Emerging Aspergillus lentulus infections in Taiwan: clinical and environmental surveillance.

Objectives: This study aimed to investigate the prevalence and characteristics of Aspergillus lentulus clinical and environmental isolates in Taiwan.

Methods: Aspergillus isolates obtained from patients at three hospitals and from 530 soil samples across Taiwan were screened. A. lentulus, confirmed by calmodulin sequencing, was subjected to antifungal susceptibility testing and cyp51A analyses. Soil samples yielding A. lentulus were analysed for residues of 25 azole fungicides.

Results: Nine A. lentulus isolates were identified, which included seven (1.2%, 7/601) isolates from three antifungal-naïve patients out of 601 Aspergillus section Fumigati clinical isolates and two (0.3%, 2/659) isolates out of 659 Aspergillus soil isolates. All isolates developed white colonies and failed to grow at 48°C. They were susceptible to anidulafungin but showed reduced susceptibility to amphotericin B (AmB), voriconazole and azole fungicides. One heart transplant recipient with proven invasive pulmonary aspergillosis (IPA) initially showed suboptimal response to voriconazole monotherapy but was cured with a combination of voriconazole-caspofungin, liposomal AmB (LAmB)-caspofungin, along with surgery, followed by voriconazole maintenance therapy. Among two critically ill patients with probable IPA, one survived with micafungin, while the other died of aspergillosis despite sequential isavuconazole and LAmB monotherapy. Clinical and environmental isolates sharing identical Cyp51A sequence are identified, matching the Cyp51A sequence of A. lentulus NIID0096. Flusilazole (0.0009 mg/kg) was detected in one soil sample.

Conclusions: This study raises concerns about health threat posed by human pathogenic A. lentulus originating from natural environments and underscores the need for increased clinical and laboratory vigilance regarding A. lentulus infections.