PCR-based detection of Aspergillus fumigatus and absence of azole resistance due to TR34 /L98H in a french multicenter cohort of 137 patients with fungal rhinosinusitis.

Abstract

Fungal rhinosinusitis (FRS) has a worldwide distribution, comprises distinct clinical entities but is mostly due to Aspergillus among which Aspergillusfumigatus plays a major role in European countries. Although, there is accumulating evidence for the emergence of environmentally acquired-azole resistance in A.fumigatus (such as TR34 /L98H) in various clinical settings, there is few data for patients with FRS. In this study, we aimed to investigate the prevalence of A.fumigatus azole resistance due to TR34 /L98H in a multicentre cohort of patients with FRS. One hundred and thirty-seven patients with FRS admitted between 2002 and 2016 at four French medical centres were retrospectively enrolled. Clinical and mycological findings were collected. Aspergillus fumigatus and the TR34 /L98H alteration conferring azole resistance were investigated directly from clinical samples using the commercial CE-IVD marked MycoGENIE® A.fumigatus real-time PCR assay. Fungal ball was the more frequent clinical form (n=118). Despite the presence of fungal hyphae at direct microscopic examination, mycological cultures remained negative for 83 out of the 137 patients (60.6%). The PCR assay proved to be useful allowing the identification of A.fumigatus and etiological diagnosis in 106 patients (77.4%) compared with 44 patients (32.1%) when using culture as the reference method. Importantly, neither TR34 nor L98H alterations were evidenced.