Anaerobic bacteria of purulent aural discharge from 760 patients with chronic otitis media were studied. Middle ear discharge was collected with a sterile cotton stick. The steel wool method was used for anaerobic culture. The anaerobic cultures were carried out at 37°C and the results were determined after 48 hours.
1) Nine species and 81 strains of anaerobic bacteria were isolated from 62 out of 760 patients.
2) Those anaerobic bacteria were mainly Peptococcus 40%, Bacteroides 22%, Peptostreptococcus 7.8%, Fusobacterium 6% and Veillonella 6%.
3) 97.5% of all anaerobic strains were non-spored.
4) Pure anaerobic bacteria were found at 6 cases out of the 62 patients, on the other hand, 56 cases were accompanied by 128 strains, aerobic bacteria. Those aerobic bacteria were mainly Staph. aureus 6.3%, Staph. epidermides 18.1%, Corynebacterium 20.4%, Pseudomonas aeruginosa 7.8% and Proteus mirabilis 17.3%.
General features of pure aerobic bacterial infection show a high detection of Staph. aureus and low rate of P. mirabilis, corynebacterium, Staph. epidermidis. However, in those with both aerobic and anaerobic bacteria, evidence of Staph. aureus decreased and P. mirabilis, corynebacterium and Staph. epidermides increased, comparatively.
5) In the 62 cases which revealed an anaerobic bacterial infection, cholesteatoma accounted for 34%, granulation 20%, and postoperative recurrent cases 13%.
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