Environmental occurrence of Madurella mycetomatis, the major agent of human eumycetoma in Sudan

Eumycetoma causative agents: A systematic review to inform the World Health Organization priority list of fungal pathogens

The World Health Organization, in response to the growing burden of fungal disease, established a process to develop a fungal priority pathogens list. This systematic review aimed to evaluate the epidemiology and impact of eumycetoma. PubMed and Web of Science were searched to identify studies published between 1 January 2011 and 19 February 2021. Studies reporting on mortality, inpatient care, complications and sequelae, antifungal susceptibility, risk factors, preventability, annual incidence, global distribution, and emergence during the study time frames were selected. Overall, 14 studies were eligible for inclusion. Morbidity was frequent with moderate to severe impairment of quality of life in 60.3%, amputation in up to 38.5%, and recurrent or long-term disease in 31.8%-73.5% of patients. Potential risk factors included male gender (56.6%-79.6%), younger age (11-30 years; 64%), and farming occupation (62.1%-69.7%). Mycetoma was predominantly reported in Sudan, particularly in central Sudan (37%-76.6% of cases). An annual incidence of 0.1/100 000 persons and 0.32/100  000 persons/decade was reported in the Philippines and Uganda, respectively. In Uganda, a decline in incidence from 3.37 to 0.32/100  000 persons between two consecutive 10-year periods (2000-2009 and 2010-2019) was detected. A community-based, multi-pronged prevention programme was associated with a reduction in amputation rates from 62.8% to 11.9%. With the pre-specified criteria, no studies of antifungal drug susceptibility, mortality, and hospital lengths of stay were identified. Future research should include larger cohort studies, greater drug susceptibility testing, and global surveillance to develop evidence-based treatment guidelines and to determine more accurately the incidence and trends over time.

Environmental detection of eumycetoma pathogens using multiplex real-time PCR for soil DNA in Sennar State, Sudan

BACKGROUND

Mycetoma is a chronic disease affecting the skin and subcutaneous tissue endemic in the tropical and subtropical regions. Several bacteria and fungi can cause mycetoma, but fungal mycetoma (eumycetoma) is challenging because the treatment requires a combination of a long-term antifungal agent and surgery. Although the transmission route has not yet been elucidated, infection from the soil is a leading hypothesis. However, there are few soil investigation studies, and the geographical distribution of mycetoma pathogens is not well documented. Here, we used multiplex real-time PCR technology to identify three fungal species from soil samples.

METHODS

In total, 64 DNA samples were extracted from soil collected in seven villages in an endemic area in Sennar State, Sudan, in 2019. Primers and fluorescent probes specifically targeting the ribosomal DNA of Madurella mycetomatis, Falciformispora senegalensis, and F. tompkinsii were designed.

RESULTS

Multiplex real-time PCR was performed and identified the major pathogen, M. mycetomatis that existed in most sites (95%). In addition, two other pathogens were identified from some sites. This is the first report on the use of this technique for identifying the eumycetoma causative microorganisms.

CONCLUSIONS

This study demonstrated that soil DNA investigation can elucidate the risk area of mycetoma-causative agents. The results will contribute to the design of prevention measures, and further large-scale studies may be effective in understanding the natural habitats of mycetoma pathogens.

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.

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.

Estimating the burden of mycetoma in Sudan for the period 1991-2018 using a model-based geostatistical approach

Mycetoma is widespread in tropical and subtropical regions favouring arid areas with low humidity and a short rainy season. Sudan is one of the highly endemic countries for mycetoma. Estimating the population at risk and the number of cases is critical for delivering targeted and equitable prevention and treatment services. In this study, we have combined a large dataset of mycetoma cases recorded by the Mycetoma Research Centre (MRC) in Sudan over 28 years (1991-2018) with a collection of environmental and water and hygiene-related datasets in a geostatistical framework to produce estimates of the disease burden across the country. We developed geostatistical models to predict the number of cases of actinomycetoma and eumycetoma in areas considered environmentally suitable for the two mycetoma forms. Then used the raster dataset (gridded map) with the population estimates for 2020 to compute the potentially affected population since 1991. The geostatistical models confirmed this heterogeneous and distinct distribution of the estimated cases of eumycetoma and actinomycetoma across Sudan. For eumycetoma, these higher-risk areas were smaller and scattered across Al Jazirah, Khartoum, White Nile and Sennar states, while for actinomycetoma a higher risk for infection is shown across the rural districts of North and West Kurdufan. Nationally, we estimated 63,825 people (95%CI: 13,693 to 197,369) to have been suffering from mycetoma since 1991 in Sudan,51,541 people (95%CI: 9,893-166,073) with eumycetoma and 12,284 people (95%CI: 3,800-31,296) with actinomycetoma. In conclusion, the risk of mycetoma in Sudan is particularly high in certain restricted areas, but cases are ubiquitous across all states. Both prevention and treatment services are required to address the burden. Such work provides a guide for future control and prevention programs for mycetoma, highly endemic areas are clearly targeted, and resources are directed to areas with high demand.

