Madurella mycetomatis strains from mycetoma lesions in Sudanese patients are clonal

Genomics and metagenomics of Madurella mycetomatis, a causative agent of black grain mycetoma in Sudan

Madurella mycetomatis is one of the main causative agents of mycetoma, a debilitating neglected tropical disease. Improved understanding of the genomic diversity of the fungal and bacterial causes of mycetoma is essential to advances in diagnosis and treatment. Here, we describe a high-quality genome assembly of M. mycetomatis and results of the whole genome sequence analysis of 26 isolates from Sudan. We demonstrate evidence of at least seven genetically diverse lineages and extreme clonality among isolates within these lineages. We also performed shotgun metagenomic analysis of DNA extracted from mycetoma grains and showed that M. mycetomatis reads were detected in all sequenced samples with the average of 11,317 reads (s.d. +/- 21,269) per sample. In addition, 10 (12%) of the 81 tested grain samples contained bacterial reads including Streptococcus sp., Staphylococcus sp. and others.

The developed molecular biological identification tools for mycetoma causative agents: An update

Mycetoma is a chronic granulomatous inflammatory disease that is caused either by bacteria or fungi. Bacterial mycetoma (actinomycetoma) can be caused by various causative agents of the genera Nocardia, Streptomyces and Actinomadura. On the other hand, fungal mycetoma (eumycetoma) is most commonly caused by causative agents belonging to the genera Madurella, Scedosporium and Falciformispora. Early and accurate diagnosis of the causative organisms can guide proper patient management and treatment. To allow rapid and accurate species identification, different molecular techniques were developed over the past decades. These techniques can be protein based (MALDI-TOF MS) as well as DNA based (Sequencing, PCR and isothermal amplification methods). In this review, we provide an overview of the different molecular techniques currently in use and identify knowledge gaps, which need to be addressed before we can implement molecular diagnostics for mycetoma in different clinical settings.

A Short-Tandem-Repeat Assay (MmySTR) for Studying Genetic Variation in Madurella mycetomatis

Madurella mycetomatis 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 (MmySTR) for genotyping of M. mycetomatis isolates predominantly from Sudan. Eleven microsatellite markers (3 dinucleotides, 4 trinucleotide repeats, and 4 tetranucleotide repeats) were selected from the M. mycetomatis 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 MmySTR 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 MmySTR assay demonstrated high stability, reproducibility, and specificity. The MmySTR assay is a promising new typing technique that can be used to genotype isolates of M. mycetomatis 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 MmySTR assay be used to establish a global reference database for future study of M. mycetomatis isolates.

The Accuracy of Histopathological and Cytopathological Techniques in the Identification of the Mycetoma Causative Agents

Mycetoma is a devastating neglected tropical disease, caused by various fungal and bacterial pathogens. Correct diagnosis to the species level is mandatory for proper treatment. In endemic areas, various diagnostic tests and techniques are in use to achieve that, and that includes grain culture, surgical biopsy histopathological examination, fine needle aspiration cytological (FNAC) examination and in certain centres molecular diagnosis such as PCR. In this retrospective study, the sensitivity, specificity and diagnostic accuracy of grain culture, surgical biopsy histopathological examination and FNAC to identify the mycetoma causative organisms were determined. The histopathological examination appeared to have better sensitivity and specificity. The histological examination results were correct in 714 (97.5%) out of 750 patients infected with Madurella mycetomatis, in 133 (93.6%) out of 142 patients infected with Streptomyces somaliensis, in 53 (74.6%) out of 71 patients infected with Actinomadura madurae and in 12 (75%) out of 16 patients infected with Actinomadura pelletierii. FNAC results were correct in 604 (80.5%) out of 750 patients with Madurella mycetomatis eumycetoma, in 50 (37.5%) out of 133 Streptomyces somaliensis patients, 43 (60.5%) out of 71 Actinomadura madurae patients and 11 (68.7%) out of 16 Actinomadura pelletierii. The mean time required to obtain the FNAC result was one day, and for the histopathological examinations results it was 3.5 days, and for grain it was a mean of 16 days. In conclusion, histopathological examination and FNAC are more practical techniques for rapid species identification than grain culture in many endemic regions.

