a necrotic skin disease caused by Mycobacterium ulcerans, have renewed hope for the molecular diagnosis of clinically suspected Buruli ulcer cases in endemic districts. If these techniques are applied at district-level hospitals or clinics, they will help facilitate early case detection with prompt treatment, thereby reducing disability and associated costs of disease management. The accuracy as well as the application of these molecular techniques at point of need is dependent on simple and fast DNA extraction. We have modified and tested a rapid extraction protocol for use with an already developed recombinase polymerase amplification assay. The entire procedure from “sample in, extraction and DNA amplification” was conducted in a mobile suitcase laboratory within 40 min. The DNA extraction procedure was performed within 15 min, with only two manipulation/pipetting steps needed. The diagnostic sensitivity and specificity of this extraction protocol together with M. ulcerans RPA in comparison with standard DNA extraction with real-time PCR was 87% (n = 26) and 100% (n = 13), respectively. We have established a simple, fast and efficient protocol for the extraction and detection of M. ulcerans DNA in clinical samples that is adaptable to field conditions.

Interactions between ecological and socio-economic drivers of Buruli ulcer burden in Sub-Saharan Africa: opportunities for an improved control

2018 ◽  
Author(s):  
Andes Garchitorena ◽  
Matthew H. Bonds ◽  
Jean-Francois Guégan ◽  
Benjamin Roche
Keyword(s):  
Socioeconomic Factors ◽  
Disease Transmission ◽  
Access To Health Care ◽  
Buruli Ulcer ◽  
Mycobacterium Ulcerans ◽  
Sub Saharan Africa ◽  
Aquatic Environments ◽  
Human Populations ◽  
Complex Interactions ◽  
Sub Saharan

This chapter provides an overview of the complex interactions between ecological and socioeconomic factors for the development and control of Buruli ulcer in Sub-Saharan Africa. We review key ecological and evolutionary processes driving the environmental persistence and proliferation of Mycobacterium ulcerans, the causative agent, within aquatic environments, as well as transmission processes from these aquatic environments to human populations. We also outline key socioeconomic factors driving the economic and health burden of Buruli ulcer in endemic regions, revealed by reciprocal feedbacks between poverty, disease transmission from exposure aquatic environments and disease progression to severe stages owing to low access to health care. The implications of such insights for disease control, both in terms of limitations of current strategies and directions for the future, are discussed.

scholarly journals Cellular Immunity Confers Transient Protection in Experimental Buruli Ulcer following BCG or Mycolactone-Negative Mycobacterium ulcerans Vaccination

PLoS ONE ◽  
2012 ◽  
Vol 7 (3) ◽  
pp. e33406 ◽  
Author(s):  
Alexandra G. Fraga ◽  
Teresa G. Martins ◽  
Egídio Torrado ◽  
Kris Huygen ◽  
Françoise Portaels ◽  
...  
Keyword(s):  
Cellular Immunity ◽  
Buruli Ulcer ◽  
Mycobacterium Ulcerans

scholarly journals Community-based geographical distribution of Mycobacterium ulcerans VNTR-genotypes from the environment and humans in the Nyong valley, Cameroon

2021 ◽  
Vol 49 (1) ◽  
Author(s):  
Francis Zeukeng ◽  
Anthony Ablordey ◽  
Solange E. Kakou-Ngazoa ◽  
Stephen Mbigha Ghogomu ◽  
David N’golo Coulibaly ◽  
...  
Keyword(s):  
Environmental Samples ◽  
Tandem Repeats ◽  
Buruli Ulcer ◽  
Variable Number ◽  
Mycobacterium Ulcerans ◽  
Community Based ◽  
Human Samples ◽  
Route Of Transmission ◽  
Mode Of Transmission ◽  
Animal Reservoirs

Abstract Background Genotyping is a powerful tool for investigating outbreaks of infectious diseases and it can provide useful information such as identifying the source and route of transmission, and circulating strains involved in the outbreak. Genotyping techniques based on variable number of tandem repeats (VNTR) are instrumental in detecting heterogeneity in Mycobacterium ulcerans (MU) and also for discriminating MU from other mycobacteria species. Here, we describe and map the distribution of MU genotypes in Buruli ulcer (BU) endemic communities of the Nyong valley in Cameroon. We also tested the hypothesis of whether the suspected animal reservoirs of BU that share the human microhabitat are shedding contaminated fecal matters and saliva into their surrounding environments. Methods Environmental samples from suspected MU-risk factors and lesion swabs from human patients were sampled in BU-endemic communities and tested for the presence of MU by qPCR targeting three independent sequences (IS2404, IS2606, KR-B). Positive samples to MU were further genotyped by VNTR with confirmation by sequencing of four loci (MIRU1, Locus 6, ST1, Locus 19). Results MU was detected in environmental samples including water bodies (23%), biofilms (14%), detritus (10%), and in human patients (73%). MU genotypes D, W, and C were found both in environmental and human samples. The micro geo-distribution of MU genotypes from communities showed that genotype D is found both in environmental and human samples, while genotypes W and C are specific to environmental samples and human lesions, respectively. No obvious focal grouping of MU genotypes was observed at the community scale. An additional survey in the human microhabitat suggests that domestic and wild animals do not shed MU in their saliva and feces in sampled communities. Conclusions VNTR typing uncovered different MU genotypes circulating in the endemic communities of the Akonolinga district. A MU environmental genotype was found in patients, yet the mechanism of contamination remains to be investigated; and recovering MU in culture from the environment remains key priority to enable a better understanding of the mode of transmission of BU. We also conclude that excretions from suspected animals are unlikely to be major sources of MU in the Nyong Valley in Cameroon.

