A Case of Coinfection in a Chronic Maxillary Sinusitis of Odontogenic Origin : Identification of Dialister pneumosintes

Introduction: In this report, we discuss the case of a 39-year-old woman presenting with a case of chronic maxillary sinusitis. Methods: Dialister pneumosintes, Staphylococcus epidermidis, and Peptostreptococcus spp. were isolated from endosinusal samples obtained during surgery. The patient showed extensive periodontopathy and had undergone prior endodontic treatment for endodontic infection of teeth #13, #14, and #15, which failed and presumably acted as a bridge for the sinusal infection. After nasosinusal surgery, consisting of opening and toilet of the maxillary sinus, combined with extraction of the 3 previously mentioned teeth and antibiotic treatment, the patient showed complete healing. Results: S. epidermidis and Peptostreptococcus spp. were identified with a traditional biochemical test and confirmed by pyrosequencing. Conversely, D. pneumosintes could not be identified with the conventional method, but it was identified using DNA pyrosequencing. In addition, to better understand the role and the virulence of this bacterium in odontogenic sinusitis, we have evaluated the ability of D. pneumosintes to produce biofilms onto inert surfaces. D. pneumosintes is a known endodontic and periodontal pathogen found in necrotic pulp, subgingival plaque, and deep periodontal pockets. Conclusions: To our knowledge, the pathogenic role of D. pneumosintes in odontogenic sinusitis has never been evidenced. Thus, its detection in endosinusal specimens may provide a significant insight into the pathogenesis of this relevant medical condition.