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

Emerging therapeutics: The imidazo[1,2-b]pyridazine scaffold as a novel drug candidate for eumycetoma, a neglected tropical disease

Mycetoma is a neglected invasive infection endemic in tropical and subtropical regions, presenting as a chronic subcutaneous inflammatory mass that can spread to deeper structures, leading to deformities, disabilities, and potentially mortality. The current treatment of eumycetoma, the fungal form of mycetoma, involves antifungal agents, such as itraconazole, combined with surgical intervention. However, this approach has limited success, with low cure rates and a high risk of recurrence. This study addresses to the urgent need for more effective therapeutics by designing and synthesising 47 diversely pharmacomodulated imidazo [1,2-b]pyridazine derivatives using a simple synthetic pathway with good yields and purity. Of these, 17 showed promising in vitro activity against Madurella mycetomatis, the prime causative agent of eumycetoma, with IC50 ≤ 5 μM and demonstrated significantly lower cytotoxicity compared to standard treatments in NIH-3T3 fibroblasts. Notably, compound 14d exhibited an excellent activity with an IC50 of 0.9 μM, in the same order then itraconazole (IC50 = 1.1 μM), and achieved a favourable selectivity index of 16 compared to 0.8 for itraconazole. These promising results warrant further research to evaluate the clinical potential of these novel compounds as safer, more effective treatments for eumycetoma, thus addressing a profound gap in current therapeutic strategies.

Mycetoma: A critical appraisal of educational content on YouTube

BACKGROUND

Mycetoma is a fungal neglected tropical disease. Accurate dissemination of information is critical in endemic areas. YouTube, a popular platform for health information, hosts numerous videos on mycetoma, but the quality and reliability of these videos remain largely unassessed.

METHODS

We used modified DISCERN and Global Quality Score (GQS) for reliability and quality respectively. Video duration, views, likes, and comments were recorded. Spearman's rank correlation and Mann-Whitney U tests were used to identify correlations between metrices and quality scores.

RESULTS

We included 73 mycetoma-related YouTube videos were analyzed, the median GQS score was 4.00 ((IQR = 3.33-4.00), indicating generally high-quality content, while the median mDISCERN score was 3.00 (IQR = 3.00-3.00) reflecting moderate reliability. Videos produced by professionals had significantly higher scores compared to those from consumer-generated content (p < 0.001). A significantly positive correlation was observed between video duration and both GQS (r = 0.417, p < 0.001) and mDISCERN (r = 0.343, p = 0.003). However, views, likes and comments did not significantly correlate with video quality. Additionally, videos longer in duration (p < 0.001) and older in upload date (p = 0.014) had higher quality scores.

CONCLUSIONS

The study shows that mycetoma-related videos on YouTube are generally of high quality, with moderate reliability. This emphasizes the need for expert involvement in content creation and efforts to improve health information online.

Drug Repurposing: Research Progress of Niclosamide and Its Derivatives on Antibacterial Activity

The development of antibiotic resistance complicates the treatment of infectious diseases and is a global public health threat. However, drug repurposing can address this resistance issue and reduce research and development costs. Niclosamide is a salicylanilide compound approved by the Food and Drug Administration (FDA), and it has been used clinically for treating parasitic infections for many years. Recent studies have shown that niclosamide can inhibit bacterial and fungus activity by affecting the quorum sensing system, biofilm formation, cell membrane potential, and other mechanisms. Here, we discuss recent advances in the antimicrobial applications of niclosamide and its derivatives to provide new perspectives in treating infectious diseases.

Intractable Nocardial mycetoma with possible colonisation by Candida species

A Japanese male in his 30s with no underlying medical condition presented with painless nodules after being bitten by a dog during a stay in Bali, Indonesia, 7 years earlier. He was referred to our department with multiple ulcers, nodules, and masses on the right leg. The final diagnosis was mycetoma caused by Nocardia vulneris, which may have been exacerbated by colonization of Candida parapsilosis and C. tropicalis as these yeasts were isolated by culture from the tissue. Treatment with minocycline hydrochloride and sulfamethoxazole trimethoprim showed partial efficacy, but the addition of posaconazole achieved significant efficacy. This suggests that the surmised coexistence of pathogenic yeasts of lower virulency may have made mycetoma in this case intractable.

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.

