The Importance of Mycological Diagnosis: A Scedosporium apiospermum Complex Mycetoma Case Neglected For 20 Years

Mikrobiyol Bul. 2021 Apr;55(2):256-264. doi: 10.5578/mb.20219911.

ABSTRACT

Scedosporium apiospermum complex members are opportunistic fungi that can be found in environments such as soil and polluted water. In this report, we aimed to present a case of mycetoma caused by Scedosporium apiospermum complex that developed in a 40-year-old female patient with immunocompetent system and diagnosed by fungal culture. In the anamnesis of the patient who admitted in 2015 with the complaint of more than one fistulized discharge wound, pain and swelling in the dorsal of the right hand and wrist; it was learned that her complaints started about 20 years ago with a slight swelling on the back of the wrist, and when it worsened, the abscess was drained and antibiotic treatment was initiated in a private surgical center. However, it was learned that she did not benefit from the treatments, and over time, fistulized, yellow-discharged wounds appeared on the back of her hand and wrist, and she had undergone various surgical interventions and used antibiotics. Routine laboratory tests of the patient, who did not have an underlying chronic disease, were normal. Magnetic resonance imaging (MRI) and X-ray findings were compatible with osteomyelitis and 'dot in circle' sign seen on MRI was characteristic for mycetoma. Pathological examination was interpreted as active chronic inflammatory reaction in the soft tissue and chronic osteomyelitis. Mycobacteria, bacteriological and fungal cultures of the two biopsy samples taken during surgical debridement and one month later were performed. Bacteriological and mycobacterial cultures were negative, while Scedosporium genus grew in the fungal cultures of the both samples. Isolates were identified as Scedosporium apiospermum/Pseudallescheria boydii with MALDI Biotyper (Bruker Daltonics, Bremen, Germany) system and Scedosporium boydi by sequence analysis of the ITS region. The antifungal susceptibility tests were performed according to CLSI M38-A2 criteria, and were evaluated at the 72nd hour. The minimum inhibitory concentration (MIC) values of fluconazole, caspofungin, amphotericin B, itraconazole, vorikonazole, posaconazole and isavuconazole were > 64 µg/ml, 16 µg/ml, 4 µg/ml, 16 µg/ml, 0.25 µg/ml, 2 µg/ml and 0.25 µg/ml, respectively. Voriconazole and terbinafine treatment was initiated. In the control performed in the 9th month of the treatment, it was observed that the complaints of discharge, pain and swelling were resolved, pain and swelling complaints were recovered, fistula tracts were closed and joint movements were painless. In the control MRI performed at 15th and 18th months, it was observed that there was no soft tissue involvement and the findings were compatible with osteoarthritis after infective osteomyelitis. This case whose longterm complaints improved with mycological diagnosis and appropriate treatment; reveals the importance of keeping mycological diagnosis in mind in chronic bone and soft tissue infections. Identifying the fungus to the genus and species level and arranging the treatment according to the antifungal susceptibility test results are very important in patient management.

PMID:33882656 | DOI:10.5578/mb.20219911