Role of socioeconomic factors in developing mycetoma: Results from a household survey in Sennar State, Sudan

BACKGROUND

Mycetoma is a chronic, progressively destructive disease of subcutaneous tissues and bones caused by certain species of bacteria or fungi. We conducted a cross-sectional community-based study alongside mapping of mycetoma in five administrative units with high mycetoma endemicity in the Eastern Sennar Locality, Sennar State, Sudan.

METHODS

A household survey was administered which included questions about the household members, household characteristics, economic activity and history of mycetoma. A clinical examination was conducted on all members of the household. If mycetoma was suspected, an individual questionnaire was completed collecting demographic, clinical and epidemiological data as well as information on the use of health care and associated costs. Geographical coordinates and photos of the lesions were taken, and the affected persons were referred to the medical centre for confirmation of the diagnosis and treatment. We compared the characteristics of households with confirmed cases of mycetoma with those without confirmed cases, and individuals with confirmed mycetoma with those in whom mycetoma was not confirmed.

RESULTS

In total 7,798 households in 60 villages were surveyed; 515 suspected cases were identified and 359 cases of mycetoma were confirmed. Approximately 15% of households with mycetoma had more than one household member affected by this disease. Households with mycetoma were worse off with respect to water supply, toilet facilities, electricity and electrical appliances compared to the survey households. Only 23% of study participants with mycetoma had sought professional help. Of these, 77% of patients travelled an average of six hours to visit a medical facility. More than half of patients had to pay towards their treatment. The estimated average cost of treatment was 26,957 Sudanese pounds per year (566 US dollars, exchange rate 2018).

CONCLUSIONS

Results of this survey suggest that agricultural practices and reduced access to sanitation and clean water can be risk factors in developing mycetoma. Poor access to health care and substantial financial costs were barriers to seeking treatment for mycetoma.

Metagenomic detection of eumycetoma causative agents from households of patients residing in two Sudanese endemic villages in White Nile State

Eumycetoma is a chronic debilitating fungal disease endemic to tropical and subtropical regions, with Sudan featuring the highest eumycetoma incidence. Among the 50 species of fungi most commonly associated with eumycetoma Madurella mycetomatis (M. mycetomatis) is often referenced as the most common pathogen. However, there is an enormous knowledge gap related to this neglected disease and its pathogenesis, epidemiological features, and host-specific factors that could contribute to either the host susceptibility and resistance. In this study, we were able to utilize a metagenomic approach and samples collected from clinical black grains (BG) and familiar household environments aimed to assay both the habitat of eumycetoma-associated fungi and its possible connection with eumycetoma patients living in two different eumycetoma endemic villages within the White Nile State of Sudan. DNA sequencing targeting the fungal ITS2 domain was performed on soil, animal dung, housing walls and roofs, and Acacia-species thorn samples and compared with culture-dependent methods of fungal isolation. Additionally, we compared the soil samples obtained in the endemic zone with that from non-endemic zones, including Wagga village in Kassala State and Port Sudan suburb in Port Sudan State. Overall, a total of 392 Amplicon Sequence Variants (ASVs) were detected by ITS2 metagenomics Eumycetoma causative organisms accounted for 10% of total ASVs which included 11 genera: Exserohilum (2%), Aspergillus (1.7%), Curvularia (1%), Alternaria (0.9%), Madurella (0.5%), Fusarium (0.4%), Cladosporium (0.2%) Exophiala (0.15%), and, in a lesser extent, Microascus (0.05%) Bipolaris and Acremonium (0.01%) for each. Only five genera were identified by culture method, which included Fusarium (29%), Aspergillus (28%), Alternaria (2.5%), Bipolaris (1.6%), and Chaetomium (0.8%). M. mycetomatis was detected within all the studied patients’ houses, accounting for 0.7% of total sequences. It was the first common eumycetoma-associated agent detected in soil samples and the third common in the dung and wall samples. In contrast, it was not detected in the roof or thorn samples nor in the soils from non-endemic regions. Exserohilum rostratum, Aspergillus spp and Cladosporium spp were detected in all samples. M. mycetomatis and other eumycetoma-associated fungal identified in the patients’ black grains (BG) samples by metagenomics were identified in the environmental samples. Only Acremonium alternatum and Falciformispora senegalensis, responsible for eumycetoma in two patients were not detected, suggesting the infections in these patients happened outside these endemic areas. The soil, animal dung, and houses built from the same soil and dung are the main risk factors for M. mycetomatis infection in these endemic villages. Furthermore, the poor hygienic and environmental conditions, walking barefooted, and the presence of animals within the houses increase the risk of M. mycetomatis and other fungi causing eumycetoma.