Misleading subcutaneous mycosis: a case report of subsequent clinical mycetoma-like and histological chromoblastomycosis-like lesions

Hyalohyphomycosis and phaeohyphomycosis are groups of mycoses caused by several agents and show different clinical manifestations. We report a case of an immunocompromised patient who presented rare manifestations of opportunistic mycoses: mycetoma-like hyalohyphomycosis on his right foot caused by Colletotrichum gloeosporioides, followed by cutaneous phaeohyphomycosis on his right forearm caused by Exophiala oligosperma. Further to the rarity of this case, the patient's lesion on the foot shows that the clinical aspects of mycetomas could falsely appear in other fungal infections similar to hyalohyphomycosis. We also show that the muriform cells that were seen in the direct and anatomopathological examination of the skin are not pathognomonic of chromoblastomycosis, as observed in the lesion of the patient's forearm.

Dot in circle sign on MRI in foot mycetoma

Mycetoma or Maduramycosis is a chronic granulomatous infectious condition encountered mostly in tropical and subtropical regions. It affects the deep subcutaneous tissues, which may progress to involve the muscles and bones later in the course of the disease. It can be caused by fungi (eumycetoma), and bacteria (actinomycetoma) predominantly affecting the foot. Demonstration of the causative agent by biopsy and microbiological studies helps to establish a confirmative diagnosis, and choosing correct antimicrobial therapy. However, it may be delayed resulting in increased patient morbidity. Thus, imaging plays a vital role in early recognition & prompt treatment, especially MRI which is a non-invasive procedure demonstrating the hallmark dot in circle sign. Here we report a case of mycetoma foot with pathognomic MRI findings.

Mycetoma case series in Somalia

Mycetoma is a suppurative chronic bacterial or fungal disease inoculated into the body by minor trauma which may penetrate from subcutaneous tissue to bone. Although the lower extremities are most commonly affected, rare forms can also be seen from time to time. The diagnostic triad of swelling in the affected area, multiple sinus formation, and purulent discharge with grains are typical. Definitive diagnosis is made by isolation of the causative pathogen, radiologic imaging, and histopathologic examination. Antifungal and antibacterial options are applied together with surgery. Our aim in this case series is to report and analyze 10 rare cases of mycetoma.

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).

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.

Emerging subcutaneous mycoses by opportunistic filamentous fungi: A retrospective study in Northwest Spain

BACKGROUND

Subcutaneous mycoses caused by opportunistic filamentous fungi are emerging infections in developed countries due to the longer survival of immunocompromised patients. The evidence published in relation to subcutaneous mycoses is fundamentally based on case reports and small case series.

METHODS

We performed an observational retrospective study of subcutaneous mycoses caused by opportunistic filamentous fungi diagnosed at our institution between 2017 and 2022. This study aims to estimate the incidence rate of subcutaneous mycoses, identify which fungal species are involved, and analyse which clinical variables predispose to infection and if any are associated with mortality.

RESULTS

Fifteen patients met the inclusion criteria. The median age was 61 years (range 27-84), and 80% of them were males. Alternaria spp. were the most common fungi. Two other organisms were frequently isolated: Scedosporium apiospermum and Fusarium solani. Among patients infected with F. solani, 66.7% died. The most common clinical presentation was suppurative nodules in the lower limbs and the main risk factors for infection were immunosuppressants, corticosteroids, previous trauma and transplantation, but they were not particularly associated with increased mortality. A statistically significant association with mortality was only found in the case of positive blood culture (p = <.001).

CONCLUSIONS

Phaeohyphomycosis has a lower risk of dissemination, especially when compared to subcutaneous mycoses caused by hyalohyphomycetes. It is important to convey the severity of these skin infections to the physicians involved in the treatment and follow-up of susceptible patients to avoid misdiagnosis and delays in the treatment, especially in the case of hyalohyphomycosis.

Primary mycetoma of the calcaneum: Case report on an unusual hazard of barefoot walking

INTRODUCTION

Mycetoma is a rare tropical fungal infection characterized by a clinical triad of subcutaneous swelling, multiple discharging sinuses, and a purulent discharge containing granules. If left untreated, the disease can progress from cutaneous to intraosseous and can cause osteomyelitis. In very rare instances labeled "primary mycetoma", the fungus is insidiously inoculated directly into the bone and causes osteomyelitis without any preceding cutaneous involvement. This can make the diagnosis very difficult.

PRESENTATION OF CASE

A twelve-year-old girl with a history of walking barefoot, presented with pain and inability to bear weight on her left foot. There was no overlying cutaneous involvement. X-ray showed an osteolytic lesion in the calcaneum. After the failure of antibiotic treatment, the diseased bone was excised. Black granules were discovered inside the lesion and their histopathology confirmed a diagnosis of primary eumycetoma. After some time, the disease relapsed, necessitating another debridement. This occurred many times with worsened severity in each successive episode. Because of worsening disease and failure of both antifungal and surgical treatment, foot amputation was done.

