Merits and pitfalls of currently used diagnostic tools in mycetoma

Tracheoesophageal fistula due to Candida and Actinomyces co-infection: A case report and comprehensive review of the literature

Acquired benign tracheoesophageal fistulas and bronchoesophageal fistulas (TEF) are typically associated with granulomatous mediastinal infections, 75% of which are iatrogenic. Candida albicans and Actinomyces are commonly occurring organisms, but are uncommon etiologies of TEF. Normal colonization and the slow growth characteristics of some species of these agents rarely result in infection, mycetoma, and broncholithiasis, and thus, delays in diagnosis and treatment are likely. Few reports describe C. albicans or Actinomyces spp. as the etiology of TEF or broncholithiasis. Herein, we report a case of benign acquired TEF secondary to coinfection of Candida and Actinomyces complicated by the formation of an actinomycetoma and broncholithiasis and a comprehensive literature review to highlight the unique nature of this presentation and offer a diagnostic algorithm for diagnosis and treatment of TEFs. Following a presentation of three months of productive cough, choking sensation, night sweats, and weight loss, a bronchoscopy revealed a fistulous connection between the esophagus and the posterior right middle lobe. Pathology identified a calcified fungus ball and a broncholith secondary to the co-infection of Candida and Actinomyces. This unique presentation of Candida and Actinomyces co-infection and the associated diagnostic algorithm are presented as education and a useful tool for clinicians.

The Mycetoma Research Center, University of Khartoum, Sudan's experience in community engagement initiatives spans 3 decades

Mycetoma profoundly affects marginalised communities, especially in impoverished and remote areas with limited access to healthcare. This chronic and debilitating inflammatory disease highlights the typical issues of neglected tropical diseases (NTDs), such as insufficient attention, funding, and resources, which perpetuate neglect and suffering. Patients often delay seeking medical help, leading to advanced disease stages, severe complications, and lasting disabilities. The lack of medical infrastructure and skilled healthcare professionals worsens the situation, causing delays in diagnosis and inadequate treatment. Engaging affected communities in tailored interventions is essential to tackle these challenges, promote collaboration, raise awareness, and mobilise resources to improve healthcare access and enhance diagnostic and treatment capabilities. Since 1991, the Mycetoma Research Center (MRC) at the University of Khartoum, Sudan, has led community engagement initiatives aimed at improving the quality of life for mycetoma-affected individuals through education, advocacy, and local collaboration. In this communication, the MRC shares its extensive experience in community engagement to benefit mycetoma-affected communities.

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.

Naphthylisoquinoline alkaloids: novel agents against the causative pathogens of eumycetoma and actinomycetoma-en route to broad-spectrum antimycetomal drugs

Mycetoma is a devastating neglected tropical infection of the subcutaneous tissues. It is caused by fungal and bacterial pathogens recognized as eumycetoma and actinomycetoma, respectively. Mycetoma treatment involves diagnosing the causative microorganism as a prerequisite to prescribing a proper medication. Current therapy of fungal eumycetoma causative agents, such as Madurella mycetomatis, consists of long-term antifungal medication with itraconazole followed by surgery, yet with usually unsatisfactory clinical outcomes. Actinomycetoma, on the contrary, usually responds to treatment with co-trimoxazole and amikacin. Therefore, there is a pressing need to discover novel broad-spectrum antimicrobial agents to circumvent the time-consuming and costly diagnosis. Using the resazurin assay, a series of 23 naphthylisoquinoline (NIQ) alkaloids and related naphthoquinones were subjected to in vitro screening against two fungal strains of M. mycetomatis and three bacterial strains of Actinomadura madurae and A. syzygii. Seven NIQs, mostly dimers, showed promising in vitro activities against at least one strain of the mycetoma-causative pathogens, while the naphthoquinones did not show any activity. A synthetic NIQ dimer, 8,8'''-O,O-dimethylmichellamine A (18), inhibited all tested fungal and bacterial strains (IC50 = 2.81-12.07 µg/mL). One of the dimeric NIQs, michellamine B (14), inhibited a strain of M. mycetomatis and significantly enhanced the survival rate of Galleria mellonella larvae infected with M. mycetomatis at concentrations of 1 and 4 µg/mL, without being toxic to the uninfected larvae. As a result, broad-spectrum dimeric NIQs like 14 and 18 with antimicrobial activity are considered hit compounds that could be worth further optimization to develop novel lead antimycetomal agents.

Evaluation of a computational model for mycetoma-causative agents identification

BACKGROUND

The therapeutic strategy for mycetoma relies heavily on the identification of the causative agents, which are either fungal or bacterial. While histopathological examination of surgical biopsies is currently the most used diagnostic tool, it requires well-trained pathologists, who are lacking in most rural areas where mycetoma is endemic. In this work we propose and evaluate a machine learning approach that semi-automatically analyses histopathological microscopic images of grains and provides a classification of the disease as eumycetoma or actinomycetoma.

