[Bacteriological evaluation in chronic otitis media]

Abstract

Introduction: In chronic otitis media bacterial infection is often a cause of exacerbation in the clinical course and failure in treatment. The aim of the study was to investigate the incidence and profile of the aerobic bacterial flora in chronic otitis media and to determine the drug susceptibility of selected isolated bacteria.

Material and methods: The samples of 274 consecutive middle ear discharges taken from 228 patients with chronic otitis media were analysed (which constitutes 41.3% all bacteriological examinations made during 3 years). The smears were obtained using sterile cotton swabs, then incubated and identified. Drug susceptibility was determined by disc-diffusion method.

Results: Monocultures were observed in 77% and mixed infections in 17.5% of smears, no growth was found in 5.5%. The 308 pathogen isolates were recovered, among them--273 bacterial (88.6%) and 35--fungal (11.4%). Twenty five species of bacterial microorganisms were found, among them the most common isolates were Staphylococcus aureus--42.9% and Pseudomonas aeruginosa---19.8%. Rarely were recovered Acinetobacter spp.--4.1%, Proteus mirabilis--37%, Proteus vulgaris--3.3% and methicillin-resistant Staphylococcus--1.5% of bacterial isolates. Among fungal pathogens (n=35) Aspergillus spp. was isolated in 37.1%, and Candida albicans--22.9% of cases.

Conclusions: (1) Aerobic pathogens ---aphylococcus aureus and Pseudomonas aeruginosa were most frequently found microorganisms in chronic otitis media. (2) Mixed infections comprised only a 17.5% of all cultured cases of chronic otitis media. (3) Pseudomonas aeruginosa was highly susceptible in vitro to imipenem (100%), piperacillin-tazobactam (100%), ceftazidime (98%) and amikacin (89.7%), less susceptible to ciprofloxacin (77.6%) and much less susceptible to pefloxacin (33.6%) and cefotaxim (33.3%).