DISCUSSION

Primary mycetoma is an insidious fungal infection that causes osteomyelitis without any cutaneous findings. Timely diagnosis and treatment provide the best chance of preventing an amputation.

CONCLUSION

A high index of suspicion must be maintained for patients presenting with symptoms of osteomyelitis without any skin involvement so that timely diagnosis and treatment can prevent the progression of the disease and the need for amputation.

Actinomycetoma distal radius mimic osteosarcoma: A case report of a rare presentation

Key Clinical Message

Actinmomycetma is a granulomatous infection with a presentation was very similar to osteosarccoma. Multidisciplinary team and triple assessments are extremely important to prevent misdiagnosis, surgical treatment in combination with medical treatment followed by regular clinical and radiological follow-up can be a limb-saving procedure in such cases.

Abstract

Various conditions may mimic osteosarcoma. The differential diagnosis of osteosarcoma is broad; Includes tumors, infection, trauma, and inflammatory processes arising from the musculoskeletal system. A proper history, examination, diagnostic imaging studies, and pathological analysis are essential to establish a precise diagnosis. This case report serves to illustrate the significance of recognizing the similarities between these two lesions and other rare features that will help to differentiate between actinomycetoma and osteosarcoma, to prevent late or misdiagnosis.

Mycetoma (Madura foot): A Case Report of a Rare Tropical Disease in Turkey

Mycetoma is a chronic discharging infection involving the skin, subcutaneous tissue, fascia, and bone, which is endemic in tropical and subtropical countries. We report a rare case of mycetoma localized on the foot of a patient living in a country with a temperate climate. A 32-year-old male patient presented with painless swelling in the right foot. He had undergone surgery 3 years ago with the same complaints. Magnetic resonance imaging revealed a 90 × 65 × 37 mm cystic soft tissue lesion in the posterior of the right ankle. Histological analysis identified the fungus. Extensive resection was performed. Mycetoma is characterized by chronic granulomatous inflammatory response, often associated with sinus tract formations due to fungal (eumycetoma) or bacterial (actinomycetoma) organisms. Here we provide a literature review and highlight the importance of increasing awareness toward mycetoma, particularly in non-endemic regions.

Updated Review on Nocardia Species: 2006-2021

This review serves as an update to the previous Nocardia review by Brown-Elliott et al. published in 2006 (B. A. Brown-Elliott, J. M. Brown, P. S. Conville, and R. J. Wallace. Jr., Clin Microbiol Rev 19:259-282, 2006, https://doi.org/10.1128/CMR.19.2.259-282.2006). Included is a discussion on the taxonomic expansion of the genus, current identification methods, and the impact of new technology (including matrix-assisted laser desorption ionization-time of flight [MALDI-TOF] and whole genome sequencing) on diagnosis and treatment. Clinical manifestations, the epidemiology, and geographic distribution are briefly discussed. An additional section on actinomycotic mycetoma is added to address this often-neglected disease.

Development and validation of a resazurin assay for in vitro susceptibility testing of Actinomadura madurae: a common causative agent of actinomycetoma

OBJECTIVES

Actinomycetoma is a chronic granulomatous disease affecting skin, subcutaneous tissue, fascia, muscle and bones. With increasing resistance against commonly used treatment regimens, susceptibility testing is urgently needed.

METHODS

We developed an in vitro susceptibility assay for Actinomadura madurae, one of the common causative agents of actinomycetoma, employing resazurin for endpoint reading. Using this assay, reproducible MICs were determined for the most commonly used antibacterial agents for actinomycetoma treatment. The tested antibacterial agents included trimethoprim/sulfamethoxazole, amikacin, streptomycin, amoxicillin, ceftriaxone, gentamicin, ciprofloxacin, doxycycline, imipenem, linezolid, penicillin G and rifampicin.

RESULTS

Following the clinical breakpoints as stated by CLSI, 100% of the tested strains were susceptible to trimethoprim/sulfamethoxazole (MIC 0.03/0.59-1/19 mg/L), amikacin (MIC 0.0078-0.25 mg/L), doxycycline (MIC <0.25-1 mg/L) and linezolid (MIC <0.25-2 mg/L), 90% to ciprofloxacin (MIC <0.25-2 mg/L), 80% to ceftriaxone (MIC <0.5 to >64 mg/L) and imipenem (MIC <0.25-32 mg/L) and only 20% to amoxicillin (MIC <0.5 to >64 mg/L) and rifampicin (MIC 0.5 to >32 mg/L).

CONCLUSIONS

Determinations of MICs by visual readings of colour changes versus spectrophotometric readings were comparable. This convenient visual reading has the advantage of feasible implementation in endemic settings.

