Unusual fungemia caused by non-marneffei Talaromyces in an immunocompetent host

Talaromyces, a genus phylogenetically related to Penicillium, is saprophytic except for Talaromyces marneffei. Herein, we describe the first documented case of fungemia caused by Talaromyces tumuli.

A case without overt predisposing conditions had suffered from recurrent bacteremia of various causes over the past 3 years and was admitted due to prolonged fever despite antimicrobial therapy this time. Three sets of blood cultures were negative at admission. On hospitalization day (HD) 5, two sets of blood cultures obtained via a subclavian venous catheter (SVC) became positive for hyphae in aerobic vials only with detection time of 67 h, respectively. Subculture of positive blood culture vial to Sabouraud dextrose agar yielded blue-green colonies without production of red pigments. Microscopic examination showed biverticillate Penicillium-like conidiophores and species identification using the MALDI Biotyper sirius System (Bruker) resulted in a first-rank match to Talaromyces funiculosus with non-reliable identification score of 1.63. Sequencing of the regions of ITS, BenA, CaM, and RPB2 genes identified it as T. tumuli. Subsequent blood cultures remained positive for it on six episodes until removal of the SVC on HD 18, despite voriconazole treatment.

This case was the first case of a central venous catheter-associated bloodstream infection caused by T. tumuli.