Protective Efficacy of a DNA Vaccine Encoding Antigen 85A from Mycobacterium bovis BCG against Buruli Ulcer

ABSTRACT Buruli ulcer, caused by Mycobacterium ulcerans, is characterized by deep and necrotizing skin lesions, mostly on the arms and legs. Together with tuberculosis and leprosy, this mycobacterial disease has become a major health problem in tropical and subtropical regions, particularly in central and western Africa. No specific vaccine is available for Buruli ulcer. There is, however, evidence in the literature that suggests a cross-reactive protective role of the tuberculosis vaccine M. bovis BCG. To identify potential mechanisms for this cross-protection, we identified and characterized the M. ulcerans homologue of the important protective mycobacterial antigen 85 (Ag85A) from BCG. The homologue is well conserved in M. ulcerans, showing 84.1% amino acid sequence identity and 91% conserved residues compared to the sequence from BCG. This antigen was sufficiently conserved to allow cross-reactive protection, as demonstrated by the ability of M. ulcerans- infected mice to exhibit strong cellular immune responses to both BCG and its purified Ag85 complex. To further address the mechanism of cross-reactive protection, we demonstrate here that prior vaccination with either BCG or plasmid DNA encoding BCG Ag85A is capable of significantly reducing the bacterial load in the footpads ofM. ulcerans- infected mice, as determined by Ziehl-Neelsen staining and by actual counting of CFU on 7H11 Middlebrook agar. Together, the results reported here support the potential of a cross-protective Ag85-based future vaccine against tuberculosis, Buruli ulcer, and leprosy.

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Clinical and Bacteriological Efficacy of Rifampin-Streptomycin Combination for Two Weeks followed by Rifampin and Clarithromycin for Six Weeks for Treatment of Mycobacterium ulcerans Disease

Antimicrobial Agents and Chemotherapy ◽

10.1128/aac.02165-13 ◽

2013 ◽

Vol 58 (2) ◽

pp. 1161-1166 ◽

Cited By ~ 45

Author(s):

Richard O. Phillips ◽

Fred S. Sarfo ◽

Mohammed K. Abass ◽

Justice Abotsi ◽

Tuah Wilson ◽

...

Keyword(s):

Bacterial Load ◽

Buruli Ulcer ◽

Positive Culture ◽

Mycobacterium Ulcerans ◽

Tissue Samples ◽

Content Type ◽

Western Africa ◽

Apparent Loss ◽

Before And After ◽

Tropical Areas

ABSTRACTBuruli ulcer, an ulcerating skin disease caused byMycobacterium ulceransinfection, is common in tropical areas of western Africa. We determined the clinical and microbiological responses to administration of rifampin and streptomycin for 2 weeks followed by administration of rifampin and clarithromycin for 6 weeks in 43 patients with small laboratory-confirmed Buruli lesions and monitored for recurrence-free healing. Bacterial load in tissue samples before and after treatment for 6 and 12 weeks was monitored by semiquantitative culture. The success rate was 93%, and there was no recurrence after a 12-month follow-up. Eight percent had a positive culture 4 weeks after antibiotic treatment, but their lesions went on to heal. The findings indicate that rifampin and clarithromycin can replace rifampin and streptomycin for the continuation phase after rifampin and streptomycin administration for 2 weeks without any apparent loss of efficacy.

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Genome-wide association study of Buruli ulcer in rural Benin

10.1101/19012096 ◽

2019 ◽

Author(s):

Jeremy Manry ◽

Quentin B. Vincent ◽

Maya Chrabieh ◽

Lazaro Lorenzo ◽

Ioannis Theodorou ◽

...

Keyword(s):

Association Study ◽

Odds Ratio ◽

Genome Wide Association Study ◽

Buruli Ulcer ◽

Missense Variant ◽

Skin Lesions ◽

Mycobacterium Ulcerans ◽

Genome Wide Association ◽

Genome Wide ◽

Autophagy Pathway

AbstractBuruli ulcer, caused by Mycobacterium ulcerans, is the third mycobacterial disease worldwide characterized by devastating necrotizing skin lesions. The role of host genetics in susceptibility to Buruli ulcer has long been suggested. We conduct the first genome-wide association study of Buruli ulcer on a combined sample of 1,524 well characterized patients and controls from rural Benin. Two-stage analyses identify two novel associated loci located within lincRNA genes: rs9814705 in ENSG00000240095.1 (P = 2.85×10−7; odds ratio = 1.80 [1.43-2.27]), and rs76647377 in LINC01622 (P = 9.85×10−8; hazard ratio = 0.41 [0.28-0.60]). Furthermore, we replicate the protective effect of allele G of a missense variant located in ATG16L1, and previously shown to decrease bacterial autophagy (rs2241880, P = 0.003; odds ratio = 0.31 [0.14-0.68]). Our results suggest lincRNAs and the autophagy pathway as critical factors in the development of Buruli ulcer.

