Buruli ulcer lesions in HIV-positive patient.
Ontology highlight
ABSTRACT:
SUBMITTER: Kibadi K
PROVIDER: S-EPMC3321952 | biostudies-literature |
REPOSITORIES: biostudies-literature
Similar Datasets
Project description:BackgroundBuruli ulcer (BU), caused by Mycobacterium ulcerans, is increasing in incidence in Victoria, Australia. To improve understanding of disease transmission, we aimed to map the location of BU lesions on the human body.MethodsUsing notification data and clinical records review, we conducted a retrospective observational study of patients diagnosed with BU in Victoria from 1998-2015. We created electronic density maps of lesion locations using spatial analysis software and compared lesion distribution by age, gender, presence of multiple lesions and month of infection.FindingsWe examined 579 patients with 649 lesions; 32 (5.5%) patients had multiple lesions. Lesions were predominantly located on lower (70.0%) and upper (27.1%) limbs, and showed a non-random distribution with strong predilection for the ankles, elbows and calves. When stratified by gender, upper limb lesions were more common (OR 1·97, 95% CI 1·38-2·82, p<0·001) while lower limb lesions were less common in men than in women (OR 0·48, 95% CI 0·34-0·68, p<0·001). Patients aged ≥ 65 years (OR 3·13, 95% CI 1·52-6·43, p = 0·001) and those with a lesion on the ankle (OR 2·49, 95% CI 1·14-5·43, p = 0·02) were more likely to have multiple lesions. Most infections (71.3%) were likely acquired in the warmer 6 months of the year.InterpretationComparison with published work in Cameroon, Africa, showed similar lesion distribution and suggests the mode of M. ulcerans transmission may be the same across the globe. Our findings also aid clinical diagnosis and provide quantitative background information for further research investigating disease transmission.
| S-EPMC5584971 | biostudies-literature
Project description:BackgroundCurrent laboratory diagnosis of Buruli ulcer (BU) is based on microscopic detection of acid fast bacilli, quantitative real-time PCR (qPCR), histopathology or cultivation. Insertion sequence (IS) 2404 qPCR, the most sensitive method, is usually only available at reference laboratories. The only currently available point-of-care test, microscopic detection of acid fast bacilli (AFB), has limited sensitivity and specificity.Methodology/ principal findingsHere we analyzed AFB positive tissue samples (n = 83) for the presence, distribution and amount of AFB. AFB were nearly exclusively present in the subcutis with large extracellular clusters being most frequently (67%) found in plaque lesions. In ulcerative lesions small clusters and dispersed AFB were more common. Beside this, 151 swab samples from 37 BU patients were analyzed by IS2404 qPCR and ZN staining in parallel. The amount of M. ulcerans DNA in extracts from swabs correlated well with the probability of finding AFB in direct smear microscopy, with 56.1% of the samples being positive in both methods and 43.9% being positive only in qPCR. By analyzing three swabs per patient instead of one, the probability to have at least one positive swab increased from 80.2% to 97.1% for qPCR and from 45% to 66.1% for AFB smear examination.Conclusion / significanceOur data show that M. ulcerans bacteria are primarily located in the subcutis of BU lesions, making the retrieval of the deep subcutis mandatory for examination of tissue samples for AFB. When laboratory diagnosis is based on the recommended less invasive collection of swab samples, analysis of three swabs from different areas of ulcerative lesions instead of one increases the sensitivity of both qPCR and of smear microscopy substantially.
