Buruli ulcer: Mycobacterium ulcerans infection

2010 ◽  
pp. 848-850
Author(s):  
Wayne M. Meyers ◽  
Bouke de Jong ◽  
Françoise Portaels
Keyword(s):  
South America ◽  
East Asia ◽  
Subcutaneous Tissue ◽  
Buruli Ulcer ◽  
Central Africa ◽  
Mycobacterium Ulcerans ◽  
South East Asia ◽  
Tropical Wetlands ◽  
West And Central Africa ◽  
Water Vegetation

Buruli ulcer is caused by Mycobacterium ulcerans, which secretes a cytotoxic and immunosuppressive toxin, mycolactone. The disease is characterized by necrosis of skin, subcutaneous tissue, and bone, and is re-emerging as a potentially disabling affliction of inhabitants of tropical wetlands. Major foci are in West and Central Africa, but there are minor endemic foci in Australia, Mexico, South America, and South-East Asia. It is not contagious; environmental sources include water, vegetation, and insects, with humans probably becoming infected by traumatic introduction of the bacillus into the skin from the overlying ...

Buruli ulcer: Mycobacterium ulcerans infection

2020 ◽  
pp. 1167-1170
Author(s):  
Bouke de Jong ◽  
Françoise Portaels ◽  
Wayne M. Meyers
Keyword(s):  
Polymerase Chain Reaction ◽  
Subcutaneous Tissue ◽  
Buruli Ulcer ◽  
Central Africa ◽  
Skin Grafting ◽  
Surgical Excision ◽  
Mycobacterium Ulcerans ◽  
West And Central Africa ◽  
Cutaneous Nodule ◽  
Polymerase Chain

Buruli ulcer is caused by Mycobacterium ulcerans, which secretes a cytotoxic and immunosuppressive toxin, mycolactone. The disease is characterized by necrosis of skin, subcutaneous tissue, and bone, and is re-emerging as a potentially disabling affliction of inhabitants of tropical wetlands. Major foci are in West and Central Africa with an increasing focus in Australia, Mexico, South America, and Southeast Asia. It is not contagious; environmental sources include water, vegetation, and insects, with humans probably becoming infected by traumatic introduction of the bacillus into the skin from the overlying M. ulcerans-contaminated surface in most instances. Clinical presentation may be as a cutaneous nodule, undermined ulcer, plaque, or widely disseminated oedematous lesion. Clinical diagnosis is often accurate by experienced clinicians, and smears for acid-fast bacilli, culture, polymerase chain reaction assays, and histopathology are confirmatory. Treatment was formerly by wide surgical excision and skin grafting, yet antibiotics have now been found effective, including an all-oral regimen.

scholarly journals Buruli Ulcer (Acha-ere): Pathogenesis and Manifestation

2019 ◽  
pp. 1-5
Author(s):  
Elendu C. Onwuchekwa ◽  
Uzochukwu G. Ekeleme ◽  
Oliver Onu-Osi ◽  
Okonudo P. Osezele
Keyword(s):  
Subcutaneous Tissue ◽  
Buruli Ulcer ◽  
Central Africa ◽  
Mycobacterium Ulcerans ◽  
Actin Dynamics ◽  
Tropical Regions ◽  
West And Central Africa ◽  
Chronic Skin ◽  
Pass Through ◽  
Syndrome Protein

Infection of subcutaneous tissue with Mycobacterium ulcerans can lead to chronic skin ulceration known as Buruli ulcer. It has been reported in over 33 countries around the world, the greatest burden of disease is in the tropical regions of West and Central Africa, Australia, and Japan. It primarily affects children aged 5-15 years. Buruli ulcers generally begin as a painless dermal papule or subcutaneous edematous nodule, which over a period of weeks to months, breaks down to form an extensive necrotic ulcer with undermined edges. The pathogenesis of this neglected tropical disease is dependent on a lipidlike toxin, mycolactone, which diffuses through tissue away from the infecting organisms and elucidate its cytotoxic and immunosuppressive properties. The underlying molecular targets for mycolactone are: First, it can target scaffolding proteins (such as Wiskott Aldrich Syndrome Protein), which control actin dynamics in adherent cells and therefore lead to detachment and cell death. Second, it prevents the co-translational translocation (and therefore production) of many proteins that pass through the endoplasmic reticulum for secretion or placement in cell membranes.  Treatment includes a prolonged course of antibiotics and surgical debridement. Early identification and treatment are key, as lesions heal with scarring that can be a significant source of morbidity.

scholarly journals Genotyping Mycobacterium ulcerans and Mycobacterium marinum by Using Mycobacterial Interspersed Repetitive Units

2005 ◽  
Vol 187 (5) ◽  
pp. 1639-1647 ◽  
Author(s):  
Pieter Stragier ◽  
Anthony Ablordey ◽  
Wayne M. Meyers ◽  
Françoise Portaels
Keyword(s):  
Tandem Repeats ◽  
Central Africa ◽  
Mycobacterium Ulcerans ◽  
Pathogenic Species ◽  
Missing Link ◽  
Potential Value ◽  
Related Organism ◽  
Geographic Origins ◽  
West And Central Africa ◽  
Unique Genotype

