Eumycetoma pedis due to Exophiala jeanselmei

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.

Osteoarticular Mycoses

Osteoarticular mycoses are chronic debilitating infections that require extended courses of antifungal therapy and may warrant expert surgical intervention. As there has been no comprehensive review of these diseases, the International Consortium for Osteoarticular Mycoses prepared a definitive treatise for this important class of infections. Among the etiologies of osteoarticular mycoses are Candida spp., Aspergillus spp., Mucorales, dematiaceous fungi, non-Aspergillus hyaline molds, and endemic mycoses, including those caused by Histoplasma capsulatum, Blastomyces dermatitidis, and Coccidioides species. This review analyzes the history, epidemiology, pathogenesis, clinical manifestations, diagnostic approaches, inflammatory biomarkers, diagnostic imaging modalities, treatments, and outcomes of osteomyelitis and septic arthritis caused by these organisms. Candida osteomyelitis and Candida arthritis are associated with greater events of hematogenous dissemination than those of most other osteoarticular mycoses. Traumatic inoculation is more commonly associated with osteoarticular mycoses caused by Aspergillus and non-Aspergillus molds. Synovial fluid cultures are highly sensitive in the detection of Candida and Aspergillus arthritis. Relapsed infection, particularly in Candida arthritis, may develop in relation to an inadequate duration of therapy. Overall mortality reflects survival from disseminated infection and underlying host factors.

Cutaneous Phaeohyphomycosis of the Right Hand Caused by Exophiala jeanselmei: A Case Report and Literature Review

Exophiala spp. is increasingly reported as a pathogen causing the cutaneous, subcutaneous or invasive infection. In this report, we present a case of cutaneous phaeohyphomycosis due to E. jeanselmei on the right hand of a farmer, who suffered from this disease three years ago which had not been definitely diagnosed until he was admitted to our hospital. In our hospital, a potential fungal pathogen was observed by histopathological examination, and then was recovered and identified as E. jeanselmei by sequencing its internal transcribed spacer region. After 4 weeks of antifungal treatment, his hand recovered very well. To investigate the in vitro susceptibility of E. jeanselmei isolates to antifungal agents and compare the characteristics of their related infections among immunocompetent and immunocompromised patients, we reviewed 84 cases published in PubMed database between 1980 and 2020.

Clinical Spectrum, Molecular Characterization, Antifungal Susceptibility Testing of Exophiala spp. From India and Description of a Novel Exophiala Species, E. arunalokei sp. nov

Introduction

Exophiala spp. are important opportunist pathogens causing subcutaneous or even fatal disseminated infections in otherwise both immunosuppressed and healthy individuals but there are no systematic studies on the isolates of Exophiala species from India.

Methods

Twenty-four isolates of Exophiala species were retrieved from the National Culture Collection of Pathogenic Fungi (NCCPF) and identified phenotypically and by molecular methods (ITS region sequencing) followed by antifungal susceptibility testing (AFST) as per CLSI-M38A3 guidelines. A review of the literature of cases from India was performed up to 1^st January 2021 using the Medline and Cochrane database.

Results

E. dermatitidis (n = 8), E. jeanselmei (n = 6), E. spinifera (n = 6), E. mesophila (n = 1), E. oligosperma (n = 1), E. xenobiotica (n = 1) were identified and the sequencing of ITS, β-tubulin and β-actin revealed a novel species, E. arunalokei sp. nov. (n = 1). The ITS sequence phylogram of E. jeanselmei revealed that the majority (83%) formed a separate cluster close to type A while majority (75%) of E. dermatitidis were type B. The MIC50 (mg/L) of amphotericin, itraconazole, voriconazole, micafungin, caspofungin, anidulafungin, and posaconazole, was 1, 0.25, 0.125, 0.12, 0.125, 0.062, and 0.062, respectively. Sixteen more cases were identified on the literature review and a significant association of E. dermatitidis with history of surgical procedures (p = 0.013), invasive disease (p = 0.032) and of E. mesophila with tuberculosis (p = 0.026) was seen.

Conclusion

This, to the best of our knowledge is the first study from India elucidating the molecular and clinical characteristics of Exophiala species and the first Indian report of human infection due to E. xenobiotica and E. arunalokei.

Treatment of Madura foot: a systematic review

REVIEW QUESTION/OBJECTIVE

The objective of this review was to determine the best available evidence on the most effective treatment of Madura foot.

INTRODUCTION

Madura foot or mycetoma is a chronic granulomatous soft-tissue infection that is endemic to several regions of Africa and Asia. It may be of fungal (eumycetoma) or bacterial (actinomycetoma) origin, warranting therapy with either antifungal or antibacterial medication as well as surgery. Without timely intervention, it often results in lifelong disability. However, it is unclear what regimes are most effective for treatment.