METHODS

The computational model is based on radiomics and partial least squares. It is assessed on a dataset that includes 890 individual grains collected from 168 patients originating from the Mycetoma Research Centre in Sudan. The dataset contained 94 eumycetoma cases and 74 actinomycetoma cases, with a distribution of the species among the two causative agents that is representative of the Sudanese distribution.

RESULTS

The proposed model achieved identification of causative agents with an accuracy of 91.89%, which is comparable to the accuracy of experts from the domain. The method was found to be robust to a small error in the segmentation of the grain and to changes in the acquisition protocol. Among the radiomics features, the homogeneity of mycetoma grain textures was found to be the most discriminative feature for causative agent identification.

CONCLUSION

The results presented in this study support that this computational approach could greatly benefit rural areas with limited access to specialized clinical centres and also provide a second opinion for expert pathologists to implement the appropriate therapeutic strategy.

Towards enhanced control of mycetoma: a roadmap to achieve the UN's sustainable development goals by 2030

Mycetoma is a neglected tropical disease (NTD) with devastating morbidity and stigma. Despite increased awareness and international collaboration, the burden of mycetoma is largely unknown and diagnosis and treatment are difficult. Addressing mycetoma globally aligns with several United Nation's Sustainable Development Goals (SDGs). Little progress has been made since the WHO's NTD roadmap publication in 2020. The Global Mycetoma Working Group proposes an enhanced mycetoma-control roadmap to meet the SDGs, stimulate progress and improve the lives of patients experiencing mycetoma. By aligning mycetoma management with the goals and targets of this enhanced roadmap, it becomes possible to leverage existing resources, infrastructure and partnerships to improve the lives of affected individuals and communities. This updated assessment is designed for the benefit of health workers and providers in mycetoma-endemic areas, NTD government officials, civil society and funding and implementing agencies.

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.

Invasive Eumycotic mycetoma of the nasal septum in a post-dialysis patient: A case report

BACKGROUND

Mycetoma is a slowly progressive chronic granulomatous disease of the skin, subcutaneous tissue, and underlying or adjacent cartilage or bone. Most commonly involves the foot region. Other parts such as the knee, arm, leg, head, neck, thigh, perineum, chest, abdominal walls, facial bones, mandible, paranasal sinuses, eyelid, vulva, orbit, and scrotum are seldom affected.

METHODS

This is a rare presentation of Eumycotic mycetoma involving the nasal septum. Surgical debridement is done under local anesthesia. Histopathological examination of debrided specimen guided in the diagnosis and treatment.

RESULTS

Histopathological examination is the one that confirms the diagnosis and rules out the other granulomatous conditions and fungal rhinitis causing septal perforation.

CONCLUSIONS

In an immunocompromised state, we know that mucormycosis and zygomycosis are known to cause aggressive complications like orbital invasion and palatal perforation by vascular route. However, other fungal infections also can lead to septal perforations whenever there is lessened resistance by the mucosal barrier due to trauma (nasal intubations).

The nutritional status of mycetoma affected patients seen at the Mycetoma Research Center, Sudan

Nutrition plays a critical and crucial role in addressing neglected tropical diseases (NTDs) and their complications, as they often contribute to malnutrition, which can worsen the impact of these conditions. Therefore, it is necessary to investigate the nutritional status of mycetoma patients, which has not been explored previously. This descriptive cross-sectional hospital-based study was conducted at the Mycetoma Research Center (MRC), University of Khartoum, Sudan. The study included 179 confirmed mycetoma patients and an equal number of age- and sex-matched normal controls. The nutritional status of the mycetoma patients was assessed and compared with that of the control group. The majority of the patients were young adults with varying educational levels, predominantly from Central Sudan. The foot was the most commonly affected part; most patients had lesions more than 10 cm in diameter. The Body Mass Index (BMI) was calculated for both study groups, revealing that 43.5% of the patients and 53.6% of controls had a normal BMI. Furthermore, 36% of patients were underweight, contrasting with only 11% in the control group. Correlation analyses indicated no significant associations between BMI and age groups, educational levels, daily meals, food quantity, and appetite in the study population (p > 0.05). Similarly, no significant differences were observed in BMI concerning disease duration and affected sites (p = 0.0577). The Kruskal-Wallis test did not reveal significant differences in BMI means among the groups. The study revealed that most participants consumed three meals daily, and the control group showed a more robust appetite and consumed more food than the patient group (p = 0.005). Nevertheless, there were no significant differences in the consumption of different food types between the patient and control groups and among different BMI categories (p = 0.025 and 0.040, respectively).

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.

A surgeon's trial success of curing pedal eumycetoma

Mycetoma is a chronic infection of underlying fungal (eumycetoma) or bacterial (actinomycetoma) origin. It is characterised by a clinical triad of tumour-like swelling, actively draining sinuses and macroscopic grains of characteristic colours.We the case of a 66-year-old woman on immunosuppressive therapy presenting with eumycetoma of the foot (Madura foot). The fungal organism cultured was Acrophialophora fusisporaThis case was managed with a combination of extensive surgical debridement, and packing with calcium sulfate (Stimulan) beads impregnated with vancomycin and voriconazole. As far as the authors are aware, this is a novel adjunct to the surgical treatment of deep fungal infection in the foot.Eumycetoma treated with surgery and oral antifungal therapy leads to cure rates of 25%-35%. This novel treatment seems to bear further investigation for the potential to improve cure rates. At 8 months follow-up, our patient appears to be making good progress with no current signs of recurrence.

