Study of bacterial pathogens causing chronic suppurative otitis media and the antibiotic susceptibility pattern of the isolates at a tertiary care centre in Kochi

Background: Chronic suppurative otitis media (CSOM) is defined as chronic inflammation of middle ear and mastoid cavity presenting with recurrent ear discharges through a tympanic membrane perforation. Complications of CSOM were frequent in pre-antibiotic era. Injudicious use of antibiotics led to the emergence of multi-drug resistant strains and complications in return. To isolate the organisms associated with CSOM in a tertiary care centre and to detect their antibiogram. Methods: In this clinical, prospective, cross sectional study, a total of 100 patients clinically diagnosed with CSOM were enrolled from January to December 2019 (1 year). Results: Of the 100 samples collected, predominant bacteria were isolated in 58 patients (58%). The most common isolate was Pseudomonas aeruginosa (29 isolates) followed by Staphylococcus aureus (24), Klebsiella species (3) and 1 isolate each of Pneumococci and Acinetobacter species. Among the 29 isolates of Pseudomonas aeruginosa , 8 (28%) were multidrug resistant. Sensitivity was 100% to imipenem followed by 97% to meropenem,79% to gentamicin, 76% to amikacin, 66% to ciprofloxacin, 41% to piperacillin tazobactam and 17% to ceftazidime. Of the 24 isolates of Staphylococcus aureus , 4 (16%) were methicillin resistant Staphylococcus aureus (MRSA). Conclusions: Pseudomonas aeruginosa was the most common isolate, of which 28% were multi drug resistant. This calls for the judicious use of antibiotics and alternative measures for treatment of drug resistant strains. Formulating an antibiotic policy based on the local antibiogram can help in preventing the emergence and spread of resistant pathogens.