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.

Mycetoma: Development of Diagnosis and Treatment

Mycetoma describes a heterogeneous group of cutaneous and subcutaneous infections caused by either fungi (eumycetomas) or bacteria (actinomycetomas). It is characterized by a triad of clinical symptoms: painless subcutaneous tumor-like swelling, multiple sinuses and fistulas, and discharged grains in pus. This predominantly affects the feet in more than 70% of patients. It is endemic in the "mycetoma belt" regions, including Africa, South America, and South Asia. Autochthonous mycetoma is rare in the United States of America (USA). We recently reported a Latin American immigrant with eumycetoma in the State of Maryland, USA. With millions of immigrants from endemic regions, the true number of mycetomas in the USA is most likely higher than currently recognized. With the aim to raise the awareness of clinicians about mycetoma, especially dermatologists and podiatrists, we update the development of the epidemiology, etiology, clinical presentations, pathogenesis, diagnosis, differential diagnosis, and treatment 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.

Mycetoma due to Aspergillus flavus in a diabetic patient: Case report and literature review

Diabetes mellitus patients are prone to cutaneous and subcutaneous fungal infections due to pathogenic fungi, including dermatophytes, Mucorales, Candida, Aspergillus, and Fusarium species. Here, we report a case of A. flavus mycetoma confirmed by isolation and molecular identification. The case was a 38-year-old male farmer with a seven-year history of type 2 diabetes mellitus, living in Khuzestan, southwest of Iran. The patient presented with a right foot swelling associated with a nodule and multiple discharging sinuses following trauma sustained on the foot while working barefoot on the rice farm, a year ago. The nodule appeared at the site of the trauma two months after the injury. The initial diagnosis was based on direct microscopic examination of lesions scraping using 20% potassium hydroxide and radiology. Molecular analysis confirmed the isolates to be A. flavus. In vitro susceptibility of the isolate to voriconazole, posaconazole, caspofungin, itraconazole, and amphotericin B was determined. Treatment with voriconazole (200 mg twice daily) stopped the purulent discharge, reduced the swelling, and improved the clinical condition within two months. The study emphasizes the importance of wearing footwear to prevent skin trauma as the main risk factor of patient involvement.

Eumycetoma, A Neglected Tropical Disease in the United States

Eumycetoma, caused by fungi, is a neglected tropical disease. It is endemic in the "mycetoma belt" countries but rare in North America. We report a case of pedal eumycetoma in the state of Maryland. A 51-year-old male immigrant from Guatemala presented with multiple, enlarging nodules on the dorsal surface of his left great toe present for 1 year, and a new one in the left arch area present for 6 months. The nodular lesions were surgically excised in two separate operations. Pathologic evaluation of all nodules revealed eumycetomas characterized by the Splendore-Hoeppli phenomenon, showing an amorphous eosinophilic center filled with numerous fungal hyphae, observed on periodic acid-Schiff-stained slides, with a surrounding cuff of neutrophils. Polymerase chain reaction-based sequencing identified Cladosporium cladosporioides in the tissues. The patient was further treated with oral fluconazole for 2 months. The patient recovered well postoperatively and had no recurrence at 20-month follow-up. In conclusion, even though eumycetoma is regarded as a rare disease in North America, its incidence may be higher than reported because of millions of immigrants from endemic regions in the United States, which highlights the need to raise awareness of this devastating disease in the medical community. Eumycetoma needs to be differentiated from other infectious and noninfectious benign and malignant lesions. Optimal treatment includes surgical excision with antifungal therapy.

Eumycetoma Osteomyelitis Calcaneus in Adolescent; report of case and literature review

BACKGROUND

Mycetoma is the most common neglected disease in humans. It is a chronic, progressive, and destructive disease primarily caused by fungi or bacteria characterized by formation of dark pale grains commonly involve skin, soft tissue and rarely bone.

CASE PRESENTATION

A 19 year old male patient with chronic right ankle pain, swelling and abscess formation for more than 1 year, patient was treated repeatedly with incision and drainage without any success. No X-ray, biopsy or swab for culture and sensitivity had been considered through the course of presentation. Patient was referred to Omdurman hospital where osteomyelitis secondary euomycetoma infection has been confirmed based on radiological and pathological assessment. Patient was treated surgically with aggressive debridement and bone curettage plus postoperative Itraconazole for 1 year.

CONCLUSION

Clinicians must consider osteomyelitis as important differential diagnosis during initial assessment Eumycetoma infection in adults. Aggressive bone curettage followed by regular X-ray follow up can be limb saving procedure in such cases.

