Study of aerobic bacterial isolates and their antibiotic susceptibility pattern in chronic suppurative otitis media

Background : Chronic suppurative otitis media (CSOM) is a disease of multiple etiology and its importance lies in its chronicity and dreaded complications. Both Gram positive and negative organisms are responsible for infection of the middle ear. Due to advent of newer and sophisticated antibiotics, the microbiological flora is changing constantly. This requires a reappraisal of the flora in CSOM and their in vitro antibiotic sensitivity pattern in cases of CSOM, which do not respond to local antibiotics. The frequent presence of CSOM in general practice and its poor response to the routine treatment are the factors responsible for undertaking this study. Materials and Methods : One hundred and twenty six patients with CSOM were prospectively studied. They had chronic ear discharge and had not received antibiotics for the previous five days. Swabs were taken and cultured for bacteria. The standard method of isolation and identification was followed. Antimicrobial susceptibility of the bacterial isolates was performed by Kirby-Bauer's disc diffusion method. Results: Analysis of bacterial flora of the present study showed predominance of Gram negative bacilli (69.84%). The highest incidence (45.24%) was that of Pseudomonas aeruginosa followed by Staphylococcus aureus (22.22%). Amikacin was found to be the most effective drug. Conclusion: This study suggests that the common etiological agents for CSOM were Pseudomonas aeruginosa followed by Staphylococcus aureus . Amikacin was found to be the drug of choice.