In mycetoma endemic regions, the medical and health settings are commonly suboptimal, and only a few diagnostic tests and techniques are available. That had badly affected the patients’ proper diagnosis and management and thus the late presentation of patients with advanced disease. In this retrospective study, the experience of the MRC on the common in use diagnostic tests in the period between 1991 and 2018 is presented. In this study, the sensitivity, specificity rates and diagnostic accuracy of grain culture, surgical biopsy histopathological examination and FNAC to identify the mycetoma causative organisms were determined. The histopathological examination appeared to have better sensitivity and specificity. Furthermore, the grain culture identification needs high experience, it is the tedious procedure, and cross-contamination is common hence misdiagnosis is frequent. It can be concluded that histopathological examination and FNAC are more practical techniques for rapid species identification than grain culture in many endemic regions with poor diagnostic setting.

VNTR confirms the heterogeneity of Madurella mycetomatis and is a promising typing tool for this mycetoma causing agent

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.

Mycetoma laboratory diagnosis: Review article

Mycetoma is a unique neglected tropical disease caused by a substantial number of microorganisms of fungal or bacterial origins. Identification of the causative organism and the disease extension are the first steps in the management of the affected patients and predicting disease treatment outcome and prognosis.

Different laboratory-based diagnostic tools and techniques were developed over the years to determine and identify the causative agents. These include direct microscopy and cytological, histopathological, and immunohistochemical techniques in addition to the classical grain culture. More recently, various molecular-based techniques have joined the mycetoma diagnostic armamentarium. The available mycetoma diagnostic techniques are of various specificity and sensitivity rates. Most are invasive, time consuming, and operator dependent, and a combination of them is required to reach a diagnosis. In addition, they need a well-equipped laboratory and are therefore not field friendly.

This review aims to provide an update on the laboratory investigations used in the diagnosis of mycetoma. It further aims to assist practising health professionals dealing with mycetoma by outlining the guidelines developed by the Mycetoma Research Centre, University of Khartoum, WHO collaborating centre on mycetoma following a cumulative experience of managing more than 7,700 mycetoma patients.

Mycetoma: a unique neglected tropical disease

Mycetoma can be caused by bacteria (actinomycetoma) or fungi (eumycetoma) and typically affects poor communities in remote areas. It is an infection of subcutaneous tissues resulting in mass and sinus formation and a discharge that contains grains. The lesion is usually on the foot but all parts of the body can be affected. The causative microorganisms probably enter the body by a thorn prick or other lesions of the skin. Mycetoma has a worldwide distribution but is restricted to specific climate zones. Microbiological diagnosis and characterisation of the exact organism causing mycetoma is difficult; no reliable serological test exists but molecular techniques to identify relevant antigens have shown promise. Actinomycetoma is treated with courses of antibiotics, which usually include co-trimoxazole and amikacin. Eumycetoma has no acceptable treatment at present; antifungals such as ketoconazole and itraconazole have been used but are unable to eradicate the fungus, need to be given for long periods, and are expensive. Amputations and recurrences in patients with eumycetoma are common.

Mycetoma caused by Madurella mycetomatis: a completely neglected medico-social dilemma

Mycetoma is a debilitating disease with a highly particular geographical distribution. The mycetoma belt circles the entire world just above the equator and defines the region with the highest prevalence and incidence. Although the disease is seen in Central America, India and all across Africa, Sudan seems to be the homeland of mycetoma. Mycetoma is an infectious disease caused either by bacteria (actinomycetoma) or true fungi (eumycetoma). In Sudan most cases are caused by the fungal species Madurella mycetomatis. The precise natural habitat of this fungus is still an enigma, but its DNA can easily be found in soil and plant samples in endemic areas. Although the entire human population in these areas are in regular contact with the fungus, most individuals are unaffected. Thus mycetoma is an ideal clinical and experimental model system for the study of host-pathogen interactions. Also, given its relative importance locally, improvements in clinical and laboratory diagnostics and knowledge of the epidemiology of the disease are badly needed. This chapter describes the current state of affairs in the field of eumycetoma caused by M. mycetomatis. The value of laboratory research on this disease and future perspective for control and prevention of the infection are discussed.