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Increasing Experience with Primary Oral Medical Therapy for Mycobacterium ulcerans Disease in an Australian Cohort

Antimicrobial Agents and Chemotherapy ◽

10.1128/aac.02853-15 ◽

2016 ◽

Vol 60 (5) ◽

pp. 2692-2695 ◽

Cited By ~ 22

Author(s):

N. Deborah Friedman ◽

Eugene Athan ◽

Aaron L. Walton ◽

Daniel P. O'Brien

Keyword(s):

Medical Therapy ◽

Subcutaneous Tissue ◽

Buruli Ulcer ◽

Skin Lesions ◽

Antimicrobial Treatment ◽

Mycobacterium Ulcerans ◽

Content Type ◽

Southeastern Australia ◽

Observational Cohort ◽

Stage 1

ABSTRACTBuruli ulcer (BU) is a necrotizing infection of subcutaneous tissue that is caused byMycobacterium ulceransand is responsible for disfiguring skin lesions. The disease is endemic to specific geographic regions in the state of Victoria in southeastern Australia. Growing evidence of the effectiveness of antibiotic therapy forM. ulceransdisease has evolved our practice to the use of primarily oral medical therapy. An observational cohort study was performed on all confirmedM. ulceranscases treated with primary rifampin-based medical therapy at Barwon Health between October 2010 and December 2014 and receiving 12 months of follow-up. One hundred thirty-two patients were managed with primary medical therapy. The median age of patients was 49 years, and nearly 10% had diabetes mellitus. Lesions were ulcerative in 83.3% of patients and at WHO stage 1 in 78.8% of patients. The median duration of therapy was 56 days, with 22 patients (16.7%) completing fewer than 56 days of antimicrobial treatment. Antibiotic-associated complications requiring cessation of one or more antibiotics occurred in 21 (15.9%) patients. Limited surgical debridement was performed on 30 of these medically managed patients (22.7%). Cure was achieved, with healing within 12 months, in 131 of 132 patients (99.2%), and cosmetic outcomes were excellent. Primary rifampin-based oral medical therapy forM. ulceransdisease, combined with either clarithromycin or a fluoroquinolone, has an excellent rate of cure and an acceptable toxicity profile in Australian patients. We advocate for further research to determine the optimal and safest minimum duration of medical therapy for BU.

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Co-infection of HIV in patients with Buruli ulcer disease in Central Ghana

BMC Infectious Diseases ◽

10.1186/s12879-021-06009-7 ◽

2021 ◽

Vol 21 (1) ◽

Author(s):

Yaw Ampem Amoako ◽

Aloysius Dzigbordi Loglo ◽

Michael Frimpong ◽

Bernadette Agbavor ◽

Mohammed Kabiru Abass ◽

...

Keyword(s):

Bacterial Load ◽

Buruli Ulcer ◽

Interferon Γ ◽

Mycobacterium Ulcerans ◽

Hiv Viral Load ◽

Integration Of Care ◽

Ulcer Disease ◽

Hiv Coinfection ◽

Lesion Type ◽

Lesion Severity

Abstract Background Previous studies have reported that presence and severity of Buruli ulcer (BU) may reflect the underlying immunosuppression in HIV infected individuals by causing increased incidence of multiple, larger and ulcerated lesions. We report cases of BU-HIV coinfection and the accompanying programmatic challenges encountered in central Ghana. Methods Patients with PCR confirmed BU in central Ghana who were HIV positive were identified and their BU01 forms were retrieved and reviewed in further detail. A combined 16S rRNA reverse transcriptase / IS2404 qPCR assay was used to assess the Mycobacterium ulcerans load. The characteristics of coinfected patients (BU+HIV+) were compared with a group of matched controls. Results The prevalence of HIV in this BU cohort was 2.4% (compared to national HIV prevalence of 1.7%). Eight of 9 BU+HIV+ patients had a single lesion and ulcers were the most common lesion type. The lesions presented were predominantly category II (5/9) followed by category I lesions. The median (IQR) time to healing was 14 (8–28) weeks in the BU+HIV+ compared to 28 (12–33) weeks in the control BU+HIV− group (p = 0.360). Only one BU+HIV+ developed a paradoxical reaction at week 16 but the lesion healed completely at week 20. The median bacterial load (16SrRNA) of BU+HIV+ patients was 750 copies /ml (95% CI 0–398,000) versus 500 copies/ml (95% CI 0–126,855,500) in BU+HIV− group. Similarly, the median count using the IS2404 assay was 500 copies/ml (95% CI 0–500) for BU+HIV+ patients versus 500 copies/ml (95% CI 500–31,000) for BU+HIV− patients. BU+HIV− patients mounted a significantly higher interferon-γ response compared to the BU+HIV+ co-infected patients with respective median (range) responses of [1687(81.11–4399) pg/ml] versus [137.5(4.436–1406) pg/ml, p = 0.03]. There were challenges with the integration of HIV and BU care in this cohort. Conclusion The prevalence of HIV in the BU+ infected population was not significantly increased when compared to the prevalence of HIV in the general population. There was no clear relationship between BU lesion severity and HIV viral load or CD4 counts. Efforts should be made to encourage the integration of care of patients with BU-HIV coinfection.

