New species of Madurella, causative agents of black-grain mycetoma

An updated list of eumycetoma causative agents and their differences in grain formation and treatment response

SUMMARYIn 2023, the World Health Organization designated eumycetoma causative agents as high-priority pathogens on its list of fungal priority pathogens. Despite this recognition, a comprehensive understanding of these causative agents is lacking, and potential variations in clinical manifestations or therapeutic responses remain unclear. In this review, 12,379 eumycetoma cases were reviewed. In total, 69 different fungal species were identified as causative agents. However, some were only identified once, and there was no supporting evidence that they were indeed present in the grain. Madurella mycetomatis was by far the most commonly reported fungal causative agent. In most studies, identification of the fungus at the species level was based on culture or histology, which was prone to misidentifications. The newly used molecular identification tools identified new causative agents. Clinically, no differences were reported in the appearance of the lesion, but variations in mycetoma grain formation and antifungal susceptibility were observed. Although attempts were made to explore the differences in clinical outcomes based on antifungal susceptibility, the lack of large clinical trials and the inclusion of surgery as standard treatment posed challenges in drawing definitive conclusions. Limited case series suggested that eumycetoma cases caused by Fusarium species were less responsive to treatment than those caused by Madurella mycetomatis. However, further research is imperative for a comprehensive understanding.

A Novel Report of mycetoma with Spinal Spread due to Madurella fahalli from India

Eumycetoma caused by Madurella fahalii, a drug-resistant fungus, has never been reported in India. Here, we describe a fatal case of eumycetoma with spinal involvement due to M. fahalii for the first time in India.

Complete Genome Sequence of the Itraconazole Decreased Susceptible Madurella fahalii Type-Strain CBS 129176

Madurella fahalii is a causative agent of the implantation mycosis mycetoma with decreased susceptibility to itraconazole, the preferred therapeutic drug to combat mycetoma. Here, we report the M. fahalii type-strain CBS 129176 genome assembly and annotation to identify a glutamic acid insert near the azole-binding pocket in the Cyp51A protein.

Changes in fungal taxonomy: mycological rationale and clinical implications

Numerous fungal species of medical importance have been recently subjected to and will likely continue to undergo nomenclatural changes as a result of the application of molecular approaches to fungal classification together with abandonment of dual nomenclature. Here, we summarize those changes affecting key groups of fungi of medical importance, explaining the mycological (taxonomic) rationale that underpinned the changes and the clinical relevance/importance (where such exists) of the key nomenclatural revisions. Potential mechanisms to mitigate unnecessary taxonomic instability are suggested, together with approaches to raise awareness of important changes to minimize potential clinical confusion.

Mycetoma and the environment

Mycetoma is a chronic, incapacitating, destructive inflammatory disease with many serious damaging impacts. Currently, there is no control or prevention program as many of its epidemiological characteristics, such as the causative organisms' ecological niche, natural habitat, primary reservoir, transmission mode, geographical distribution, incidence, and prevalence, remain unclear. This may be due to a lack of research interest, as mycetoma is still a neglected disease and the scarcity of accurate molecular diagnostic techniques in disease-endemic regions for accurate causative microorganisms identification and mapping. With this background, this study set out to address this knowledge gap by considering the mycetoma environmental occurrence predictors. The medical literature obtained data showed a close association between mycetoma occurrence and its environment. The causative microorganisms are available in the environment in active or dormant forms. Animal dung may be a natural niche and reservoir for these organisms, and thorns may facilitate the subcutaneous inoculation. Some environmental factors, such as the soil type and consistency, temperature, water sources, aridity index, and thorny trees, may be risk factors. The population in endemic areas socioeconomic, hygiene, and health education status are contributory factors for mycetoma. The individual's genetic and immunological backgrounds may determine the disease's susceptibility and resistance. Environmental conditions and personal hygiene improvement are mandatory to reduce disease occurrence. Mycetoma spatial mapping can detect disease cluster areas and then develop public health strategies for early case detection and management to reduce the disease burden. More research interests and facilities are needed to understand disease pathogenesis and appropriate patient management better.

Specific and sensitive loop-mediated isothermal amplification (LAMP) method for Madurella strains, eumycetoma filamentous fungi causative agent

BACKGROUND

Filamentous fungi of the genus Madurella are the primary causative agents of mycetoma, a disease observed in tropical and subtropical regions. Since early diagnostics based on a morphological approach are difficult and have many shortcomings, a molecular diagnostic method suitable for rural settings is required. In this study, we developed the loop-mediated isothermal amplification (LAMP) method to present a foundational technique of the diagnosis of Madurella spp. (M. mycetomatis, M. pseudomycetomatis, M. tropicana, and M. fahalii), the common causative organisms of eumycetoma.

PRINCIPAL FINDINGS

We successfully designed a primer pair targeting the rDNAs of three Madurella spp. excluding M. fahalii, and detected up to 100 fg of genomic DNA extracted from isolates of M. mycetomatis and 1 pg of M. pseudomycetomatis and M. tropicana, within one hour. Second, a primer pair specific to M. mycetomatis, the most common causative species, or M. fahalii, a drug-resistant species, was constructed, and the detection limit of both primer pairs was 1 pg. The designed primers accurately distinguished 16 strains of the genus Madurella from various fungal species known to cause mycetomas.

CONCLUSION

In summary, we established the first model of a LAMP detection method that rapidly and sensitively detects and identifies Madurella isolates for clinical diagnostics. Moreover, the combined designed primer sets could identify mycetoma-causing strains simultaneously.

