Aerobic Bacterial Profile and Antibiotic Susceptibility Pattern of Chronic Suppurative Otitis Media in a Tertiary Care Centre in Kerala

BACKGROUND Chronic suppurative otitis media is a notorious middle ear infection in the developing countries which if left untreated can lead to serious intra and extracranial complications. We wanted to identify the bacterial pathogens causing CSOM and to determine their antibiotic susceptibility pattern. METHODS The in-patients & out-patients from the Department of E.N.T. over a period of one year were recruited and evaluated in the study. Ear swabs collected from the 135 clinically diagnosed cases of CSOM were processed in the microbiology laboratory. The bacterial isolates were identified, and their antibiotic susceptibility testing was done. RESULTS Bacterial growth was obtained from 100 out of the 135 samples of which 37.5% of the isolates were Pseudomonas aeruginosa, 21.5% Staphylococcus aureus, 5.9% Klebsiella pneumoniae, 3.7% Escherichia coli etc. Maximum antibiotic resistance was observed towards Ciprofloxacin, Gentamicin and Ceftazidime in Pseudomonas aeruginosa. Among the multi-drug resistant Gram-negative isolates, 20 were Extended Spectrum Beta Lactamase producers, 10 were AmpC beta lactamase producers and 10 were Metallo Beta Lactamase producers. CONCLUSIONS The bacterial isolates were found to be highly resistant to fluroquinolones and aminoglycosides, the most commonly used topical antibiotics for CSOM, in this study. Culture and antibiotic susceptibility testing of the bacterial isolates are therefore essential to help clinicians in better management of the cases and reduce the emergence of antibiotic resistant strains.