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Medical Mycology Jul 2022Eumycetoma is a neglected tropical infection of the subcutaneous tissue, characterized by tumor-like lesions and most commonly caused by the fungus Madurella...
UNLABELLED
Eumycetoma is a neglected tropical infection of the subcutaneous tissue, characterized by tumor-like lesions and most commonly caused by the fungus Madurella mycetomatis. In the tissue, M. mycetomatis organizes itself in grains, and within a single lesion, thousands of grains can be present. The current hypothesis is that all these grains originate from a single causative agent, however, this hypothesis was never proven. Here, we used our recently developed MmySTR assay, a highly discriminative typing method, to determine the genotypes of multiple grains within a single lesion. Multiple grains from surgical lesions obtained from 11 patients were isolated and genotyped using the MmySTR panel. Within a single lesion, all tested grains shared the same genotype. Only in one single grain from one patient, a difference of one repeat unit in one MmySTR marker was noted relative to the other grains from that patient. We conclude that within these lesions the grains originate from a single clone and that the inherent unstable nature of the microsatellite markers may lead to small genotypic differences.
LAY ABSTRACT
In lesions of the implantation mycosis mycetoma many Madurella mycetomatis grains are noted. It was unknown if grains arose after implantation of a single isolate or a mixture of genetically diverse isolates. By typing the mycetoma grains we showed that all grains within a single lesion were clonal and originated from a single isolate.
Topics: Animals; Genotype; Madurella; Mycetoma
PubMed: 35833294
DOI: 10.1093/mmy/myac051 -
Medical Mycology Feb 2022Eumycetoma is a neglected tropical disease, and Madurella mycetomatis, the most common causative agent of this disease forms black grains in hosts. Melanin was...
UNLABELLED
Eumycetoma is a neglected tropical disease, and Madurella mycetomatis, the most common causative agent of this disease forms black grains in hosts. Melanin was discovered to be one of the constituents in grains. Melanins are hydrophobic, macromolecular pigments formed by oxidative polymerisation of phenolic or indolic compounds. M. mycetomatis was previously known to produce DHN-melanin and pyomelanin in vitro. These melanin was also discovered to decrease M. mycetomatis's susceptibility to antifungals itraconazole and ketoconazole in vitro. These findings, however, have not been confirmed in vivo. To discover the melanin biosynthesis pathways used by M. mycetomatis in vivo and to determine if inhibiting melanin production would increase M. mycetomatis's susceptibility to itraconazole, inhibitors targeting DHN-, DOPA- and pyomelanin were used. Treatment with DHN-melanin inhibitors tricyclazole, carpropamid, fenoxanil and DOPA-melanin inhibitor glyphosate in M. mycetomatis infected Galleria mellonella larvae resulted in presence of non-melanized grains. Our finding suggested that M. mycetomatis is able to produce DOPA-melanin in vivo. Inhibiting DHN-melanin with carpropamid in combination with the antifungal itraconazole also significantly increased larvae survival. Our results suggested that combination treatment of antifungals and melanin inhibitors can be an alternative treatment strategy that can be further explored. Since the common black-grain eumycetoma causing agents uses similar melanin biosynthesis pathways, this strategy may be applied to them and other eumycetoma causative agents.
LAY SUMMARY
Melanin protects fungi from environmental stress and antifungals. We have discovered that Madurella mycetomatis produces DHN-, pyomelanin and DOPA-melanin in vivo. Inhibiting M. mycetomatis DHN-melanin biosynthesis increases therapeutic value of the antifungal itraconazole in vivo.
Topics: Animals; Antifungal Agents; Dihydroxyphenylalanine; Itraconazole; Madurella; Mycetoma
PubMed: 35064672
DOI: 10.1093/mmy/myac003 -
PLoS Neglected Tropical Diseases Aug 2022Eumycetoma is a chronic debilitating fungal disease endemic to tropical and subtropical regions, with Sudan featuring the highest eumycetoma incidence. Among the 50...
