Pseudomonas aeruginosa and Periodontal Pathogens in the Oral Cavity and Lungs of Cystic Fibrosis Patients: a Case-Control Study

Abstract

Cystic fibrosis (CF) is the most frequent lethal genetic disease in the Caucasian population. Lung destruction is the principal cause of death by chronicPseudomonas aeruginosacolonization. There is a high prevalence of oropharyngeal anaerobic bacteria in sputum of CF patients. This study was carried out due to the lack of results comparing subgingival periodontal pathogenic bacteria between the oral cavity and lungs in patients with CF in relation withP. aeruginosapresence. Our first goal was to detectP. aeruginosain oral and sputum samples by culture and molecular methods and to determine clonality of isolates. In addition, subgingival periodontal anaerobic bacteria were searched for in sputum. A cross-sectional pilot case-control study was conducted in the CF Reference Center in Roscoff, France. Ten CF patients with a ΔF508 homozygous mutation (5 chronically colonized [CC] and 5 not colonized [NC]) were enrolled.P. aeruginosawas detected in saliva, sputum, and subgingival plaque samples by real-time quantitative PCR (qPCR). Subsequently, periodontal bacteria were also detected and quantified in subgingival plaque and sputum samples by qPCR. In CC patients,P. aeruginosawas recovered in saliva and subgingival plaque samples. SixteenP. aeruginosastrains were isolated in saliva and sputum from this group and compared by pulsed-field gel electrophoresis (PFGE). Subgingival periodontal anaerobic bacteria were found in sputum samples. A lower diversity of these species was recovered in the CC patients than in the NC patients. The presence of the sameP. aeruginosaclonal types in saliva and sputum samples underlines that the oral cavity is a possible reservoir for lung infection.