In this pilot study, using a metagenomic approach, we revealed in two Sudanese eumycetoma endemic villages within the While Nile State in Sudan, the habitat of M. mycetomatis and other fungal species responsible for eumycetoma. Although never isolated in culture, M. mycetomatis represented the most abundant eumycetoma-associated species found within soil samples and the third most common species within dung and housing wall samples. All the eumycetoma-associated fungal species detected by metagenomic in black grains samples were identified in patient’s houses, except Falciformispora senegalensis and Acremonium alternatum. The findings obtained in this study provided insight into the habitat of eumycetoma-associated causative species and improved knowledge on eumycetoma origin and risk factors in endemic villages. Furthermore, despite the limited number of samples, these results suggest the main prevention measurements to contain eumycetoma in these endemic areas. These measurements include using gloves and alternative materials to endemic soil and animal dung in building the wall of the houses walls, constructing animal fences and appropriate use of footwear.

Spectrum of Mucormycosis Before and During COVID-19: Epidemiology, Diagnosis, and Current Therapeutic Interventions

Purpose of Review

More than half a billion people have been infected and 6.2 million killed by the severe acute respiratory syndrome coronavirus type 2 (SARS-CoV-2) since the start of the pandemic in 2019. Systemic glucocorticoids are a double-edged sword, on the one hand, life-saving in treating COVID-19 complications while on the other hand, potentially leading to life-and-limb-threatening opportunistic fungal infections. Mucormycosis (MM) is caused by the mucormycetes family. Although rare, it is characterized by high mortality and significant morbidity. The gross similarities observed with other fungal infections which respond to different treatment regimens have made it all the more imperative to quickly and sensitively diagnose and treat MM. This review discusses the epidemiology of MM before and during the COVID-19 pandemic, associated risk factors, COVID-19-associated MM, diagnosis, and current therapeutic interventions.

Recent Findings

There has been a widespread and worrisome trend of rising in cases of MM, worldwide, but more so in the Indian subcontinent, where it is nicknamed the “black fungus.” This upsurge has picked up the pace ever since the start of the COVID-19 pandemic. Necrosis is secondary to the angio-invasive and pro-thrombotic nature of the mold resulting in extensive lesions presenting mostly as rhino-orbital MM (ROM) and rhino-orbito-cerebral MM (ROCM). Infection is mostly observed in subjects with underlying risk factors such as uncontrolled diabetes, those receiving hematopoietic stem cell transplant, and/or on corticosteroid or immunosuppressive therapy, although it is widely suspected that other factors such as iron and zinc may play a role in the pathogenesis of MM. The “One world one guideline” strategy advocates both prophylactic anti-fungal therapy along with aggressive, prompt, and individualized treatment with anti-fungal drugs such as amphotericin B in addition to vigorous surgical intervention. High-risk groups need particularly rapid diagnosis although empirical anti-fungal therapy may not be delayed. Speeding diagnostic turnaround times are essential to institute early therapy, and there is much scope for newer modalities such as PCR, matrix-assisted laser desorption ionization-time of flight mass spectrometry, and whole-genome sequencing in such endeavors. The results of strict monitoring of blood glucose levels along with rational and limited use of steroids and immunomodulatory drugs have proven to be a significant preventive measure.

Summary

The significant rise in cases of MM worldwide has necessitated viewing each case with a strong index of suspicion. Adoption of rapid diagnostics, early antifungal therapy, and prompt surgical interventions are essential, while high-risk groups need particular focused care which may include prophylactic anti-fungal therapy, limited steroid use, and meticulous control of the underlying disease. Developing quicker and more sensitive diagnostic modalities has great potential to improve the detection and management of MM.

Detection of multiple mycetoma pathogens using fungal metabarcoding analysis of soil DNA in an endemic area of Sudan

Mycetoma is a tropical disease caused by several fungi and bacteria present in the soil. Fungal mycetoma and eumycetoma are especially challenging to treat; therefore, prevention, early diagnosis, and early treatment are important, but it is also necessary to understand the geographic distribution of these pathogenic fungi. In this study, we used DNA metabarcoding methodology to identify fungal species from soil samples. Soil sampling was implemented at seven villages in an endemic area of Sennar State in Sudan in 2019, and ten sampling sites were selected in each village according to land-use conditions. In total, 70 soil samples were collected from ground surfaces, and DNA in the soil was extracted with a combined method of alkaline DNA extraction and a commercial soil DNA extraction kit. The region for universal primers was selected to be the ribosomal internal transcribed spacer one region for metabarcoding. After the second PCR for DNA library preparation, the amplicon-based DNA analysis was performed using next-generation sequencing with two sets of universal primers. A total of twelve mycetoma-causative fungal species were identified, including the prime agent, Madurella mycetomatis, and additional pathogens, Falciformispora senegalensis and Falciformispora tompkinsii, in 53 soil samples. This study demonstrated that soil DNA metabarcoding can elucidate the presence of multiple mycetoma-causative fungi, which may contribute to accurate diagnosis for patient treatment and geographical mapping.