Comparison of Disc Diffusion, Etest, and a Modified CLSI Broth Microdilution Method for In Vitro Susceptibility Testing of Itraconazole, Posaconazole, and Voriconazole against Madurella mycetomatis

For many fungal infections, in vitro susceptibility testing is used to predict if an isolate is resistant or susceptible to the antifungal agent used to treat the infection. For Madurella mycetomatis, the main causative agent of mycetoma, in vitro susceptibility testing currently is not performed on a routine basis. The current in vitro susceptibility testing method is labor-intensive, and sonication must be done to generate a hyphal inoculum. For endpoint visualization, expensive viability dyes are needed. Here, we investigated if the currently used in vitro susceptibility method could be adapted to make it amendable for use in a routine setting which can be used in low-income countries, where mycetoma is endemic. First, we developed a methodology in which hyphal fragments can be generated without the need for sonication, by comparing different bead beating methodologies. Next, in vitro susceptibility was assessed using standard broth microdilution assays as well as disc diffusion, Etest, and VIPcheck methodologies. We demonstrate that after a hyphal suspension is generated by glass bead beating, disc diffusion, Etest, and VIPcheck can be used to determine susceptibility of Madurella mycetomatis to itraconazole, posaconazole, and voriconazole. The MICs found with Etest were comparable to those obtained with our modified CLSI-based broth microdilution in vitro susceptibility assay for itraconazole and posaconazole. Furthermore, we found an inverse relationship between the zones of inhibition and MICs obtained with the Etest and those obtained by the modified CLSI broth microdilution technique.

Niclosamide Is Active In Vitro against Mycetoma Pathogens

Redox-active drugs are the mainstay of parasite chemotherapy. To assess their repurposing potential for eumycetoma, we have tested a set of nitroheterocycles and peroxides in vitro against two isolates of Madurella mycetomatis, the main causative agent of eumycetoma in Sudan. All the tested compounds were inactive except for niclosamide, which had minimal inhibitory concentrations of around 1 µg/mL. Further tests with niclosamide and niclosamide ethanolamine demonstrated in vitro activity not only against M. mycetomatis but also against Actinomadura spp., causative agents of actinomycetoma, with minimal inhibitory concentrations below 1 µg/mL. The experimental compound MMV665807, a related salicylanilide without a nitro group, was as active as niclosamide, indicating that the antimycetomal action of niclosamide is independent of its redox chemistry (which is in agreement with the complete lack of activity in all other nitroheterocyclic drugs tested). Based on these results, we propose to further evaluate the salicylanilides, niclosamidein particular, as drug repurposing candidates for mycetoma.

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.

Human actinomycetoma caused by Actinomadura mexicana in Sudan: the first report

Mycetoma is a localized, chronic, granulomatous disease that can be caused by fungi (eumycetoma) or bacteria (actinomycetoma). Of the 70 different causative agents implicated in mycetoma worldwide, Actinomadura madurae is the only one that causes multiple cases on all continents. Recently, new Actinomadura species were described as causative agents of human mycetoma. One of these new causative agents was Actinomadura mexicana, which was identified in Latin America. Here we demonstrate that this causative agent is not confined to Latin America and that it is also a causative agent of actinomycetoma in Sudan. The disease was managed by antibiotic treatment alone and resulted in complete cure after 6 months of treatment, which is quick when compared with actinomycetoma cases caused by other Actinomadura species.

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.

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.

Eumycetoma of the Foot due to Fusarium solani in a Person with Diabetes Mellitus: Report of a Case and Review of Literature

Eumycetomas are chronic suppurative granulomas caused by fungi characterised by invasive tumefactive lesions, sinuses and discharging grains. Herein, we describe a case of pedal eumycetoma due to Fusarium solani sensu stricto in a person with diabetes mellitus. A 45-year-old gentleman presented with an insidious onset swelling over his right foot with nodules and discharging grains. He had received itraconazole and anti-tuberculous therapy elsewhere, without response. Re-evaluation included a biopsy which confirmed eumycetoma and newly diagnosed diabetes. Surgical excision followed by histopathological, microbiological and multigene sequencing analyses [translation elongation factor, calmodulin and internal transcribed spacer region of rDNA] of the mould on culture were performed. Histopathology revealed septate fungal hyphae amidst a dense inflammatory infiltrate (Splendore-Hoeppli) reaction. Oral voriconazole was started and good glycemic control attained. Tissue growth sequences showed > 99% similarity with Fusarium solani sensu stricto. Antifungal susceptibility testing showed lowest MIC to voriconazole (0.5 mg/L). The patient showed excellent response to combined therapeutic modality with a near-complete resolution in size of lesion and obliteration of sinuses following 4 months of therapy and is planned for prolonged voriconazole therapy till complete radiological resolution. Diabetes predisposes to fungal infections of foot but eumycetomas are uncommon. Combined surgery and antifungals can improve morbidity and avoid amputations.