| S-EPMC4890796 | biostudies-literature
Project description:Buruli ulcer (BU) is a tropical infectious disease caused by Mycobacterium ulcerans. BU causes profound skin ulcerations and eventually bone infections. Life-long functional sequelae are observed in more than 20% of patients, most of whom are children. Several observations, in particular the large variability in the clinical severity of the disease after infection, suggested the role of human genetic factors in the development of BU. Here, we report two children with severe BU, born of consanguineous parents. The deep genetic exploration of this family led to the identification of a small deletion on chromosome 8 in both patients. The corresponding article is in press in PloS Neglected Tropical Diseases
2018-04-23 | GSE113496 | GEO
Project description:BackgroundBuruli ulcer caused by Mycobacterium ulcerans is an infection of the subcutaneous tissue leading to chronic necrotising skin ulcers. The pathogenesis is associated with the cytocidal and immunosuppressive activities of a macrolide toxin. Histopathological hallmark of progressing disease is a poor inflammatory response despite of clusters of extracellular bacilli. While traditionally wide excision of the infected tissue was the standard treatment, provisional WHO guidelines now recommend an eight week pre-treatment with streptomycin and rifampicin.Methodology/principal findingsWe conducted a detailed immunohistochemical analysis of tissue samples from Buruli patients who received antibiotic treatment. Cellular immune response along with bacterial load and distribution were monitored. We demonstrate that this treatment leads to the development of highly organized cellular infiltration surrounding areas of coagulative necrosis. Diffuse infiltrates, granulomas and dense lymphocyte aggregation close to vessels were observed. Mycobacterial material was primarily located inside mononuclear phagocytes and microcolonies consisting of extracellular rod-shaped mycobacteria were no longer found. In observational studies some patients showed no clinical response to antibiotic treatment. Corresponding to that, one of five lesions analysed presented with huge clusters of rod-shaped bacilli but no signs of infiltration.Conclusions/significanceResults signify that eight weeks of antibiotic treatment reverses local immunosuppression and leads to an active inflammatory process in different compartments of the skin. Structured leukocyte infiltrates with unique signatures indicative for healing processes developed at the margins of the lesions. It remains to be analysed whether antibiotic resistance of certain strains of M. ulcerans, lacking patient compliance or poor drug quality are responsible for the absent clinical responses in some patients. In future, analysis of local immune responses could serve as a suitable surrogate marker for the efficacy of alternative treatment strategies.
| S-EPMC2041817 | biostudies-literature
Project description:We reviewed Buruli ulcer (BU) surveillance in Benin, using the World Health Organization BU02 form. We report results of reliable routine data collected on 2,598 new and recurrent cases from 2003 through 2005.
| S-EPMC2857274 | biostudies-literature
Project description:Buruli ulcer (BU), caused by Mycobacterium ulcerans is a chronic necrotizing skin disease. It usually starts with a subcutaneous nodule or plaque containing large clusters of extracellular acid-fast bacilli. Surrounding tissue is destroyed by the cytotoxic macrolide toxin mycolactone produced by microcolonies of M. ulcerans. Skin covering the destroyed subcutaneous fat and soft tissue may eventually break down leading to the formation of large ulcers that progress, if untreated, over months and years. Here we have analyzed the bacterial flora of BU lesions of three different groups of patients before, during and after daily treatment with streptomycin and rifampicin for eight weeks (SR8) and determined drug resistance of the bacteria isolated from the lesions. Before SR8 treatment, more than 60% of the examined BU lesions were infected with other bacteria, with Staphylococcus aureus and Pseudomonas aeruginosa being the most prominent ones. During treatment, 65% of all lesions were still infected, mainly with P. aeruginosa. After completion of SR8 treatment, still more than 75% of lesions clinically suspected to be infected were microbiologically confirmed as infected, mainly with P. aeruginosa or Proteus miriabilis. Drug susceptibility tests revealed especially for S. aureus a high frequency of resistance to the first line drugs used in Ghana. Our results show that secondary infection of BU lesions is common. This could lead to delayed healing and should therefore be further investigated.