Mycetoma, a chronic subcutaneous and cutaneous disease, designated as a "neglected tropical disease," is prevalent in dry and hot climates. Fungal mycetoma is caused by more than 50 species of soil-dwelling pathogenic fungi, and its diagnosis and treatment can be challenging. The prevention of infection and early diagnosis and treatment are essential, and for this purpose, environmental assessment to understand the fungal habitat is necessary. In this study, we performed DNA metabarcoding analysis using next-generation sequencing (NGS) for mycetoma pathogens from environmental soil samples in Sudan. The results suggest that multiple causative agents of fungal mycetoma are widespread regardless of the environment and can be a source of infection anywhere in an endemic area. Based on the results of this study, we expect that the investigation of fungi in soil using NGS technology may help identify infection routes and create risk maps for the prevention of mycetoma.

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.

Dental and Oral Manifestations of COVID-19 Related Mucormycosis: Diagnoses, Management Strategies and Outcomes

It has been nearly two years since the pandemic caused by the novel coronavirus disease (COVID-19) has affected the world. Several innovations and discoveries related to COVID-19 are surfacing every day and new problems associated with the COVID-19 virus are also coming to light. A similar situation is with the emergence of deep invasive fungal infections associated with severe acute respiratory syndrome 2 (SARS-CoV-2). Recent literature reported the cases of pulmonary and rhino-cerebral fungal infections appearing in patients previously infected by COVID-19. Histopathological analysis of these cases has shown that most of such infections are diagnosed as mucormycosis or aspergillosis. Rhino-orbital-cerebral mucormycosis usually affects the maxillary sinus with involvement of maxillary teeth, orbits, and ethmoidal sinuses. Diabetes mellitus is an independent risk factor for both COVID-19 as well as mucormycosis. At this point, there is scanty data on the subject and most of the published literature comprises of either case reports or case series with no long-term data available. The aim of this review paper is to present the characteristics of COVID-19 related mucormycosis and associated clinical features, outcome, diagnostic and management strategies. A prompt diagnosis and aggressive treatment planning can surely benefit these patients.

Clinical epidemiological characteristics of mycetoma in Eastern Sennar locality, Sennar State, Sudan

Mycetoma epidemiological features remain uncharacterised. Few studies have been conducted in a community-based setting to explore the epidemiological features and risk factors for mycetoma in Sudan. To bridge this gap, this study was conducted in Eastern Sennar Locality, Sennar State, Sudan, to report the clinical, epidemiological characteristics of mycetoma patients and the disease burden in the state. We used cluster sampling; sixty villages were randomly selected across the locality's five administrative units, and a household-to-household survey was conducted. We collected data using pre-designed questionnaires at the community, household, and individual levels. We performed descriptive analyses of the data and produced prevalence maps using ArcGIS 10.5 ([ESRI] Inc., Redlands CA, USA). A total of 41,176 individuals were surveyed, and 359 mycetoma patients were identified. The overall prevalence of mycetoma was 0.87% (95%CI = 0.78-0.97%), the prevalence among males was 0.83% (95%CI = 0.71-0.96%), and females 0.92% (95% CI = 0.79-1.06%). Individuals in the age group 31-45 years had the highest prevalence among the different age groups (1.52%, 95% CI = 1.23-1.86%). The prevalence map showed patients clustered within the central and north-eastern part of the locality, while villages in the south-western part had few or no cases. In conclusion, this clinical epidemiological study is pioneering and shows that mycetoma is prevalent in certain parts of Sudan. This data obtained will support the design of measures to reduce the disease burden in the state. The survey procedures and protocols can be adopted for further studies in Sudan and beyond.

A possible role for ticks in the transmission of Madurella mycetomatis in a mycetoma-endemic village in Sudan

BACKGROUND

Currently there is a wide knowledge gap in our understanding of mycetoma epidemiological characteristics, including the infection route.

METHODS

A cross-sectional descriptive epidemiological study was carried out to determine the role of exposure to animals and insects such as ticks in the transmission of eumycetoma in two adjacent villages at eastern Sudan.

RESULTS

Significant differences were found between the two villages in the level of contact and exposure to animals and ticks, the percentages of people bitten by ticks, participation in cleaning animal pens and knowledge of the medical importance of ticks. In the village with a high mycetoma prevalence rate, there were high infestation rates of ticks in domestic animals. Hyalomma and Rhipicephalus species were the most prevalent species in houses with mycetoma patients and together they constituted 83% of the total collection. Pool screening of vectors for the detection of Madurella mycetomatis recombinant RNA genes showed one positive pool from Rhipicephalus evertsi following amplification of the universal fungal primer and one positive sample from Hyalomma rufipes following the use of a specific primer.

