title: Bacterial flora in the nasopharynx and nasal cavity of healthy young men.
abstract: The bacterial flora of the nose and nasopharynx was studied in 86 healthy young men. Common pathogens (Haemophilus influenzae and Streptococcus pneumoniae) were isolated from only 6% of all 172 nasal cavities. The same pathogens were isolated from 27% of 86 nasopharyngeal samples. H. influenzae dominated over S. pneumoniae both in the nose and the nasopharynx. No culture either from the nose or nasopharynx grew Streptococcus pyogenes. Potentially pathogenic bacteria, non-group-A hemolytic streptococci and various groups of Neisseria meningitidis were isolated from the nasopharynx in 20% of the subjects. According to the present study healthy adults do not carry group-A hemolytic streptococci in the nose and seldom if ever in the pharynx. Thus, isolation of S. pyogenes by bacterial culture is suggestive of a bacterial infection by this agent at these sites. Isolation of hemolytic streptococci other than group A from the pharynx does not necessarily indicate bacterial infection, and the same holds true for H. influenzae and S. pneumoniae.
authors.affiliation: Department of Otorhinolaryngology, Central Military Hospital, Helsinki, Finland.
authors.forename: J
authors.initials: J
authors.lastname: Ylikoski
authors.forename: S
authors.initials: S
authors.lastname: Savolainen
authors.forename: H
authors.initials: H
authors.lastname: Jousimies-Somer
mesh_terms: D000293:Adolescent; D000328:Adult; D001419:Bacteria / Q000302:isolation & purification*; D006801:Humans; D008297:Male; D009296:Nasal Cavity / Q000382:microbiology*; D009305:Nasopharynx / Q000382:microbiology*