Prevalence and Antibiotic-Resistance Indices of Bacterial Pathogens of Otitis Media among Patients Attending a Tertiary Hospital in Calabar, Nigeria

Background: Otitis media is linked to middle ear inflammation and sequelae, frequently occurring in infants and early childhood dealing with the accumulation of fluid behind the eardrum. It is often associated with the absence of timely and appropriate antibacterial interventions. Aim: To investigate the identity and antibiogram of bacterial agents of otitis media among patients attending a tertiary health facility in Calabar, Nigeria. Methods: Ear specimens collected from a total of 70 subjects were processed by conventional bacteriological methods for isolation and identification of pathogens. Antibiotic susceptibility testing was carried out on all the isolates using the Kirby-Bauer disk diffusion method. Multiple antibiotic resistance (MAR) indices of the isolates were evaluated. Results: The prevalence of bacterial otitis media was 72.9% in the study population. A total of 51 bacterial isolates including Pseudomonas aeruginaosa (26), Staphylococcus aureus (17), Proteus mirabilis (6), and Klebsiella pneumoniae (2) were found. Isolates of P. aeruginosa and S. aureus showed high susceptibility to amoxicillin-clavulanate (92.3%) and ciprofloxacin (88.3%), respectively. The prevalence of multidrug resistant (MDR) isolates was 25.4%. MDR percentages such as 100%, 33.3%, 30.7% and 29.4% were reported for isolates of K. pneumoniae, P. mirabilis, P. aeruginosa and S. aureus respectively. MAR indexing revealed high values ranging from 0.4 to 0.87 for all the isolates. Conclusion: High susceptibility of the predominant isolates to amoxicillin-clavulanate and ciprofloxacin may underscore the drugs’ potential as antibiotics of choice for prompt treatment of otitis media in the population. However, the overall high drug-resistance indices of the isolates would suggest dire implications for empiric antibacterial therapy in the population. Choice of antibiotics for treatment of bacterial infections in this population should be driven by results of microbiological drug-susceptibility tests.