Nature and antibiotic sensitivity of bacteria isolated from childhood otitis media

We have cultivated tympanal discharge from 1,336 children diagnosed with acute otitis between 1991 and 1994. There was no growth of microorganisms from 399 specimens /25%/. The distribution of the positive isolates was as follows: Pneumococcus 212, Hemophilus influenzae 86, Staphylococcus aureus 261, Moraxella catarrhalis 5, Beta-hemolytic, Streptococcus 37, Enterococcus faecalis 27, Gram-negative organisms 465 and Blastomyces 4. The antibiotic sensitivity pattern was determined by the disc diffusion method. 51% of Pneumococci was found to be resistant to Penicillin and it's derivates and 54% was resistant to macrolide antibiotics. 17% of Hemophilus influenzae was ampicillin resistant, producing beta-lactamase. Practically all of Staphylococcus aureus strains were Penicillin resistant but sensitive to Oxacillin. However, resistance to macrolide antibiotics was nearly 10% among these strains. The sensitivity pattern of Gram negative organisms isolated from tympanal discharge was similar to Gram negatives isolated from other body sites. Targeted antibiotic therapy /effect, dose, time of initiation of therapy, cost! /is important together with clinical observation of the effect of treatment. In order to apply proper therapy, the nature of the causative microorganism should be established by culturing secretions obtained during procedures, such as tympanal puncture or from instruments, like the myringotome lancet.