Background:

Mucormycosis is a severe fungal infection that is challenging to diagnose as traditional methods lack sensitivity and serological testing is unavailable. This study aimed to evaluate the MucorGenius® PCR assay on respiratory and biopsy samples from high-risk patients with probable/proven invasive pulmonary aspergillosis (IPA), mucormycosis, or possible invasive mold infections (IMIs).

Methods:

This multicenter cohort study was conducted across 4 sites in Austria, Belgium and the UK. A total of 132 respiratory and biopsy samples from 114 patients with IMI diagnosed in clinical routine (10 proven IPA, 13 proven mucormycosis, 62 probable IPA, 5 probable mucormycosis, and 35 possible IMI according to EORTC/MSGERC 2020 and FUNDICU criteria; 11 IPA/mucormycosis coinfections) were analyzed using the MucorGenius® PCR assay in ISO-certified laboratories. Results were compared with standard fungal diagnostics.

Results:

Mucorales DNA was detected in 37/132 samples (28%) including 29 BAL fluids, 1 bronchial aspirate, 1 endotracheal aspirate, and 6 biopsies from 37 patients. Sensitivity was 94.4% (17/18) for detecting probable/proven mucormycosis (including 11 cases routinely diagnosed with IPA/mucormycosis coinfection). Among 72 patients with probable/proven IPA, 21 (29.2%) tested positive for Mucorales DNA, including 11 missed by routine diagnostics. Mucorales DNA was also detected in 9/35 (25.7%) of patients with possible IMI.

Conclusions:

MucorGenius® PCR showed high sensitivity for detecting Mucorales and may support improved diagnosis of probable mucormycosis when included as a mycological criterion. It appears particularly valuable for identifying Aspergillus-Mucorales coinfections and detecting mucormycosis in patients with host factors, clinical or radiological evidence of IMI when routine diagnostics are negative.