Comparing the performance of the common used eumycetoma diagnostic tests

OBJECTIVES

Mycetoma is a neglected tropical implantation disease caused by 70 different infectious agents. Identifying the causative organism to the species level is essential for appropriate patient management. Ultrasound, histopathology, culture and two species-specific PCRs are most the commonly used methods for species identification in endemic regions. The aim of this study was to compare the diagnostic performance of these commonly used assays using sequencing of barcoding genes as the gold standard.

METHODS

This descriptive cross-sectional study was conducted at the Mycetoma Research Centre, University of Khartoum, Sudan. It included 222 patients suspected of fungal mycetoma caused by Madurella mycetomatis.

RESULTS

154 (69.3%) were correctly identified by ultrasound, histology, culture and both species-specific PCRs. In 60 patients, at least one of the diagnostic tests failed to identify M. mycetomatis. Five patients had no evidence of eumycetoma, and for three, only the ultrasound was indicative of mycetoma. The two species-specific PCRs were the most sensitive and specific methods, followed by culture and histology. Ultrasound was the least specific as it only allowed differentiation between actinomycetoma and eumycetoma. The time to result was 9.38 minutes for ultrasound, 3.76 hours for PCR, 8.5 days for histopathology and 21 days for grain culturing.

CONCLUSION

Currently, PCR directly on DNA isolated from grains is the most rapid and reliable diagnostic tool to identify M. mycetomatis eumycetoma.

Diagnostics to support mycetoma management-Development of two target product profiles

OBJECTIVE

Mycetoma is a neglected tropical disease caused by more than 70 different microorganisms and identified by the WHO as one of the high-priority diseases for developing diagnostic tests. To ensure the production of diagnostic assays for use by clinical staff in endemic regions, target product profiles (TPPs) were designed.

METHODS

We describe the development of two TPPs: one for a diagnostic test able to identify the causative agent of mycetoma and another that would determine when treatment could be stopped. The TPPs were developed by considering product use, design, performance, product configuration and costs.

RESULTS

Version 1.0 TPPs for two uses were posted by WHO for a 1-month online public consultation on 25 October 2021, and the final TPP was posted online on 5 May 2022.

CONCLUSION

A major difficulty encountered in developing both TPPs was the large number of agents able to cause mycetoma and the lack of specific biomarkers for most of them.

Epidemiological cut-off values for itraconazole and ravuconazole for Madurella mycetomatis, the most common causative agent of mycetoma

BACKGROUND

Eumycetoma is a neglected tropical disease. It is a chronic inflammatory subcutaneous infection characterised by painless swellings which produce grains. It is currently treated with a combination of itraconazole and surgery. In an ongoing clinical study, the efficacy of fosravuconazole, the prodrug of ravuconazole, is being investigated. For both itraconazole and ravuconazole, no clinical breakpoints or epidemiological cut-off values (ECV) to guide treatment are currently available.

OBJECTIVE

To determine tentative ECVs for itraconazole and ravuconazole in Madurella mycetomatis, the main causative agent of eumycetoma.

MATERIALS AND METHODS

Minimal inhibitory concentrations (MICs) for itraconazole and ravuconazole were determined in 131 genetically diverse clinical M. mycetomatis isolates with the modified CLSI M38 broth microdilution method. The MIC distributions were established and used to determine ECVs with the ECOFFinder software. CYP51A sequences were sequenced to determine whether mutations occurred in this azole target gene, and comparisons were made between the different CYP51A variants and the MIC distributions.

RESULTS

The MICs ranged from 0.008 to 1 mg/L for itraconazole and from 0.002 to 0.125 mg/L for ravuconazole. The M. mycetomatis ECV for itraconazole was 1 mg/L and for ravuconazole 0.064 mg/L. In the wild-type population, two CYP51A variants were found for M. mycetomatis, which differed in one amino acid at position 499 (S499G). The MIC distributions for itraconazole and ravuconazole were similar between the two variants. No mutations linked to decreased susceptibility were found.

CONCLUSION

The proposed M. mycetomatis ECV for itraconazole is 1 mg/L and for ravuconazole 0.064 mg/L.

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

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

A scoping review of mycetoma profile in Egypt: revisiting the global endemicity map

Mycetoma is a chronic infectious disease endemic in sub-Saharan Africa (SSA), India and parts of South and North America. The epidemiologic profile of the disease in Egypt, which neighbours SSA, has not been explored previously. Therefore we conducted a scoping review of the literature on mycetoma in Egypt. We searched the literature comprehensively on MEDLINE and Google Scholar using free-text words and Medical Subject Headings and terms. Both published and non-peer-reviewed (grey literature) articles were included. The initial search identified 133 reports. Of these, only eight were found to be relevant and were included in the study. The total number of mycetoma patients was 59, reported between 1949 and 2015. There was a predilection for eumycetoma (44 of 59) patients (75%), while actinomycetoma constituted 15 patients (25%). Six patients were female, 28 were male and 25 were unreported. Children and adolescents constituted 3 of 59 (5%), 52 (88%) were adults and age was not provided for 4 patients. Only four patients (7%) were non-autochthonous. The incidence of mycetoma in Egypt is higher than previously reported. Egypt is probably a low-endemic country. An accurate estimate of the prevalence and epidemiology of mycetoma necessitates further research collaboration.

