Unusual Fungemia Caused by Talaromyces funiculosus in an Immunocompetent Host

Talaromyces funiculosus is an unusual and opportunistic pathogen. This case describes a bloodstream infection caused by the rare fungus Talaromyces funiculosus, originating from a hepatic abscess. A 53-year-old female presented acutely with high fever, chills, abdominal pain, and markedly elevated inflammatory markers. Imaging suggested suspected hepatic abscess. The patient showed poor response to antibiotics. On hospitalization day (HD) 5, blood culture yielded positive results, with microscopic examination revealing fungal hyphae. Based on these findings, caspofungin was empirically added to the existing treatment regimen of cefoperazone-sulbactam and metronidazole, and percutaneous catheter drainage of the abscess was performed. The preliminary identification was performed via blood culture, lactophenol cotton blue staining, MALDI-TOF mass spectrometry. The pathogen was confirmed as T. funiculosus by the sequences of ITS, BenA and RPB2 genes. Furthermore, culture of the abscess fluid confirmed a co-infection with Klebsiella pneumoniae, suggesting a potential synergistic bacterium-fungus pathogenic mechanism. The patient subsequently defervesced, with inflammatory markers returning to normal levels. Early blood culture and image-guided aspiration are warranted in patients with idiopathic or refractory hepatic abscesses to expand the pathogen detection spectrum.