Epidemiologic Aspects of Mycetoma in Africa

Mycetoma is a chronic, disabling infection caused by fungi or actinomycetes that affects the disadvantaged rural populations of arid tropical regions. The identification of etiological agents is long, difficult, and often imprecise or unsuccessful. Recently developed molecular methods can be used to identify causal agents at the species level. However, diagnosis can only be implemented in specialized laboratories. For these reasons, the distribution of causal agents in endemic African countries remains approximate. It is known that the pathogenic organisms of mycetoma are present in the environment, introduced as a result of injuries or trauma. There are still unknowns concerning the natural habitats of agents and the mode of infection. A potential association between mycetoma and acacia was uncovered in Sudan, allowing the elaboration of a risk map of the country. A new hypothesis for the mode of contamination involves the intervention of an intermediate host. The first surveys in Sudanese endemic villages gave a higher prevalence than the previous estimates, indicating that the prevalence of mycetoma in endemic African countries has previously been underestimated.

Madurella mycetomatis grains within a eumycetoma lesion are clonal

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.

OUP accepted manuscript

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.

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.

Eumycetoma Medical Treatment: Past, Current Practice, Latest Advances and Perspectives

Mycetoma is a neglected tropical disease that is associated with poor communities and socioeconomically impaired individuals in the tropical and sub-tropical areas. Interestingly, the disease is caused by either bacteria (actinomycetoma) or fungus (eumycetoma). The latter form of the disease, eumycetoma, is the most common type in Africa. Eumycetoma is characterized by a prolonged disease duration and low cure rate. The effective case management of eumycetoma largely depends on the accurate diagnosis and identification of the causative agent to the species level and evaluating its susceptibility to the available drugs. This review summarizes the currently available and used antifungal agents for the treatment of eumycetoma and discusses optimizing the newly developed antifungals as a potential second line for eumycetoma treatment.

A Case of Trauma-Induced Falciformispora lignatilis Eumycetoma in a Renal Transplant Recipient

Mycetoma is a chronic, granulomatous, subcutaneous infection caused by several species of fungi and soil-inhabiting bacteria, and is divided into eumycetoma and actinomycetoma, respectively. Endemicity is described with worldwide distribution within the “mycetoma belt”; however, the global burden is ill-defined. Mycetoma is rare in Australia, with only a few published case reports. Over time, the breadth of eumycetoma pathogens has expanded with local epidemiology accounting for variations in regional prevalence. Direct inoculation of pathogens typically heralds the triad of subcutaneous mass, sinus formation and discharging grains. We describe a case of eumycetoma in a 48-year-old male Filipino renal transplant recipient who presented with a painless slow-growing elbow lesion. Ultrasonography revealed two ovoid masses and surgical excision ensued. Histopathology revealed necrotising granulomata with numerous chestnut-brown thick-walled cells, septate hyphae, and occasional grains. On suspicion of localised chromoblastomycosis, the isolate was sent to a reference laboratory which identified the fungus as Falciformispora lignatilis, an organism not hitherto associated with human infection. Amongst the solid organ transplant cohort, similar atypical presentations have been described. Clinicians need to consider eumycetoma where an epidemiological link with the tropics exists, especially in atypical presentations in transplant recipients, including absent preceding trauma.

In vitro susceptibility testing for black grain eumycetoma causative agents

Eumycetoma is a neglected tropical implantation mycosis characterized by large subcutaneous swellings. Inside the infected tissue, the causative agents are found in grains. The most common causative agents form black grains and are sterile upon isolation. In vitro susceptibility assays were developed for eumycetoma causative agents. They were based on the Clinical and Laboratory Standards Institute M38A protocol and modified to enable the use of hyphae as a starting inoculum. To ease endpoint reading, viability dyes such as resazurin or XTT have been used. So far the in vitro susceptibility assays developed have mainly been used to establish if causative agents are inhibited in growth by various antifungal agents, but not for clinical decision making. For drug discovery, the assay proved useful in determining which compounds were able to prevent hyphal growth. However, a clear correlation between in vitro inhibition in terms of the half maximal inhibitory concentration or 50% minimum inhibitory concentration (MIC50) and therapeutic efficacy assayed in a novel model system in terms of Galleria mellonella larval survival was not found. For clinical decision making, a range of MICs were found for each antifungal agent. However, no clinical breakpoints have been established for any of the causative agents. For itraconazole, the MIC50 of most causative agents was below the attainable serum levels, which might indicate that they are susceptible. However, before in vitro susceptibility can be used in clinical decision making for mycetoma, a correlation between MIC and clinical outcome needs to be made.

The development of a novel diagnostic PCR for Madurella mycetomatis using a comparative genome approach

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.

Mycetoma is a neglected tropical disease characterised by tumorous swellings and grain formation. This disease can be caused by more than 70 different micro-organisms and is categorised into actinomycetoma (caused by bacteria) and eumycetoma (caused by fungi). The most common causative agent of mycetoma is the fungus Madurella mycetomatis. Diagnosis of eumycetoma is often only done clinically or by histopathological examination and culturing of the grains. Unfortunately, that often leads to misidentifications. Molecular identification is currently the most reliable method to identify the causative agents. However, we have recently discovered that the only M. mycetomatis species-specific PCR primers cross-reacts to Madurella pseudomycetomatis. Since all Madurella species cause eumycetoma and have different susceptibilities to antifungal agents, it is important to be able to accurately identify them to the species level. Here we have used a comparative genome approach to identify and design new M. mycetomatis species-specific PCR primers. These primers can be used to identify M. mycetomatis directly from grains and do not cross-react with any of the other eumycetoma causative agents tested. We, therefore, recommended the use of these primers in reference centres and local laboratories to identify M. mycetomatis to the species level.

Diagnostic implications of mycetoma derived from Madurella pseudomycetomatis isolates from Mexico

BACKGROUND

At the dermatology service of the General Hospital of Mexico City, Mexico, two patients, father and son, with black-grain mycetoma were seen. The grains were isolated, and the cultured fungi were identified as Madurella mycetomatis based on morphology. Using the M. mycetomatis specific PCR, amplicons of a different size than that of the M. mycetomatis type strain were obtained.

