Aerobic bacteriology of chronic suppurative otitis media and its antibiotic susceptibility pattern in a tertiary care hospital, Bagalkot

Abstract

Background: Chronic Suppurative Otitis Media (CSOM) remains one of the most common childhood chronic infectious diseases worldwide, affecting diverse racial and cultural groups both in developing and industrialized countries. India is one of the countries with highest CSOM prevalence (>6%) where urgent attention is needed. Infection usually results from bacterial, fungal and in some cases secondary to other viral infections like upper respiratory tract infections and tuberculosis. It is a common cause of conductive deafness which may lead to delayed development of speech and language in children and fatal intracranial complications. Change in the bacteriological scenario with indiscriminate use of antimicrobial agents has been associated with the emergence of multiple drug resistant strains. Therefore, the present study was carried out to determine the aerobic bacteria involved and their antibiotic susceptibility pattern in patients with CSOM. Methods: Ninety-three clinically diagnosed cases of CSOM of all age groups and both the sexes attending ENT OPD and admitted in ENT wards were studied. Two swabs were taken from each patient, one for Gram's staining and the other one for culture onto blood agar and MacConkey agar. After isolation, Gram stain, and biochemical reactions were done according to the procedures. Antibiotic susceptibility testing was done by Kirby-Bauer disc diffusion method. Results: 90.3% of the total samples yielded bacterial growth, while 9.68% were sterile. A total number of 10 different bacterial species were isolated from 89 isolates. The most common organism isolated was P.aeruginosa (30.3%) followed by S. aureus (27%), P. mirablilis (11.2%), K. pneumoniae (9%), E. coli (5.6%), CONS (5.6%), C. freundi (5.6%), Acinetobacter spp (2.2%), S. pyogenes (2.2%) and P.vulgaris (1.1%). Among Gram negative isolates the most sensitive drugs were amikacin and ofloxacin with 93.1% sensitivity, followed by piperacillin + tazobactam (88.9%) and ciprofloxacin (81%). Amoxyclav was the most resistant antibiotic (10.3%). The most effective antibiotic against gram positive bacteria in the present study was found to be ofloxacin and vancomycin (both 100% sensitivity), followed by chloramphenicol (96%). Ampicillin was the most resistant antibiotic, only 19.4% organisms were sensitive to it. Conclusion:The most common organism isolated was P.aeruginosa followed by S. aureus. The most effective antibiotic against gram positive bacteria was found to be ofloxacin. Among gram negative isolates the most sensitive drugs were amikacin and ofloxacin.