The normal microbial flora of the outer ear canal in healthy Norwegian individuals.
The microbial flora of the outer ear canal was determined for 77 healthy individuals (M = 44, F = 33). No growth of any microbe was found in 5% of males and 15% of females. Coagulase-negative staphylococci, dominated by Staphylococcus epidermidis, were the commonest microbe group found (83% of persons sampled). Staphylococcus aureus was found in 7% males and no females. Diptheroids were cultured from 32% of the samples. The only Gram-negative rod found was Hafnia alvei in 4% of individuals. No Vibrio spp. or anaerobic Gram-negative organisms were found. A variety of yeasts and moulds were seen, significantly (p = 0.02) more often in males. In a separate experiment, Malassezia furfur was found in 4/9 males and 0/10 females sampled. Various sampling techniques (dry swab, second dry swab, moist swab) that were compared showed broadly similar results. The normal flora of the outer ear canal is predominantly Gram-positive and the use of a dry swab seems to be a satisfactory method for sample-taking from this area.
Dibb
W L
WL
Microbiology Department, Central Hospital, Fredrikstad, Norway.
D000293:Adolescent; D000328:Adult; D000368:Aged; D001431:Bacteriological Techniques; D002648:Child; D004424:Ear Canal / Q000382:microbiology*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009664:Norway; D013211:Staphylococcus aureus / Q000302:isolation & purification; D013212:Staphylococcus epidermidis / Q000302:isolation & purification