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.

Abdominal wall actinomycotic mycetoma involving the bowel: a rare entity

Actinomycotic mycetoma is a disease of the tropical region and usually presents as a chronic, suppurative and deforming granulomatous infection. We present an unusual case of actinomycotic mycetoma of the abdominal wall that was found to infiltrate into the bowel. A 51 year-old man presented with pain and swelling in the left flank of 2-year duration. Even after comprehensive preoperative evaluation with advanced radiological imaging, biochemistry and pathology, the diagnosis could not be arrived at. Histopathological examination of the excised specimen after the surgery guided to the diagnosis of actinomycotic mycetoma, which entirely changed the management in the postoperative period. We propose that mycetoma should be kept as a possible differential diagnosis for anterior abdominal wall swelling in the indicated clinical setting and the investigations be done keeping the same in mind. Otherwise, a lot of valuable time may be lost allowing the disease to progress further.

The global distribution of actinomycetoma and eumycetoma

Background

Mycetoma, a chronic infection of the skin and underlying structures, affects those with a close relationship to the land, often in resource-poor areas of the world. Whether caused by any one of a variety of fungus or bacteria, mycetoma causes significant disability and mortality. Acknowledged as a neglected tropical disease (NTD) by the World Health Organization (WHO) in 2016, mycetoma is susceptible to being misunderstood, misdiagnosed, and mismanaged. In an effort to shift the balance in favor of recognition and effective treatment, sound epidemiological understanding is required.

Methods and findings

In this paper, a literature review of case reports and series (332 papers in total) is presented as three maps. We identified 19,494 cases dating from 1876 to 2019, with cases contracted in 102 countries. The first map shows where mycetoma has ever been reported, the second shows how many cases have been reported, and the third shows the ratio of eumycetoma (fungal) to actinomycetoma (bacterial). Most cases are found in Mexico, India, and Sudan, where mycetoma is studied rigorously. We identified emergence of new geographical loci, including the United States, Venezuela, Italy, China, and Australia. Notably, mycetoma is reported far outside the tropics. In the Americas, bacterial forms dominate, whereas, in Africa and Asia, the picture is more varied.

Conclusions

With better understanding of the epidemiology of mycetoma, more can be done to direct education, preventive measures, and treatment to at-risk areas, enabling a reduction in disease burden.

Mycetoma is an ancient and misunderstood chronic disease. Affecting the skin and subcutaneous structures, infection often occurs in the feet of land laborers and can be caused by several otherwise rare human pathogens. Traditionally seen as a tropical disease, it affects those in resource-poor regions. The best methods of diagnosis are rarely available in these areas; late diagnosis increases the need for invasive surgical treatment. Available medical treatment can be prohibitively expensive. Early diagnosis and identification of the causative agent is necessary for effective treatment. For this paper, a literature review was undertaken to find all published cases of mycetoma linked to a location and the data used to create three maps. The maps show where mycetoma has ever been reported, how many cases have been reported, and what kind of microorganism was present. We included 19,494 cases, most of which occurred in Mexico, Sudan, and India. Notably, some cases arose far outside the tropics. In the Americas, most cases are bacterial; elsewhere, the picture is more varied. Many gaps remain in the epidemiological study of mycetoma, but this paper aims to shed light on the significant reach of the disease, with a view to increasing its visibility on the global stage and, therefore, the scope for reducing the burden of this neglected tropical disease.

Innate Inspiration: Antifungal Peptides and Other Immunotherapeutics From the Host Immune Response

The purpose of this review is to describe antifungal therapeutic candidates in preclinical and clinical development derived from, or directly influenced by, the immune system, with a specific focus on antimicrobial peptides (AMP). Although the focus of this review is AMP with direct antimicrobial effects on fungi, we will also discuss compounds with direct antifungal activity, including monoclonal antibodies (mAb), as well as immunomodulatory molecules that can enhance the immune response to fungal infection, including immunomodulatory AMP, vaccines, checkpoint inhibitors, interferon and colony stimulating factors as well as immune cell therapies. The focus of this manuscript will be a non-exhaustive review of antifungal compounds in preclinical and clinical development that are based on the principles of immunology and the authors acknowledge the incredible amount of in vitro and in vivo work that has been conducted to develop such therapeutic candidates.

