|Year : 2014 | Volume
| Issue : 2 | Page : 94-95
Mycetoma caused by Exophiala jeanselmei
Sathyabhama, Sulekha Bhageerathi, Shini Raj
Department of Microbiology, Government Medical College, Thiruvananthapuram, Kerala, India
|Date of Web Publication||14-Nov-2014|
Department of Microbiology, Government Medical College, Thiruvananthapuram, Kerala
Source of Support: None, Conflict of Interest: None
Exophiala jeanselmei is clinically redefined as a rare agent of subcutaneous lesions of traumatic origin eventually causing mycetoma. A case of eumycetoma of foot in a 42-year-old male was clinically diagnosed as dermoid cyst and was microbiologically confirmed as eumycetoma. This case is reported for its uncommon clinical presentation and etiological agent, Exophiala jeanselmei. The patient recovered completely after treatment with Ketoconazole.
Keywords: Eumycetoma, Exophiala jeanselmei, Ketoconazole
|How to cite this article:|
Sathyabhama, Bhageerathi S, Raj S. Mycetoma caused by Exophiala jeanselmei. J Acad Clin Microbiol 2014;16:94-5
| Introduction|| |
Localized, slowly progressive, subcutaneous infections caused by fungi or actinomycetes are known as eumycetoma or actinomycetoma, respectively. The organisms are traumatically implanted into the deep dermis or subcutaneous tissue from the natural environment and cause a subcutaneous infection characterized by large aggregates of fungal filaments. It does not often spread beyond the locality of the initial site of infection and is seldom fatal.  Gill described the disease for the first time in India in a dispensary in Madura district, hence the derivation of Madura foot.  In India, about 65% of the cases are of actinomycetoma and the rest are of eumycetoma.  Exophiala jeanselmei has been reported as infrequently responsible for eumycetoma. 
| Case report|| |
A 42-year-old male patient, resident of Thiruvananthapuram presented with swelling over the right foot of two years duration at the Outpatient Department of Surgery at General Hospital, Thiruvananthapuram, Kerala in September 2013. He was a diabetic and hypertensive working in animal husbandry. There was a history of injury of the same foot with a wooden splinter two and half years earlier. Examination revealed a painless indurated swelling on the right foot measuring 5 1.5 cm at the lateral aspect of the first metatarsal bone. There was no significant regional lymphadenopathy. Systemic examination was within normal limits.
Investigations: FNAC was done, which was suggestive of suppurative lesion of fungal etiology. The lesion was excised and the whitish discharge was sent to our lab for fungal culture.
Microscopic examination of 10%KOH mount revealed fungal hyphae. The specimen was inoculated on Sabouraud's dextrose agar and kept at 22˚C and 37˚C. After 10 days, black-colored colonies with velvety texture were observed. Lactophenol cotton blue (LPCB) mount showed cells resembling yeast cells except for the light brown pigment [Figure 1]. On further incubation the colonies turned gray with a jet black reverse [Figure 2]. Slide culture was done which showed septate pigmented hyphae of 4-5 μm diameter with stick like conidiophores tapered at the tip and topped at the apices with clusters of elliptical conidia [Figure 3]. Nitrate was reduced to nitrite. The microscopic morphology and conidiogenesis seen were compatible with Exophiala jeanselmei.
|Figure 3: Slide culture of E. jeanselmei showing conidiophores and clusters of elliptical conidia|
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Oral Ketoconazole was given for two months. No adverse effects were reported.
| Discussion|| |
Eumycetoma is characterized by a prolonged incubation period, slow and unremarkable clinical course and multiple causative agents.  The genus Exophiala is widely distributed in the environment and may cause infections both in immunocompromised and immunocompetent patients.  In several instances, it remains undiagnosed perhaps due to lack of facilities in mycology.  Currently, diagnosis of E. jeanselmei is achieved through the use of sequence data of the Internal Transcribed Spacer (ITS) region of ribosomal DNA (rDNA), which reflects the taxonomy of this group. 
Patients cured by medical treatment demonstrate many histological changes at the site of lesion, and that includes replacement of the neutrophils that usually surround the grains with lymphocytes and giant cells. Fibrosis is common in the mycetoma lesion and granuloma formation with type 3 tissue reaction is indicative of complete cure.  Surgery may be required in protracted cases because most of the drugs do not penetrate the infected tissues adequately to eradicate the causative organism. 
The management of mycetoma is highly challenging for the clinicians. For eumycetoma, Ketoconazole or Itraconazole is used. Conventional and liposomal formulations of Amphotericin B is recommended for eumycetoma caused by Madurella and Fusarium species. 
In this case, the lesion was excised and the patient was successfully treated with Ketoconazole. In conclusion, greater awareness of the disease on the part of the clinician is needed to suspect and investigate for mycotic etiology, especially in the absence of response to antibacterial therapy.
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[Figure 1], [Figure 2], [Figure 3]