Mycetoma of the foot caused by Fusarium solani: identification of the etiologic agent by DNA sequencing

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.

The First Case of Fusarium falciforme Eumycetoma in Sudan and an Extensive Literature Review about Treatment Worldwide

Eumycetoma is an infectious disease caused by various fungal pathogens. The disease is characterised by black and pale-yellowish grain discharge. In this communication, we report a case of eumycetoma with a pale grain foot-eumycetoma caused by Fusarium falciforme. The patient presented at the outpatient clinic of the Mycetoma Research Centre in Sudan. The causative agent was initially misidentified as Aspergillus nidulans based on its seemingly similar histopathological appearance. However, sequencing the internally transcribed spacer region of the extracted grain confirmed infection with Fusarium falciforme. Although the patient received Itraconazole and underwent surgical excision, the disease was recurrent. To our knowledge, this is the first report on Fusarium falciforme causing eumycetoma in Sudan, indicating the expansion of the geographical distribution of this pathogen. This calls for raising the awareness of healthcare providers and improving the diagnostic and surveillance systems in at-risk areas to improve the case management and reduce the threat of further spread. Considering the potential impacts of F. falciforme infection including threatening the global health, food security, and ecosystem balance, as well as loss of biodiversity and negative socioeconomic changes in endemic countries, we recommend the implementation of an integrated transdisciplinary One Health strategy for the prevention and control of emerging infectious diseases including F. falciforme.

An Illustrative Report of Three Cases of Madura Foot with Diagnostic and Treatment Features

Introduction

Madura foot is a rare infective granulomatous foot disease. The burden of this disease has significantly declined in recent years due to better generalized living conditions. Hence, the diagnosis can be quite often missed by the new generation orthopedic surgeon for other more similar conditions. Early diagnosis and prompt treatment is crucial for better outcome and limb survival. We here present the clinical picture of three such Madura foot cases.

Case Series

In this study, three Indian males aged between 40 and 60 years of rural background presented to our department with chronic multiple discharging sinuses of the foot. They were initially treated for several months in their local health centers without any improvement. Finally, they came to our institution where they were thoroughly inspected and underwent various investigations such as magnetic resonance imaging (MRI) and histopathological examination. They were referred across various departments such as dermatology, general surgery and orthopedics, and eventually got correct diagnosis. Treatment was promptly started with oral itraconazole, an antifungal drug, and one patient undergoing additional surgical debulking of the disease which lead to gradual healing of the disease as evident by disappearance of sinuses and return of normal skin in 6-12 months.

Conclusion

Madura foot is very characteristic, although it may mimic more prevalent infectious conditions. The characteristic multiple discharging sinuses with extrusions of sulphur granules and MRI findings of "dot in circle" should clinch the diagnosis quickly. Medical therapy should be continued for at least 12 months even if there is resolution of disease in the early or mid-phase of treatment. Debulking of the disease will aid in early recovery and reduce abnormal swelling or appearance of the foot.

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.

Molecular identification of clinical isolates of Fusarium in Colombia

OBJECTIVE

Identifying Fusarium isolates from mycosis symptomatic patients through molecular techniques as PCR and sequencing.

METHODS

In this study, samples were taken from 101 mycosis symptomatic patients in-between 2004-2006. To determine isolates belonging to the Fusarium genus, the DNAr 28S region was amplified through PCR and specific PCR primers further confirmed their identity to the species level. Additionally, in order to confirm the identity of the species of the isolates, 75 isolates of these were analyzed by partial sequencing of the 28S rDNA and the TEF1-α gene.

RESULTS

The 28S rDNA portion detected all 101 isolates as belonging to Fusarium and the PCR specific primers detected 52 and 29 isolates as F. oxysporum and F. solani, respectively; 34 and 41 of these, afterwards studied by partial sequencing of the 28S rDNA and TEF1- α genes respectively, were effectively identified by the technique.

CONCLUSION

From all the molecular markers used to identify Fusarium isolates, the sequence of the TEF1-α gene provided the best resolution in the identification of species level; however it is possible to discriminate between F. oxysporum and F. solani isolates by PCR, in most of the cases, what is important considering the simplicity of the technique and a faster diagnosis.