INCLUSION CRITERIA

This review considered studies that included individuals of all ages with Madura foot (actinomycetoma or eumycetoma) as confirmed by microbiological or histological studies. Studies that evaluated antibiotic and antifungal regimens (any drug, dosage, frequency, duration) as well as surgical interventions (wound debridement, advanced excision or limb amputation) for Madura foot were included. Outcomes of interest were disease resolution (as determined by complete healing of mycetoma lesion after treatment), recurrence (return of mycetoma lesion after successful treatment) and mortality. Although this review considered both experimental and epidemiological study designs for inclusion, only case series and individual case reports were identified and were therefore included in the review.

METHODS

A three-step search strategy, involving an initial search, a second more comprehensive search using identified keywords and a third search involving the reference lists of included articles, was utilized. Ten databases were searched. An additional 13 sources were searched for gray and/or unpublished literature. Included studies were assessed by two independent reviewers for methodological validity prior to inclusion in the review using standardized critical appraisal instruments from the Joanna Briggs Institute. Disagreements were resolved through discussion or with a third reviewer. A data extraction tool was used to extract data on interventions, populations, study designs and outcomes of significance to the review question. Statistical pooling was not possible, therefore a narrative synthesis was performed.

RESULTS

Thirty-one studies were included in the review (27 case reports and four case series). A total of 47 patients with Madura foot were analyzed. Twenty-five had eumycetoma, 21 actinomycetoma and one had both. Therapy involved varying dosages of sulfa drugs (co-trimoxazole and dapsone), amikacin and tetracyclines administered for the therapy of actinomycetoma with resolution of disease in all affected patients. The azole derivatives (itraconazole, ketoconazole, voriconazole, fluconazole and miconazole) as well as co-trimoxazole were the most commonly employed drugs for eumycetoma, with resolution of disease in 88% of included patients. Surgery was performed in a total of 21 patients with resolution of disease in all cases. The overall resolution rate following therapy was 95.7%.

CONCLUSION

Therapy for Madura foot is informed by case series and case reports which provide low level evidence for practice. Antimicrobials in conjunction with surgery lead to resolution of disease.

Chaetomium atrobrunneum causing human eumycetoma: The first report

In this communication, a case of black grain eumycetoma produced by the fungus C. atrobrunneum is reported. The patient was initially misdiagnosed with M. mycetomatis eumycetoma based on the grains’ morphological and cytological features. However, further aerobic culture of the black grains generated a melanised fungus identified as C. atrobrunneum by conventional morphological methods and by internal transcribed spacer 2 (ITS2) ribosomal RNA gene sequencing. This is the first-ever report of C. atrobrunneum as a eumycetoma-causative organism of black grain eumycetoma. It is essential that the causative organism is identified to the species level, as this is important for proper patient management and to predict treatment outcome and prognosis.

"A fine needle aspiration cytology in time saves nine" - cutaneous phaeohyphomycosis caused by Exophiala jeanselmei in a renal transplant patient: Diagnosis by fine needle aspiration cytology

Infections by dematiaceous fungi are an emerging group of infectious diseases worldwide with a variety of clinical presentations. Though generally localized, they can disseminate in immunocompromised settings, therefore, early diagnosis and prompt therapy can prevent significant morbidity and mortality in these patients. Fungi of genus Exophiala are common causative organisms; however, Exophiala jeanselmei (E. jeanselmei) has not yet been reported from environmental sources in India. We present here the case of a renal transplant recipient who presented with an innocuous lesion on the foot, diagnosed on fine needle aspiration cytology (FNAC) as phaeohyphomycosis, and promptly treated with excision and antifungal therapy. To the best of our knowledge, this is the first case report from India of E. jeanselmei causing phaeohyphomycosis in a transplant recipient and highlights the role a cytopathologist can play in the timely management of such cases.

Phaeohyphomycosis Due to Exophiala jeanselmei: An Emerging Pathogen in India--Case Report and Review

We present a rare case of a 30-year-old woman who presented with a swelling on the lateral aspect of her left forearm, present since 6 months, adjacent to a 16-year-old burn scar. X-ray of elbow joint and forearm revealed the subcutaneous nature of the swelling. Giemsa and periodic acid-Schiff-stained smears and potassium hydroxide mount of fine-needle aspirate of the swelling revealed dematiaceous, branching, and septate fungal hyphae. Fungal culture of the aspirated pus showed growth of Exophiala jeanselmei. Histopathological examination revealed brown-coloured hyphae with foreign body giant cell reaction and palisading granulomas in the surrounding tissue. The patient was successfully treated with surgical excision of the swelling. All the cases of phaeohyphomycosis due to Exophiala spp. in India are also reviewed.

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.