Fungus culture and PCR in nasal lavage samples of patients with chronic rhinosinusitis.

Chronic rhinosinusitis (CRS) affects approximately 15 % of the adult population in industrialized countries. Fungi have been recognized as important pathogens in CRS in the immunocompromised host. Recently, fungi have been detected in more than 90 % of nasal lavages (NLs) in immunocompetent patients with CRS. Employing NLs of immunocompetent patients with CRS in the present study, the detection rates for fungi by culture techniques were compared with the results of different fungus-specific PCR assays. Standard fungal cultures were performed on NLs from 77 patients with CRS. NLs were also tested for the presence of fungal DNA by a panfungal assay with and without specific probes for Candida spp. and Aspergillus spp./Penicillium spp., and an Aspergillus-specific nested PCR assay. Nineteen of the 77 samples (25 %) grew fungi. Fungus-specific DNA was detected in 34 of 77 NLs (44 %). Twelve samples were positive for both culture and panfungal PCR, whereas seven specimens grew fungi in culture, but were negative in panfungal PCR, and an additional seven samples were positive in panfungal PCR, but negative in culture. The combination of culture and all employed PCR assays detected fungi in 39 patients (50 %). This study demonstrated that PCR and conventional culture techniques could be complementary diagnostic techniques to detect fungi in nasal specimens from CRS patients.