CONCLUSION

The findings indicate a possible role of ticks in the transmission of eumycetoma causative agents. However, further in-depth studies are needed to verify this.

Global scientific research progress in mycetoma: a bibliometric analysis

BACKGROUND

Mycetoma is a neglected tropical disease that attracts little attention in regard to research and publications and hence this study was undertaken to determine the trends and global scientific research output in mycetoma-related fields.

METHODS

Mycetoma data were retrieved from the Web of Science (WoS) and Scopus databases. The MeSH Browser was used to extract relevant keywords. Biblioshiny software (R-studio cloud), VOSviewer v. 1.6.6 and SPSS software were used for data management.

RESULTS

Research trends on mycetoma increased globally from 1999 to 2020. The results were 404 documents (4444 citations) in WoS and 513 documents (5709 citations) in Scopus, and the average number of citations per article was 11 in WoS and 11.13 in Scopus. There was a significant association between the total number of citations and the total citations per year in both WoS (r=0.833, p<0.0001) and Scopus (r=0.926, p<0.0001). Sudan, India, the Netherlands and Mexico were the top-ranking productive countries for mycetoma publications in WoS, while India, the USA and Mexico were the top-ranking countries in Scopus. Articles on mycetoma were mainly published in PLoS Neglected Tropical Diseases, the International Journal of Dermatology and the Journal of Clinical Microbiology. A. H. Fahal from the Mycetoma Research Centre, University of Khartoum, Sudan, had the highest number of citations in mycetoma research during 1999-2020, followed by W. W. J. van de Sande from the Erasmus Medical Centre, University of Rotterdam, the Netherlands, during 2003-2020.

CONCLUSION

The analysis provides insight into a global overview of Mycetoma research. In addition, the analysis holds a better understanding of the development trends that have emerged in Mycetoma over the past 21 years, which can also offer a scientific reference for future research.

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.

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.

Diversity and geographic distribution of soil streptomycetes with antagonistic potential against actinomycetoma-causing Streptomyces sudanensis in Sudan and South Sudan

BACKGROUND

Production of antibiotics to inhibit competitors affects soil microbial community composition and contributes to disease suppression. In this work, we characterized whether Streptomyces bacteria, prolific antibiotics producers, inhibit a soil borne human pathogenic microorganism, Streptomyces sudanensis. S. sudanensis represents the major causal agent of actinomycetoma - a largely under-studied and dreadful subcutaneous disease of humans in the tropics and subtropics. The objective of this study was to evaluate the in vitro S. sudanensis inhibitory potential of soil streptomycetes isolated from different sites in Sudan, including areas with frequent (mycetoma belt) and rare actinomycetoma cases of illness.

RESULTS

Using selective media, 173 Streptomyces isolates were recovered from 17 sites representing three ecoregions and different vegetation and ecological subdivisions in Sudan. In total, 115 strains of the 173 (66.5%) displayed antagonism against S. sudanensis with different levels of inhibition. Strains isolated from the South Saharan steppe and woodlands ecoregion (Northern Sudan) exhibited higher inhibitory potential than those strains isolated from the East Sudanian savanna ecoregion located in the south and southeastern Sudan, or the strains isolated from the Sahelian Acacia savanna ecoregion located in central and western Sudan. According to 16S rRNA gene sequence analysis, isolates were predominantly related to Streptomyces werraensis, S. enissocaesilis, S. griseostramineus and S. prasinosporus. Three clusters of isolates were related to strains that have previously been isolated from human and animal actinomycetoma cases: SD524 (Streptomyces sp. subclade 6), SD528 (Streptomyces griseostramineus) and SD552 (Streptomyces werraensis).

CONCLUSION

The in vitro inhibitory potential against S. sudanensis was proven for more than half of the soil streptomycetes isolates in this study and this potential may contribute to suppressing the abundance and virulence of S. sudanensis. The streptomycetes isolated from the mycetoma free South Saharan steppe ecoregion show the highest average inhibitory potential. Further analyses suggest that mainly soil properties and rainfall modulate the structure and function of Streptomyces species, including their antagonistic activity against S. sudanensis.

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.

