Chronic suppurative otitis media: optimizing initial antibiotic therapy in a tertiary care setup

A prospective study was done to determine the clinico-microbiological profile and the antibiogram of patients with chronic suppurative otitis media. Ninety-four patients presenting with tympanic perforation and ear discharge of more than 3 months were studied. Middle ear swabs obtained aseptically were processed for culture and the isolates identified by standard procedures. Antimicrobial susceptibility testing of the aerobic bacterial isolates was performed by disc diffusion method according to clinical laboratory standards institute guidelines. Patients in the age group of 21-30 years were more commonly affected (22.3%). Male:Female ratio was 2:1.4. Of the 94 patients, 64 (68.1%) had tubo-tympanic disease and rest 30 (31.9%) presented with attico-antral disease. Monomicrobial flora was seen in 55 (58.5%) samples, 28 (29.8%) yielded polymicrobial growth and 11 (11.7%) samples were sterile. A total of 115 microbial isolates (86 aerobic bacteria, 18 anaerobic bacteria and 11 fungi) were obtained. Pseudomonas aeruginosa (32.2%) was the most common isolate followed by Staphylococcus aureus (17.4%). Amongst anaerobes, gram positive cocci were more commonly isolated (38.9%). Aspergillus spp. (72.7%) were the most common fungus isolated. Most of the Pseudomonas aeruginosa isolates (25, 67.6%) were susceptible to all the antibiotics. Among the commonly used topical agents in the treatment of CSOM, tobramycin was the most effective (83.8%), followed by gentamicin (78.1%), ciprofloxacin (75.6%) and neomycin (3.5%). Periodic monitoring of the microbiological profile along with their sensitivity pattern is essential for formulating an effective antibiotic policy for CSOM.