Systematic whole-genome sequencing reveals an unexpected diversity among actinomycetoma pathogens and provides insights into their antibacterial susceptibilities

Mycetoma is a neglected tropical chronic granulomatous inflammatory disease of the skin and subcutaneous tissues. More than 70 species with a broad taxonomic diversity have been implicated as agents of mycetoma. Understanding the full range of causative organisms and their antibiotic sensitivity profiles are essential for the appropriate treatment of infections. The present study focuses on the analysis of full genome sequences and antibiotic inhibitory concentration profiles of actinomycetoma strains from patients seen at the Mycetoma Research Centre in Sudan with a view to developing rapid diagnostic tests. Seventeen pathogenic isolates obtained by surgical biopsies were sequenced using MinION and Illumina methods, and their antibiotic inhibitory concentration profiles determined. The results highlight an unexpected diversity of actinomycetoma causing pathogens, including three Streptomyces isolates assigned to species not previously associated with human actinomycetoma and one new Streptomyces species. Thus, current approaches for clinical and histopathological classification of mycetoma may need to be updated. The standard treatment for actinomycetoma is a combination of sulfamethoxazole/trimethoprim and amoxicillin/clavulanic acid. Most tested isolates had a high IC (inhibitory concentration) to sulfamethoxazole/trimethoprim or to amoxicillin alone. However, the addition of the β-lactamase inhibitor clavulanic acid to amoxicillin increased susceptibility, particularly for Streptomyces somaliensis and Streptomyces sudanensis. Actinomadura madurae isolates appear to have a particularly high IC under laboratory conditions, suggesting that alternative agents, such as amikacin, could be considered for more effective treatment. The results obtained will inform future diagnostic methods for the identification of actinomycetoma and treatment.

Ultrasound-guided Fine Needle Aspiration Cytology significantly improved mycetoma diagnosis

Background

Ultrasound (US)‐guided fine‐needle aspiration cytology (US‐FNAC) has improved the diagnosis of many malignancies, infections and other diseases as it is safe, simple, quick and accurate. In mycetoma, it is assumed that this technique may have a better diagnostic yield than the conventional FNAC as it can accurately identify the optimal site for the aspiration.

Objective

To compare the diagnostic yield of conventional FNAC with US‐FNAC.

Methods

This descriptive cross‐sectional hospital‐based study included 80 patients with clinically suspected mycetoma.

Results

Of the 80 patients included, 35 proved to have actinomycetoma, and 37 had eumycetoma based on surgical biopsies, histopathological examination and the culture of grains. Eight patients appeared to have no mycetoma. For actinomycetoma diagnosis, the US‐guided FNAC improved sensitivity to 97% and negative predictive value (NPV) to 83% compared to the conventional FNAC, which had 63% sensitivity; and NPV of 28%. No improvement was found for specificity. For eumycetoma, the conventional FNAC had 86.5% sensitivity, 100% specificity, 100% PPV and 37.5% NPV. The US‐FNAC for the diagnosis of eumycetoma had 100% sensitivity and specificity.

Conclusions and relevance

The obtained results showed that US‐FNAC is better than the conventional FNAC with lower false‐negative results. It can accurately distinguish between the two types of mycetoma, allowing rapid initiation of proper treatment. The technique can be used in rural areas with low resources and for epidemiological surveys as a quick screening tool for patients suspected of mycetoma.

Eumycetoma Causative Agents are Inhibited in vitro by Luliconazole, Lanoconazole and Ravuconazole

Introduction

Eumycetoma is a subcutaneous mutilating disease that can be caused by many different fungi. Current treatment consists of prolonged itraconazole administration in combination with surgery. In many centres, due to their slow growth rate, the treatment for eumycetoma is often started before the causative agent is identified. This harbours the risk that the causative fungus is not susceptible to the given empirical therapy. In the open‐source drug program MycetOS, ravuconazole and luliconazole were promising antifungal agents that were able to inhibit the growth of Madurella mycetomatis, the most common causative agent of mycetoma. However, it is currently not known whether these drugs inhibit the growth of other eumycetoma causative agents.

Materials and methods

Here, we determined the in vitro activity of luliconazole, lanoconazole and ravuconazole against commonly encountered eumycetoma causative agents. MICs were determined for lanoconazole, luliconazole and ravuconazole against 37 fungal isolates which included Madurella species, Falciformispora senegalensis, Medicopsis romeroi and Trematosphaeria grisea and compared to those of itraconazole.

