Microbiology of acute and chronic maxillary sinusitis associated with an odontogenic origin.

OBJECTIVES : To study the microbiology of sinusitis associated with odontogenic origin. METHODS : Aspirates of 20 acutely and 28 chronically infected maxillary sinuses that were associated with odontogenic infection were processed for aerobic and anaerobic bacteria. RESULTS : A total of 66 isolates were recovered from the 20 cases of acute sinusitis (3.3/specimen), 16 aerobic and facultatives, and 50 anaerobic. Aerobes alone were recovered in 2 (10%) specimens, anaerobes only in 10 (50%), and mixed aerobic and anaerobic bacteria in 8 (40%). The predominant aerobic were alpha-hemolytic streptococci (5), microaerophilic streptococci (4), and Staphylococcus aureus (2). The predominant anaerobes were anaerobic Gram-negative bacilli (22), Peptostreptococcus (12), and Fusobacterium spp. (9). A total of 98 isolates were recovered from the 28 cases of chronic sinusitis (3.5/patient): 21 aerobic and facultatives and 77 anaerobic. Aerobes were recovered in 3 (11%) instances, anaerobes only in 11 (39%), and mixed aerobic and anaerobic bacteria in 14 (50%). The predominant aerobes were alpha-hemolytic streptococci (7), microaerophilic streptococci (4), and S. aureus (5). The predominant anaerobes were Gram-negative bacilli (41), Peptostreptococcus (16), and Fusobacterium spp. (12). Thirteen beta-lactamase-producing bacteria (BLPB) were recovered from 10 (50%) patients with acute sinusitis and 25 BLPB from 21 (75%) patients with chronic sinusitis. No correlation was found between the predisposing odontogenic conditions and the microbiological findings. CONCLUSIONS : These data illustrate the similar microbiology of acute and chronic maxillary sinusitis associated with odontogenic infection where anaerobic bacteria predominate in both types of infections.