Fusarium: The versatile pathogen

Fusarium is an emerging human opportunistic pathogen of growing importance, especially among immunosuppressed haematology patients due to an increased incidence of disseminated infections over the past two decades. This trend is expected only to continue due to the advances in medical and surgical technologies that will prolong the lives of the severely ill, making these patients susceptible to rare opportunistic infections. Production of mycotoxins, enzymes such as proteases, angio-invasive property and an intrinsically resistant nature, makes this genus very difficult to treat. Fusarium is frequently isolated from the cornea and less commonly from nail, skin, blood, tissue, Continuous Ambulatory Peritoneal Dialysis (CAPD) fluid, urine and pleural fluid. Conventional microscopy establishes the genus, but accurate speciation requires multilocus sequence typing with housekeeping genes such as internal transcribed spacer, translation elongation factor-1α and RPB1 and 2 (largest and second largest subunits of RNA polymerase), for which expansive internet databases exist. Identifying pathogenic species is of epidemiological significance, and the treatment includes immune reconstitution by granulocyte-colony-stimulating factor, granulocyte macrophage-colony-stimulating factor and a combination of the most active species - specific antifungals, typically liposomal amphotericin-B and voriconazole. However, patient outcome is difficult to predict even with in vitro susceptibility with these drugs. Therefore, prevention methods and antifungal prophylaxis have to be taken seriously for these vulnerable patients by vigilant healthcare workers. The current available literature on PubMed and Google Scholar using search terms 'Fusarium', 'opportunistic invasive fungi' and 'invasive fusariosis' was summarised for this review.

Fusarium species causing eumycetoma: Report of two cases and comprehensive review of the literature

Recently, mycetoma was added to the World Health Organization's list of neglected tropical disease priorities. Fusarium as a genus has been reported to cause eumycetoma, but little is known about the species involved in this infection and their identification. In this study, molecular tools were applied to identify Fusarium agents from human eumycetoma cases. The partial translation elongation factor 1-alpha (TEF-1α) gene was used as diagnostic parameter. Two additional cases of eumycetoma, due to F. keratoplasticum and F. pseudensiforme, respectively, are presented. A systematic literature review was performed to assess general features, identification, treatment and outcome of eumycetoma infections due to Fusarium species. Of the 20 reviewed patients, the majority (75%) were male. Most agents belonged to the F. solani species complex, ie F. keratoplasticum, F. pseudensiforme, and an undescribed lineage of F. solani. In addition, F. thapsinum, a member of Fusarium fujikuroi species complex was encountered. The main antifungal drugs used were itraconazole, ketoconazole and amphotericin B, but cure rates were low (15%). Partial response or relapse was observed in some cases, and a case ended in amputation. Clinical management of eumycetoma due to Fusarium is complex and combination therapy might be required to increase cure rates.

Fatal Fusarium solani species complex infections in elasmobranchs: the first case report for black spotted stingray (Taeniura melanopsila) and a literature review

Fusarium species are environmental saprophytic fungi. Among the many Fusarium species, members of the Fusarium solani species complex (FSSC) are the most prevalent and virulent in causing human and animal infections. In this study, we describe the first case of fatal FSSC infection in a black spotted stingray and three concomitant infections in scalloped hammerhead sharks. In the stingray, cutaneous lesions were characterised by ulcers and haemorrhage of the ventral pectoral fin, or 'ray', especially around the head; while cutaneous lesions in the sharks were characterised by ulcers, haemorrhage, as well as white and purulent exudates at the cephalic canals of the cephalofoil and lateral line. Histological sections of the cutaneous lesions revealed slender (1-4 μm in diameter), branching, septate fungal hyphae. Internal transcribed spacer region and 28S nrDNA sequencing of the fungal isolates from the fish showed two isolates were F. keratoplasticum (FSSC 2) and the other two were FSSC 12. Environmental investigation revealed the FSSC strains isolated from water and biofilms in tanks that housed the elasmobranchs were also F. keratoplasticum and FSSC 12. Fusarium is associated with major infections in elasmobranchs and FSSC 12 is an emerging cause of infections in marine animals. DNA sequencing is so far the most reliable method for accurate identification of Fusarium species.