The disabling consequences of Mycetoma

Mycetoma is a neglected tropical disease endemic in tropical and subtropical countries, particularly Sudan. The disease is characterised by the triad of painless subcutaneous mass, multiple sinuses and discharge that contain grains. It is a chronic, debilitating disease most commonly affecting the feet or hands and leads to substantial morbidity, loss of function and even amputation. It predominantly affects poor, rural populations and patients typically present late with advanced disease and complications. In this descriptive cross-sectional study, we characterise the disabling consequences of mycetoma. The study included 300 patients; 228 (76%) male and 72 (24%) female with confirmed mycetoma seen at the Mycetoma Research Centre, University of Khartoum, Sudan in the period May 2016 and January 2017. The study design was based upon the International Classification of Functioning, Disability and Health, examining the impact of mycetoma on eight life domains. Our major finding is that mycetoma is a significantly disabling disease. Over 60% of the study population (181 patients) had moderate impairment or difficulty in at least one domain variable. The important disability was mobility impairment and walking difficulty that was reported in 119 patients (39.7%). There was significant pain associated with mycetoma lesions in 103 patients (34%), challenging the traditional view of mycetoma as a painless disease. The economic burden was also found to be substantial, with 126 patients (46.7%) reporting barriers to their ability to sustain themselves. This is the first study evaluating the disabling consequences of mycetoma and shows clear areas for intervention and further research. Options for mitigating social and economic impacts include routine integration of analgesia and physiotherapy into treatment protocols, and adapting educational provision and working practices based on disability assessment. Our data show that mycetoma is a public health issue with direct implications on quality of life.

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.

Rahman ME, Suliman SH, El Mamoun MAG, El Amin HM. A holistic approach to the mycetoma management

Mycetoma, one of the badly neglected tropical diseases, it is a localised chronic granulomatous inflammatory disease characterised by painless subcutaneous mass and formation of multiple sinuses that produce purulent discharge and grains. If untreated early and appropriately, it usually spread to affect the deep structures and bone resulting in massive damage, deformities and disabilities. It can also spread via the lymphatics and blood leading to distant secondary satellites associated with high morbidity and mortality. To date and despite progress in mycetoma research, a huge knowledge gap remains in mycetoma pathogenesis and epidemiology resulting in the lack of objective and effective control programmes. Currently, the available disease control method is early case detection and proper management. However, the majority of patients present late with immense disease and for many of them, heroic substantial deforming surgical excisions or amputation are the only prevailing treatment options. In this communication, the Mycetoma Research Center (MRC), Sudan shares its experience in implementing a new holistic approach to manage mycetoma patients locally at the village level. The MRC in collaboration with Sennar State Ministry of Health, Sudan had established a region mycetoma centre in one of the endemic mycetoma villages in the state. The patients were treated locally in that centre, the local medical and health personals were trained on early case detection and management, the local community was trained on mycetoma advocacy, and environmental conditions improvement. This comprehensive approach had also addressed the patients' socioeconomic constraints that hinder early presentation and treatment. This approach has also included the active local health authorities, community and civil society participation and contributions to deliver the best management. This holistic approach for mycetoma patients' management proved to be effective for early case detection and management, optimal treatment and treatment outcome and favourable disease prognosis. During the study period, the number of patients with massive lesions and the amputation rate had dropped and that had reduced the disease medical and socioeconomic burdens on patients and families.

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.

Yucatán in black and red: Linking edaphic analysis and pyrosequencing-based assessment of bacterial and fungal community structures in the two main kinds of soil of Yucatán State

Yucatán State is dominated by two kinds of soil, named "Black Leptosol" and "Red Leptosol", which are interwoven across the State. In this work, we analyzed the relation between the edaphic characteristics and the bacterial and fungal community structures in these two kinds of Leptosol. The results revealed that Black Leptosol (BlaS) had a higher content of calcium carbonates, organic matter, nitrogen, and phosphorus than Red Leptosol (RedS). The most outstanding difference in the bacterial community structure between BlaS and RedS was that while in BlaS Actinobacteria was the most abundant phylum (43.7%), followed by Acidobacteria (26.9%) and Proteobacteria (23.6%), in RedS the bacterial community was strongly dominated by Acidobacteria (83%). Two fungal phyla were identified in both kinds of soil; Ascomycota, with 77% in BlaS and 56% in RedS, and Basidiomycota, with 22% in RedS and only 0.67% in BlaS. The most relevant difference between the two fungal communities was that excepting for Fusarium sp., all the species they had were different. Thus, in contrast with bacterial communities, where most of the major OTUs were present in both kinds of soil, fungal communities appeared to be unique to each kind of Leptosol.

A Polymorphism in the Chitotriosidase Gene Associated with Risk of Mycetoma Due to Madurella mycetomatis Mycetoma--A Retrospective Study

Background

Madurella mycetomatis is the most prevalent causative agent of eumycetoma in Sudan, an infection characterized by the formation of grains. Many patients are exposed to the causative agent, however only a small number develop infection. M. mycetomatis contains chitin in its cell wall, which can trigger the human immune system. Polymorphisms in the genes encoding for the chitin-degrading enzymes chitotriosidase and AMCase were described, resulting in altered chitinase activity. We investigated the association between 4 of these polymorphisms and the incidence of M. mycetomatis mycetoma in a Sudanese population.