Pleurostomophora ochracea, a novel agent of human eumycetoma with yellow grains

The first yellow-grain fungal mycetoma, in a 60-year-old man from Central Sudan, is reported. Morphological and phylogenetic analysis of the ribosomal small subunit (SSU), large subunit (LSU), internal transcribed spacer (ITS), β-tubulin (BT2), actin (ACT1), and elongation factor (TEF1) genes revealed that the isolate deviated from any known agent of mycetoma; it clustered in the genus Pleurostoma (anamorph genus, Pleurostomophora) in the order Calosphaeriales. The novel species, here named Pleurostomophora ochracea, is characterized by phenotypic features. The species proved to be highly susceptible to itraconazole, ketoconazole, posaconazole, and voriconazole, but not to fluconazole. The fungus was inhibited by caspofungin at 8 μg/ml, while no inhibition was found with 5-flucytosine (MIC > 64 μg/ml). Compared to other members of the genus Pleurostomophora, P. ochracea is slow growing, with a relatively high optimum growth temperature (36 to 37°C). This is the first case of a yellow-grain fungal mycetoma; yellow grains are otherwise of bacterial nature. Our case emphasizes that identification of mycetoma agents by the color of the grain only is not sufficient and may lead to inappropriate therapy.

Phylogenetic analysis of the complete mitochondrial genome of Madurella mycetomatis confirms its taxonomic position within the order Sordariales

BACKGROUND

Madurella mycetomatis is the most common cause of human eumycetoma. The genus Madurella has been characterized by overall sterility on mycological media. Due to this sterility and the absence of other reliable morphological and ultrastructural characters, the taxonomic classification of Madurella has long been a challenge. Mitochondria are of monophyletic origin and mitochondrial genomes have been proven to be useful in phylogenetic analyses.

RESULTS

The first complete mitochondrial DNA genome of a mycetoma-causative agent was sequenced using 454 sequencing. The mitochondrial genome of M. mycetomatis is a circular DNA molecule with a size of 45,590 bp, encoding for the small and the large subunit rRNAs, 27 tRNAs, 11 genes encoding subunits of respiratory chain complexes, 2 ATP synthase subunits, 5 hypothetical proteins, 6 intronic proteins including the ribosomal protein rps3. In phylogenetic analyses using amino acid sequences of the proteins involved in respiratory chain complexes and the 2 ATP synthases it appeared that M. mycetomatis clustered together with members of the order Sordariales and that it was most closely related to Chaetomium thermophilum. Analyses of the gene order showed that within the order Sordariales a similar gene order is found. Furthermore also the tRNA order seemed mostly conserved.

CONCLUSION

Phylogenetic analyses of fungal mitochondrial genomes confirmed that M. mycetomatis belongs to the order of Sordariales and that it was most closely related to Chaetomium thermophilum, with which it also shared a comparable gene and tRNA order.

Negative pressure wound therapy and skin graft in madura foot treatment

Madura foot is a rare, loca, chronic granulomatous skin infection which commonly affects the adult male foot. Medical treatment reduces the size of the lesion but surgical excision is necessary for radical treatment. We present a case of a 59 year old male farmer diagnosed as actinomadura of the right foot treated with medical treatment, total excision, negative pressure wound therapy and split thickness skin graft.

Mycetoma or synovial sarcoma? A case report with review of the literature

Mycetoma, also commonly referred to as Madura foot, is statistically rare in the United States. However, it is endemic to other parts of the world. It is a pseudotumor characterized by a triad of tumefaction, draining sinuses, and grains. Two types exist, with each caused by different groups of organisms that require different treatment approaches. Therefore, the exact diagnosis and culture of the organism is vital to successful treatment outcomes. Synovial sarcoma, in contrast, is a malignancy much more commonly seen in the United States. It is characterized by a well-circumscribed, often palpable, mass that is usually well delineated on magnetic resonance imaging. It has characteristic histologic and genetic features that help distinguish it from other soft tissue masses. We present a case of a soft tissue mass diagnosed in the United States. The patient had several clinical and radiographic features of synovial sarcoma but the histologic outcome was mycetoma. The case is followed by a review of the published data.