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

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

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

Madura foot: two case reports, review of the literature, and new developments with clinical correlation

"Madura foot" or pedal mycetoma is a rare destructive infection of the skin and subcutaneous tissues of the foot, progressing to involve muscle and bone. The infection can be caused by both bacteria and fungi. Infection typically follows traumatic implantation of bacteria or fungal spores, which are present in soil or on plant material. Clinically, this entity can be difficult to diagnose and can have an indolent and progressive course. Early diagnosis is important to prevent patient morbidity and mortality. We present two cases of pedal mycetoma, review the literature, review new developments in diagnosis, and discuss magnetic resonance imaging (MRI) features of this unusual entity.

Granulomatous pododermatitis in the digits caused by Fusarium proliferatum in a cat

To the best of our knowledge, we present here the first report of a case involving granulomatous pododermatitis caused by Fusarium proliferatum in a 10-year-old female cat. A cutaneous mass developed on the foot-pad of the right hind leg. Nodular granulomatous dermatitis with numerous macrophages and multinucleated giant cells containing cytoplasmic fungal structures were revealed on histological examination. Periodic acid-Schiff reaction and Fungi-Fluor staining clearly revealed irregular, septate fungal hyphae englobed by macrophages and multinucleated giant cells. Polymerase chain reaction and sequence analysis targeting three domains of the extracted fungal DNA revealed 100% amplicon homology with F. proliferatum.

Fusarium infection: report of 26 cases and review of 97 cases from the literature

Fusarium species is a ubiquitous fungus that causes opportunistic infections. We present 26 cases of invasive fusariosis categorized according to the European Organization for Research and Treatment of Cancer/Mycoses Study Group (EORTC/MSG) criteria of fungal infections. All cases (20 proven and 6 probable) were treated from January 2000 until January 2010. We also review 97 cases reported since 2000. The most important risk factors for invasive fusariosis in our patients were compromised immune system, specifically lung transplantation (n = 6) and hematologic malignancies (n = 5), and burns (n = 7 patients with skin fusariosis), while the most commonly infected site was the skin in 11 of 26 patients. The mortality rates among our patients with disseminated, skin, and pulmonary fusariosis were 50%, 40%, and 37.5%, respectively. Fusarium solani was the most frequent species, isolated from 49% of literature cases. Blood cultures were positive in 82% of both current study and literature patients with disseminated fusariosis, while the remaining 16% had 2 noncontiguous sites of infection but negative blood cultures. Surgical removal of focal lesions was effective in both current study and literature cases. Skin lesions in immunocompromised patients should raise the suspicion for skin or disseminated fusariosis. The combination of medical monotherapy with voriconazole or amphotericin B and surgery in such cases is highly suggested.

Fusarium solani causing quasi-invasive infection of the foot in an immunocompetent middle-aged man from South India

Fusarium Solani is commonly found in soil, and it is associated with infections in immunocompromised individuals. Fusaroium solani causing infection in immunocompetent adult male is rare and usually overlooked. We report a case of mycetoma caused by Fusariom solani in an immunocompetent adult male from South India.

The Madura Foot

“Mycetoma” means a fungal tumor. Mycetoma is a chronic, granulomatous, subcutaneous tissue infection caused by both bacteria (actinomycetoma) and fungi (eumycetoma). This chronic infection was termed Madura foot and eventually mycetoma, owing to its etiology. Inoculation commonly follows minor trauma, predominantly to the foot and hence is seen more among the barefoot-walking populations, common among adult males aged 20 to 50 years. The hallmark triad of the disease includes tumefaction, fistulization of the abscess, and extrusion of colored grains. The color of these extruded grains in the active phase of the disease offers a clue to diagnosis. Radiology, ultrasonology, cytology, histology, immunodiagnosis, and culture are tools used in diagnosis. Recently, DNA sequencing has also been used successfully. Though both infections manifest with similar clinical findings, Actinomycetoma has a rapid course and can lead to amputation or death secondary to systemic spread. However, actinomycetomas are more responsive to antibiotics, whereas eumycetomas require surgical excision in addition to antifungals. Complications include secondary bacterial infections that can progress to full-blown bacteremia or septicemia, resulting in death. With extremely disfiguring sequelae, following the breakdown of the nodules and formation of discharging sinuses, it poses a therapeutic challenge.