Methodology

Polymorphisms studied in 112 eumycetoma patients and 103 matched controls included a 24-bp insertion in the chitotriosidase gene (rs3831317), resulting in impaired chitinase activity and single nucleotide polymorphism (SNP) in the AMCase gene (rs61756687), resulting in decreased AMCase activity. Also, a SNP (rs41282492) and a 10-bp insertion in the 5’UTR region of the AMCase gene (rs143789088) were studied, both resulting in increased AMCase activity. DNA was isolated from blood and genotypes were determined using PCR-RFLP.

Principal Findings

Histological staining proved the presence of chitin in the fungal grain. The polymorphism resulting in decreased chitotriosidase activity was associated with increased odds of eumycetoma (odds ratio 2.9; p = 0.004). No association was found for the polymorphisms in the genes for AMCase (all p>0.05).

Conclusion

Decreased chitotriosidase activity was associated with increased risk of M. mycetomatis mycetoma.

Madurella mycetomatis mycetoma is a chronic fungal infection, resulting frequently in mutilating lesions. The causative agents are found in soil, however, many people are exposed but most do not develop mycetoma. Characteristic for mycetoma is that the fungus organizes itself in a grain once inside the body. Here we showed that this grain contains chitin. The immune system of the host will try to eliminate the grains by producing cytokines and enzymes, including the chitin-degrading chitinases. We showed that both human chitinases AMCase and chitotriosidase bind to fungal chitin in the grain. We also investigated 4 polymorphisms in the genes for these chitinases, and we found that a polymorphism in the gene for chitotriosidase, resulting in enzyme inactivity, was associated with increased risk for mycetoma. Based on these findings, we hypothesized that chitotriosidase is important in the pathogen-eliminating immune response, resulting in clearance of the infection. We assumed that absence of chitotriosidase results in increased AMCase production and thus in grain formation. In this study we identified a risk factor for the development of M. mycetomatis mycetoma, however the disease is multifactorial and other factors also play a role.

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.

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.

A new model for management of mycetoma in the Sudan

Patients with mycetoma usually present late with advanced disease, which is attributed to lack of medical and health facilities in endemic areas, poor health education and low socio-economic status. With this background, an integrated patient management model at the village level was designed to address the various problems associated with mycetoma. The model was launched in an endemic village in the Sudan, between 2010 and 2013. This model is described in a prospective, descriptive, community-based study, aimed to collect epidemiological, ecological, and clinical data and to assess knowledge, attitude and practice (KAP) in order to design effective and efficient management measures. In this study, the prevalence of mycetoma was 14.5 per 1,000 inhabitants. The patients were farmers, housewives and children of low socio-economic status, and no obvious risk group was detected. All had surgery performed in a mobile surgical unit in the village which encouraged patients to present early with small early lesion leading to a good clinical outcome. The close contact with the Acacia tree thorns, animals and animal dung, walking bare footed and practising poor hygiene may all have contributed to the development of mycetoma in the village. Knowledge of mycetoma was poor in 96.3% of the study population, 70% had appropriate attitudes and beliefs towards interaction with mycetoma patients and treatment methods, and 49% used satisfactory or good practices in the management of mycetoma. Knowledge and practices on mycetoma were found to be significantly associated with age. Based on the KAP and epidemiological data, several health education sessions were conducted in the village for different target groups. The integrated management approach adopted in this study is unique and appeared successful and seems suitable as an immediate intervention. While for the longer term, establishment of local health facilities with trained health staff remains a priority.

The Mycetoma Research Centre (MRC) in Sudan adopted an integrated village management model in an attempt to encourage patients to present early for treatment. The model consisted of a house to house survey to detect mycetoma suspected patients and to refer them for further management, KAP, epidemiological and ecological studies. In this study, 33 new patients were detected, and no definite risk factor was detected. However, contact with thorns, animals and animal dung may have contributed to the development of mycetoma. All patients had medical treatment and wide local surgical excisions in a mobile surgical unit at the village, except one with massive lesion who was referred to the MRC for further management. As the study population's knowledge, attitude and practice to mycetoma were poor, several health education sessions were conducted. This integrated management approach proved to be practical and successful. The various problems associated with the late presentation of patients and poor treatment outcome were addressed simultaneously at village level. That had encouraged patients to present early with small lesions with good outcome. However, for the longer term management of mycetoma patients, establishment of local medical and health facilities with qualified health staff remains essential and urgent.

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.