OBJECTIVE

To determine the causative agent of the two black-grain mycetoma cases and develop non-culture-based diagnostic tools to identify them to the species level.

METHODS

The M. mycetomatis specific, the internal transcribed spacer (ITS) region, β-tubulin (BT) and ribosomal binding protein 2 (RBP2) PCRs were used to confirm the identity of the isolates. Genetic variation was established by amplification fragment length polymorphisms. To determine the antifungal susceptibility profile, the Sensititre™ YeastOne™ assay was used. To develop a species-specific PCR primers were designed on the sequenced PCR amplicon from the M. mycetomatis specific PCR.

RESULTS

By analyzing the ITS, BT and RBP2 regions the isolates were identified as Madurella pseudomycetomatis. The isolates from father and son were similar but not identical to M. pseudomycetomatis from Venezuela and one from an unknown origin. Madurella pseudomycetomatis isolates were inhibited by itraconazole, posaconazole and voriconazole but showed increased MIC values for amphotericin B and fluconazole. They were not inhibited by the echinocandins and five flucytosine. The two patients were treated with itraconazole resulting in cure for the father while the son was lost to follow-up. The species-specific PCR developed for M. pseudomyceotmatis was discriminative and specific.

CONCLUSION

Madurella pseudomycetomatis is genetically diverse with same susceptibility profile as M. mycetomatis and causes eumycetoma in Latin America. The M. pseudomycetomatis specific PCR can be used to identify this causative agent to the species level; however, this needs to be validated in an endemic setting.

The genus Madurella: Molecular identification and epidemiology in Sudan

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.

Eumycetoma is a neglected fungal disease endemic in Africa, India, and Latin America. Black-grain eumycetoma is the most common type in Africa and is mainly caused by Madurella spp. The Sudan, and in particular Gezira State, central Sudan is hyperendemic for black-grain eumycetoma. Patients with this type of mycetoma are treated with surgery in combination with antifungal therapy. In this study, we collected surgical biopsies from patients attending Gezira Mycetoma Center to directly identify the etiology of black-grain eumycetoma in this state. We also studied the epidemiology of the disease based on the demography of the patients’ population. Our result showed that the highest endemic regions were Southern Gezira (76.6%) and Northern Sinnar (23.4%). By applying direct PCR and sequencing we confirmed that the most common etiology of the disease is Madurella mycetomatis (88.2%). In addition, we found one case of M. fahalii and the first Sudanese case of M. tropicana and Sphaerulina rhododendricola.

Mycetoma epidemiology, diagnosis management, and outcome in three hospital centres in Senegal from 2008 to 2018

Mycetoma is a neglected tropical disease caused by various actinomycetes or fungi. The disease is characterized by the formation of tumor like-swellings and grains. Senegal is an endemic country where mycetoma cases are under-or misdiagnosed due to the lack of capacities and knowledge among health workers and the community; and where the management of eumycetoma, burdened by a high amputation rate, is currently inadequate. This study aimed to update data on the epidemiology of mycetoma cases diagnosed in three hospital centres in Senegal over a 10 years-period. A total of 193 patients, diagnosed from 2008 to 2018, were included in the study. The most frequent presentation was eumycetoma (47.2%); followed by actinomycetoma (36.8%); it remained undetermined in 16.1% of the patients. The mean age was 38.3 years (68.4% of the patients were between 15 and 45 years-old); the male: female ratio was a 2.94; and most were farmers. One hundred fifty-six (80.8%) patients had used phytotherapy before attending the hospital. Mycetoma was mainly located to the lower limbs (91.2%). Grains were observed in 85% of the patients; including white (25.6%) and yellow (4.3%) grains. The etiological diagnosis was complex, resulting in negative direct microscopy, culture and/or histopathology findings, which explains that 16.1% remained uncharacterized. In most of cases, actinomycetoma were treated with a combination of cotrimoxazole, amoxicillin/clavulanic acid, and streptomycin; whereas eumycetoma cases were treated with terbinafine. The surgery was done in 100 (51.8%) of the patients including 9 in actinomycetoma, 78 in eumycetoma and 13 in undetermined form. The high number of uncharacterized mycetoma in this study, the delay in attending a qualified health-care facility, and the lack of available adequate antifungal drug, point out the need to strengthen mycetoma management capacities in Senegal.

Madurella real-time PCR, a novel approach for eumycetoma diagnosis

The genus Madurella comprising four species, M. fahalii, M. mycetomatis, M. pseudomycetomatis, and M. tropicana, represents the prevalent cause of eumycetoma worldwide. The four species are phenotypically similar and cause an invariable clinical picture, but differ markedly in their susceptibility to antifungal drugs, and epidemiological pattern. Therefore, specific identification is required for optimal management of Madurella infection and to reveal proper epidemiology of the species. In this study, a novel multiplex real-time PCR targeting the four Madurella species was developed and standardized. Evaluation of the assay using reference strains of the target and non-target species resulted in 100% specificity, high analytical reproducibility (R2 values >0.99) and a lowest detection limit of 3 pg target DNA. The accuracy of the real-time PCR was further assessed using biopsies from eumycetoma suspected patients. Unlike culture and DNA sequencing as gold standard diagnostic methods, the real-time PCR yielded accurate diagnosis with specific identification of the causative species in three hours compared to one or two weeks required for culture. The novel method reduces turnaround time as well as labor intensity and high costs associated with current reference methods.

