Identification of bacteria associated with spreading odontogenic infections by 16S rRNA gene sequencing

Objective To determine the bacterial species associated with spreading odontogenic infections (SOIs). Study design Pus samples from 4 cases of SOI were analyzed by microbiological culture methods for the presence of bacteria, and by polymerase chain reaction (PCR) amplification, cloning, and sequencing of bacterial 16S rRNA genes. Results Culture methods identified species from the genera Prevotella , Streptococcus , and Fusobacterium , as well as anaerobic streptococci. Molecular detection methods identified a far more diverse microflora. The predominant genus detected was Prevotella , representing 102 (50.2%) of 203 clones analyzed. Prevotella oris was the most abundant species identified, representing 45 (22.2%) of 203 clones analyzed. Twelve clones (5.9%) represented uncultivable species, namely Prevotella PUS9.180, an uncultured Peptostreptococcus species, and an uncultured bacterium belonging to the Bacteroidetes phylum. Conclusions Prevotella species may play an important role in SOIs, and further work to examine in more detail the pathogenicity determinants of these organisms and associated host responses is warranted.