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Efficacy of the Combination Rifampin-Streptomycin in Preventing Growth of Mycobacterium ulcerans in Early Lesions of Buruli Ulcer in Humans

Antimicrobial Agents and Chemotherapy ◽

10.1128/aac.49.8.3182-3186.2005 ◽

2005 ◽

Vol 49 (8) ◽

pp. 3182-3186 ◽

Cited By ~ 167

Author(s):

S. Etuaful ◽

B. Carbonnelle ◽

J. Grosset ◽

S. Lucas ◽

C. Horsfield ◽

...

Keyword(s):

Body Weight ◽

Antibiotic Therapy ◽

Antibiotic Treatment ◽

Buruli Ulcer ◽

Surgical Excision ◽

Skin Lesions ◽

Mycobacterium Ulcerans ◽

Early Lesions ◽

Culture Positive ◽

Culture Negative

ABSTRACT Mycobacterium ulcerans disease is common in some humid tropical areas, particularly in parts of West Africa, and current management is by surgical excision of skin lesions ranging from early nodules to extensive ulcers (Buruli ulcer). Antibiotic therapy would be more accessible to patients in areas of Buruli ulcer endemicity. We report a study of the efficacy of antibiotics in converting early lesions (nodules and plaques) from culture positive to culture negative. Lesions were excised either immediately or after treatment with rifampin orally at 10 mg/kg of body weight and streptomycin intramuscularly at 15 mg/kg of body weight daily for 2, 4, 8, or 12 weeks and examined by quantitative bacterial culture, PCR, and histopathology for M. ulcerans. Lesions were measured during treatment. Five lesions excised without antibiotic treatment and five lesions treated with antibiotics for 2 weeks were culture positive, whereas three lesions treated for 4 weeks, five treated for 8 weeks, and three treated for 12 weeks were culture negative. No lesions became enlarged during antibiotic treatment, and most became smaller. Treatment with rifampin and streptomycin for 4 weeks or more inhibited growth of M. ulcerans in human tissue, and it provides a basis for proceeding to a trial of antibiotic therapy as an alternative to surgery for early M. ulcerans disease.

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HIGH RATES OF APOPTOSIS IN HUMAN MYCOBACTERIUM ULCERANS CULTURE-POSITIVE BURULI ULCER SKIN LESIONS

American Journal of Tropical Medicine and Hygiene ◽

10.4269/ajtmh.2005.73.410 ◽

2005 ◽

Vol 73 (2) ◽

pp. 410-415 ◽

Cited By ~ 26

Author(s):

DOUGLAS S. WALSH ◽

KITTINUN HUSSEM ◽

PANITA GOSI ◽

KHIN SAW AYE MYINT ◽

WAYNE M. MEYERS ◽

...

Keyword(s):

Buruli Ulcer ◽

Skin Lesions ◽

Mycobacterium Ulcerans ◽

Culture Positive

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CLINICAL AND HISTOLOGIC FEATURES OF SKIN LESIONS IN A CYNOMOLGUS MONKEY EXPERIMENTALLY INFECTED WITH MYCOBACTERIUM ULCERANS (BURULI ULCER) BY INTRADERMAL INOCULATION

American Journal of Tropical Medicine and Hygiene ◽

10.4269/ajtmh.2007.76.132 ◽

2007 ◽

Vol 76 (1) ◽

pp. 132-134 ◽

Cited By ~ 16

Author(s):

DOUGLAS S. WALSH ◽

WAYNE M. MEYERS ◽

RODOLFO M. ABALOS ◽

FRANÇOISE PORTAELS ◽

EDUARDO C. DELA CRUZ ◽

...

Keyword(s):

Cynomolgus Monkey ◽

Buruli Ulcer ◽

Skin Lesions ◽

Mycobacterium Ulcerans

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Enhanced immune response and protection efficacy of a DNA vaccine constructed by linkage of the Mycobacterium tuberculosis Ag85B-encoding gene with the BVP22-encoding gene

Journal of Medical Microbiology ◽

10.1099/jmm.0.004267-0 ◽

2009 ◽

Vol 58 (4) ◽

pp. 462-468 ◽

Cited By ~ 6

Author(s):

Wanhong Yao ◽

Shengwu Liu ◽

Xueju Qu ◽

Shaobo Xiao ◽

Yan Liu ◽

...