Mycetoma, a progressive and disfiguring disease, is one of the neglected tropical diseases, caused by both bacteria and fungi. Eumycetoma is the fungal type and mainly caused by species of the genus Madurella. Madurella mycetomatis is the most prevalent species worldwide. However, other species such as M. fahalii, M. pseudomycetomatis, and M. tropicana can also cause mycetoma and have a different susceptibility towards the drug used for treating mycetoma patients. Currently, we lack a rapid and non-culture-based technique that can readily identify these four species from clinical samples. Due to its sensitivity, and specificity, real-time PCR is re-recognized by European Organization for Research and Treatment of Cancer (EORTC) to directly identify fungal agents from clinical samples. We developed and validated a multiplex real-time PCR-based technique using the least expensive chemistry to identify Madurella species within 3–4 hours. Development of such a technique will allow rapid diagnosis of eumycetoma and timely initiation of appropriate antifungal therapy.

Recurrent eumycetoma caused by novel species Madurella pseudomycetomatis: A case report

Mycetoma is a chronic-granulomatous disease characterized by the inflammation, swollen organ, draining sinuses containing blood, pus, and grains. We present a case of madura foot with novel etiologic agent Madurella pseudomycetomatis. Diagnosis was based on morphologic, physiologic, histipathologic and molecular methods. In vitro antifungal susceptibility tests revealed that MIC values for itraconazole, amphotericin B, and posaconazole were 0.0313 μg/ml, 0.0313 μg/ml, and 0.004 μg/ml, respectively. The patient was treated and recovered by itraconazole(400 mg/day) after prolonged course.

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.

Closing the mycetoma knowledge gap

On 28th May 2016, mycetoma was recognized as a neglected tropical disease by the World Health Organization. This was the result of a 4-year journey starting in February 2013 with a meeting of global mycetoma experts. Knowledge gaps were identified and included the incidence, prevalence, and mapping of mycetoma; the mode of transmission; the development of methods for early diagnosis; and better treatment. In this review, we review the road to recognition, the ISHAM working group meeting in Argentina, and we address the progress made in closing the knowledge gaps since 2013. Progress included adding another 9000 patients to the literature, which allowed us to update the prevalence map on mycetoma. Furthermore, based on molecular phylogeny, species names were corrected and four novel mycetoma causative agents were identified. By mapping mycetoma causative agents an association with Acacia trees was found. For early diagnosis, three different isothermal amplification techniques were developed, and novel antigens were discovered. To develop better treatment strategies for mycetoma patients, in vitro susceptibility tests for the coelomycete agents of black grain mycetoma were developed, and the first randomized clinical trial for eumycetoma started early 2017.

Mycetoma: The Spectrum of Clinical Presentation

Mycetoma is a chronic infection, newly designated by the World Health Organization (WHO) as a neglected tropical disease, which is endemic in tropical and subtropical regions. It follows implantation of infectious organisms, either fungi (eumycetomas) or filamentous bacteria (actinomycetomas) into subcutaneous tissue, from where infection spreads to involve skin, bone and subcutaneous sites, leading to both health related and socioeconomic problems. In common with other NTDs, mycetoma is most often seen in rural areas amongst the poorest of people who have less access to health care. The organisms form small microcolonies that are discharged onto the skin surface via sinus tracts, or that can burrow into other adjacent tissues including bone. This paper describes the clinical features of mycetoma, as early recognition is a key to early diagnosis and the institution of appropriate treatment including surgery. Because these lesions are mostly painless and the majority of infected individuals present late and with advanced disease, simplifying early recognition is an important public health goal.

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.

Rapid and Robust Identification of the Agents of Black-Grain Mycetoma by Matrix-Assisted Laser Desorption Ionization-Time of Flight Mass Spectrometry

Eumycetoma, a chronic fungal infection endemic in India, Indonesia, and parts of Africa and South and Central America, follows traumatic implantation of saprophytic fungi and frequently requires radical surgery or amputation in the absence of appropriate treatment. Fungal species that can cause black-grain mycetomas include Madurella spp., Falciformispora spp., Trematosphaeria grisea, Nigrograna mackinnonii, Pseudochaetosphaeronema larense, Medicopsis romeroi, and Emarellia spp. Rhytidhysteron rufulum and Parathyridaria percutanea cause similar subcutaneous infections, but these infections lack the draining sinuses and fungal grains characteristic of eumycetoma. Accurate identification of the agents of subcutaneous fungal infection is essential to guide appropriate antifungal therapy. Since phenotypic identification of the causative fungi is often difficult, time-consuming molecular approaches are currently required. In the study described here we evaluated whether matrix-assisted laser desorption ionization-time of flight (MALDI-TOF) mass spectrometry might allow the accurate identification of eumycetoma agents and related fungi. A panel of 57 organisms corresponding to 10 different species from confirmed cases of eumycetoma and subcutaneous pedal masses, previously formally identified by PCR amplification and sequencing of internal transcribed spacer 1 (ITS1), was employed. Representative isolates of each species were used to create reference MALDI-TOF spectra, which were then used for the identification of the remaining isolates in a user-blinded manner. Here, we demonstrate that MALDI-TOF mass spectrometry accurately identified all of the test isolates, with 100%, 90.4%, and 67.3% of isolates achieving log scores greater than 1.8, 1.9, and 2.0, respectively.

Name Changes for Fungi of Medical Importance, 2012 to 2015

This article lists proposed new or revised species names and classification changes associated with fungi of medical importance for the years 2012 through 2015. While many of the revised names listed have been widely adopted without further discussion, some may take longer to achieve more general usage.

