Discrepancies in the recovery of bacteria from multiple sinuses in acute and chronic sinusitis.

The microbiology of acute and chronic sinusitis has been studied extensively. Establishing the concomitant distribution of the causative organisms in cases that involve multiple sinuses is of scientific and practical importance. This study evaluated the aerobic and anaerobic microbiology of acute and chronic sinusitis in patients with involvement of multiple sinuses. The 155 patients evaluated had sinusitis of either the maxillary, ethmoid or frontal sinuses (any combination) and had organisms recovered from two to four concomitantly infected sinuses. Similar aerobic, facultatively anaerobic and anaerobic organisms were recovered from all groups of patients. In patients who had organisms isolated from two sinuses and had acute sinusitis, 31 (56 %) of the 55 isolates were found only in a single sinus, and 24 (44 %) were recovered concomitantly from two sinuses. In those with chronic infection 31 (34 %) of the 91 isolates were recovered only from a single sinus, and 60 (66 %) were found concomitantly from two sinuses. Anaerobic bacteria were more often isolated concomitantly from two sinuses (50 of 70) than aerobic and facultatively anaerobic (ten of 21, P < 0.05). Similar findings were observed in patients who had organisms isolated from three or four sinuses. beta-Lactamase-producing bacteria were more often isolated from patients with chronic infection (58-83 %) as compared to those with acute infections (32-43 %). These findings illustrate that there are differences in the distribution of organisms in single patients who suffer from infections in multiple sinuses and emphasize the importance of obtaining cultures from all infected sinuses.