A study of antibacterial and antifungal properties of human cerumen

Abstract

Objective: To investigate the effect of human cerumen on the growth of Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa and Candida albicans. Study Design: Prospective study Setting: The study was conducted in the Department of Otolaryngology-Head and neck Surgery and Department of Microbiology, at a tertiary care teaching hospital in southern India. Materials and Methods: Cerumen samples were collected from 120 healthy cases by using sterile Jobson Horn Probe. Sterile samples were taken and further tested. The bacterial strains were cultured on nutrient agar and Candida was grown on SDA. Serial 10 fold dilutions of the test organisms were made using normal saline acting as control and using 3.5% cerumen suspension as test and were incubated at 37°C for 12 hours. Subcultures were performed from test as well as control tubes to assess the inhibitory activity of human cerumen. Results: Of 120 samples, only sterile samples were tested. At dilutions of 1 in 10 3 there was complete inhibition of Escherichia coli and Pseudomonas aeruginosa in all samples, complete inhibition of Staphylococcus aureus in 83.3% samples and Candida albicans in 80% samples. The order of inhibition demonstrated by cerumen in the present study was Escherichia coli > Pseudomonas aeruginosa > Staphylococcus aureus > Candida albicans. Conclusion: Human cerumen has antibacterial and antifungal properties against the commonest bacterial and fungal pathogens. Other than the physical barrier, wax acts as protective coating over the external auditory canal. Hence, routine wax removal/ear cleaning is not mandatory unless impacted wax is leading to earache or conductive hearing loss.