Phenotypic and molecular characterization of Madurella pseudomycetomatis sp. nov., a novel opportunistic fungus possibly causing black-grain mycetoma

A case of black-grain mycetoma occurring on the lower jaw with an odontogenic origin, which to our knowledge is the first case reported in China, is presented here. The clinical manifestation, histopathological morphology, and microbiological features are described. The new species, Madurella pseudomycetomatis, isolated from the black grains discharged by this patient, was analyzed using sequence data of the multiloci of ribosomal DNA (rDNA) and its ability to ferment carbohydrate as well as morphology. The analyses of the internal transcribed spacer (ITS) region and the D1/D2 hypervariable region of the 28S ribosomal gene sequences support a new species designation. Antifungal susceptibility testing was conducted, indicating that Madurella pseudomycetomatis was highly susceptible to itraconazole, voriconazole, and amphotericin B; moderately susceptible to terbinafine; and resistant to fluconazole and flucytosine.

A new technique for the diagnosis of mycetoma using fixed blocks of aspirated material

The aim of this prospective study was to evaluate the use of the cell block technique as a safe, accurate and quick tool for the cytodiagnosis of mycetoma. The study included 240 patients with suspected mycetoma. The suspected lesion was aspirated and the aspirated material was processed to form cell blocks. The cell blocks were processed as described for routine tissue histopathological examination. Haematoxylin/eosin-stained sections were reviewed to identify the morphological features of the mycetoma grains and the different inflammatory tissue reactions. The findings were compared with those seen in histopathological sections. The different mycetoma grains showed distinct morphological features on the cell block that were identical to those seen in histopathological sections. Distinction between eumycetoma and actinomycetoma and their classification according to the causative agent were possible. The cell block technique had sensitivities of 87.5% and 85.7% for eumycetoma and actinomycetoma, respectively, and there were no statistical differences in the findings obtained by the cell block and histopathological techniques. The technique is simple, rapid, specific, sensitive and inexpensive. It can be used in the routine diagnosis of mycetoma and to obtain grains for culture identification. The cell blocks can be preserved for a long period for future studies.

Human mycetoma

BACKGROUND

Mycetoma is a tropical superficial fungal infection endemic in parts of Africa. It affects the foot and leg commonly, but any part of the body may be involved. Mycetoma presents with characteristic discharging sinuses containing fungal granules, a picture that is pathognomonic. However, the disease may present without these characteristic features, thus causing diagnostic difficulty with other chronic granulomatous infections such as tuberculosis or benign skin lesions.

METHODS

A review of four male and three female patients aged 28-70 years with mycetoma seen during a six-year period.

RESULTS

The duration of the lesion before presentation was between two and six years (median five years). Clinical presentation included pigmented cutaneous nodules, depigmented spots, multiple discharging sinuses, or a fungating mass with bone erosion, involving almost any part of the body (face, trunk, and leg). The range of clinical misdiagnoses included skin tuberculosis, fibroma, amelanotic melanoma, basal-cell carcinoma, and brain tumor. Histologic examination of tissue biopsies showed amorphous aggregates of eosinophilic granules in a background of chronic suppurative inflammation.

CONCLUSION

Mycetoma is a disease with sporadic occurrence in our environment. The presentation and clinical course may be confused with those of many skin diseases. Knowledge of mycetoma pathology is important for prompt diagnosis and treatment of this indolent clinical entity.

Low rate of carriage of macrolide-resistant group B streptococci in pregnant women in The Netherlands

OBJECTIVES

To describe prevalence of phenotypic and genotypic macrolide-resistance among GBS isolates in pregnant women and explore the possibility of clonal spread of resistant GBS isolates in a multicultural population.

STUDY DESIGN

Antimicrobial resistance patterns of 107 GBS isolates obtained from asymptomatic pregnant women were determined using E-tests. Macrolide resistance genes mef(A), erm(TR) and erm(B) were determined with PCR and a subset of 39 isolates, including the 8 isolates harbouring macrolide resistance genes, was subjected to RAPD analysis to detect clonal spreading.