| S-EPMC3642065 | biostudies-other
Project description:BackgroundIn the Cameroon, previous efforts to identify Buruli ulcer (BU) through the mobilization of community health workers (CHWs) yielded poor results. In this paper, we describe the successful creation of a BU community of practice (BUCOP) in Bankim, Cameroon composed of hospital staff, former patients, CHWs, and traditional healers.Methods and principle findingsAll seven stages of a well-defined formative research process were conducted during three phases of research carried out by a team of social scientists working closely with Bankim hospital staff. Phase one ethnographic research generated interventions tested in a phase two proof of concept study followed by a three- year pilot project. In phase three the pilot project was evaluated. An outcome evaluation documented a significant rise in BU detection, especially category I cases, and a shift in case referral. Trained CHW and traditional healers initially referred most suspected cases of BU to Bankim hospital. Over time, household members exposed to an innovative and culturally sensitive outreach education program referred the greatest number of suspected cases. Laboratory confirmation of suspected BU cases referred by community stakeholders was above 30%. An impact and process evaluation found that sustained collaboration between health staff, CHWs, and traditional healers had been achieved. CHWs came to play a more active role in organizing BU outreach activities, which increased their social status. Traditional healers found they gained more from collaboration than they lost from referral.Conclusion/ significanceSetting up lines of communication, and promoting collaboration and trust between community stakeholders and health staff is essential to the control of neglected tropical diseases. It is also essential to health system strengthening and emerging disease preparedness. The BUCOP model described in this paper holds great promise for bringing communities together to solve pressing health problems in a culturally sensitive manner.
| S-EPMC5889189 | biostudies-literature
Project description:BackgroundBuruli ulcer (BU), caused by Mycobacterium ulcerans, is a neglected tropical disease frequently leading to permanent disabilities. The ulcers are treated with rifampicin and streptomycin, wound care and, if necessary surgical intervention. Professionals have exclusively shaped the research agenda concerning management and control, while patients' perspective on priorities and preferences have not explicitly been explored or addressed.Methodology/principal findingsTo get insight into patient perception of the management and control of Buruli ulcer a mixed methods research design was applied with a questionnaire and focus group discussions among former BU patients. Data collection was obtained in collaboration with a local team of native speakers in Ghana. A questionnaire was completed by 60 former patients and four focus group discussions were conducted with eight participants per group. Former patients positively evaluated both the effectiveness of the treatment and the financial contribution received for the travel costs to the hospitals. Pain experienced during treatment procedures, in particular wound care and the streptomycin injections, and the side-effects of the treatment were negatively evaluated. Former patients considered the development of preventive measures and knowledge on the transmission as priorities. Additionally, former patients asked for improved accessibility of health services, counselling and economic support.ConclusionsThese findings can be used to improve clinical management and to guide the international research agenda.
| S-EPMC5226828 | biostudies-literature
Project description:Microbiome samples derived from Buruli ulcer wounds and non-Buruli ulcer skin ulcerations
| PRJEB14948 | ENA
Project description:A well-known histopathological feature of diseased skin in Buruli ulcer (BU) is coagulative necrosis caused by the Mycobacterium ulcerans macrolide exotoxin mycolactone. Since the underlying mechanism is not known, we have investigated the effect of mycolactone on endothelial cells, focussing on the expression of surface anticoagulant molecules involved in the protein C anticoagulant pathway. Congenital deficiencies in this natural anticoagulant pathway are known to induce thrombotic complications such as purpura fulimans and spontaneous necrosis. Mycolactone profoundly decreased thrombomodulin (TM) expression on the surface of human dermal microvascular endothelial cells (HDMVEC) at doses as low as 2 ng/ml and as early as 8 hrs after exposure. TM activates protein C by altering thrombin's substrate specificity, and exposure of HDMVEC to mycolactone for 24 hours resulted in an almost complete loss of the cells' ability to produce activated protein C. Loss of TM was shown to be due to a previously described mechanism involving mycolactone-dependent blockade of Sec61 translocation that results in proteasome-dependent degradation of newly synthesised ER-transiting proteins. Indeed, depletion from cells determined by live-cell imaging of cells stably expressing a recombinant TM-GFP fusion protein occurred at the known turnover rate. In order to determine the relevance of these findings to BU disease, immunohistochemistry of punch biopsies from 40 BU lesions (31 ulcers, nine plaques) was performed. TM abundance was profoundly reduced in the subcutis of 78% of biopsies. Furthermore, it was confirmed that fibrin deposition is a common feature of BU lesions, particularly in the necrotic areas. These findings indicate that there is decreased ability to control thrombin generation in BU skin. Mycolactone's effects on normal endothelial cell function, including its ability to activate the protein C anticoagulant pathway are strongly associated with this. Fibrin-driven tissue ischemia could contribute to the development of the tissue necrosis seen in BU lesions.
| S-EPMC4504485 | biostudies-literature