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PLoS Neglected Tropical Diseases Dec 2020Eumycetoma is a neglected tropical disease most commonly caused by the fungus Madurella mycetomatis. Identification of eumycetoma causative agents can only be reliably...
BACKGROUND
Eumycetoma is a neglected tropical disease most commonly caused by the fungus Madurella mycetomatis. Identification of eumycetoma causative agents can only be reliably performed by molecular identification, most commonly by species-specific PCR. The current M. mycetomatis specific PCR primers were recently discovered to cross-react with Madurella pseudomycetomatis. Here, we used a comparative genome approach to develop a new M. mycetomatis specific PCR for species identification.
METHODOLOGY
Predicted-protein coding sequences unique to M. mycetomatis were first identified in BLASTCLUST based on E-value, size and presence of orthologues. Primers were then developed for 16 unique sequences and evaluated against 60 M. mycetomatis isolates and other eumycetoma causing agents including the Madurella sibling species. Out of the 16, only one was found to be specific to M. mycetomatis.
CONCLUSION
We have discovered a predicted-protein coding sequence unique to M. mycetomatis and have developed a new species-specific PCR to be used as a novel diagnostic marker for M. mycetomatis.
Topics: Cross Reactions; Fungal Proteins; Humans; Madurella; Mycetoma; Neglected Diseases; Polymerase Chain Reaction; Species Specificity
PubMed: 33326425
DOI: 10.1371/journal.pntd.0008897 -
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 -
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 Oct 2020Mycetoma is a chronic infectious disease that can be caused by fungi or bacteria, Madurella mycetomatis and Nocardia brasiliensis are frequent etiologic agents of this...
Mycetoma is a chronic infectious disease that can be caused by fungi or bacteria, Madurella mycetomatis and Nocardia brasiliensis are frequent etiologic agents of this disease. Mycetoma produced by bacteria is known as actinomycetoma. In mycetoma produced by fungi (eumycetoma) and actinomycetoma, diagnosis of the disease is based on clinical findings: severe inflammation, with deformities of affected tissues, abscesses, fistulae, sinuses and discharge of purulent material that contains micro colonies of the etiologic agent. Microscopic examination of infected tissue is similar regardless of the offending microbe; hallmark of infected tissue is severe inflammation with abundant neutrophils around micro colonies and granuloma formation with macrophages, lymphocytes, dendritic and foamy cells. Even though medical treatment is available for mycetoma patients, amputation, or surgical intervention is frequently needed. The pathogenesis of actinomycetoma is little known, most information was obtained from experimental animal models infected with bacteria. In other experimental mice infections with different microbes, it was demonstrated that nitric oxide is responsible for the intracellular killing of Mycobacterium tuberculosis by activated macrophages. Nitric oxide is a free radical with potent stimulatory and suppressive effects in innate and adaptive immunity. The unstable nitric oxide molecule is produced by action of nitric oxide synthases on L-arginine. There are three nitric oxide synthases expressed in different cells and tissues, two are constitutively expressed one in neurons, and the other in endothelial cells and one that is inducible in macrophages. Aminoguanidine is a competitive inhibitor of inducible nitric oxide synthase. Its administration in experimental animals may favor or harm them. We used aminoguanidine in mice infected with Nocardia brasiliensis, and demonstrated that all treated animals were protected from actinomycetoma development. Anti N. brasiliensis antibodies and T cell proliferation were not affected, but inflammation was reduced.
Topics: Animals; Disease Progression; Female; Guanidines; Humans; Macrophages; Mice; Mice, Inbred BALB C; Mycetoma; Neutrophils; Nitric Oxide; Nitric Oxide Synthase Type II; Nocardia
PubMed: 33091049
DOI: 10.1371/journal.pntd.0008775 -
Antimicrobial Agents and Chemotherapy Oct 2020
Correction for Nyuykonge et al., "Pyomelanin Secretion in Interferes with Spectrophotometric Endpoint Reading Using the Sensititre YeastOne alamarBlue Assay but Not with Visual Endpoint Reading".
PubMed: 33082231
DOI: 10.1128/AAC.01848-20 -
PLoS Neglected Tropical Diseases Aug 2020
Review
Topics: Antifungal Agents; Humans; Madurella; Mycetoma
PubMed: 32853199
DOI: 10.1371/journal.pntd.0008307 -
PLoS Neglected Tropical Diseases Jul 2020Eumycetoma (mycotic mycetoma) is the fungal form of mycetoma, a subcutaneous infection occurring in individuals living in endemic areas of the disease. The Sudan is...
