The bacteriology of perimandibular space infections.

The bacteriology of 21 perimandibular clised-space infections was studied prospectively using optimal bacteriological techniques to collect, transport, and process specimens. There was an average of six microbial species per specimen, including approximately four anaerobes and two aerobes. The predominant aerobes were alpha-hemolytic and non-hemolytic streptococci; the predominant anaerobes were peptostreptococci, Bacteroides melaninogenicus, and Fusobacterium nucleatum. These findings indicate that most perimandibular space infections involve a polymicrobial flora in which anaerobic bacteria are the dominant isolates. Antimicrobial decisions should account for these observations, particularly in cases where cultural data are not available or when anaerobic cultures are not performed with optimal techniques.