Climate, soil type, and geographic distribution of actinomycetoma cases in Northeast Mexico: A cross-sectional study

Background

Mycetoma is a chronic, granulomatous infection of subcutaneous tissue, that may involve deep structures and bone. It can be caused by bacteria (actinomycetoma) or fungi (eumycetoma). There is an epidemiological association between mycetoma and the environment, including rainfall, temperature and humidity but there are still many knowledge gaps in the identification of the natural habitat of actinomycetes, their primary reservoir, and their precise geographical distribution. Knowing the potential distribution of this infection and its ecological niche in endemic areas is relevant to determine disease management strategies and etiological agent habitat or reservoirs.

Methodology/principal findings

This was an ambispective descriptive study of 31 patients with actinomycetoma. We determined the biophysical characteristics including temperature, precipitation, soil type, vegetation, etiological agents, and mapped actinomycetoma cases in Northeast Mexico. We identified two disease cluster areas. One in Nuevo Leon, with a predominantly kastanozems soil type, with a mean annual temperature of 22°, and a mean annual precipitation of 585.2 mm. Herein, mycetoma cases were produced by Actinomadura pelletieri, Actinomadura madurae, Nocardia brasiliensis, and Nocardia spp. The second cluster was in San Luis Potosí, where lithosols soil type predominates, with a mean annual temperature of 23.5° and a mean annual precipitation of 635.4 mm. In this area, all the cases were caused by N. brasiliensis. A. madurae cases were identified in rendzinas, kastanozems, vertisols, and lithosols soils, and A. pelletieri cases in xerosols, kastanozems, and rendzinas soils. Previous thorn trauma with Acacia or Prosopis plants was referred by 35.4% of subjects. In these states, the presence of thorny plants, such as Acacia spp., Prosopis spp., Senegalia greggi, Vachellia farnesiana and Vachellia rigidula, are common.

Conclusions/significance

Mapping this neglected tropical infection aids in the detection of disease cluster areas, the development of public health strategies for early diagnosis and disease prediction models; this paves the way for more ecological niche etiological agent research.

Host genetic susceptibility to mycetoma

Mycetoma is one of the badly neglected tropical diseases, characterised by subcutaneous painless swelling, multiple sinuses, and discharge containing aggregates of the infecting organism known as grains. Risk factors conferring susceptibility to mycetoma include environmental factors and pathogen factors such as virulence and the infecting dose, in addition to host factors such as immunological and genetic predisposition. Epidemiological evidence suggests that host genetic factors may regulate susceptibility to mycetoma and other fungal infections, but they are likely to be complex genetic traits in which multiple genes interact with each other and environmental factors, as well as the pathogen, to cause disease. This paper reviews what is known about genetic predisposition to fungal infections that might be relevant to mycetoma, as well as all studies carried out to explore host genetic susceptibility to mycetoma. Most studies were investigating polymorphisms in candidate genes related to the host immune response. A total of 13 genes had allelic variants found to be associated with mycetoma, and these genes lie in different pathways and systems such as innate and adaptive immune systems, sex hormone biosynthesis, and some genes coding for host enzymes. None of these studies have been replicated. Advances in genomic science and the supporting technology have paved the way for large-scale genome-wide association and next generation sequencing (NGS) studies, underpinning a new strategy to systematically interrogate the genome for variants associated with mycetoma. Dissecting the contribution of host genetic variation to susceptibility to mycetoma will enable the identification of pathways that are potential targets for new treatments for mycetoma and will also enhance the ability to stratify ‘at-risk’ individuals, allowing the possibility of developing preventive and personalised clinical care strategies in the future.

Draft Genome Sequences of Three Clinical Isolates of Madurella mycetomatis, the Major Cause of Black-Grain Mycetoma

The draft genomes of three fungal clinical isolates of Madurella mycetomatis from patients with mycetoma are presented. No finished genome is currently available for this important fungus. Therefore, the addition of these new draft genomes will help us better understand the diversity and pathogenicity of this important species.

The draft genomes of three fungal clinical isolates of Madurella mycetomatis from patients with mycetoma are presented. No finished genome is currently available for this important fungus. Therefore, the addition of these new draft genomes will help us better understand the diversity and pathogenicity of this important species.

New Developments in Bacterial, Viral, and Fungal Cutaneous Infections

PURPOSE OF REVIEW

This review highlights clinically relevant updates to common and significant bacterial, viral, and fungal cutaneous infection within the past 5 years. Recent developments are presented so that the clinician may provide evidence-based, high-quality patient care.

RECENT FINDINGS

New resistance patterns in cutaneous pathogens have recently emerged as a result of inappropriate antimicrobial use. Several new FDA-approved antimicrobials have been approved to treat such infections, including multi-drug resistant pathogens. Several organizational guidelines for cutaneous infection management have been updated with new recommendations for screening, diagnostic, and treatment strategies.