Madura's foot in a renal transplant patient: report of a case

A 40-year-old kidney transplant male recipient was hospitalized for chronic abscess of the right foot in a context of immunodepression. The patient came from Djibouti and was in Belgium for a few days. He presented a right foot with a swelling localized on the first metatarsophalangeal joint which was excoriated (Figures 1 and 2) and was self-treated ineffectively with various local antiseptics for several months. He was in the operating room for an open biopsy done by plantar and dorsal approach to confirm the fungal infection. Treatment was not started with oral itraconazole because of the good evolution of the lesion. Pain diminished after a few days, and the patient was able to walk after a few weeks.

Fusarium soloni mycetoma

A young apparently healthy, non-diabetic, HIV non-reactive woman presented with a mycetoma-like lesion on right buttock. Discharge was scanty, and mycotic grains were not seen. Biopsy of sinus track was obtained for microscopy and culture. Microscopic examination revealed plenty of fungal hyphae in direct microscopic examination of grounded tissues in saline; KOH, Gram's, and H and E-stained smears. All the three inoculated slants of Sabouraud's media yielded heavy growth of Fusarium solani. Presence of numerous hyphal fragments in direct microscopy and heavy growth of F. solani in all three slants indicative of etiological role of fungus in the present case. It is probably a first report of F. soloni mycetoma from India.

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

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

Eumycetoma of the hand caused by Leptosphaeria tompkinsii and refractory to medical therapy with voriconazole

We report on the first case of eumycetoma caused by the organism Leptosphaeria tompkinsii to be diagnosed and possibly acquired within the United Kingdom. Conventional culture of fungal grains and surgical tissue specimens was negative and the diagnosis was achieved using panfungal polymerase chain reaction and sequencing technology. Despite limited surgical resection and prolonged antifungal therapy with voriconazole, the patient developed progressive disease with mycetoma bone involvement. This case highlights the usefulness of molecular diagnostic techniques in eumycetoma where organisms may fail to grow with conventional culture or be difficult to identify morphologically. It also reminds us that eumycetoma is a difficult infection to treat and despite optimism regarding the efficacy of the newer triazole antifungals in this condition, treatment failures may still occur.

A case of primary localized cutaneous infection due to Fusarium oxysporum

Fusarium is a ubiquitous hyalohyphomycete isolated from food, widespread in the environment (plants, soil) and present at all latitudes. Fusarium oxysporum and Fusarium solani are the most frequent pathogenic species, followed by F. moniliforme and F. chlamydosporum. Infections due to this mold may be disseminated or localized. Localized forms include cutaneous and subcutaneous infection, onychomycosis, endophtalmitis, otitis, sinusitis, arthritis, osteomyelitis, and brain abscess. Disseminated forms are those in which two or more noncontiguous sites may be involved. These latter are observed in patients with severe neutropenia. Wounds, digital ulcers, onychomycosis, and paronychia are the typical cutaneous portal of entry. We report a case of primary localized cutaneous infection due to Fusarium in a 29-year-old woman presenting with a nodular lesion, partially ulcerated, asymptomatic on the first finger of the left hand, appeared 4 months earlier. Histological examination showed spongiosis and acanthosis in the stratum corneum, ulceration and inflammation with prevalently mononucleate cells and septate and branched fungal structures in the epidermis and in dermis. The fungus was identified as Fusarium oxysporum by culture of biopsy fragments on Sabouraud dextrose agar with chloramphenicol. The culture was deposited in the culture collection of the mycology section of IHEM, Brussels (IHEM21984 col no. 125). The patient had normal immune status and was successfully treated with surgical excision. Recovery was confirmed at follow-up 8 months later.

The dot-in-circle sign in Madura foot

The literature states that proper management of Madura foot strongly depends on accurate identification of the causative organism. We describe the case of a patient with Madura foot who was diagnosed with eumycetoma after the dot-in-circle sign, which has been previously reported in regard to magnetic resonance images of this lesion, was observed on both ultrasound and magnetic resonance images.

LEVEL OF CLINICAL EVIDENCE

4.

