Bacterial profile and antibiotics susceptibility pattern of ear swabs among students in tertiary institutions in Anambra state

Bacterial colonisation of the external ear canal represents an important risk factor for community-associated otitis externa, particularly among young adults with frequent exposure to shared environments. This cross-sectional study assessed the prevalence, bacterial profile, and antibiotic susceptibility patterns of ear swab isolates obtained from 107 asymptomatic undergraduate students in a tertiary institution in Anambra State, Nigeria. A total of 46 samples (42.99%) yielded significant bacterial growth, of which Staphylococcus aureus was the predominant isolate, accounting for 40 (86.96%) of all positive cultures, followed by Staphylococcus epidermidis 3 (6.52%) and Pseudomonas aeruginosa 3 (6.52%). No Enterobacterales species were isolated. Staphylococcus aureus demonstrated high resistance to β-lactam antibiotics, particularly amoxicillin/clavulanic acid (95%) and cefotaxime (87.5%), but retained notable susceptibility to azithromycin (80%) and fluoroquinolones, including ofloxacin (75%) and levofloxacin (72.5%). All P. aeruginosa isolates were resistant to imipenem and amoxicillin/clavulanic acid but fully susceptible to ofloxacin and levofloxacin. In conclusion, the moderate prevalence of bacterial colonisation among students, dominated by Staphylococcus aureus with lesser contributions from Staphylococcus epidermidis and Pseudomonas aeruginosa, alongside high resistance to commonly used β-lactam antibiotics but retained susceptibility to fluoroquinolones and azithromycin, highlights the need for continuous surveillance and rational antibiotic use to prevent the emergence and spread of resistant otic pathogens.