Study of bacterial flora in children's with hearing aid earmoulds in Ahvaz, Iran.

The aim of this study was to determine the presence and nature of bacterial flora on hearing aids earmoulds in a children's population. The study population consisted of 119 children referred to Imam Ali and Rudaky Schools in Ahvaz, Iran. Three samples were taken from surface of hearing aids earmoulds; canal in hearing aid wearers and ear without hearing aids earmoulds. The samples were cultured directly onto blood agar and MacConkey agar plates. According to preliminary examination, necessary standard biochemical tests were performed on grown bacteria and the organisms were identified as per standard identification criteria. Totally, 66 samples (61.1%) from hearing aids earmoulds and 124 samples (52.1%) from both ear canal without hearing aids earmoulds were culture positive, which 73 (58.9%) and 51 (41.1%) were from right and left ears, respectively. The majority of isolated bacteria from earmoulds were Coagulase-Negative Staphylococci (CNS) 40 (60.6%) and Polybacterial flora 14 (21.2%) and the least isolated bacteria were Pseudomonas aeruginosa and Staphylococcus aureus. In conclusion, although the majority of isolated bacteria were common normal flora of the ear, however a few pathogens were isolated as well. So, it is very important to educate the people with hearing aids earmoulds about proper cleaning and disinfection procedure to prevent any serious ear canal infection.