Phenotypic Assessment of Bacterial and Fungal Colonization on Mobile Phone Earpieces of University Students in Port Harcourt, Nigeria

Abstract

Background: Mobile phones are high-contact personal devices that may serve as reservoirs for pathogenic microorganisms. Accessories such as earpieces maintain prolonged contact with the ear canal and may facilitate microbial transmission. Aim: This study investigated bacterial and fungal colonization of mobile phone earpieces used by university students and evaluated the antimicrobial susceptibility profiles of recovered bacterial isolates. Methods: A cross-sectional descriptive study was conducted on twenty (n = 20) mobile phone earpieces collected from students at Rivers State University, Port Harcourt, Nigeria. Swab samples were cultured on selective bacteriological and mycological media. Isolates were identified using standard microbiological techniques. Antimicrobial susceptibility testing was performed using the Kirby–Bauer disk diffusion method following CLSI (2023) guidelines. A total of thirty-six (n = 36) bacterial isolates were recovered and tested. Results: All earpieces (20/20; 100%) yielded microbial growth. Bacterial isolates included Staphylococcus aureus (15/20; 75%), Staphylococcus epidermidis (12/20; 60%), Escherichia coli (5/20; 25%), and Pseudomonas aeruginosa (4/20; 20%). Fungal isolates included Candida spp. (8/20; 40%) and Aspergillus spp. (5/20; 25%). Reduced susceptibility was highest against amoxicillin (13/36; 36.1%), erythromycin (11/31; 35.5%), and tetracycline (12/36; 33.3%). Multidrug resistance (MDR), defined as resistance to at least one agent in three or more antimicrobial classes, was observed in S. aureus (4/15; 26.7%) and P. aeruginosa (2/4; 50%). Ciprofloxacin (5 µg) demonstrated the highest sensitivity rates (30/36; 83.3%). Conclusion: Mobile phone earpieces serve as reservoirs for potentially pathogenic and multidrug-resistant microorganisms. Regular disinfection and improved hygiene practices are recommended to reduce microbial transmission risks.