Results

Ravuconazole, luliconazole and lanoconazole showed high activity against all eumycetoma causative agents tested with median minimal inhibitory concentrations (MICs) ranging from 0.008–2 µg/ml, 0.001–0.064 µg/ml and 0.001–0.064 µg/ml, respectively. Even Ma. fahalii and Me. romeroi, which are not inhibited in growth by itraconazole at a concentration of 4 µg/ml, were inhibited by these azoles.

Conclusion

The commonly encountered eumycetoma causative agents are inhibited by lanoconazole, luliconazole and ravuconazole. These drugs are promising candidates for further evaluation as potential treatment for eumycetoma.

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.

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.

Actinomycetoma laboratory-based diagnosis: a mini-review

Mycetoma is a chronic granulomatous inflammatory disease that is caused either by fungi (eumycetoma) or bacteria (actinomycetoma). The latter is caused by various actinomycetes of the genera Nocardia, Streptomyces and Actinomadura. They have different geographical distributions within mycetoma-endemic regions. In parts of Latin America, Nocardia species are more often encountered while in Africa, Streptomyces species dominate. For instituting a proper patient treatment plan, accurate identification of the causative organism is vital. For actinomycetoma, different laboratory-based techniques have been developed during recent decades. These include direct microscopy, cytology, histopathology and serology. More recently, different molecular techniques and matrix-assisted laser desorption ionisation-time of flight mass spectrometry have been included as diagnostic methods for actinomycetoma. In this review, an update on the laboratory techniques currently in use for the identification of actinomycetoma-causative agents to the species level is presented.

Mycetoma imaging: the best practice

Mycetoma is a recognised neglected tropical disease that for a long time has been accorded inadequate attention across the globe. It is a chronic destructive inflammatory disease caused by fungi (eumycetoma) or actinomycetes (actinomycetoma). Mycetoma treatment depends on an accurate and precise diagnosis. The cornerstone for proper disease diagnosis is identification of the causative organisms, but also critical for diagnosis and management planning is determination of its extent along and across tissue planes. An initial diagnosis is made after clinical assessment. Clinical examination alone does not identify the causative organism nor does it detect the spread of disease along the different tissue planes and bone. Imaging techniques, such as radiography, ultrasonography, computed tomography scan and magnetic resonance imaging can be used to determine the extent of lesions. In this communication, the Mycetoma Research Centre, World Health Organization Collaborating Centre on Mycetoma, University of Khartoum, presents its experience and recommendations on mycetoma diagnostic imaging.

A study of 87 mycetoma patients seen at three health facilities in Nouakchott, Mauritania

BACKGROUND

Mycetoma is a chronic, progressive and destructive inflammatory disease that affects the skin, subcutaneous and other tissues. The objective of this study was to identify all cases of mycetoma diagnosed in three health facilities in Nouakchott, Mauritania during 2016-2018.

METHODS

This retrospective hospital-based study was conducted at the Dermatology, Orthopedics, Mycology and Pathology departments of the National Hospital Center of Nouakchott, the Military Hospital of Nouakchott and the National Institute for Research in Public Health of Nouakchott.

RESULTS

Eighty-seven patients were included in this study. They comprised 65 male patients (74.71%) and 22 females (25.28%) with a gender ratio of 4:1. The mean age was 41.87 y and ages ranged from 14 to 70 y. The most common age group was 40-45 y (11%). The foot was the most frequently affected site seen in 60 patients (69%), followed by ankle and hand with 6 patients each (7%). In the study, 56 patients (64%) had regional lymphadenopathy. Forty-nine patients (56%) had bone involvement. Thirty-two patients (37%) had medical treatment. Twenty-seven patients (87%) received fluconazole and four patients (13%) had co-trimoxazole treatment.

CONCLUSION

The mycetoma patients seen in these three centres were mainly male farmers from rural areas. The lesions were seen mainly in the lower limbs and the majority had bone involvement radiologically.

The challenges of recruitment in clinical trials in developing countries: the Mycetoma Research Centre experience

Mycetoma is a chronic disease caused either by fungi (eumycetoma) or bacteria (actinomycetoma). Treatment remains suboptimal and based on personal clinical experience. Recently, the Mycetoma Research Centre (MRC), a WHO Collaborating Centre on mycetoma, began the first-ever double-blind clinical trial. Here, we report the challenges and barriers faced in the recruitment and retention of patients in the MRC experience. Patient recruitment and retention are critical determinants of clinical trial success and yet a substantial number of trials fail to reach their recruitment goals. Recruitment challenges are identified throughout the different stages of the clinical trial, starting from planning, participant screening and intervention, through to retaining participants for the entire study duration. The MRC made efforts to address these challenges to ensure the constant flow of patients. The recruitment committee at the MRC conducted training workshops for the medical staff in the endemic areas, along with regular meetings with health authorities and local leaders. Moreover, telemedicine technology was used to examine patients in endemic areas. Challenges and barriers facing clinical trial conduct need to be examined thoroughly to ensure actionable, evidence-based recommendations for improving patient recruitment and retention. In conclusion, effective patient recruitment and retention are based on three pillars, which are proper clinical trial design and protocol development, realistic and feasible trial site selection, and objective communication with the trial stakeholders.