Eumycetoma is a chronic debilitating fungal disease endemic to tropical and subtropical regions, with Sudan featuring the highest eumycetoma incidence. Among the 50 species of fungi most commonly associated with eumycetoma Madurella mycetomatis (M. mycetomatis) is often referenced as the most common pathogen. However, there is an enormous knowledge gap related to this neglected disease and its pathogenesis, epidemiological features, and host-specific factors that could contribute to either the host susceptibility and resistance. In this study, we were able to utilize a metagenomic approach and samples collected from clinical black grains (BG) and familiar household environments aimed to assay both the habitat of eumycetoma-associated fungi and its possible connection with eumycetoma patients living in two different eumycetoma endemic villages within the White Nile State of Sudan. DNA sequencing targeting the fungal ITS2 domain was performed on soil, animal dung, housing walls and roofs, and Acacia-species thorn samples and compared with culture-dependent methods of fungal isolation. Additionally, we compared the soil samples obtained in the endemic zone with that from non-endemic zones, including Wagga village in Kassala State and Port Sudan suburb in Port Sudan State. Overall, a total of 392 Amplicon Sequence Variants (ASVs) were detected by ITS2 metagenomics Eumycetoma causative organisms accounted for 10% of total ASVs which included 11 genera: Exserohilum (2%), Aspergillus (1.7%), Curvularia (1%), Alternaria (0.9%), Madurella (0.5%), Fusarium (0.4%), Cladosporium (0.2%) Exophiala (0.15%), and, in a lesser extent, Microascus (0.05%) Bipolaris and Acremonium (0.01%) for each. Only five genera were identified by culture method, which included Fusarium (29%), Aspergillus (28%), Alternaria (2.5%), Bipolaris (1.6%), and Chaetomium (0.8%). M. mycetomatis was detected within all the studied patients' houses, accounting for 0.7% of total sequences. It was the first common eumycetoma-associated agent detected in soil samples and the third common in the dung and wall samples. In contrast, it was not detected in the roof or thorn samples nor in the soils from non-endemic regions. Exserohilum rostratum, Aspergillus spp and Cladosporium spp were detected in all samples. M. mycetomatis and other eumycetoma-associated fungal identified in the patients' black grains (BG) samples by metagenomics were identified in the environmental samples. Only Acremonium alternatum and Falciformispora senegalensis, responsible for eumycetoma in two patients were not detected, suggesting the infections in these patients happened outside these endemic areas. The soil, animal dung, and houses built from the same soil and dung are the main risk factors for M. mycetomatis infection in these endemic villages. Furthermore, the poor hygienic and environmental conditions, walking barefooted, and the presence of animals within the houses increase the risk of M. mycetomatis and other fungi causing eumycetoma.
Topics: Animals; Madurella; Metagenomics; Mycetoma; Neglected Diseases; Soil
PubMed: 36040926
DOI: 10.1371/journal.pntd.0010385 -
Antimicrobial Agents and Chemotherapy Feb 2021We present an susceptibility assay for hyphae using resazurin for endpoint reading. Using this assay, reproducible MICs were obtained for amphotericin B, itraconazole,...
We present an susceptibility assay for hyphae using resazurin for endpoint reading. Using this assay, reproducible MICs were obtained for amphotericin B, itraconazole, voriconazole, posaconazole, terbinafine, and micafungin. Results were comparable with those of a 2,3-bis-(2-methoxy-4-nitro-5-sulfophenyl)-2-tetrazolium-5-carboxanilide salt (XTT)-based susceptibility assay. The lowest MICs were obtained for itraconazole and posaconazole (MIC, 0.016 µg/ml) followed by voriconazole (MIC, 0.063 µg/ml). Amphotericin B, micafungin, and terbinafine appeared much less effective.
