Profiling Drug Susceptibility and Species Identification of Aspergillus Isolates From Patients With Superficial...

Aspergillus infections pose significant challenges in clinical management due to rising resistance rates and limited diagnostic accuracy. Superficial infections, particularly in immunocompetent individuals, are often understudied, despite their prevalence in specific populations.

This study aimed to characterise the distribution and antifungal susceptibility patterns of Aspergillus isolates from a tertiary hospital in Shandong, China, and evaluate the performance of matrix-assisted laser desorption time-of-flight (MALDI-TOF) mass spectrometry versus multi-gene sequencing for species identification.

A total of 120 Aspergillus isolates were collected from patients with localised aspergillosis (nails, external auditory canal, cornea, sub-throat secretions) between 2020 and 2021. Species identification was performed using MALDI-TOF and multi-gene sequencing (ITS, BenA, CaM, RPB2). Antifungal susceptibility testing was conducted for micafungin, azoles (itraconazole, voriconazole, posaconazole, fluconazole), and amphotericin B following standard protocols.

Species Identification: MALDI-TOF identified 52.5% of isolates to the species level, whereas multi-gene sequencing achieved 100% accuracy. Aspergillus terreus was the most prevalent species (38.3%). Antifungal Susceptibility: Micafungin showed the highest resistance rate (40%), followed by amphotericin B (reduced susceptibility in 31.7%). Azoles demonstrated low resistance (3.3%-6.7%) except for fluconazole (21.7%). Clinical Correlates: Superficial infections were most common in middle-aged/elderly patients (68.3%), frequently linked to external trauma (41.7%) or environmental exposure (35.8%).

Multi-gene sequencing outperformed MALDI-TOF for Aspergillus identification. A. terreus dominance and micafungin resistance highlight regional epidemiological trends. Natamycin and nystatin remain cost-effective first-line topical options. Enhanced surveillance in trauma-prone and environmentally exposed populations is warranted.