Fusarium infections in immunocompromised patients

Fusarium species cause a broad spectrum of infections in humans, including superficial, locally invasive, and disseminated infections. The clinical form of fusariosis depends largely on the immune status of the host and the portal of entry, with superficial and localized disease occurring mostly in immunocompetent patients and invasive and disseminated disease affecting immunocompromised patients. Risk factors for severe fusariosis include prolonged neutropenia and T-cell immunodeficiency, especially in hematopoietic stem cell transplant recipients with severe graft-versus-host disease. The most frequent presentation of disseminated fusariosis is a combination of characteristic cutaneous lesions and positive blood cultures, with or without lung or sinus involvement. The prognosis is poor and is determined largely by degree of immunosuppression and extent of infection, with virtually a 100% death rate among persistently neutropenic patients with disseminated disease. These infections may be clinically suspected on the basis of a constellation of clinical and laboratory findings, which should lead to prompt therapy. Treatment options include the lipid formulations of amphotericin B, voriconazole, and posaconazole. Prevention of fusarial infection among high-risk patients should be considered.

Structural differences between Fusarium strains investigated by FT-IR spectroscopy

The structural characteristics of Fusarium have received attention from both pure and applied scientists. Because many genes and physiological mechanisms are involved in the development of a particular structure type, this research is complicated. For revealing the structure of macromolecule in these fungal cells, FT-IR spectroscopy combined with multivariate statistical analysis was performed to characterize the structure of protein and polysaccharide of spores and mycelia obtained from different culture medium. The second derivative FT-IR spectra exhibited strain-specific infrared characteristics in the protein secondary structure sensitive amide I region. The region between 750 and 950 cm(-1) assigned to alpha- and beta-glucans was investigated for studied samples. Principal components analysis (PCA) allowed us to separate mycelia into two clusters according to different growth medium, indicating that spectra of strains may have been greatly affected by cultivation conditions.

Mycotic cysts: report of 21 cases including eight pheomycotic cysts from Saudi Arabia

BACKGROUND

Mycotic cysts are subcutaneous cystic granulomas caused by either dematiaceous (pigmented) fungi (pheomycotic cysts) or eumycotic (nonpigmented fungi) present in soil, wood, and decaying plant material. These fungi gain access to the tissues via a wooden splinter or thorn. No deep tissue involvement or extension to bone is known to occur.

METHODS

We reviewed our surgical pathology files for the last 32 years. All cases with the diagnosis of cysts with fungi, thorns, or splinters and associated granulomatous and acute inflammation were reviewed. Gomori's silver and periodic acid-Schiff stains were performed in all cases.

RESULTS

Twenty-one cases of mycotic cyst were found, including eight pheomycotic cysts (one with a recurrent lesion seen 11 months after the initial excision of the cyst). Thirteen cysts had nonpigmented fungal hyphae. There were 14 males and seven females, with an age range of 5-76 years. The dorsum of the foot was the most frequently affected site (12 cases). Four cases involved the fingers, two involved the knee area, two involved the big toe, and one each involved the leg, ankle, and forearm. The cysts measured 0.6-4.5 cm in diameter. Histologically, there was granulomatous inflammation with a variable degree of neutrophilic infiltrate giving central abscess formation. Twelve cases showed a wooden splinter. All cases were positive for fungal organisms, mostly septate hyphae and spores that were highlighted by special stains. Fungal pigment, ranging from yellow-brown to light brown to black, was observed in eight cases. No extension to deep tissues was noted. The clinical impression varied widely including ganglion, sebaceous cyst, giant cell tumor of the tendon sheath, and lipoma. One patient was immunosuppressed following renal transplantation. All patients were treated by simple excision. No antifungal chemotherapy was needed or administered in any of the patients. One patient had a recurrence of his lesion within 1 year as a result of inadequate initial excision. A second re-excision was curative.

CONCLUSION

Mycotic cysts are uncommonly encountered lesions that can be easily missed, especially in cases with scant fungal elements, thus requiring special stains to detect the organisms. We reported 21 cases of mycotic cyst, including eight pheomycotic cysts, with emphasis on the histopathologic recognition of this unusual entity.

