An exploratory study of microbial diversity in sinus infections of cystic fibrosis patients by molecular methods

BackgroundFor the first time microorganisms in CF sinuses are investigated by molecular methods in response to an absence of anaerobes in CF sinus samples during a two-year period at the Copenhagen CF center.MethodsEndoscopic sinus surgery was performed in 19 CF patients. DNA from intact bacterial cells was investigated by 16S rRNA gene analysis and quantitative PCR. Results were compared to culture-dependent routine diagnosis.ResultsMolecular methods showed a large microbial diversity, which included undetected anaerobes that may play a pathogenic role. Importantly, the culture methods did not always detect known CF pathogens. Quantitative PCR showed generally a higher abundance of classic CF pathogens e.g. Pseudomonas aeruginosa and Staphylococcus aureus compared with the anaerobe Propionibacterium acnes.ConclusionsThe results indicate that the culture methods in some cases may not be suitable as stand-alone method for this patient group, as diversity may be underestimated and important species undetected.