Metagenomics of black grains: new highlights in the understanding of eumycetoma

BACKGROUND

Eumycetoma is a chronic subcutaneous granulomatous disease that is endemic in Sudan and other countries. It can be caused by eight different fungal orders. The gold standard diagnostic test is culture, however, culture-independent methods such as imaging, histopathological and molecular techniques can support diagnosis, especially in cases of negative cultures.

METHODS

The amplicon-based internal transcribed spacer 2 metagenomic technique was used to study black grains isolated from 14 tissue biopsies from patients with mycetoma. Furthermore, mycological culture and surgical biopsy histopathological examinations of grains were performed.

RESULTS

Madurella mycetomatis (n=5) and Falciformispora spp. (n=4) organisms were identified by culture and confirmed by metagenomics. Metagenomics recognised, at the species level, Falciformispora as Falciformispora tompkinsii (n=3) and Falciformispora senegalensis (n=1), while in culture-negative cases (n=5), Madurella mycetomatis (n=3), Falciformispora senegalensis (n=1) and Fusarium spp. (n=1) were identified. Interestingly, the metagenomics results showed a 'consortium' of different fungi in each sample, mainly Ascomycota phylum, including various species associated with eumycetoma. The microbial co-occurrence in eumycetoma showed the co-presence of Madurella with Trichoderma, Chaetomium, Malasseziales and Sordariales spp., while Falciformispora co-presented with Inocybe and Alternaria and was in mutual exclusion with Subramaniula, Aspergillus and Trichothecium.

CONCLUSION

Metagenomics provides new insights into the aetiology of eumycetoma in samples with negative culture and into the diversity and complexity of grains mycobiota, calling into question the accuracy of traditional culture for the identification of causative agents.

Spinal and cranio-cervical mycetoma: a difficult surgery, with poor prognosis

BACKGROUND

Few central nervous systems (CNS) cases of actinomycetoma have been recorded in the literature, and most were reported in tropical and subtropical regions. The management of this invasive infection is difficult, especially when it affects the spine and the cranio-cervical regions.

CASE

We report an unusual case of a cranio-cervical junction actinomycetoma, in a patient presenting a cerebellar syndrome from brainstem compression. The CT scan showed a compressive solid osteolytic lesion in the cranio-cervical junction. The patient underwent cranio-cervical decompression and lesion resection. The diagnosis of actinomycetoma was confirmed on immune-histochemistry and molecular analysis. At 4 months' follow-up, the patient presented a fatal recurrence disseminating within the cerebellum and the spine.

CONCLUSION

The surgical treatment of CNS actinomycetoma presented poor prognosis and a disseminating recurrence. We believe that clinicians and surgeons must be informed about these "new" infectious pathologies that are so difficult to treat, especially with the arrival of migrant patients from endemic countries in conflict.

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.

18- and 70-MHz Ultrasonography of Actinomycetoma of the Foot Correlated with Clinical and Histologic Findings

We present the ultrasonographic morphology of an actinomycetoma of the foot at 18 and 70 MHz (high-frequency and ultrahigh-frequency ultrasound, respectively), and describe an ultrasonographic sign that may help to discriminate between eumycetoma and actinomycetoma called the "bright hyperechoic halo." To date, this is the first report on the morphology of mycetoma at 70 MHz with a clinical, ultrasonographic, and histologic correlation of the images, which provides ultrasound images that are very similar to the lower magnification of histology.

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

Madurella mycetomatis is the major causative agent of eumycetoma, a neglected tropical infection characterized by painless subcutaneous lesions, inflammation, and grains draining from multiple sinuses. To study the epidemiology of mycetoma, a robust discriminatory typing technique is needed. We describe the use of a short-tandem-repeat assay (MmySTR) for genotyping of M. mycetomatis isolates predominantly from Sudan. Eleven microsatellite markers (3 dinucleotides, 4 trinucleotide repeats, and 4 tetranucleotide repeats) were selected from the M. mycetomatis MM55 genome using the Tandem Repeats Finder software. PCR amplification primers were designed for each microsatellite marker using primer3 software and amplified in a multicolor multiplex PCR approach. To establish the extent of genetic variation within the population, a collection of 120 clinical isolates from different regions was genotyped with this assay. The 11 selected MmySTR markers showed a large genotypic heterogeneity. From a collection of 120 isolates, 108 different genotypes were obtained. Simpson's diversity index (D) value for individual markers ranged from 0.081 to 0.881, and the combined panel displayed an overall D value of 0.997. The MmySTR assay demonstrated high stability, reproducibility, and specificity. The MmySTR assay is a promising new typing technique that can be used to genotype isolates of M. mycetomatis Apart from the possible contribution of host factors, the genetic diversity observed among this group of isolates might contribute to the different clinical manifestations of mycetoma. We recommend that the MmySTR assay be used to establish a global reference database for future study of M. mycetomatis isolates.

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.

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.

