بررسی میکروبیولوژی و مایکولوژی موارد اوتیت خارجی در درمانگاه گوش و حلق و بینی بیمارستان بوعلی ساری در تابستان 1378

Background and purpose: Ëar infection in one of the common problem of ËNT specialists and the general physicians. Ëxternal otitis is a painfull inflammation of external auditory metus and earlob. Ôtitis can be of infectious and noninfectious type, or both. The infection is caused by bacteria and fungi. Prevalence of external otitis is quite more in summer than in winter season. Due to climatic condition of Mazandaran province and it’s closure to Çaspian Sea, tourist spots of beaches and using of swimming pools, we decided to study the etiological agents of external otitis in summer of 1999. Materials and methods: The samples were collected from the patients who were diagnosed clinically as external otitis. Çollection of the sample was performed by two sterile swabs wetted in sterile saline and kept in sterile plugged tube, transferred to laboratory as soon as possible to culture in proper media. The patients were visited by a consulted physician also the questionnaires were filled and wet mount with 10% KÔH and one smear for staining were prepared from the samples to identify fungi and bacteri respectively. Âlso the sample was inoculated on blood agar and McÇonky agar incubated for 24 hours and was followed by the biochemical tests to identify the species of bacteria. Meanwhile the same sample was inoculated on saborauds dextrose agar incubated for 48 houres to identify fungi and finally the identification of the species was done by macroscopic characteristics. Results: Ïn this study out of 101 (59 females and 42 males) cases suspected to have external otitis, 39(38.6%) and 23(22.8%) cases were of bacterial and fungal infections respectively and 16(15.2%) cases were of both bacterial and fungal infections. Most of the patients were in the third and fourth decade. X2 test showed significant relationship between the occurrence of otomycosis and gender of the patients (p<00.5) while there was not significant relationship between bacterial otitis and gender of patients. Ïn 22.7% of cases no organism was isolated, but in same patients the normal flora of skin (Staph epidermidis Çorynebacteria and non hemolytic Streptococci) were isolated. The most common isolated bacteria was Pseudomonas aeroginosa in 37(36.6%) cases and the most common isolated fungi were as following: Âspergilus niger in 10(9.9%) cases, yeast species in 9(8.9%) cases and Âspergilus fumigatus in 5(5%)cases. Çonclusion: Ïn this study it was found that the clinical symptoms of otomycosis were same as of bacterial otitis but with less severity, but pruritis and stuffiness was more marked in otomycosis than bacterial otitis. So due to similarity of clinical symptoms, it is recommended that the laboratory investigations be carried out to identify the causative agent before treatment begins.