Coelomycetous Fungi in the Clinical Setting: Morphological Convergence and Cryptic Diversity

Human infections by coelomycetous fungi are becoming more frequent and range from superficial to systemic dissemination. Traumatic implantation of contaminated plant material is the most common cause. The typical morphological feature of these fungi is the production of asexual spores (conidia) within fruiting bodies called conidiomata. This study aimed to determine the distribution of the coelomycetes in clinical samples by a phenotypic and molecular study of a large set of isolates received from a U.S. reference mycological institution and by obtaining the in vitro antifungal susceptibility pattern of nine antifungals against a selected group of isolates. A total of 230 isolates were identified by sequencing the D1 and D2 domains of the large subunit (LSU) nuclear ribosomal RNA (nrRNA) gene and by morphological characterization. Eleven orders of the phylum Ascomycota were identified: Pleosporales (the largest group; 66.1%), Botryosphaeriales (19.57%), Glomerellales (4.35%), Diaporthales (3.48%), Xylariales (2.17%), Hysteriales and Valsariales (0.87%), and Capnodiales, Helotiales, Hypocreales and Magnaporthales (0.43% each). The most prevalent species were Neoscytalidium dimidiatum, Paraconiothyrium spp., Phoma herbarum, Didymella heteroderae, and Epicoccum sorghinum The most common anatomical site of isolation was superficial tissue (66.5%), followed by the respiratory tract (17.4%). Most of the isolates tested were susceptible to the majority of antifungals, and only flucytosine showed poor antifungal activity.

Molecular identification of unusual Mycetoma agents isolated from patients in Venezuela

Mycetoma is a chronic granulomatous, subcutaneous disease endemic in tropical and subtropical countries. It is currently a health problem in rural areas of Africa, Asia and South America. Nine cases of mycetoma were analysed in a retrospective study. All isolates were identified by morphological features. The level of species identification was reached by molecular tools. Definitive identification of fungi was performed using sequence analysis of the ITS of the ribosomal DNA region and the ribosomal large-subunit D1/D2. Identification of actinomycetes was accomplished by the 16S rRNA gene sequence. Six unusual clinical isolates were identified: Aspergillus ustus, Cyphellophora oxyspora, Exophiala oligosperma, Madurella pseudomycetomatis, Nocardia farcinica and Nocardia wallacei. The prevalence of mycetoma in Venezuela remains unknown. This study represents the first report in the literature of mycetoma caused by unusual pathogens identified by molecular techniques.

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 and their treatment]

Mycetoma are chronic subcutaneous infections, endemic in dry tropical regions. It can be caused either by actinomycetes or by fungi, presenting as filamentous grains in vivo. The foot is the most common localization. The main complication is osseous involvement. Patients are rural workers living in areas situated far from medical centers. Too often, they reach well-equipped hospitals with advanced mutilating lesions. Early case detection is the first condition for good therapeutic results. Clinical presentations of actinomycetoma and eumycetoma are similar, only biological diagnosis can distinguish the two etiological forms. This distinction is essential as medical therapy for each is radically different. Precise identification of the causal agent is required for targeted treatment but it can only be realized in rare specialized laboratories. For actinomycetoma, standard therapy is trimethoprim-sulphamethoxazole (STX). Duration of treatment period is one-year minimum. In case of poor response to STX or high risk of dissemination, a combination with amikacin gave high cure rate. Other options as amoxicillin-clavulanate are available. Medical cure of actinomycetoma is generally obtained with antibiotic treatments and surgical indications are exceptional. Disappointing results were observed using antifungal in the treatment of eumycetoma and medical therapy must be completed with surgical excision. Itraconazole is now the most used drug, new triazoles are on evaluation.

Novel Taxa Associated with Human Fungal Black-Grain Mycetomas: Emarellia grisea gen. nov., sp. nov., and Emarellia paragrisea sp. nov

Eumycetoma is a debilitating, chronic, fungal infection that is endemic in India, Indonesia, and parts of Africa and South and Central America. It remains a neglected tropical disease in need of international recognition. Infections follow traumatic implantation of saprophytic fungi and frequently require radical surgery or amputation in the absence of appropriate treatment. Several fungal species can cause black-grain mycetomas, including Madurella spp. (Sordariales), Falciformispora spp., Trematosphaeria grisea, Biatriospora mackinnonii, Pseudochaetosphaeronema larense, and Medicopsis romeroi (all Pleosporales). We performed phylogenetic analyses based on five loci on 31 isolates from two international culture collections to establish the taxonomic affiliations of fungi that had been isolated from cases of black-grain mycetoma and historically classified as Madurella grisea Although most strains were well resolved to species level and corresponded to known agents of eumycetoma, six independent isolates, which failed to produce conidia under any conditions tested, were only distantly related to existing members of the Pleosporales Five of the six isolates shared >99% identity with each other and are described as Emarellia grisea gen. nov. and sp. nov; the sixth isolate represents a sister species in this novel genus and is described as Emarellia paragrisea. Several E. grisea isolates were present in both United Kingdom and French culture collections and had been isolated independently over 6 decades from cases of imported eumycetoma. Four of the six isolates involved patients that had originated on the Indian subcontinent. All isolates were all susceptible in vitro to the azole antifungals, but had elevated MICs with caspofungin.

Application of Isothermal Amplification Techniques for Identification of Madurella mycetomatis, the Prevalent Agent of Human Mycetoma

Appropriate diagnosis and treatment of eumycetoma may vary significantly depending on the causative agent. To date, the most common fungus causing mycetoma worldwide is Madurella mycetomatis. This species fails to express any recognizable morphological characteristics, and reliable identification can therefore only be achieved with the application of molecular techniques. Recombinase polymerase amplification (RPA) and loop-mediated isothermal amplification (LAMP) are proposed as alternatives to phenotypic methods. Species-specific primers were developed to target the ribosomal DNA (rDNA) internal transcribed spacer (ITS) region of M. mycetomatis. Both isothermal amplification techniques showed high specificity and sufficient sensitivity to amplify fungal DNA and proved to be appropriate for detection of M. mycetomatis. Diagnostic performance of the techniques was assessed in comparison to conventional PCR using biopsy specimens from eumycetoma patients. RPA is reliable and easy to operate and has the potential to be implemented in areas where mycetoma is endemic. The techniques may be expanded to detect fungal DNA from environmental samples.

