Detection of fungi in the nasal mucosa using polymerase chain reaction.

Abstract

Fungi have been increasingly recognized as important pathogens in sinusitis. However, detection of fungus with conventional culture techniques is insensitive and unreliable. Polymerase chain reaction (PCR) is an exquisitely sensitive assay that can detect the DNA of 10 or less fungal elements. The aim of this study was to compare the sensitivity of conventional culture techniques using PCR analysis. Nasal swabs and DNA samples were collected from the nasal cavities of control subjects and patients with chronic sinusitis. Fungal-specific PCR analysis and standard cultures were performed on every sample. chi2 analysis was used to test for statistical differences between groups. PCR analysis detected fungal DNA in 42% and 40% of control subjects and patients with chronic sinusitis while standard cultures were positive in 7% and 0%, respectively. There was no statistically significant difference in the prevalence of fungi in the normal volunteers and patients with chronic rhinosinusitis. PCR is significantly more sensitive than nasal swab cultures in detecting the presence of fungi in nasal mucosa. In addition, our study suggests that the presence of fungi alone is insufficient to implicate it as the pathogen in chronic sinusitis.