Keyword(s):

Immune Response ◽

Mycobacterium Tuberculosis ◽

Dna Vaccine ◽

Plasmid Dna ◽

Histopathological Examination ◽

Protective Efficacy ◽

Bacterial Load ◽

Dna Encoding ◽

Promising Tool ◽

Encoding Gene

Plasmid DNA vaccines have been widely explored for use in tuberculosis immunization but their immunogenicity needs improvement. In the present study, we incorporated the bovine herpesvirus 1 VP22 (BVP22)-encoding gene, which encodes a protein that demonstrates a capability for disseminating the expressed antigen to neighbouring cells, into a DNA vector in which it was fused to the Ag85B-encoding gene of Mycobacterium tuberculosis (Mtb), and investigated whether this linkage could enhance immune response and protective efficacy in C57BL/6 mice compared to plasmid DNA encoding Ag85B alone. After immunization in mice, Ag85B-specific ELISA antibodies and spleen lymphocyte proliferative responses induced by DNA co-expressing BVP22 and Ag85B were significantly higher than those obtained in mice immunized with Ag85B-encoding DNA alone, except for the number of gamma interferon secreting cells. In addition, based on histopathological examination and bacterial-load determination in lung and spleen, protection against intravenous Mtb H37Rv challenge evoked by the BVP22–Ag85B DNA immunization exceeded the response elicited by Ag85B DNA alone, which was not significantly different from that provided by Bacillus Calmette–Guérin (BCG). These results suggested that DNA vaccine consisting of BVP22 and Ag85B-encoding DNA enhanced immune response and protection against intravenous Mtb H37Rv challenge in mice, indicating that BVP22-encoding DNA might be a promising tool to enhance TB DNA vaccine efficacy.

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Chronic wounds in Sierra Leone: Searching for Buruli ulcer, a NTD caused by Mycobacterium ulcerans, at Masanga Hospital

PLoS Neglected Tropical Diseases ◽

10.1371/journal.pntd.0009862 ◽

2021 ◽

Vol 15 (10) ◽

pp. e0009862

Author(s):

Helen R. Please ◽

Jonathan H. Vas Nunes ◽

Rashida Patel ◽

Gerd Pluschke ◽

Mohamed Tholley ◽

...

Keyword(s):

Sierra Leone ◽

Chronic Wounds ◽

Financial Burden ◽

Bacterial Load ◽

Buruli Ulcer ◽

Mycobacterium Ulcerans ◽

Lower Limbs ◽

World Health ◽

High Morbidity ◽

Surgical Interventions

Background Chronic wounds pose a significant healthcare burden in low- and middle-income countries. Buruli ulcer (BU), caused by Mycobacterium ulcerans infection, causes wounds with high morbidity and financial burden. Although highly endemic in West and Central Africa, the presence of BU in Sierra Leone is not well described. This study aimed to confirm or exclude BU in suspected cases of chronic wounds presenting to Masanga Hospital, Sierra Leone. Methodology Demographics, baseline clinical data, and quality of life scores were collected from patients with wounds suspected to be BU. Wound tissue samples were acquired and transported to the Swiss Tropical and Public Health Institute, Switzerland, for analysis to detect Mycobacterium ulcerans using qPCR, microscopic smear examination, and histopathology, as per World Health Organization (WHO) recommendations. Findings Twenty-one participants with wounds suspected to be BU were enrolled over 4-weeks (Feb-March 2019). Participants were predominantly young working males (62% male, 38% female, mean 35yrs, 90% employed in an occupation or as a student) with large, single, ulcerating wounds (mean diameter 9.4cm, 86% single wound) exclusively of the lower limbs (60% foot, 40% lower leg) present for a mean 15 months. The majority reported frequent exposure to water outdoors (76%). Self-reports of over-the-counter antibiotic use prior to presentation was high (81%), as was history of trauma (38%) and surgical interventions prior to enrolment (48%). Regarding laboratory investigation, all samples were negative for BU by microscopy, histopathology, and qPCR. Histopathology analysis revealed heavy bacterial load in many of the samples. The study had excellent participant recruitment, however follow-up proved difficult. Conclusions BU was not confirmed as a cause of chronic ulceration in our cohort of suspected cases, as judged by laboratory analysis according to WHO standards. This does not exclude the presence of BU in the region, and the definitive cause of these treatment-resistance chronic wounds is uncertain.

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