Humicola sp. as a Cause of Peritoneal Dialysis-Associated Peritonitis

Peritoneal dialysis is the renal replacement modality used by ∼20% of patients with end-stage kidney disease (S. McDonald, P. Clayton, and K. Hurst, p. 6.2-6.27, in ANZDATA 2012 Annual Report, 35th ed., 2012). A major complication of peritoneal dialysis is the development of peritonitis. We describe a case of Humicola sp. causing peritoneal dialysis (PD)-associated peritonitis, successfully treated with a prolonged course of antifungal therapy.

Mycetoma in the Sudan: an update from the Mycetoma Research Centre, University of Khartoum, Sudan

This communication reports on the Mycetoma Research Centre of the University of Khartoum, Sudan experience on 6,792 patients seen during the period 1991–2014.The patients were predominately young (64% under 30 years old) males (76%). The majority (68%) were from the Sudan mycetoma belt and 28% were students. Madurella mycetomatis eumycetoma was the most common type (70%). In 66% of the patients the duration of the disease was less than five years, and 81% gave a history of sinuses discharging mostly black grains (78%). History of trauma at the mycetoma site was reported in 20%. Local pain was reported in 27% of the patients, and only 12% had a family history of mycetoma. The study showed that 57% of the patients had previous surgical excisions and recurrence, and only 4% received previous medical treatment for mycetoma. Other concomitant medical diseases were reported in 4% of the patients. The foot (76%) and hand (8%) were the most commonly affected sites. Less frequently affected sites were the leg and knee (7%), thigh (2%), buttock (2%) and arm and forearm (1%). Rare sites included the chest wall, head and neck, back, abdominal wall, perineum, oral cavity, tongue and eye. Multiple sites mycetoma was recorded in 135 (2%) of cases. At presentation, 37% of patients had massive lesions, 79% had sinuses, 8% had local hyper-hydrosis at the mycetoma lesion, 11% had regional lymphadenopathy, while 6% had dilated tortuous veins proximal to the mycetoma lesions. The diagnosis of mycetoma was established by combined imaging techniques and cytological, histopathological, serological tests and grain culture. Patients with actinomycetoma received a combination of antimicrobial agents, while eumycetoma patients received antifungal agents combined with various surgical excisions. Surgical excisions in the form of wide local excision, debridement or amputation were done in 807 patients, and of them 248 patients (30.7%) had postoperative recurrence. Different types of amputations were done in 120 patients (1.7%).

Many researchers consider the Sudan as the mycetoma homeland. The first report on mycetoma was at the turn of the eighteenth century, and since then many documents on mycetoma have been reported. However, there is no recent report on mycetoma in the country. In 1977 Mahgoub published data on mycetoma in Sudan, but no more data were published until the MRC was established. The present study reports on 6,792 patients with mycetoma seen and managed at the MRC in a period of 23 years. This is the largest reported number of cases on the disease at national and international levels. The clinical presentations of the reported patients were in line with the previous reports on mycetoma from the Sudan and elsewhere. Still, many patients presented late with advanced disease and enormous disabilities and deformities. Some of them had a fatal outcome due to several complications. Despite advances in the diagnosis and treatment of this disease, outcome is still unsatisfactory. There is a need for more research to develop effective treatment of mycetoma and field friendly diagnostic techniques. Adequate preventive and control measures to reduce the disease morbidity and mortality are needed.

Head and neck mycetoma: the mycetoma research centre experience

Mycetoma is a unique neglected tropical disease which is endemic in what is known as the "mycetoma belt". The disease has many devastating impacts on patients and communities in endemic area and is characterised by massive deformity, destruction and disability. Mycetoma is commonly seen in the foot and hand and less frequent in other parts of the body. Mycetoma of the head and neck is a rarity and is associated with high morbidity and even mortality if not treated early. In this communication we report on 49 patients with head and neck mycetoma followed up at the Mycetoma Research Centre in Khartoum. Most of the reported patients had actinomycetoma and the majority were young adult males from mycetoma endemic areas in the Sudan. Most of them were students, farmers and workers. Prior to presentation the majority had long disease duration and the cause was multifactorial. Advanced disease with massive lesion, deformity and disability was the common presentation. There was no obvious history of local trauma, familial tendency or other predisposing factor identified in this group of patients. MRI and CT scan were the most accurate diagnostic tools to determine the disease extent. The treatment outcome was rather poor and characterised by low cure rate, poor outcome and high follows-up dropout. Such a gloomy outcome calls for structured and objective health education programs.

Eumycetoma and actinomycetoma--an update on causative agents, epidemiology, pathogenesis, diagnostics and therapy

Mycetoma is a chronic putrid infection of the cutaneous and subcutaneous tissue concerning predominantly the feet, and more rarely other body parts. Mycetoma can be caused by both fungi (eumycetoma) and bacteria (actinomycetoma). Mode of infection is an inoculation of the causative microorganism via small injuries of the skin. The clinical correlate of both forms of mycetoma is tumescence with abscesses, painless nodules, sinuses and discharge. The latter is commonly serous-purulent and contains grains (filamentous granules) which can be expressed for diagnostic purposes. Distinctive for both eumycetoma and actinomycetoma, are the formation of grains. Grains represent microcolonies of the microorganism in vivo in the vital tissue. The most successful treatment option for eumycetomas offers itraconazole in a dosage of 200 mg twice daily. This triazole antifungal is considered as 'gold standard' for eumycetomas. Alternatively, the cheaper ketoconazole was widely used, however, it was currently stopped by the FDA. Actinomycetomas should be treated by the combination of trimethoprim-sulphamethoxazole (co-trimoxazole 80/400 to 160/800 mg per day) and amikacin 15 mg/kg body weight per day. Mycetomas are neglected infections of the poor. They are more than a medical challenge. In rural areas of Africa, Asia and South America mycetomas lead to socio-economic consequences involving the affected patients, their families and the society in general.