SUMMARY

Clinicians should be aware of the most recent evidence and guidelines for the management of cutaneous infections in order to reduce the emergence of antimicrobial resistance and most effectively treat their patients.

Clinical characteristics and treatment of actinomycetoma in northeast Mexico: A case series

Background

Mycetoma is a neglected tropical disease characterized by nodules, scars, abscesses, and fistulae that drain serous or purulent material containing the etiological agent. Mycetoma may be caused by true fungi (eumycetoma) or filamentous aerobic bacteria (actinomycetoma). Mycetoma is more frequent in the so-called mycetoma belt (latitude 15° south and 30° north around the Tropic of Cancer), especially in Sudan, Nigeria, Somalia, India, Mexico, and Venezuela. The introduction of new antibiotics with fewer side effects, broader susceptibility profiles, and different administration routes has made information on actinomycetoma treatment and outcomes necessary. The objective of this report was to provide an update on clinical, therapeutic, and outcome data for patients with actinomycetoma attending a reference center in northeast Mexico.

Methodology/principal findings

This was a retrospective, cross-sectional, descriptive study of 31 patients (male to female ratio 3.4:1) diagnosed with actinomycetoma by direct grain examination, histopathology, culture, or serology from January 2009 to September 2018. Most lesions were caused by Nocardia brasiliensis (83.9%) followed by Actinomadura madurae (12.9%) and Actinomadura pelletieri (3.2%). About 50% of patients had bone involvement, and the right leg was the most commonly affected region in 38.7% of cases. Farmers/agriculture workers were most commonly affected, representing 41.9% of patients. The most commonly used treatment regimen was the Welsh regimen (35.5% of cases), a combination of trimethoprim/sulfamethoxazole (TMP/SMX) plus amikacin, which had a 90% cure rate, followed by TMP/SMX plus amoxicillin/clavulanic acid in 19.4% of cases with a cure rate of 100%. In our setting, 28 (90.3%) patients were completely cured and three (9.7%) were lost to follow-up. Four patients required multiple antibiotic regimens due to recurrences and adverse effects.

Conclusions/significance

In our sample, actinomycetoma was predominantly caused by N. brasiliensis. Most cases responded well to therapy with a combination of TMP/SMX with amikacin or TMP/SMX and amoxicillin/clavulanic acid. Four patients required multiple antibiotics and intrahospital care.

Mycetoma is a chronic skin disease that can invade bone or underlying organs. Inadequate treatment may lead to long-lasting disability. Information about treatment is scarce. We report the outcomes of 31 patients with a diagnosis of bacterial actinomycetoma attending a tertiary care hospital in northeast Mexico. Most cases were treated with a combination of antibiotics including TMP/SMX plus amikacin or TMP/SMX plus amoxicillin/clavulanic acid. Cure was achieved in 90% of patients and only one required surgery.

Actinomycetoma caused by Gordonia westfalica: first reported case of human infection

Bacteria of the genus Gordonia are rarely involved in human infections. We report here the case of a 30-year-old man from Guinea Buissau with mycetoma of the foot. 16S DNA sequencing after surgical biopsy identified Gordonia westfalica. To our knowledge, this is the first report of human infection caused by G. westfalica.

Characterization of Foot Mycetoma Using Sonography and Color Doppler Imaging

BACKGROUND AND OBJECTIVE

Mycetoma of the foot, commonly referred to as Madura foot, is a chronic granulomatous infection, which impacts vascularization of the affected region. This study aimed to evaluate foot mycetoma using Doppler and sonography techniques to identify the principle sonographic features and blood flow patterns associated with the condition.

MATERIALS AND METHODS

This was a cross-sectional prospective single-center study conducted at the Mycetoma Research Center (MCR) in Khartoum State, Sudan. Sixty patients with Madura foot were examined using a Duplex ultrasound machine with a 7-10 MHZ linear probe. Data was analyzed using SPSS software. The distribution of demographic data was evaluated by simple descriptive statistics. Statistical tests was performed using Student's independent t-tests to compare different forms of mycetoma and Chi-square tests to examine differences in blood flow patterns between fungal (eumycetoma) and bacterial (actinomycetoma) forms of the infection.

RESULTS

The presence of multiple cavities and aggregated grains were more common in eumycetoma than in actinomycetoma. The echotexture was significantly more heterogeneous in eumycetoma than in actinomycetoma (p = 0.03). Eumycetoma had higher vascularity than actinomycetoma.

CONCLUSION

Mycetoma has characteristic sonographic features and patterns of vascularity, which are essential to differentiate between the fungal and bacterial forms of mycetoma.