Hélène Guegan1, Xavier Iriart2, Marie-Elisabeth Bougnoux3, Antoine Berry2, Florence Robert-Gangneux4, Jean-Pierre Gangneux4. 1. University of Rennes, CHU Rennes, Inserm, EHESP, Irset - UMR_S 1085, Rennes, France. Electronic address: helene.guegan@chu-rennes.fr. 2. Service de Parasitologie-Mycologie, CHU Toulouse, 31059, Toulouse, France; Centre de Physiopathologie de Toulouse Purpan (CPTP), Université de Toulouse, CNRS, INSERM, UPS, 31059, Toulouse, France. 3. Université de Paris, Parasitology-Mycology unit, AP-HP, Groupe Hospitalier Necker Enfants Malades, 75015, Paris, France. 4. University of Rennes, CHU Rennes, Inserm, EHESP, Irset - UMR_S 1085, Rennes, France.
Abstract
OBJECTIVES: We aimed to assess the clinical relevance of the marketed pan-mucorales real-time PCR assay MucorGenius® (Pathonostics) on pulmonary specimens relative to that of in-house PCR assays and conventional mycology for the diagnosis of mucormycosis. METHODS: In total, 319 pulmonary samples from severely immunosuppressed patients at risk for invasive mold disease (IMD) were retrospectively included. Direct examination, mycological culture, and PCR testing were performed using three genus-specific in-house mucorales real-time PCR assays and MucorGenius®PCR. Results from Aspergillus testing, including galactomannan and PCR, were also collected. RESULTS: The 319 patients were graded according to modified EORTC-MSG criteria as proven/probable mucormycosis (n=6), proven/probable invasive aspergillosis (IA) (n=63), Aspergillus-mucorales co-infections (n=4), possible IMD (n=152), and excluded IMD (n=94). The in-house and MucorGenius®PCR assays were positive for 33 (10.3%) and 27 (8.5%) samples, respectively, whereas culture was positive for only 10 (3.1%). The in-house and MucorGenius®PCR assays showed a sensitivity of 100% (10/10) and 90% (9/10) and a specificity of 95.7% and 97.9%, respectively. Both PCR assays allowed the detection of mucorales DNA in samples from 10 possible cases and six IA, all missed by culture. CONCLUSIONS: MucorGenius® showed good performance, despite missing some low fungal burden. Combining mucorales PCR with EORTC-MSG criteria greatly improved the diagnosis of mucormycosis.
OBJECTIVES: We aimed to assess the clinical relevance of the marketed pan-mucorales real-time PCR assay MucorGenius® (Pathonostics) on pulmonary specimens relative to that of in-house PCR assays and conventional mycology for the diagnosis of mucormycosis. METHODS: In total, 319 pulmonary samples from severely immunosuppressed patients at risk for invasive mold disease (IMD) were retrospectively included. Direct examination, mycological culture, and PCR testing were performed using three genus-specific in-house mucorales real-time PCR assays and MucorGenius®PCR. Results from Aspergillus testing, including galactomannan and PCR, were also collected. RESULTS: The 319 patients were graded according to modified EORTC-MSG criteria as proven/probable mucormycosis (n=6), proven/probable invasive aspergillosis (IA) (n=63), Aspergillus-mucorales co-infections (n=4), possible IMD (n=152), and excluded IMD (n=94). The in-house and MucorGenius®PCR assays were positive for 33 (10.3%) and 27 (8.5%) samples, respectively, whereas culture was positive for only 10 (3.1%). The in-house and MucorGenius®PCR assays showed a sensitivity of 100% (10/10) and 90% (9/10) and a specificity of 95.7% and 97.9%, respectively. Both PCR assays allowed the detection of mucorales DNA in samples from 10 possible cases and six IA, all missed by culture. CONCLUSIONS: MucorGenius® showed good performance, despite missing some low fungal burden. Combining mucorales PCR with EORTC-MSG criteria greatly improved the diagnosis of mucormycosis.
Authors: Sean X Zhang; N Esther Babady; Kimberly E Hanson; Amanda T Harrington; Paige M K Larkin; Sixto M Leal; Paul M Luethy; Isabella W Martin; Preeti Pancholi; Gary W Procop; Stefan Riedel; Seyedmojtaba Seyedmousavi; Kaede V Sullivan; Thomas J Walsh; Shawn R Lockhart Journal: J Clin Microbiol Date: 2021-06-18 Impact factor: 5.948