Seventeen years of subcutaneous infection by Aspergillus flavus; eumycetoma confirmed by immunohistochemistry

Abstract

Chronic subcutaneous infections caused by Aspergillus species are considered to be extremely rare. Because these fungi are among the most common laboratory contaminants, their role as eumycetoma causative agents is difficult to ascertain. Here, we report the first case of A. flavus eumycetoma confirmed by isolation, molecular identification and immunohistochemical analysis. Patient was a 55-year-old male from Sudan suffering from eumycetoma on his left foot for a period of 17 years. He developed swelling, sinuses and white grain discharge was observed. He has been operated nine times and was treated with several regimens of ketoconazole and itraconazole without improvement. Initial diagnosis based on histology and radiology was Scedosporium eumycetoma. However, examination of the biopsy revealed A. flavus, which was identified by molecular analysis and MALDI-TOF MS. Immunohistochemistry using antibody directed against Aspergillus species was positive. Because of the earlier treatment failures with ketoconazole and itraconazole, therapy with voriconazole was initiated. However, in vitro susceptibility testing yielded a lower Minimum Inhibitory Concentration (MIC) value for itraconazole (0.25 μg ml(-1) ) than for voriconazole (1 μg ml(-1) ). Based on the presented results, A. flavus can be considered as one of the agents of white-grain eumycetoma.

Clinical presentation and management of mycetoma in gezira mycetoma center in Sudan

“…Vast majority of cases reported to have the mycetoma at the lower limbs (82%), all other cases reported to have the lesion in the upper limbs (18%). This is consistent with the last updated study in Sudan in 2015 by Fahal A, et al who found that, the foot (76%) and hand (8%) were the most commonly affected sites (Ahmed et al 2015). But they reported less frequently affected sites such as leg and knee (7%), thigh (2%), buttock (2%) and arm and forearm (1%).…”

Molecular identification of unusual Mycetoma agents isolated from patients in Venezuela

“…Cutaneous infections caused by opportunistic fungi have been isolated in immunosuppressed patients . However, the Aspergillus species caused wide spectrum of clinical infection and some are the aetiological agent of eumycetoma …”

Aspergillus: An uncommon pathogen of eumycetoma

“…A. fumigatus, A. nidulans, and A. terreus as the causative agent(Ahmed et al, 2015). To the best of our knowledge, we could not find any report of eumycetoma secondary to A. ustus, A. calidoustus, or A. pseudodeflectus.…”

“…The most common causative agent of eumycetoma is Madurella mycetomatis . Aspergillus has been rarely implicated in eumycetoma with A. flavus, A. fumigatus, A. nidulans, and A. terreus as the causative agent (Ahmed et al, ). To the best of our knowledge, we could not find any report of eumycetoma secondary to A. ustus, A. calidoustus , or A. pseudodeflectus .…”