Topics: Antifungal Agents; Itraconazole; Madurella; Microbial Sensitivity Tests; Oxazines; Voriconazole; Xanthenes
PubMed: 33318015
DOI: 10.1128/AAC.01338-20 -
Antimicrobial Agents and Chemotherapy Aug 2021For many fungal infections, susceptibility testing is used to predict if an isolate is resistant or susceptible to the antifungal agent used to treat the infection. For...
For many fungal infections, susceptibility testing is used to predict if an isolate is resistant or susceptible to the antifungal agent used to treat the infection. For Madurella mycetomatis, the main causative agent of mycetoma, susceptibility testing currently is not performed on a routine basis. The current susceptibility testing method is labor-intensive, and sonication must be done to generate a hyphal inoculum. For endpoint visualization, expensive viability dyes are needed. Here, we investigated if the currently used susceptibility method could be adapted to make it amendable for use in a routine setting which can be used in low-income countries, where mycetoma is endemic. First, we developed a methodology in which hyphal fragments can be generated without the need for sonication, by comparing different bead beating methodologies. Next, susceptibility was assessed using standard broth microdilution assays as well as disc diffusion, Etest, and VIPcheck methodologies. We demonstrate that after a hyphal suspension is generated by glass bead beating, disc diffusion, Etest, and VIPcheck can be used to determine susceptibility of Madurella mycetomatis to itraconazole, posaconazole, and voriconazole. The MICs found with Etest were comparable to those obtained with our modified CLSI-based broth microdilution susceptibility assay for itraconazole and posaconazole. Furthermore, we found an inverse relationship between the zones of inhibition and MICs obtained with the Etest and those obtained by the modified CLSI broth microdilution technique.
Topics: Antifungal Agents; Disk Diffusion Antimicrobial Tests; Itraconazole; Madurella; Microbial Sensitivity Tests; Triazoles; Voriconazole
PubMed: 34181477
DOI: 10.1128/AAC.00433-21 -
Revista Espanola de Quimioterapia :... Dec 2022
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Mycopathologia Dec 2018Mycetoma is a chronic inflammatory process caused either by fungi (eumycetoma) or bacteria (actinomycetoma). In this retrospective study, we report epidemiologic and...
BACKGROUND
Mycetoma is a chronic inflammatory process caused either by fungi (eumycetoma) or bacteria (actinomycetoma). In this retrospective study, we report epidemiologic and histopathological data of mycetoma observed in the Lome Hospital, Togo in a 25-year period (1992-2016).
METHODOLOGY
This is a retrospective study, over a period of 25 years, to analyze epidemiological and etiological findings of mycetomas seen in the single laboratory of pathological anatomy of the Lomé, Togo.
RESULTS
A total of 61 cases were retrieved from which only 33 cases were included which where clinically and microbiologically confirmed. The mean age of the patients was 29.7 ± 1.34 and a sex ratio (M/F) of 1.5. The majority of patients were farmers (n = 23 cases; 69.7%). Diagnosed etiologic agents were fungal in 24 cases (72.7%) and actinomycotic cases in 9 cases (27.3%). The fungal mycetomas consisted of Madurella mycetomatis (black grains) and Falcifomispora senegaliensis (black grains). The actinomycotic agents were represented by Actinomadura madurae (white grains), Actinomadurae pelletieri (red grains) and Nocardia sp. (yellow grains).
CONCLUSION
This report represents a single-center study which provides epidemiologic and histopathological data of mycetoma cases in Togo.
Topics: Actinobacteria; Adolescent; Adult; Aged; Child; Cross-Sectional Studies; Female; Fungi; Histocytochemistry; Hospitals; Humans; Male; Middle Aged; Mycetoma; Retrospective Studies; Togo; Young Adult
PubMed: 29557534
DOI: 10.1007/s11046-018-0260-y -
Persoonia Dec 2014Eumycetoma is a chronic fungal infection characterised by large subcutaneous masses and the presence of sinuses discharging coloured grains. The causative agents of...