ABSTRACT A novel category of variable tandem repeats (VNTR) called mycobacterial interspersed repetitive units (MIRUs) has been identified for Mycobacterium ulcerans (n = 39), M. marinum (n = 27), and one related organism. Fifteen MIRU loci were identified in the genome of M. marinum and were used to genotype M. ulcerans, M. marinum, and an M. marinum-like organism that is considered a possible missing link between M. marinum and M. ulcerans. Seven MIRU loci were polymorphic, and locus-specific PCRs for four of these loci differentiated seven M. ulcerans genotypes, four M. marinum genotypes, and a unique genotype for the missing link organism. The seven M. ulcerans genotypes were related to six different geographic origins of isolates. All isolates from West and Central Africa, including old and recent isolates, belonged to the same genotype, emphasizing the great spatiotemporal homogeneity among African isolates. Unlike the M. ulcerans genotypes, the four M. marinum genotypes could not be clearly related to the geographic origins of the isolates. According to MIRU-VNTR typing, all M. ulcerans and M. marinum isolates of American origin were closely related, suggesting a common American ancestor for these two pathogenic species on the American continents. MIRU typing has significant potential value for discriminating between reoccurrence and reinfection for M. ulcerans disease.

scholarly journals Advances in the Treatment of Yaws

2018 ◽  
Vol 3 (3) ◽  
pp. 92 ◽  
Author(s):  
Michael Marks
Keyword(s):  
Soft Tissues ◽  
Central Africa ◽  
Standard Of Care ◽  
World Health ◽  
South East Asia ◽  
The Pacific ◽  
West And Central Africa ◽  
Resistance To Penicillin ◽  
Health Organization ◽  
Oral Azithromycin

Yaws is one of the three endemic treponematoses and is recognised by the World Health Organization as a neglected tropical disease. Yaws is currently reported in 15 countries in the Pacific, South-East Asia, West and Central Africa, predominantly affects children, and results in destructive lesions of the skin and soft tissues. For most of the twentieth century penicillin-based treatment was the standard of care and resistance to penicillin has still not been described. Recently, oral azithromycin has been shown to be an effective treatment for yaws, facilitating renewed yaws eradication efforts. Resistance to azithromycin is an emerging threat and close surveillance will be required as yaws eradication efforts are scaled up globally.

scholarly journals Mycobacterium ulcerans Population Genomics To Inform on the Spread of Buruli Ulcer across Central Africa

mSphere ◽  
2019 ◽  
Vol 4 (1) ◽  
Author(s):  
Koen Vandelannoote ◽  
Delphin Mavinga Phanzu ◽  
Kapay Kibadi ◽  
Miriam Eddyani ◽  
Conor J. Meehan ◽  
...  
Keyword(s):  
Disease Control ◽  
Population Genomics ◽  
Demographic History ◽  
Buruli Ulcer ◽  
Central Africa ◽  
Mycobacterium Ulcerans ◽  
Evolutionary Trajectory ◽  
Content Type ◽  
Mode Of Transmission ◽  
The Impact

ABSTRACT Buruli ulcer is a neglected tropical disease of skin and subcutaneous tissue caused by infection with the pathogen Mycobacterium ulcerans. Many critical issues for disease control, such as understanding the mode of transmission and identifying source reservoirs of M. ulcerans, are still largely unknown. Here, we used genomics to reconstruct in detail the evolutionary trajectory and dynamics of M. ulcerans populations at a central African scale and at smaller geographical village scales. Whole-genome sequencing (WGS) data were analyzed from 179 M. ulcerans strains isolated from all Buruli ulcer foci in the Democratic Republic of the Congo, The Republic of Congo, and Angola that have ever yielded positive M. ulcerans cultures. We used both temporal associations and the study of the mycobacterial demographic history to estimate the contribution of humans as a reservoir in Buruli ulcer transmission. Our phylogeographic analysis revealed one almost exclusively predominant sublineage of M. ulcerans that arose in Central Africa and proliferated in its different regions of endemicity during the Age of Discovery. We observed how the best sampled endemic hot spot, the Songololo territory, became an area of endemicity while the region was being colonized by Belgium (1880s). We furthermore identified temporal parallels between the observed past population fluxes of M. ulcerans from the Songololo territory and the timing of health policy changes toward control of the Buruli ulcer epidemic in that region. These findings suggest that an intervention based on detecting and treating human cases in an area of endemicity might be sufficient to break disease transmission chains, irrespective of other reservoirs of the bacterium. IMPORTANCE Buruli ulcer is a destructive skin and soft tissue infection caused by Mycobacterium ulcerans. The disease is characterized by progressive skin ulceration, which can lead to permanent disfigurement and long-term disability. Currently, the major hurdles facing disease control are incomplete understandings of both the mode of transmission and environmental reservoirs of M. ulcerans. As decades of spasmodic environmental sampling surveys have not brought us much closer to overcoming these hurdles, the Buruli ulcer research community has recently switched to using comparative genomics. The significance of our research is in how we used both temporal associations and the study of the mycobacterial demographic history to estimate the contribution of humans as a reservoir in Buruli ulcer transmission. Our approach shows that it might be possible to use bacterial population genomics to assess the impact of health interventions, providing valuable feedback for managers of disease control programs in areas where health surveillance infrastructure is poor.

