A 16-year survey of changes in bacterial isolates associated with chronic suppurative otitis media

Bacteria were isolated and cultured from the ears of outpatients with chronic suppurative otitis media (OMC) who attended the otologic clinics of Kyushu University Hospital from 1976 to 1991. Bacterial isolates were analyzed retrospectively to determine their incidences and antibiotic sensitivities. Staphylococcus aureus and Pseudomonas aeruginosa were the most commonly isolated organisms. The incidence of S. aureus infections gradually rose over 16 years, while the incidence of Proteus infections gradually declined. The frequency of isolation of glucose non-fermenting gram-negative rod (NF-GNR) species, fungi and anaerobic bacteria gradually increased. The species of bacteria isolated from OMC cases with acute and chronic infections, cholesteatoma and postoperative infections were compared. Over the 16 years, the isolation of S. aureus increased in frequency. The differences in each type of OMC ceased to exist. S. aureus were quite sensitive to most of the antibiotics tested, whereas Ps. aeruginosa and NF-GNR showed poor sensitivity.