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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 -
Colloids and Surfaces. B, Biointerfaces Jun 2021In this study, a laccase from Madurella mycetomatis (MmLac) was produced heterologously in Pichia pastoris; the initial immobilization in a metal-organic framework (MOF)...
In this study, a laccase from Madurella mycetomatis (MmLac) was produced heterologously in Pichia pastoris; the initial immobilization in a metal-organic framework (MOF) (MmLac/ZIF-8) was achieved using zinc nitrate and 2-methylimidazole. Due to the instability of MmLac/ZIF-8 in an acidic medium, a silica layer was created on the surface of MmLac/MOF-8. The immobilized laccase composite (silica@MmLac/ZIF-8) obtained was further treated with glutaraldehyde (silica@Glu-MmLac/ZIF-8) to increase stability of composite. Fourier-transform infrared spectroscopy, X-ray diffraction and scanning electron microscopy techniques were used to confirm the immobilization of MmLac and to investigate the morphology of the immobilized laccase samples. The MmLac samples were also characterised in terms of optimum pH, temperature and thermal stability. The optimum pH of all the MmLac samples was determined to be 4.0. The free MmLac showed maximum activity at 55 °C, whereas both silica@MmLac/ZIF-8 and silica@Glu-MmLac/ZIF-8 were maximumly active at 65 °C. The silica@MmLac/ZIF-8 and silica@Glu-MmLac/ZIF-8 were 9.3- and 11.8-fold higher in stability, respectively, than the free MmLac at 65 °C. Furthermore, both silica@MmLac/ZIF-8 and silica@Glu-MmLac/ZIF-8 showed a higher bleaching performance than free MmLac on cotton woven fabric. According to these results, silica@MmLac/ZIF-8 and silica@Glu-MmLac/ZIF-8 may be promising candidates for biocatalysts in laccase-based biotechnological applications.
Topics: Enzyme Stability; Enzymes, Immobilized; Laccase; Madurella; Nanocomposites; Saccharomycetales; Silicon Dioxide
PubMed: 33690061
DOI: 10.1016/j.colsurfb.2021.111672 -
Medical Mycology Nov 2023Mycetoma is a neglected tropical disease commonly caused by the fungus Madurella mycetomatis. Standard treatment consists of extensive treatment with itraconazole in...
Mycetoma is a neglected tropical disease commonly caused by the fungus Madurella mycetomatis. Standard treatment consists of extensive treatment with itraconazole in combination with surgical excision of the infected tissue, but has a low success rate. To improve treatment outcomes, novel treatment strategies are needed. Here, we determined the potential of manogepix, a novel antifungal agent that targets the GPI-anchor biosynthesis pathway by inhibition of the GWT1 enzyme. Manogepix was evaluated by determining the minimal inhibitory concentrations (MICs) according to the CLSI-based in vitro susceptibility assay for 22 M. mycetomatis strains and by in silico protein comparison of the target protein. The synergy between manogepix and itraconazole was determined using a checkerboard assay. The efficacy of clinically relevant dosages was assessed in an in vivo grain model in Galleria mellonella larvae. MICs for manogepix ranged from <0.008 to >8 mg/l and 16/22 M. mycetomatis strains had an MIC ≥4 mg/ml. Differences in MICs were not related to differences observed in the GWT1 protein sequence. For 70% of the tested isolates, synergism was found between manogepix and itraconazole in vitro. In vivo, enhanced survival was not observed upon admission of 8.6 mg/kg manogepix, nor in combination treatment with 5.7 mg/kg itraconazole. MICs of manogepix were high, but the in vitro antifungal activity of itraconazole was enhanced in combination therapy. However, no efficacy of manogepix was found in an in vivo grain model using clinically relevant dosages. Therefore, the therapeutic potential of manogepix in mycetoma caused by M. mycetomatis seems limited.
Topics: Animals; Itraconazole; Madurella; Mycetoma; Antifungal Agents
PubMed: 37960934
DOI: 10.1093/mmy/myad118 -
Mycoses Jun 2023Eumycetoma is a chronic subcutaneous inflammatory fungal infection most often caused by the fungus Madurella mycetomatis. Using a species-specific PCR on DNA directly...
BACKGROUND
Eumycetoma is a chronic subcutaneous inflammatory fungal infection most often caused by the fungus Madurella mycetomatis. Using a species-specific PCR on DNA directly isolated from grains is currently the most reliable method for species identification. However, so far, PCR has been performed on grains obtained through deep-seated surgical biopsies, which are invasive procedures. Grains can also be obtained via ultrasound-guided fine-needle aspiration (US-FNA). Here we determined the diagnostic performance of species-specific PCRs performed on samples obtained through US-FNA.
METHODS
From 63 patients, US-FNA was performed to obtain eumycetoma grains; 34 patients also underwent a deep-seated biopsy. From the grains, DNA was isolated, and one pan-fungal and two M. mycetomatis-specific PCRs were performed. The sensitivity and specificity were determined.
