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Bacterial, Mycobacterial, and Spirochetal (Nonvenereal) Infections
Published in Ayşe Serap Karadağ, Lawrence Charles Parish, Jordan V. Wang, Roxburgh's Common Skin Diseases, 2022
Definition: There are over 190 different mycobacterial species, and most are innocuous; however, some of these species are pathogenic. Mycobacterial species, other than Mycobacterium tuberculosis and Mycobacterium leprae causing tuberculosis and leprosy respectively, are classified as atypical mycobacteria. There are a number of pathogenic atypical mycobacteria, such as Mycobacterium marinum and Mycobacterium ulcerans, which can lead to uncommon skin manifestations
Lower legs
Published in Richard Ashton, Barbara Leppard, Differential Diagnosis in Dermatology, 2021
Richard Ashton, Barbara Leppard
A Buruli ulcer begins as a firm, painless, subcutaneous nodule which either heals spontaneously or ulcerates. Ulcers can remain small and heal without treatment, or spread rapidly undermining the skin over large areas, even an entire limb. It is due to Mycobacterium ulcerans, which is found in waterbugs in swamps. The organism enters the skin through a cut or abrasion, usually in children who play in and around swamps in tropical Africa or Mexico. The diagnosis can be confirmed by taking a smear from the necrotic base of the ulcer and finding acid-fast bacilli on Ziehl-Neilson stain.
Wound healing and ulcers
Published in Ronald Marks, Richard Motley, Common Skin Diseases, 2019
Persistent infection with tuberculosis, Mycobacterium ulcerans or syphilis causes ulcerative conditions directly due to an infection. Any ulcerated area becomes contaminated by microbes in the environment and often this ‘secondary infection’ causes further tissue destruction.
wIRA: hyperthermia as a treatment option for intracellular bacteria, with special focus on Chlamydiae and Mycobacteria
Published in International Journal of Hyperthermia, 2020
Nicole Borel, Anna Maria Sauer-Durand, Mark Hartel, Jasmin Kuratli, Peter Vaupel, Nicole Scherr, Gerd Pluschke
Mycobacterium ulcerans produces the polyketide exotoxin mycolactone, which plays a key role in the pathogenesis of BU and has cytotoxic, analgesic, and immunosuppressive properties [37]. Exposure of different types of mammalian cells to low nanomolar concentrations of mycolactone A/B leads to cell death within 2–3 days [37]. While mycolactone is produced locally by the extracellular M. ulcerans bacteria in the skin, there is evidence that nontoxic concentrations in the periphery induce systemic immunosuppressive activity [38]. Macrophages and lymphocytes accumulate at the margin of the necrotic core of BU lesions, but infiltrating leukocytes seem to be killed by mycolactone surrounding the M. ulcerans clusters in the subcutaneous tissue [39]. Interference with the production of mycolactone may thus be sufficient for achieving therapeutic efficacy.
Thermal field formation during wIRA-hyperthermia: temperature measurements in skin and subcutis of piglets as a basis for thermotherapy of superficial tumors and local skin infections caused by thermosensitive microbial pathogens
Published in International Journal of Hyperthermia, 2019
Helmut Piazena, Werner Müller, Wolfgang Pendl, Sereina von Ah, Veronika H. Cap, Petra J. Hug, Xaver Sidler, Gerd Pluschke, Peter Vaupel
Respective therapeutic interventions use skin surface temperatures of about 40 °C in the ulcerated area for several hours per day for about 2 months. Temperatures above 37 °C are needed to inactivate and eliminate the pathogen in the infected tissue [31,32,34]. According to Ruf et al. [35] the causative thermosensitive pathogen Mycobacterium ulcerans is located at depths in the tissue up to about 13 mm. In contrast to the sole thermally based treatment [28–35], Kuratli et al. [36] have described nonthermal reduction of chlamydial infectivity by wIRA in combination with visible radiation. This thermotherapeutic concept, that is, eradication of thermosensitive bacteria by hyperthermia, has been described in detail recently [37–43].
State-of-the-art treatment strategies for nontuberculous mycobacteria infections
Published in Expert Opinion on Pharmacotherapy, 2020
Maria-Carmen Muñoz-Egea, Nerea Carrasco-Antón, Jaime Esteban
Despite the increasing number of recently developed antibiotics, as described above, there are still many issues that need to be solved to achieve better of patients with NTM diseases. More possibilities for the development of new molecules with activity against NTM are being studied. In this sense, the antimycobacterial activity of Micromeria barbata, Eucalyptus globulus, and Juniperus excelsa essential oils extracted from Lebanese plants was investigated against selected Mycobacterium spp. strains including Mycobacterium tuberculosis subsp. tuberculosis, multidrug-resistant M. tuberculosis, Mycobacterium kansasii, and Mycobacterium gordonae. All tested essential oils showed high antimycobacterial activity against targeted strains. Their data showed that M. barbata, E. globulus, and J. excelsa essential oils totally inhibit mycobacterial growth. This is the first study regarding the antimycobacterial activity of essential oils, and shows promising results, which encourages more investigation on these medicinal plants, especially M. barbata [114]. Currently, the anti-Mycobacterium ulcerans activity of some plants has been scientifically confirmed, including Ficus binjamina, Ficus elastica, Ficus saussureana, and Terminalia superba. Extracts of these plants have become important therapeutic developments in the treatment of Buruli ulcer [115]. Other anti-Mycobacterium ulcerans compounds are derived from Sorindeia juglandifolia and Holarrhena floribunda [116]. These studies show that natural products represent potential alternatives to standard therapies for use as curative medicine for M. ulcerans disease.