Microbial Patterns and Antibiotic Resistance in Otitis Media Association with Local and Systemic Biochemical Indicators

Background: Otitis media (OM) is a prevalent ear infection that contributes significantly to outpatient consultations, particularly in developing regions. Accurate identification of the causative organisms and their antibiotic susceptibility patterns is essential to guide effective treatment and prevent chronic complications. Objective: This study aimed to determine the bacterial etiology of OM, evaluate antibiotic resistance patterns, and analyze the associated clinical and biochemical features among patients in Kirkuk city, Iraq. Methods: A cross-sectional study was conducted from February to November 2024 in outpatient clinics of the Kirkuk Health Directorate. Ninety patients diagnosed clinically with OM were included. Ear discharge samples were collected and subjected to culture, biochemical identification, and antibiotic sensitivity testing using the Kirby-Bauer disc diffusion method. Blood samples were analyzed for white blood cell count, CRP, ESR, and other hematological parameters. Results: Clinical manifestations were dominated by ear pain (75.6%), ear discharge (57.8%), and hearing loss (48.9%). Microbiological analysis revealed Streptococcus pneumoniae (27.78%) and Pseudomonas aeruginosa (22.22%) as the most common isolates, followed by Klebsiella pneumoniae, Staphylococcus aureus, Escherichia coli, Haemophilus influenzae, and Staphylococcus epidermidis. Antibiotic susceptibility testing showed S. pneumoniae had the highest sensitivity to ceftriaxone (26.67%), levofloxacin (25.56%), and ciprofloxacin (24.44%). In contrast, P. aeruginosa exhibited resistance to several agents, responding best to gentamicin (16.67%). Biochemical markers supported a bacterial etiology, with elevated white blood cell counts (11.2 × 10³/μL), C-reactive protein (18.5 mg/L), and erythrocyte sedimentation rate (24.3 mm/hr). Neutrophil predominance (68.3%) reinforced the inflammatory nature of the disease. Acute OM was the most frequent presentation (46.7%), with unilateral involvement seen in 67.8% of cases. Conclusion: This study highlights the bacterial spectrum and resistance trends in OM patients, underscoring the importance of local microbiological surveillance and targeted antibiotic therapy to improve patient outcomes and guide antimicrobial stewardship efforts in Iraq