Eumycetoma (mycotic mycetoma) is the fungal form of mycetoma, a subcutaneous infection occurring in individuals living in endemic areas of the disease. The Sudan is hyperendemic for mycetoma, with the highest incidence being reported from Gezira State, Central Sudan. The present study was conducted at the Gezira Mycetoma Center and aimed to determine the cause of black-grain eumycetoma in the state and describe its epidemiology. Black-grain specimens were collected during the surgical operation and direct detection of the causative agent was performed using M. mycetomatis species-specific PCR and ITS PCR followed by sequencing. Black-grain was reported from 93.3% of all confirmed mycetoma cases (n = 111/119), with a prevalence in young males. Of the 91 samples subjected to direct PCR, 90.1% (n = 82) gave positive results. The predominant species (88.2%) was Madurella mycetomatis. One sample was identified as M. fahalii, one as M. tropicana, and one matched the phytopathogenic species Sphaerulina rhododendricola. The highest endemic zones were Southern Gezira (76.6%) and Northern Sinnar (23.4%). The study confirmed that direct molecular detection on grains provides rapid and specific diagnosis of agents of eumycetoma.
Topics: Adolescent; Adult; Aged; Child; Child, Preschool; Female; Humans; Infant; Madurella; Male; Middle Aged; Mycetoma; Phylogeny; Sudan; Young Adult
PubMed: 32730340
DOI: 10.1371/journal.pntd.0008420 -
IDCases 2020Mycetoma is a progressive destructive disease causing severe disability, if untreated, in otherwise healthy people. Susceptible populations are usually adult males and...
Mycetoma is a progressive destructive disease causing severe disability, if untreated, in otherwise healthy people. Susceptible populations are usually adult males and disease is characterized by the triad of tumor formation, presence of grains and draining sinuses. Here, we report a case of mycetoma of a young female, manifested only as a painful swelling over left ankle which was initially suspected as a malignancy. The preliminary diagnosis of mycetoma came with the presence of characteristic "dot in circle" sign in radiological evaluation which was confirmed by the positive fungal culture of 2nd biopsy for .
PubMed: 32528849
DOI: 10.1016/j.idcr.2020.e00857 -
Microbiology Resource Announcements Apr 2020The draft genomes of three fungal clinical isolates of from patients with mycetoma are presented. No finished genome is currently available for this important fungus....
The draft genomes of three fungal clinical isolates of from patients with mycetoma are presented. No finished genome is currently available for this important fungus. Therefore, the addition of these new draft genomes will help us better understand the diversity and pathogenicity of this important species.
PubMed: 32299891
DOI: 10.1128/MRA.01533-19 -
PLoS Neglected Tropical Diseases Apr 2020Mycetoma is a neglected chronic and granulomatous infection primarily associated with the fungal pathogen Madurella mycetomatis. Characteristic of this infection is the...
Mycetoma is a neglected chronic and granulomatous infection primarily associated with the fungal pathogen Madurella mycetomatis. Characteristic of this infection is the formation of grains. However, the processes leading to grain formation are not known. In this study, we employed a proteomic approach to characterise M. mycetomatis grain formation in Galleria mellonella larvae and map the processes leading to grain formation over time. For this, at 1 day, 3 days and 7 days post-inoculation, proteins from grains and hemolymph were extracted and analysed by label-free mass spectrometry. A total of 87, 51 and 48 M. mycetomatis proteins and 713, 997, 18 G. mellonella proteins were found in grains on day 1, 3 and 7 post-inoculation respectively. M. mycetomatis proteins were mainly involved in cellular metabolic processes and numerous enzymes were encountered. G. mellonella proteins were primarily involved in the nodulation process. The proteins identified were linked to nodulation and grain formation and four steps of grain formation were identified. The results of this proteomic approach could in the future be used to design novel strategies to interfere with mycetoma grain formation and to combat this difficult to treat infection.
Topics: Animals; Disease Models, Animal; Larva; Madurella; Moths; Mycetoma; Proteomics
PubMed: 32267851
DOI: 10.1371/journal.pntd.0008190