Drug sensitivity pattern of the pathogenic microorganisms causing atticoantral type of chronic suppurative otitis media
INTRODUCTION Chronic suppurative otitis media (CSOM) is the most common cause of childhood hearing impairment in the developing countries and atticoantral type is associated with increased incidence of intracranial and extracranial complications. This study was undertaken to define the microbiology of atticoantral type of chronic otitis media and the antibiotic sensitivity pattern, thereby reducing the potential risks of complications. MATERIALS AND METHODS A retrospective study was done in the Department of Otolaryngology, JIPMER, Puducherry from the year August 2003 to October 2009 using the medical record department database to retrieve the patient details. During this study period, 223 children with atticoantral type CSOM consisting of 126 males and 97 females with an age range of 1-14 years were assessed. Patients with persistent otorrhea for more than 3 months with atticoantral type of chronic otitis media were selected. The exudates were collected under sterile conditions and inoculated onto culture media; bacterial growth and antibiotic sensitivity pattern were studied. RESULTS Nine species of micro organisms were isolated from the middle ear aspirate, Pseudomonas aeruginosa being the most predominant isolate constituting about 32% (72 discharging ears) of the total isolates followed by Proteus mirabilis (20% of isolates) and Staphylococcus aureus (19% of isolates). Gram negative organisms accounted 58% of total isolates and gram positive organisms constituted 22% isolates. Candida albicans and methicillin resistant S. aureus were identified in 4% and 2% of isolates, respectively. 100% of Pseudomonas isolates showed susceptibility to ceftazidime and a high sensitivity (92% of isolates) to ciprofloxacin and 88% isolates were sensitive to amikacin. 100% of P. mirabilis isolated from inoculates showed sensitivity to ceftazidime and ciprofloxacin. It also showed 87-97% sensitivity to ceftriaxone, amikacin and ampicillin. All (100%) of the Staphylococcus isolates were sensitive to vancomycin and 84-86% were sensitive to ciprofloxacin and erythromycin. In general, gram negative organisms showed increased sensitivity to ceftazidime, ciprofloxacin and amikacin, while gram positive organisms to vancomycin, erythromycin and ciprofoxacin. CONCLUSION Continuous and periodic evaluation of microbiological pattern and antibiotic sensitivity of cholesteatomatous CSOM is necessary to decrease the potential risks of complications by early institution of appropriate systemic and topical antibiotic alongside mastoid exploration. We believe that our data may contribute to an effective medical management of chronic suppurative otitis media with cholesteatoma. Since the most common organisms in our clinical set up being P. aeruginosa, P. mirabilis and S. aureus, which showed a percentage susceptibility of 100% to ceftazidime and vancomycin, thus making it an empirical antibiotic combination therapy of choice in the recent times.