Correlation between microbiology and previous sinus surgery in patients with chronic maxillary sinusitis

Aspirates of 108 chronically inflamed maxillary sinuses were processed for aerobic and anaerobic bacteria. There were 295 bacterial isolates: 109 aero bic and facultative, and 186 anaerobic. The predominant aerobic isolates we re Staphylococcus aureus (17 isolates), alpha -hemolytic streptococci (14), Pseudomonas aeruginosa (12), Moraxella catarrhalis (10), and Haemophilus s pp (8). The predominant anaerobes were Peptostreptococcus spp (61), Prevote lla spp (45), Fusobacterium spp (15), and Propionibacterium acnes (11). Ana lysis of the medical histories revealed a correlation only between the micr obial results and previous sinus surgery. Pseudomonas aeruginosa and gram-n egative aerobic bacilli (GNAB) were more often isolated in patients who had surgery (9 of 33 patients had P aeruginosa and 17 had GNAB) than in patien ts who did not have surgery (3 of 75 had P aeruginosa and 7 had GNAB; p < . 001). Anaerobes were isolated more often in patients who did not have surge ry (69 of 75 patients) than in those who had previous surgery (21 of 33 pat ients: p < .001). These findings illustrate the unique microbiological feat ures of chronic maxillary sinusitis that persist after sinus surgery.