RESULTS

Resistance to erythromycin and clindamycin was found in 8% and 7%, respectively. Macrolide resistance genes mef(A), erm(TR) and erm(B) were found in 1, 2 and 5 isolates, respectively; only five of these eight isolates exhibited both genotypic as well as phenotypic resistance. One genotype occured in 36% of the subset.

CONCLUSIONS

Earlier reports on prevalence of phenotypic resistance were confirmed. Among the susceptible isolates one clonal type of GBS was clearly predominant; one of the resistant isolates shared its genotype. When such clonal types acquire resistance traits in the future, GBS disease may become harder to control.

Molecular mechanisms of pathogenicity: how do pathogenic microorganisms develop cross-kingdom host jumps?

It is common knowledge that pathogenic viruses can change hosts, with avian influenza, the HIV, and the causal agent of variant Creutzfeldt-Jacob encephalitis as well-known examples. Less well known, however, is that host jumps also occur with more complex pathogenic microorganisms such as bacteria and fungi. In extreme cases, these host jumps even cross kingdom of life barriers. A number of requirements need to be met to enable a microorganism to cross such kingdom barriers. Potential cross-kingdom pathogenic microorganisms must be able to come into close and frequent contact with potential hosts, and must be able to overcome or evade host defences. Reproduction on, in, or near the new host will ensure the transmission or release of successful genotypes. An unexpectedly high number of cross-kingdom host shifts of bacterial and fungal pathogens are described in the literature. Interestingly, the molecular mechanisms underlying these shifts show commonalities. The evolution of pathogenicity towards novel hosts may be based on traits that were originally developed to ensure survival in the microorganism's original habitat, including former hosts.

Fungal infections

Tropical mycoses vary from the commonplace to the rare and exotic but they are seen regularly even as imported conditions and it is important to consider the diagnosis, where possible, in individuals who have visited remote areas. Patients may present many years after they have left an endemic area with subcutaneous or endemic systemic mycoses. In establishing a diagnosis, it is always important to take an accurate travel history so that the movements of the individual can be correlated with the potential risk for exposure to infection.

Molecular identification of black-grain mycetoma agents

Black-grain mycetomas are subcutaneous devastating chronic infections due to several dematiaceous fungi. They are diagnosed mostly in tropical countries. Identification of these fungi with standard mycological procedures is difficult because of their poor or delayed sporulation. The aim of this study was thus to assess the accuracy of molecular identification of these fungi. A total of 54 strains, mostly of clinical origin, were used, including 15 Madurella mycetomatis, 6 Madurella grisea, 12 Leptosphaeria senegalensis, 4 Leptosphaeria tompkinsii, 6 Pyrenochaeta spp., 4 Curvularia lunata, and 7 Exophiala jeanselmei strains. The internal transcribed spacer 1 (ITS1)-5.8S-ITS2 DNA region was amplified by using universal fungal primers and sequenced. Both intra- and interspecies sequence similarities were assessed. Madurella mycetomatis appeared to be a homogeneous species. More intraspecies variations were found for C. lunata and E. jeanselmei, leading, in some instances, to changes in the initial identification. L. senegalensis and L. tompkinsii showed intraspecies similarities of >99%, but similarity between the two species was <88%. Intergenera and interspecies variations were important, with sequence homologies of <81% between genera. In contrast, Pyrenochaeta romeroi and M. grisea appeared to be heterogeneous, with intraspecies similarities of 40 to 100% and 53 to 100%, respectively, which suggest either erroneous identification or the need for taxonomic revision. Epidemiological and therapeutic studies could benefit from a precise identification of the fungi responsible for black-grain mycetoma based not only on phenotypical characteristics but also on ITS sequencing.