RESULTS
Of the 63 patients who underwent US-FNA, 78% (49/63) had evidence of eumycetoma based on cytology and 93.7% (59/63) based on species-specific PCRs. In the 34 patients for whom surgical biopsies were performed as well, 31 patients had a positive PCR for M. mycetomatis when DNA was isolated from the deep-seated biopsy, and 30 had a positive PCR when DNA was obtained from the US-FNA material. This resulted in a 96.8% sensitivity, and 100% specificity with 97.1% diagnostic accuracy for PCR performed on US-FNA.
CONCLUSION
PCR performed on the US-FNA material has a similar sensitivity and specificity as PCR performed on deep-seated biopsies. Therefore, when using PCR, a deep-seated biopsy may not be necessary to obtain grains.
Topics: Humans; Biopsy, Fine-Needle; Madurella; Mycetoma; Polymerase Chain Reaction; Nucleic Acid Amplification Techniques; Inflammation
PubMed: 36740735
DOI: 10.1111/myc.13572 -
Journal of Clinical Microbiology Feb 2021is the major causative agent of eumycetoma, a neglected tropical infection characterized by painless subcutaneous lesions, inflammation, and grains draining from...
is the major causative agent of eumycetoma, a neglected tropical infection characterized by painless subcutaneous lesions, inflammation, and grains draining from multiple sinuses. To study the epidemiology of mycetoma, a robust discriminatory typing technique is needed. We describe the use of a short-tandem-repeat assay (STR) for genotyping of isolates predominantly from Sudan. Eleven microsatellite markers (3 dinucleotides, 4 trinucleotide repeats, and 4 tetranucleotide repeats) were selected from the MM55 genome using the Tandem Repeats Finder software. PCR amplification primers were designed for each microsatellite marker using primer3 software and amplified in a multicolor multiplex PCR approach. To establish the extent of genetic variation within the population, a collection of 120 clinical isolates from different regions was genotyped with this assay. The 11 selected STR markers showed a large genotypic heterogeneity. From a collection of 120 isolates, 108 different genotypes were obtained. Simpson's diversity index (D) value for individual markers ranged from 0.081 to 0.881, and the combined panel displayed an overall D value of 0.997. The STR assay demonstrated high stability, reproducibility, and specificity. The STR assay is a promising new typing technique that can be used to genotype isolates of Apart from the possible contribution of host factors, the genetic diversity observed among this group of isolates might contribute to the different clinical manifestations of mycetoma. We recommend that the STR assay be used to establish a global reference database for future study of isolates.
Topics: Genetic Variation; Humans; Madurella; Microsatellite Repeats; Mycetoma; Reproducibility of Results
PubMed: 33298608
DOI: 10.1128/JCM.02331-20 -
PLoS Neglected Tropical Diseases Apr 2024Madurella mycetomatis is the main cause of mycetoma, a chronic granulomatous infection for which currently no adequate therapy is available. To improve therapy, more...
Madurella mycetomatis is the main cause of mycetoma, a chronic granulomatous infection for which currently no adequate therapy is available. To improve therapy, more knowledge on a molecular level is required to understand how M. mycetomatis is able to cause this disease. However, the genetic toolbox for M. mycetomatis is limited. To date, no method is available to genetically modify M. mycetomatis. In this paper, a protoplast-mediated transformation protocol was successfully developed for this fungal species, using hygromycin as a selection marker. Furthermore, using this method, a cytoplasmic-GFP-expressing M. mycetomatis strain was created. The reported methodology will be invaluable to explore the pathogenicity of M. mycetomatis and to develop reporter strains which can be useful in drug discovery as well as in genetic studies.
Topics: Hygromycin B; Madurella; Protoplasts; Transformation, Genetic; Drug Resistance, Fungal; Mycetoma; Cinnamates
PubMed: 38578808
DOI: 10.1371/journal.pntd.0012092 -
Journal of Clinical Microbiology Oct 2003Molecular diversity among clinical isolates of Madurella mycetomatis, the prime fungal agent of human mycetoma in Sudan, could possibly explain the diverse clinical...
Molecular diversity among clinical isolates of Madurella mycetomatis, the prime fungal agent of human mycetoma in Sudan, could possibly explain the diverse clinical presentations of this severely debilitating infectious disease. In addition, culture-independent DNA-mediated typing tests need to be developed for this organism, since M. mycetomatis DNA, but not the organism itself, can be identified in soil, the material from which infections are thought to originate. A collection of 38 different clinical M. mycetomatis isolates was characterized by large-scale random amplification of polymorphic DNA using 20 different primer species. These analyses, involving at least 2,600 annealing sites, showed a complete lack of DNA fingerprint variation among the various isolates. From the resulting homogeneous DNA fingerprints, seven fragments were cloned and sequenced, and novel, species-specific PCR restriction fragment length polymorphism (RFLP) tests were designed. The seven PCR RFLP tests were successfully performed on the 38 different M. mycetomatis strains. However, again all M. mycetomatis DNA patterns obtained appeared to be identical, whereas patterns produced using DNAs from other fungal species were clearly discriminatory. These results suggest that there is little genetic variation among clinically relevant M. mycetomatis strains from Sudan. The data tentatively imply that different manifestations of mycetoma are due to differences in host susceptibility rather than differential virulence of the causative agent.