scholarly journals High-Dose Rifamycins Enable Shorter Oral Treatment in a Murine Model ofMycobacterium ulceransDisease

2018 ◽  
Vol 63 (2) ◽  
pp. e01478-18 ◽  
Author(s):  
Till F. Omansen ◽  
Deepak Almeida ◽  
Paul J. Converse ◽  
Si-Yang Li ◽  
Jin Lee ◽  
...  
Keyword(s):  
Oral Treatment ◽  
Buruli Ulcer ◽  
Indirect Costs ◽  
Ceiling Effect ◽  
Mycobacterium Ulcerans ◽  
High Dose ◽  
Current Standard ◽  
Standard Regimen ◽  
Content Type ◽  
Dose Dependent

ABSTRACTBuruli ulcer (BU), caused byMycobacterium ulcerans, is a neglected tropical skin and soft tissue infection that is associated with disability and social stigma. The mainstay of BU treatment is an 8-week course of rifampin (RIF) at 10 mg/kg of body weight and 150 mg/kg streptomycin (STR). Recently, the injectable STR has been shown to be replaceable with oral clarithromycin (CLR) for smaller lesions for the last 4 weeks of treatment. A shorter, all-oral, highly efficient regimen for BU is needed, as the long treatment duration and indirect costs currently burden patients and health systems. Increasing the dose of RIF or replacing it with the more potent rifamycin drug rifapentine (RPT) could provide such a regimen. Here, we performed a dose-ranging experiment of RIF and RPT in combination with CLR over 4 weeks of treatment in a mouse model ofM. ulceransdisease. A clear dose-dependent effect of RIF on both clinical and microbiological outcomes was found, with no ceiling effect observed with tested doses up to 40 mg/kg. RPT-containing regimens were more effective onM. ulcerans. All RPT-containing regimens achieved culture negativity after only 4 weeks, while only the regimen with the highest RIF dose (40 mg/kg) did so. We conclude that there is dose-dependent efficacy of both RIF and RPT and that a ceiling effect is not reached with the current standard regimen used in the clinic. A regimen based on higher rifamycin doses than are currently being evaluated against tuberculosis in clinical trials could shorten and improve therapy of Buruli ulcer.

scholarly journals Heterogeneity of Mycolactones Produced by Clinical Isolates of Mycobacterium ulcerans: Implications for Virulence

2003 ◽  
Vol 71 (2) ◽  
pp. 774-783 ◽  
Author(s):  
Armand Mve-Obiang ◽  
Richard E. Lee ◽  
Françoise Portaels ◽  
P. L. C. Small
Keyword(s):  
Clinical Evidence ◽  
Buruli Ulcer ◽  
Mycobacterium Ulcerans ◽  
Biologically Active ◽  
In Vivo Studies ◽  
Tissue Destruction ◽  
The Core ◽  
A Minor ◽  
Layer Chromatography

ABSTRACT Mycobacterium ulcerans is the causative agent of Buruli ulcer, a severe necrotizing skin disease endemic in tropical countries. Clinical evidence suggests that M. ulcerans isolates from Asia, Mexico, and Australia may be less virulent than isolates from Africa. In vivo studies suggest that mycolactone, a polyketide-derived macrolide toxin, plays a major role in the tissue destruction and immune suppression which occur in cases of Buruli ulcer. Mycolactones were extracted from 34 isolates of M. ulcerans representing strains from Africa, Malaysia, Asia, Australia, and Mexico. Thin-layer chromatography, mass spectroscopic analysis, and cytopathic assays of partially purified mycolactones from these isolates revealed that M. ulcerans produces a heterogeneous mixture of mycolactone variants. Mycolactone A/B, the most biologically active mycolactone species, was identified by mass spectroscopy as [M+Na]+ at m/z 765.5 in all cytotoxic isolates except for those from Mexico. Mycolactone C [M+Na]+ at m/z 726.3 was the dominant mycolactone species in eight Australian isolates, and mycolactone D [M+Na]+ m/z 781.2 was characteristic of two Asian strains. Mycolactone species are conserved within specific geographic areas, suggesting that there may be a correlation between mycolactone profile and virulence. In addition, the core lactone, [M+Na]+ m/z 447.4, was identified as a minor species, supporting the hypothesis that mycolactones are synthesized by two polyketide synthases. A cytopathic assay of the core lactone showed that this molecule is sufficient for cytotoxicity, although it is much less potent than the complete mycolactone.

Sign in / Sign up

Export Citation Format

Share Document