Gliding Mammals of the World

2012 ◽  
Author(s):  
Stephen Jackson ◽  
Peter Schouten
Keyword(s):  
North America ◽  
East Asia ◽  
Central Africa ◽  
The Philippines ◽  
South East Asia ◽  
Horizontal Distance ◽  
Distribution Map ◽  
Flying Squirrels ◽  
The World ◽  
First Time

The world's gliding mammals are an extraordinary group of animals that have the ability to glide from tree to tree with seemingly effortless grace. There are more than 60 species of gliding mammals including the flying squirrels from Asia, Europe and North America, the scaly-tailed flying squirrels from central Africa and the gliding possums of Australia and New Guinea. But the most spectacular of all are the colugos – or so called flying lemurs – that occur throughout South-East Asia and the Philippines. Animals that glide from tree to tree descend at an angle of less than 45 degrees to the horizontal, while those that parachute descend at an angle greater than 45 degrees. Gliding is achieved by deflecting air flowing past well-developed gliding membranes, or patagia, which form an effective airfoil that allows the animal to travel the greatest possible horizontal distance with the least loss in height. The flying squirrels and scaly-tailed flying squirrels even have special cartilaginous spurs that extend either from the wrist or elbow, respectively, to help support the gliding membrane. Gliding Mammals of the World provides, for the first time, a synthesis of all that is known about the biology of these intriguing mammals. It includes a brief description of each species, together with a distribution map and a beautiful full-colour painting. An introduction outlines the origins and biogeography of each group of gliding mammals and examines the incredible adaptations that allow them to launch themselves and glide from tree to tree.

scholarly journals Mycobacterium ulcerans infection (Buruli ulcer) in French Guiana, South America, 1969–2013: an epidemiological study

2017 ◽  
Vol 1 (2) ◽  
pp. e65-e73 ◽  
Author(s):  
Maylis Douine ◽  
Rodolphe Gozlan ◽  
Mathieu Nacher ◽  
Julie Dufour ◽  
Yann Reynaud ◽  
...  
Keyword(s):  
South America ◽  
Epidemiological Study ◽  
French Guiana ◽  
Buruli Ulcer ◽  
Mycobacterium Ulcerans

Phylogeny of the Hebe Complex (Scrophulariaceae: Veroniceae)

1993 ◽  
Vol 6 (5) ◽  
pp. 457 ◽  
Author(s):  
PJ Garnock-Jones
Keyword(s):  
New Zealand ◽  
South America ◽  
East Asia ◽  
Cladistic Analysis ◽  
New Guinea ◽  
South East Asia ◽  
New Combinations ◽  
Vegetation Types ◽  
Dispersal Events ◽  
Occurrence Of Species

The southern segregates of Veronica (Hebe, Parahebe, Chionohebe, Dementia, and Detzneria) form a monophyletic assemblage of c. 144 species found in New Guinea, Australia, New Zealand, Rapa, and South America. Most of the species occur in New Zealand, where Hebe is the largest genus and a characteristic member of many vegetation types. Cladistic analysis of the Hebe complex, based on 45 characters and 22 terminal taxa, indicates that: (1) Hebe is monophyletic if Hebe 'Paniculatae' is excluded and H. formosa is included; (2) Parahebe is paraphyletic; (3) Chionohebe is monophyletic, but is part of a larger clade which includes alpine Parahebe and possibly the monotypic Detzneria; (4) Hebe 'Paniculatae', Derwentia, and New Guinea Parahebe are monophyletic basal groups in the complex. According to this study, recognition of monophyletic genera would require six genera in the complex, supporting the recognition of Derwentia and separation of Hebe 'Paniculatae' from Hebe. Leonohebe Heads is considered polyphyletic and is not accepted; new combinations are provided for two species of Leonohebe with no name at species rank in Hebe. Competing biogeographic hypotheses have implied (1) a Gondwanan origin, or (2) migration from South-east Asia via New Guinea. An origin in Australasia from Asian ancestors best explains the topology of the basal parts of the cladogram, but at least seven dispersal events from New Zealand are postulated to explain the occurrence of species of Hebe in South America and Rapa and Parahebe, Hebe, and Chionohebe in Australia. An hypothesis which did not allow dispersal would require that nearly all the evolution in the complex occurred before the Tertiary, and hardly any since.

Sign in / Sign up

Export Citation Format

Share Document