Severe pneumonia with a massive pleural effusion in a child caused by Tilletiopsis minor: the first case from Saudi Arabia

Tilletiopsis minor, a blastoconidia-forming yeast, was isolated from a 4-year-old boy suffering from severe pneumonia. Chest x-rays revealed the progression of widespread and multiple nodular lesions, nonsymmetrical interstitial and airspace infiltrates, and consolidations. Creamy yellow, irregular, wrinkled yeastlike organisms were isolated from the pleural fluid specimens when cultured on Sabouraud dextrose agar for 5 days and incubated at 30°C. Microscopically, the organisms showed broad, irregular filaments with blastoconidia but no budding cells. Manual bench tests and automated phenotypic analyses failed to recognize the organism. This unique and rare organism (AB7-11; DSM 29469) was identified using the sequence analysis of the internal transcribed spacer region of the nuclear ribosomal DNA. It showed a precise alignment with the type strains of T minor. Subsequent to this diagnosis, and the earlier nonresponse to vancomycin and meropenem, the patient was put on liposomal amphotericin. However, the condition continued to deteriorate, and then, intravenous voriconazole was added to control the infection. Finally, the patient’s condition improved, and he was discharged in good condition after 1 month of stay in the hospital.