Eumycetoma is a chronic fungal infection characterised by large subcutaneous masses and the presence of sinuses discharging coloured grains. The causative agents of black-grain eumycetoma mostly belong to the orders Sordariales and Pleosporales. The aim of the present study was to clarify the phylogeny and taxonomy of pleosporalean agents, viz. Madurella grisea, Medicopsis romeroi (syn.: Pyrenochaeta romeroi), Nigrograna mackinnonii (syn. Pyrenochaeta mackinnonii), Leptosphaeria senegalensis, L. tompkinsii, and Pseudochaetosphaeronema larense. A phylogenetic analysis based on five loci was performed: the Internal Transcribed Spacer (ITS), large (LSU) and small (SSU) subunit ribosomal RNA, the second largest RNA polymerase subunit (RPB2), and translation elongation factor 1-alpha (TEF1) gene. In addition, the morphological and physiological characteristics were determined. Three species were well-resolved at the family and genus level. Madurella grisea, L. senegalensis, and L. tompkinsii were found to belong to the family Trematospheriaceae and are reclassified as Trematosphaeria grisea comb. nov., Falciformispora senegalensis comb. nov., and F. tompkinsii comb. nov. Medicopsis romeroi and Pseudochaetosphaeronema larense were phylogenetically distant and both names are accepted. The genus Nigrograna is reduced to synonymy of Biatriospora and therefore N. mackinnonii is reclassified as B. mackinnonii comb. Nov. Mycetoma agents in Pleosporales were phylogenetically quite diverse despite their morphological similarity in the formation of pycnidia, except for the ascosporulating genus Falciformispora (formerly in Leptosphaeria). Most of the species diagnosed from human mycetoma were found to be related to waterborne or marine fungi, suggesting an association of the virulence factors with oligotrophism or halotolerance.
PubMed: 25737597
DOI: 10.3767/003158514X684744 -
Medical Mycology Aug 2023Eumycetoma is a subcutaneous implantation mycosis often found in the foot. One of the hallmarks of eumycetoma is the formation of grains. These grains are either black...
Eumycetoma is a subcutaneous implantation mycosis often found in the foot. One of the hallmarks of eumycetoma is the formation of grains. These grains are either black or white, and the consistency and morphology differs per causative agent. The two most common causative agents of black-grain eumycetoma are Madurella mycetomatis and Falciformispora senegalensis. Since grains cannot be formed in vitro, in vivo models are needed to study grain formation. Here, we used the invertebrate Galleria mellonella to establish an in vivo grain model for F. senegalensis. Three different F. senegalensis strains were selected, and four different inocula were used to infect G. mellonella larvae, ranging from 0.04 mg/larvae to 10 mg/larvae. Larval survival was monitored for 10 days. Grain formation was studied macroscopically and histologically. The efficacy of antifungal therapy was determined for itraconazole, amphotericin B, and terbinafine. A concentration of 10 mg F. senegalensis per larva was lethal for the majority of the larvae within 10 days. At this inoculum, grains were formed within 24 h after infection. The grains produced in the larvae resembled those formed in human patients. Amphotericin B given at 1 mg/kg 4 h, 28 h, and 52 h after infection prolonged larval survival. No enhanced survival was noted for itraconazole or terbinafine. In conclusion, we developed a F. senegalensis grain model in G. mellonella larvae in which grains were formed that were similar to those formed in patients. This model can be used to monitor grain formation over time and study antifungal efficacy.
Topics: Humans; Animals; Antifungal Agents; Larva; Amphotericin B; Terbinafine; Itraconazole; Mycetoma; Disease Models, Animal; Moths
PubMed: 37451815
DOI: 10.1093/mmy/myad070 -
Acta Dermato-venereologica Mar 2015
Topics: Amputation, Surgical; Female; Foot Dermatoses; Humans; Madurella; Mycetoma; Pregnancy; Pregnancy Complications
PubMed: 25518866
DOI: 10.2340/00015555-2037