Epidemiological profile and spectrum of neglected tropical disease eumycetoma from Delhi, North India

Mycetoma is a chronic granulomatous, suppurative and progressive inflammatory disease that usually involves the subcutaneous tissue and bones after traumatic inoculation of the causative organism. In India, actinomycotic mycetoma is prevalent in south India, south-east Rajasthan and Chandigarh, while eumycetoma, which constitutes one third of the total cases, is mainly reported from north India and central Rajasthan. The objective was to determine the epidemiological profile and spectrum of eumycetoma from a tertiary care hospital in Delhi, North India. Thirty cases of eumycetoma were diagnosed by conventional methods of direct microscopy, culture and species-specific sequencing as per standard protocol. The spectrum of fungal pathogens included Exophiala jeanselmei, Madurella mycetomatis, Fusarium solani, Sarocladium kiliense, Acremonium blochii, Aspergillus nidulans, Fusarium incarnatum, Scedosporium apiospermum complex, Curvularia lunata and Medicopsis romeroi. Eumycetoma can be treated with antifungal therapy and needs to be combined with surgery. It has good prognosis if it is timely diagnosed and the correct species identified by culture for targeted therapy of these patients. Black moulds required prolonged therapy. Its low reporting and lack of familiarity may predispose patients to misdiagnosis and consequently delayed treatment. Hence health education and awareness campaign on the national and international level in the mycetoma belt is crucial.

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.

Surgical management of eumycetoma: experience from Gezira Mycetoma Center, Sudan

Background

In this study, we share our experience of different operative techniques undertaken on 584 eumycetoma patients in the Gezira Mycetoma Center.

Methods

This is a retrospective, descriptive, hospital-based study, conducted to review the surgical treatment of eumycetoma patients. We included all patients diagnosed with eumycetoma who underwent a surgical operation in the center during January 2013-December 2016.

Results

A total number of 1654 patients were seen during the study period, and their records were revised, while 584 (35.3%) of them underwent an operation and included in the study. There was a male predominance 446 (76.4%). Surgical excision of mycetoma was the commonest operation performed among 513 (87.8%) patients in comparison with amputation 71 (12.2%). Below-knee amputation and toe amputation are the commonest types of amputation in 36 (6.1%) and 14 (2.3%) patients, respectively. Clinical features determining the type of operation performed included the size of the lesion, whether or not a bone was involved, and the feasibility of primary closure. A wide surgical excision (WSE) is performed mainly when the bone is not involved and when moderate or primary closure is possible or reconstruction is feasible. Amputations will typically follow identifying bone involvement, secondary infection, and an already disabled patient.

Conclusion

The commonest procedure in our series was WSE and primary skin closure undertaken when the lesion was small (< 5 cm); there was no bone involvement, and the skin closure was achievable. Larger lesions (> 10 cm) without bone involvement were treated with excision and flap/graft. Bone involvement and large primary lesions were more likely to be managed by amputation. Recurrent and relapse of mycetoma were observed in patients with bone involvements or presented with recurrent mycetoma for the second time.

The importance of diagnostic imaging of mycetoma in the foot

BACKGROUND

Mycetoma is a chronic, localized infection caused by fungi and bacteria. It usually affects the skin, subcutaneous tissue, and bone of exposed areas with deformity of the affected limb, ulcers, and fistula; however, pain is not severe, therefore the patient comes late to hospital for care.

OBJECTIVE

To establish the diagnosis of mycetoma in the foot by imaging and identify the principal radiological signs.

MATERIALS AND METHODS

Six patients with foot mycetoma were evaluated with plain x-ray, ultrasound, and magnetic resonance (MR) after confirming the diagnosis by histopathology and culture.

RESULTS

All patients presented the MR "dot-in-circle" sign; four presented "punched out" bone lesions on plain x-ray. The six patients had fistulas, ulceration, a seropurulent exudate, edema, and a foot deformity. Four patients had N. brasiliensis infection with positive anti-Nocardia IgG antibodies, and only half presented bone lesions.

CONCLUSION

Characteristic findings were foot deformity, edema, bone lesions, ulcers, fistulas and the presence of the "dot-in-circle" sign. We recommend a comprehensive study of patients with plain x-ray and MR.

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.

Epitope-Based Peptide Vaccine Against Fructose-Bisphosphate Aldolase of Madurella mycetomatis Using Immunoinformatics Approaches

Background:

Mycetoma is a distinct body tissue destructive and neglected tropical disease. It is endemic in many tropical and subtropical countries. Mycetoma is caused by bacterial infections (actinomycetoma) such as Streptomyces somaliensis and Nocardiae or true fungi (eumycetoma) such as Madurella mycetomatis. To date, treatments fail to cure the infection and the available marketed drugs are expensive and toxic upon prolonged usage. Moreover, no vaccine was prepared yet against mycetoma.

Aim:

The aim of this study is to predict effective epitope-based vaccine against fructose-bisphosphate aldolase enzymes of M. mycetomatis using immunoinformatics approaches.