Mycetoma

Mycetoma is a granulomatous infection affecting mainly the feet and lower extremities. It can be caused either by aerobic, branched actinomycetes or by eumycetes. Most cases are found in tropical and subtropical regions. The infection is usually produced by the introduction of the etiologic agents through minor wounds caused by thorns and wood splinters. Clinically the disease begins as small, firm nodules that can enlarge to form extensive lesions with fistulae and abscesses with pus containing granules of the causative microorganisms. Antimicrobials and surgery are used in the management of mycetoma. The actinomycetomas generally respond well to antimicrobials. For eumycetomas, surgery may be required. New therapeutic options for drug-resistant cases are discussed.

Fungal infections

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

Emerging Fungi

The hyalohyphomycetes (especially Fusarium spp) have emerged as significant pathogens in severely immunocompromised patients. Human infections by Fusarium spp can be superficial or limited to single organs in otherwise healthy patients. Such infections are rare and tend to respond well to therapy. By contrast, disseminated fusarial hyalohyphomycosis affects the immunocompromised host and frequently is fatal. Successful outcome is determined by the degree of immunosuppression and the extent of the infection. These infections may be suspected clinically on the basis of a constellation of clinical and laboratory findings, which should lead to prompt therapy.

A rare European case of Madura Foot due to actinomycetes

We present a case of mycetoma by Actinomadura spp. on the foot of an Albanian young man arrived to our observation approximately 5 years after the first clinical manifestations (hard tumefaction, slightly painful upon weight-bearing and palpation and cutaneous fistulas that discharged an abundant granulomatous secretion). Direct microscopic analysis and culture of the white-yellowish grains included Gram staining, which showed extensively branched Gram-positive hyphae less than 1 mm in diameter, allowing to make a diagnosis of Actinomycetoma. Since Actinomycetoma is sensitive to drug treatment, the patient was given trimethoprim-sulfamethoxazole and amikacin twice daily for 45 days. After six months of chemotherapy, the patient's general condition improved, the swelling is slightly diminished and grain extrusion has ceased. The patient has been able to resume ambulation with normal footwear. Given the absence of liver and kidney functional alterations, the patient is scheduled to continue pharmacological treatment with trimethoprim-sulfamethoxazole.

Gangrenous necrosis of the diabetic foot caused byFusarium acutatum

Foot infections are common and serious complications of diabetic patients. We report the case of a 68-year-old patient with a diabetic foot infection that developed into a gangrenous necrosis. Fusarium spp. was isolated on two successive occasions with no other associated microorganisms. Histopathology demonstrated invasion of the fungus into the tisssue. These findings suggested an infection rather than colonization. A detailed morphological study showed that the isolate was Fusarium acutatum, which was confirmed by rDNA sequencing. This fungus is found only in Asia and has not been previously reported as a human pathogen.

Recurrent colonization of successively implanted tracheoesophageal vocal prostheses by a member of the Fusarium solani species complex

Tracheoesophageal vocal prostheses (TVP) in laryngectomized patients commonly deteriorate due to overgrowth by yeasts, particularly Candida species. We describe the first case of colonization of such devices by a member of the Fusarium solani species complex in a patient with a history of glottal carcinoma. Three isolates, from three prostheses, were found morphologically consistent with the traditional picture of F. solani. Ribosomal sequence analysis showed that the isolates belonged to a distinct, as yet apparently unnamed phylogenetic species within the F. solani species complex. This species, one of two distinct genetic types (genotype 2) traditionally considered part of the plant-pathogenic subtaxon Fusarium solani f. sp. radicicola, has not previously been identified as an agent of human or animal disease, although it is closely related to a known etiologic agent of mycetoma, an Acremonium-like species recently renamed Fusarium falciforme. Sequence and multisatellite M13 polymorphism analysis revealed no distinctions among the case isolates. Production of cyclosporine was detected for all three case isolates.

Subcutaneous fungal infections

Subcutaneous mycoses are caused by a variety of mostly tropical organisms, usually when they are implanted into the dermis or the subcutaneous tissue. They rarely disseminate or become systemic. Sporotrichosis, mycetoma, and chromoblastomycosis are more common subcutaneous mycoses than are rhinosporidiosis, zygomycosis, pheohyphomycosis, and lobomycosis.

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

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

Molecular detection and identification of agents of eumycetoma: detailed report of two cases

We describe two cases of eumycetoma in the legs. The infections could not be adequately diagnosed by classical mycology, but the causative agents were successfully identified as Madurella mycetomatis by species-specific PCR and DNA sequencing.