Translationally controlled tumor protein from Madurella mycetomatis, a marker for tumorous mycetoma progression

About 40 years ago Abs against the fungus Madurella mycetomatis were first demonstrated to be present in eumycetoma patients, a disease characterized by tumorous swellings. To date nothing is known about the individual immunoreactive Ags present in this fungus. In the present study, we identify its first immunogenic Ag, a protein homologous to the translationally controlled tumor protein (TCTP), a well-conserved histamine release factor in a range of eukaryotes. The gene for this Ag was demonstrated to be present in two variants in M. mycetomatis, with 13% aa difference between the two proteins encoded. In vitro, TCTP was secreted into the culture medium. In vivo, it was found to be expressed on hyphae present in developing stages of the eumycetoma-characteristic black grain. Significant IgG and IgM immune responses, against the whole protein and selected M. mycetomatis-specific peptides, were determined. The Ab levels correlated with lesion size and disease duration. Overall, the patients with the largest lesions had the highest Ab level, which lowered with decreasing size of the lesion. After 6-15 years of disease duration the Ab levels were the highest. TCTP is the first well-characterized immunogenic Ag, simultaneously the first monomolecular vaccine candidate, identified for the fungus M. mycetomatis.

Genotyping of Madurella mycetomatis by selective amplification of restriction fragments (amplified fragment length polymorphism) and subtype correlation with geographical origin and lesion size

One of the causative organisms of mycetoma is the fungus Madurella mycetomatis. Previously, extensive molecular typing studies identified Sudanese isolates of this fungus as clonal, but polymorphic genetic markers have not yet been identified. Here, we report on the selective amplification of restriction fragment (AFLP) analysis of 37 Sudanese clinical isolates of M. mycetomatis. Of 93 AFLP fragments generated, 25 were polymorphic, and 12 of these 25 polymorphic fragments were found in a large fraction of the strains. Comparative analysis resulted into a tree, composed of two main (clusters I and II) and one minor cluster (cluster III). Seventy-five percent of the strains found in cluster I originated from central Sudan, while the origin of the strains in cluster II was more heterogeneous. Furthermore, the strains found in cluster I were generally obtained from lesions larger than those from which the strains found in cluster II were obtained (chi-square test for trend, P = 0.03). Among the 12 more commonly found polymorphisms, 4 showed sequence homology with known genes. Marker A7 was homologous to an endo-1,4-beta-glucanase from Aspergillus oryzae, 97% identical markers A12 and B3 matched a hypothetical protein from Gibberella zeae, and marker B4 was homologous to casein kinase I from Danio rerio. The last marker seemed to be associated with strains originating from central Sudan (P = 0.001). This is the first report on a genotypic study where genetic markers which may be used to study pathogenicity in M. mycetomatis were obtained.

Mycetoma caused by Madurella mycetomatis: a neglected infectious burden

Tropical eumycetoma is frequently caused by the fungus Madurella mycetomatis. The disease is characterised by extensive subcutaneous masses, usually with sinuses draining pus, blood, and fungal grains. The disease affects individuals of all ages, although disability is most severe in adults who work outdoors. Compared with major diseases such as tuberculosis, malaria, and HIV, disease from M mycetomatis is underestimated but socioeconomically important. Many scientific case reports on mycetoma exist, but fundamental research was lacking until recently. We present a review on developments in the clinical, epidemiological, and diagnostic management of M mycetomatis eumycetoma. We describe newly developed molecular diagnostic and gene typing procedures, and their application for management of patients and environmental research. Fungal susceptibility tests have been developed as well as a mouse model of infection. These advances should greatly further our understanding of the molecular basis of eumycetoma.

In vitro susceptibilities of Madurella mycetomatis to itraconazole and amphotericin B assessed by a modified NCCLS method and a viability-based 2,3-Bis(2-methoxy-4-nitro-5- sulfophenyl)-5-[(phenylamino)carbonyl]-2H-tetrazolium hydroxide (XTT) assay

Susceptibilities of Madurella mycetomatis against amphotericin B and itraconazole in vitro were determined by protocols based on NCCLS guidelines (visual reading) and a 2,3-bis (2-methoxy-4-nitro-5-sulfophenyl)-5-[(phenylamino) carbonyl]-2H-tetrazolium hydroxide (XTT) assay for fungal viability. The XTT assay was reproducible and sensitive for both antifungals. Itraconazole (MIC at which 50% of the isolates tested are inhibited [MIC(50)]) of 0.06 to 0.13 mg/liter) was superior to amphotericin B (MIC(50) of 0.5 to 1.0 mg/liter).