Methods and materials:

Fructose-bisphosphate aldolase of M. mycetomatis sequence was retrieved from NCBI. Different prediction tools were used to analyze the nominee’s epitopes in Immune Epitope Database for B-cell, T-cell MHC class II and class I. Then the proposed peptides were docked using Autodock 4.0 software program.

Results and conclusions:

The proposed and promising peptides KYLQ show a potent binding affinity to B-cell, FEYARKHAF with a very strong binding affinity to MHC I alleles and FFKEHGVPL that shows a very strong binding affinity to MHC II and MHC I alleles. This indicates a strong potential to formulate a new vaccine, especially with the peptide FFKEHGVPL which is likely to be the first proposed epitope-based vaccine against fructose-bisphosphate aldolase of M. mycetomatis. This study recommends an in vivo assessment for the most promising peptides especially FFKEHGVPL.

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: a clinical dilemma in resource limited settings

Background

Mycetoma is a chronic mutilating disease of the skin and the underlying tissues caused by fungi or bacteria. Although recently included in the list of neglected tropical diseases by the World Health Organization, strategic control and preventive measures are yet to be outlined. Thus, it continues to pose huge public health threat in many tropical and sub-tropical countries. If not detected and managed early, it results into gruesome deformity of the limbs. Its low report and lack of familiarity may predispose patients to misdiagnosis and delayed treatment initiation. More so in situation where diagnostic tools are limited or unavailable, little or no option is left but to clinically diagnose these patients. Therefore, an overview of clinical course of mycetoma, a suggested diagnostic algorithm and proposed use of materials that cover the exposed susceptible parts of the body during labour may assist in the prevention and improvement of its management. Furthermore, early reporting which should be encouraged through formal and informal education and sensitization is strongly suggested.

Main text

An overview of the clinical presentation of mycetoma in the early and late phases, clues to distinguish eumycetoma from actinomycetoma in the field and the laboratory, differential diagnosis and a suggested diagnostic algorithm that may be useful in making diagnosis amidst the differential diagnosis of mycetoma is given. Additionally, a proposed preventive measures which may be helpful in the community is also provided. Since treatment is currently based on expert opinion, we encourage active research to establish treatment guideline for it.

Conclusion

Since delay in visiting health facility results into gruesome complication, early presentation, recognition and initiation of appropriate choice of regimen is helpful in reducing complications. The clinical overview of mycetoma and the suggested algorithm may enhance suspicion and possibly increase recognition of mycetoma in the community and further guide in differentiation of eumycetoma from actinomycetoma. There is an urgent need for research funding for mycetoma, a disease plagued by severe physical disabilities and social stigma leading to isolation.

Electronic supplementary material

The online version of this article (10.1186/s12941-018-0287-4) contains supplementary material, which is available to authorized users.

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.

Mycetomas: an epidemiological, etiological, clinical, laboratory and therapeutic review

Mycetoma is a chronic suppurative disease of the skin and subcutaneous tissue, characterized by a symptomatic triad: tumor, fistulas and grains. It can be caused by fungi (eumycetoma) and bacteria (actinomycetoma), with similar clinical features. Diagnosis is based on the clinical presentation and identification of the etiological agents in the tissue, by mycological/bacteriological, histopathological and immunohistochemical tests. It is important to specify the fungal or bacterial etiology, because the treatments are different. An approach that involves early diagnosis, the use of systemic antibiotics or antifungal agents, including surgical removal of lesions, is the basis for the treatment of these diseases. In this review, the most commonly used diagnostic methods and treatments will be discussed. Also, we will review the history of the disease through epidemiological and etiological aspects.

Case 249: Intramuscular Mycetoma

History A 21-year-old man presented with swelling of the medial aspect of the left thigh of 1-month duration. There was no history of fever or penetrating injury in the left thigh. The patient had undergone renal transplantation 7 years earlier and had been taking immunosuppressants since transplantation. He had undergone two surgeries at the same site in the medial aspect of the left thigh in the past 3 years for a similar problem. At physical examination, there was swelling in the medial aspect of the left thigh, with mild tenderness. A surgical scar was noted anterior to the swelling ( Fig 1 ). No redness or discharging sinus was present. Laboratory results were as follows: hemoglobin level, 11.3 g/dL (normal range, 13.8-17.2 g/dL); white blood cell count, 9.7 × 10⁹/L (normal range, [4-11] × 10⁹/L); neutrophil, 75% (normal range, 48%-77%); lymphocyte, 22% (normal range, 10%-24%); eosinophil, 1% (normal range, 0.3%- 7%); monocyte, 1% (normal range, 0.6%-10%); serum creatinine level, 1.3 mg/dL (114.9 μmol/L) (normal range, 0.5-1.6 mg/dL [44.2-141.4 μmol/L]); and serum glucose (random) level, 82 mg/dL (4.5 mmol/L) (normal range, 79-140 mg/dL [4.4-7.8 mmol/L]). Radiography of the left thigh showed soft-tissue swelling in the medial aspect of the left thigh, without underlying bone involvement (not shown). Ultrasonography (US) and magnetic resonance (MR) imaging of the left thigh were performed. [Figure: see text].