Topics: DNA Primers; DNA, Fungal; Humans; Madurella; Mycetoma; Mycological Typing Techniques; Polymerase Chain Reaction; Polymorphism, Restriction Fragment Length; Random Amplified Polymorphic DNA Technique; Sensitivity and Specificity; Species Specificity; Sudan
PubMed: 14532179
DOI: 10.1128/JCM.41.10.4537-4541.2003 -
PLoS Neglected Tropical Diseases Aug 2016
Topics: Adult; Antifungal Agents; Humans; Itraconazole; Joint Diseases; Madurella; Male; Mycetoma
PubMed: 27490198
DOI: 10.1371/journal.pntd.0004849 -
Mycoses Dec 2022Eumycetoma is a neglected tropical disease. It is a chronic inflammatory subcutaneous infection characterised by painless swellings which produce grains. It is currently...
BACKGROUND
Eumycetoma is a neglected tropical disease. It is a chronic inflammatory subcutaneous infection characterised by painless swellings which produce grains. It is currently treated with a combination of itraconazole and surgery. In an ongoing clinical study, the efficacy of fosravuconazole, the prodrug of ravuconazole, is being investigated. For both itraconazole and ravuconazole, no clinical breakpoints or epidemiological cut-off values (ECV) to guide treatment are currently available.
OBJECTIVE
To determine tentative ECVs for itraconazole and ravuconazole in Madurella mycetomatis, the main causative agent of eumycetoma.
MATERIALS AND METHODS
Minimal inhibitory concentrations (MICs) for itraconazole and ravuconazole were determined in 131 genetically diverse clinical M. mycetomatis isolates with the modified CLSI M38 broth microdilution method. The MIC distributions were established and used to determine ECVs with the ECOFFinder software. CYP51A sequences were sequenced to determine whether mutations occurred in this azole target gene, and comparisons were made between the different CYP51A variants and the MIC distributions.
RESULTS
The MICs ranged from 0.008 to 1 mg/L for itraconazole and from 0.002 to 0.125 mg/L for ravuconazole. The M. mycetomatis ECV for itraconazole was 1 mg/L and for ravuconazole 0.064 mg/L. In the wild-type population, two CYP51A variants were found for M. mycetomatis, which differed in one amino acid at position 499 (S499G). The MIC distributions for itraconazole and ravuconazole were similar between the two variants. No mutations linked to decreased susceptibility were found.
CONCLUSION
The proposed M. mycetomatis ECV for itraconazole is 1 mg/L and for ravuconazole 0.064 mg/L.
Topics: Humans; Madurella; Itraconazole; Mycetoma; Triazoles; Antifungal Agents
PubMed: 36005544
DOI: 10.1111/myc.13509 -
Medical Mycology Jun 2019The neglected tropical disease mycetoma is a chronic granulomatous inflammatory and infectious disease affecting various body parts. The most common causative agent is...
The neglected tropical disease mycetoma is a chronic granulomatous inflammatory and infectious disease affecting various body parts. The most common causative agent is the fungus Madurella mycetomatis. In order to study the genetic diversity of this fungus and to monitor any potential outbreaks, a good typing method that can be used in endemic settings is needed. Previous typing methods developed were not discriminative and not easy to perform in resource-limited laboratories. Variable-Number-Tandem-Repeat (VNTR) typing overcomes these difficulties and further enables interlaboratory data comparison. Therefore, in this study we developed a VNTR method for typing M. mycetomatis. Six tandem-repeats were identified in the genome of M. mycetomatis isolate MM55 using an online tandem repeats software. The variation in these repeats was determined by PCR and gel-electrophoresis on DNA obtained from 81 M. mycetomatis isolates obtained from patients. These patients originated from Sudan, Mali, Peru, and India. The 81 isolates were divided into 14 genotypes which separated into two main clusters with seven and five subdivisions, respectively. VNTR typing confirms the heterogeneity of M. mycetomatis strains and can be used to study the epidemiology of M. mycetomatis. The results presented in this article are made fully available to the scientific community on request from the Eumycetoma Working Group. We hope that this open resource approach will bridge scientific community working with mycetoma from all around the world and lead to a deeper understanding of M. mycetomatis.
Topics: Africa; Cluster Analysis; Electrophoresis, Agar Gel; Genetic Variation; Genotype; Humans; India; Madurella; Minisatellite Repeats; Molecular Typing; Mycetoma; Mycological Typing Techniques; Peru; Polymerase Chain Reaction
PubMed: 30085253
DOI: 10.1093/mmy/myy055