Respiratory pathogens in the oral cavity of hospitalized patients

Objective: The purpose of this investigation was to determine the prevalence of specific nosocomial respiratory pathogens including Acinetobacter ssp., Dialister pneumosintes, Pseudomonas spp., and Staphylococcus spp. with or without the mecA resistance gene in the oral cavity of hospitalized patients. Methods: The target population included 30 hospitalized patients (mean age 63.5±1.7 years; 77% males; 13 edentulous and 17 dentate) undergoing myocardial revasculation. Periodontal clinical assessment was performed at 6 sites per tooth in the dentate subjects. Saliva was collected from all subjects, whereas supra- and subgingival biofilm samples were obtained from 4-6 periodontal sites of each dentate subject, before orotracheal intubation and after extubation. DNA was extracted from samples, and the bacterial species and mecA gene were detected by PCR. Additionally, samples were cultivated in selective media for identification of Staphylococcus spp. Statistical differences between or within groups pre- and post-surgery were sought by Mann-Whitney and Fisher's Exact, or Wilcoxon sign tests, respectively. Results: The prevalence of the bacterial species in saliva in both groups was: Pseudomonas spp. (83.3%), Staphylococcus spp. (81.5%), Acinetobacter spp. (63.6%), D. pneumosintes (33.3%), and Pseudomonas aeruginosa (16.7%). A higher frequency of D. pneumosintes was observed in dentate (41.2%) than edentulous (23.1%) patients (p<0.05). In plaque samples, dentate subjects with >14 teeth showed a higher mean prevalence of Pseudomonas spp. (100%) compared to individuals with ≤14 teeth (69.1±12%; p=0.048). Approximately 13% of all staphylococci isolates were positive for mecA. After extubation, P. aeruginosa tended to decrease in prevalence in all samples; however, no significant changes were observed for this or the other bacteria. Conclusion: The oral cavity of edentulous or dentate individuals demonstrated to be a reservoir for pathogens associated with nosocomial respiratory infections, particularly Pseudomonas spp. Supported in part by FAPERJ, UFRJ, CNPq, Brazil. FAPERJ, UFRJ, CNPq, Brazil.