The mycetoma knowledge gap: identification of research priorities

Mycetoma is a tropical disease which is caused by a taxonomically diverse range of actinomycetes (actinomycetoma) and fungi (eumycetoma). The disease was only recently listed by the World Health Organization (WHO) as a neglected tropical disease (NTD). This recognition is the direct result of a meeting held in Geneva on February 1, 2013, in which experts on the disease from around the world met to identify the key research priorities needed to combat mycetoma. The areas that need to be addressed are highlighted here. The initial priority is to establish the incidence and prevalence of the disease in regions where mycetoma is endemic, prior to determining the primary reservoirs of the predominant causal agents and their mode of transmission to susceptible individuals in order to establish novel interventions that will reduce the impact of the disease on individuals, families, and communities. Critically, economical, reliable, and effective methods are required to achieve early diagnosis of infections and consequential improved therapeutic outcomes. Molecular techniques and serological assays were considered the most promising in the development of novel diagnostic tools to be used in endemic settings. Improved strategies for treating eumycetoma and actinomycetoma are also considered.

Mycetoma foot

Mycetoma is an uncommon chronic granulomatous infective disease of the skin, dermis and subcutaneous tissues predominantly seen in tropical countries. A patient presented to our hospital with the swelling of the left foot with a healed sinus and a painful nodule. He gave a history of sinuses in the left foot from which there was discharge of yellow granules. Culture of the ultrasound guided fine needle aspiration cytology of the nodule revealed growths of Nocardia species. The patient was treated with a multi-drug therapy along with debridement of the painful nodule. He experienced symptomatic relief and a regression of the swelling within the three months of follow-up so far. Due to the relatively slow progression of the disease, patients are diagnosed at a late stage. Hence, emphasis should be placed on health education and the importance of wearing footwear.

Phylogenetic findings suggest possible new habitat and routes of infection of human eumyctoma

Eumycetoma is a traumatic fungal infection in tropical and subtropical areas that may lead to severe disability. Madurella mycetomatis is one of the prevalent etiologic agents in arid Northeastern Africa. The source of infection has not been clarified. Subcutaneous inoculation from plant thorns has been hypothesized, but attempts to detect the fungus in relevant material have remained unsuccessful. The present study aims to find clues to reveal the natural habitat of Madurella species using a phylogenetic approach, i.e. by comparison of neighboring taxa with known ecology. Four species of Madurella were included in a large data set of species of Chaetomium, Chaetomidium, Thielavia, and Papulaspora (n = 128) using sequences of the universal fungal barcode gene rDNA ITS and the partial LSU gene sequence. Our study demonstrates that Madurella species are nested within the Chaetomiaceae, a family of fungi that mainly inhabit animal dung, enriched soil, and indoor environments. We hypothesize that cattle dung, ubiquitously present in rural East Africa, plays a significant role in the ecology of Madurella. If cow dung is an essential factor in inoculation by Madurella, preventative measures may involve the use of appropriate footwear in addition to restructuring of villages to reduce the frequency of contact with etiologic agents of mycetoma. On the other hand, the Chaetomiaceae possess a hidden clinical potential which needs to be explored.

Eumycetoma caused by Madurella mycetomatis is a common subcutaneous, mutilating fungal infection endemic in arid climate zones. Still there are many controversies on the route of infection, but traumatic inoculation of the subcutaneous tissue with the thorn or soil causative organism through minor skin trauma is a popular theory. This is due to the fact that, the origin and natural habitat of Madurella species, the prevalent mycetoma agents are still unknown. In order to predict the natural habitat of M. mycetomatis we investigated its phylogenetic relationships to species with known ecology. Two genes phylogeny based on LSU and ITS was performed for the species of the genus Madurella and representative genera from the family of Chaetomiaceae. Our findings confirmed that Madurella species are phylogenetically member of the family Chaetomiaceae. Members of this family are often found in dung and manure-enriched soil. We therefore suggest that animal dung, abundantly present in endemic villages, could be a possible niche for Madurella and plays an essential role in the onset of eumycetoma. This will help in understanding the origin of the disease and could be a base for future in depth study to investigate the presence of Madurella in dung from endemic areas.

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.

Mycetoma: Nonvenereal perineal lesions

Mycetoma is a chronic, granulomatous disease of the skin, and subcutaneous tissue, which sometimes involves muscle, bones, and neighboring organs. It is characterized by tumefaction, abscess formation, and fistulae with discharge of grains from sinuses. Mycetoma can be caused by various species of fungi (eumycetoma) and aerobic actinomycetes (actinomycetoma), which occur as saprophytes in soil or plants. A tentative diagnosis sufficient to initiate treatment may be made on the basis of grain color. For instance, melanoid grains are always caused by fungi and ochroid or pale grains by actinomycetes. Although this is not the thumbrule, there are exceptional reports too. As trauma favors infection, most lesions are on the foot and lower leg but they may occur anywhere on the body mimicking actinomycosis. However, lab investigations and culture are important tool to differentiate apart from the clinical picture. We are reporting atypical case with unusual site of presentation (perineum and thigh) of mycetoma.