Rapid identification of black grain eumycetoma causative agents using rolling circle amplification

Accurate identification of mycetoma causative agent is a priority for treatment. However, current identification tools are far from being satisfactory for both reliable diagnosis and epidemiological investigations. A rapid, simple, and highly efficient molecular based method for identification of agents of black grain eumycetoma is introduced, aiming to improve diagnostic in endemic areas. Rolling Circle Amplification (RCA) uses species-specific padlock probes and isothermal DNA amplification. The tests were based on ITS sequences and developed for Falciformispora senegalensis, F. tompkinsii, Madurella fahalii, M. mycetomatis, M. pseudomycetomatis, M. tropicana, Medicopsis romeroi, and Trematosphaeria grisea. With the isothermal RCA assay, 62 isolates were successfully identified with 100% specificity and no cross reactivity or false results. The main advantage of this technique is the low-cost, high specificity, and simplicity. In addition, it is highly reproducible and can be performed within a single day.

Treatment of eumycetoma largely depends on the causative pathogen. Identification of mycetoma agent with phenotypic features is too limited, and physiological and biochemical techniques are laborious, time-consuming and nonspecific, whereas the currently available molecular methods based on DNA sequencing are specific but extremely expensive. We describe rolling circle amplification method for identification of black grain eumycetoma using species-specific padlock probes. Eight probes were designed and successfully used for species identification and the results were easily visualized in 1% agarose gel. RCA provides a simple, reproducible, and cost-effective method for rapid identification of mycetoma agent that can be used in low-resource clinical settings.

Black Molds and Melanized Yeasts Pathogenic to Humans

A review is given of melanized fungi involved in human infection, including species forming budding cells and strictly filamentous representatives. Classically, they are known as "phaeoid" or "dematiaceous" fungi, and, today, agents are recognized to belong to seven orders of fungi, of which the Chaetothyriales and Pleosporales are the most important. Infections range from cutaneous or pulmonary colonization to systemic or disseminated invasion. Subcutaneous involvement, either primary or after dissemination, may lead to host tissue proliferation of dermis or epidermis. Particularly in the Chaetothyriales, subcutaneous and systemic infections may occur in otherwise apparently healthy individuals. Infections are mostly chronic and require extended antifungal therapy and/or surgery.

Mapping the potential risk of mycetoma infection in Sudan and South Sudan using ecological niche modeling

In 2013, the World Health Organization (WHO) recognized mycetoma as one of the neglected tropical conditions due to the efforts of the mycetoma consortium. This same consortium formulated knowledge gaps that require further research. One of these gaps was that very few data are available on the epidemiology and transmission cycle of the causative agents. Previous work suggested a soil-borne or Acacia thorn-prick-mediated origin of mycetoma infections, but no studies have investigated effects of soil type and Acacia geographic distribution on mycetoma case distributions. Here, we map risk of mycetoma infection across Sudan and South Sudan using ecological niche modeling (ENM). For this study, records of mycetoma cases were obtained from the scientific literature and GIDEON; Acacia records were obtained from the Global Biodiversity Information Facility. We developed ENMs based on digital GIS data layers summarizing soil characteristics, land-surface temperature, and greenness indices to provide a rich picture of environmental variation across Sudan and South Sudan. ENMs were calibrated in known endemic districts and transferred countrywide; model results suggested that risk is greatest in an east-west belt across central Sudan. Visualizing ENMs in environmental dimensions, mycetoma occurs under diverse environmental conditions. We compared niches of mycetoma and Acacia trees, and could not reject the null hypothesis of niche similarity. This study revealed contributions of different environmental factors to mycetoma infection risk, identified suitable environments and regions for transmission, signaled a potential mycetoma-Acacia association, and provided steps towards a robust risk map for the disease.

WHO has recognized mycetoma as one of the neglected tropical diseases (NTDs) worldwide. Studies indicate infections from soil or possibly mediated by thorn pricks, but no detailed studies have investigated effects of soil type and Acacia distributions on mycetoma in Sudan. Here, we investigated risk factors associated with mycetoma infections in Sudan using ecological niche modeling (ENM), integrating mycetoma case records, Acacia records, and geospatial data summarizing soil, land-surface temperature, and greenness. ENMs calibrated in endemic districts were transferred across Sudan, and suggested that greatest risk was in a belt across central Sudan. Mycetoma infections occur under diverse environmental conditions; we found significant niche similarity between Acacia and mycetoma. Model predictions were amply corroborated by a preliminary assessment of a much larger mycetoma case-occurrence data base. Our results revealed contributions of different environmental factors to mycetoma risk, raised hypotheses of a causal mycetoma-Acacia association, and provide steps towards a robust predictive risk map for the disease in Sudan.

Mycetoma medical therapy

Medical treatment of mycetoma depends on its fungal or bacterial etiology. Clinically, these entities share similar features that can confuse diagnosis, causing a lack of therapeutic response due to inappropriate treatment. This review evaluates the response to available antimicrobial agents in actinomycetoma and the current status of antifungal drugs for treatment of eumycetoma.

Last generation triazoles for imported eumycetoma in eleven consecutive adults

Background

Optimal management of eumycetoma, a severely debilitating chronic progressive fungal infection of skin, disseminating to bone and viscera, remains challenging. Especially, optimal antifungal treatment and duration are ill defined.

Methodology/Principal Findings

We conducted a monocentric retrospective study of 11 imported cases of eumycetoma treated by voriconazole or posaconazole for at least 6 months. Response to treatment was assessed through evolution of clinical and magnetic resonance imaging (MRI). (1→3) ß-D-glucan (BG) and positron emission tomography using [18F] fluorodeoxyglucose (PET/CT) results were also assessed. Identified species were Fusarium solani complex (n = 3); Madurella mycetomatis, (n = 3), and Exophiala jeanselmei, (n = 1). Moreover, two coelomycetes and one phaeohyphomycetes strains without species identification were retrieved. Serum BG and PET/CT were abnormal in 7/8 and 6/6 patients tested, respectively. Patients received last generation azoles for a mean duration of 25.9±18 months. Complete response (major clinical and MRI improvement) was observed in 5/11 patients, partial response (minor MRI improvement or stable MRI findings) in 5 and failure (MRI evidence of disease progression) in one, with a 73±39 [6–132] months mean follow-up. Relapse occurred in 2 patients after treatment discontinuation. Optimal outcome was associated with fungal species, initiation of last generation triazole therapy (<65 months since first symptoms), negative serum BG and PET/CT normalization.

Conclusions/Significance

MRI, PET/CT and serum BG appear as promising tools to assess optimal time of antifungal treatment for eumycetoma.

Eumycetoma is a severe chronic progressive fungal infection of skin and ultimately bone or viscera that affect mainly people with low economic status. Optimal treatment of this condition relies on medical and often surgical therapy and remains challenging because of lack of gold standard therapy and high rate of relapse after treatment discontinuation. In this retrospective study we assessed whether modern triazoles (voriconazole and posaconazole) suited to eumycetoma treatment and if tailored treatment duration, based on serial evaluation of a serum biomarker of fungal infection (Serum (1→3) ß-D-Glucan, (BD)), magnetic resonance imaging (MRI) or positron emission tomography using [18F] fluorodeoxyglucose (PET/CT) would be useful. We found that modern triazoles were efficient treatments of eumycetoma, allowing complete or partial response in 10/11 of patients, without significant side effects. Moreover, patients with treatment discontinuation based on normalization of BD, MRI or PET/CT seemed to have better long-term outcome than those with clinical cure but still abnormal BD or imaging results.

Revision of agents of black-grain eumycetoma in the order Pleosporales

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), Leptosphaeriasenegalensis, 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.

Mycetoma: experience of 482 cases in a single center in Mexico

Mycetoma is a chronic granulomatous disease. It is classified into eumycetoma caused by fungi and actinomycetoma due to filamentous actinomycetes. Mycetoma can be found in geographic areas in close proximity to the Tropic of Cancer. Mexico is one of the countries in which this disease is highly endemic. In this retrospective study we report epidemiologic, clinical and microbiologic data of mycetoma observed in the General Hospital of Mexico in a 33 year-period (1980 to 2013). A total of 482 cases were included which were clinical and microbiology confirmed. Four hundred and forty four cases (92.11%) were actinomycetomas and 38 cases (7.88%) were eumycetomas. Most patients were agricultural workers; there was a male predominance with a sex ratio of 3∶1. The mean age was 34.5 years old (most ranged from 21 to 40 years). The main affected localization was lower and upper limbs (70.74% and 14.52% respectively). Most of the patients came from humid tropical areas (Morelos, Guerrero and Hidalgo were the regions commonly reported). The main clinical presentation was as tumor-like soft tissue swelling with draining sinuses (97.1%). Grains were observed in all the cases. The principal causative agents for actinomycetoma were: Nocardia brasiliensis (78.21%) and Actinomadura madurae (8.7%); meanwhile, for eumycetomas: Madurella mycetomatis and Scedosporium boydii (synonym: Pseudallescheria boydii) were identified. This is a single-center, with long-follow up, cross-sectional study that allows determining the prevalence and characteristics of mycetoma in different regions of Mexico.

Mycetoma is a chronic, subcutaneous granulomatous disease that usually begins after traumatic inoculation with causative microorganisms. Based on its etiology, mycetoma is referred to eumycetoma when the infection is caused by filamentous fungi, and actinomycetoma when the infection is due to aerobic actinomycetes (in Mexico predominantly Nocardia brasiliensis). Establishing the etiology is extremely important since it impacts treatment regimens. Mycetoma typically presents around the Tropic of Cancer between latitude 15° South and 30° North (also known as “mycetoma belt”) affecting poor populations in Africa, Asia, and Latin America, including Mexico, which represents a highly endemic area with higher frequencies of actinomycetomas. Mycetoma usually affects males (male∶female ratio of 3∶1), agricultural or rural workers (age range 20–40 years) that typically do not have access to protective equipment. The main clinical presentation is as soft tissue swelling with sinus tract formation draining grains, which leads to diagnosis. The foot is the most commonly affected localization; however, when disease presents in high risk areas, such as the trunk, it can disseminate to the lungs and spinal cord. This report represents a single center study which provides epidemiologic, clinical, and microbiological data of mycetoma cases in different regions of Mexico.

Merits and pitfalls of currently used diagnostic tools in mycetoma

Treatment of mycetoma depends on the causative organism and since many organisms, both actinomycetes (actinomycetoma) and fungi (eumycetoma), are capable of producing mycetoma, an accurate diagnosis is crucial. Currently, multiple diagnostic tools are used to determine the extent of infections and to identify the causative agents of mycetoma. These include various imaging, cytological, histopathological, serological, and culture techniques; phenotypic characterisation; and molecular diagnostics. In this review, we summarize these techniques and identify their merits and pitfalls in the identification of the causative agents of mycetoma and the extent of the disease. We also emphasize the fact that there is no ideal diagnostic tool available to identify the causative agents and that future research should focus on the development of new and reliable diagnostic tools.

The orthopaedic aspects of mycetoma

This article presents an overview of mycetoma and offers guidelines for orthopaedic surgeons who may be involved in the care of patients with this condition.