title: Survival of Staphylococcus aureus ST398 in the human nose after artificial inoculation.
abstract: There is evidence that MRSA ST398 of animal origin is only capable of temporarily occupying the human nose, and it is therefore, often considered a poor human colonizer.We inoculated 16 healthy human volunteers with a mixture of the human MSSA strain 1036 (ST931, CC8) and the bovine MSSA strain 5062 (ST398, CC398), 7 weeks after a treatment with mupirocin and chlorhexidine-containing soap. Bacterial survival was studied by follow-up cultures over 21 days. The human strain 1036 was eliminated faster (median 14 days; range 2-21 days) than the bovine strain 5062 (median 21 days; range 7-21 days) but this difference was not significant (p = 0.065). The bacterial loads were significantly higher for the bovine strain on day 7 and day 21. 4/14 volunteers (28.6%) showed elimination of both strains within 21 days. Of the 10 remaining volunteers, 5 showed no differences in bacterial counts between both strains, and in the other 5 the ST398 strain far outnumbered the human S. aureus strain. Within the 21 days of follow-up, neither human strain 1036 nor bovine strain 5062 appeared to acquire or lose any mobile genetic elements. In conclusion, S. aureus ST398 strain 5062 is capable of adequately competing for a niche with a human strain and survives in the human nose for at least 21 days.
authors.affiliation: Department of Medical Microbiology and Infectious Diseases, Erasmus MC, Rotterdam, The Netherlands. b.slingerland@erasmusmc.nl
authors.forename: Bibi C G C
authors.initials: BC
authors.lastname: Slingerland
authors.forename: Mehri
authors.initials: M
authors.lastname: Tavakol
authors.forename: Alex J
authors.initials: AJ
authors.lastname: McCarthy
authors.forename: Jodi A
authors.initials: JA
authors.lastname: Lindsay
authors.forename: Susan V
authors.initials: SV
authors.lastname: Snijders
authors.forename: Jaap A
authors.initials: JA
authors.lastname: Wagenaar
authors.forename: Alex
authors.initials: A
authors.lastname: van Belkum
authors.forename: Margreet C
authors.initials: MC
authors.lastname: Vos
authors.forename: Henri A
authors.initials: HA
authors.lastname: Verbrugh
authors.forename: Willem J B
authors.initials: WJ
authors.lastname: van Wamel
mesh_terms: D000328:Adult; D058491:Bacterial Load; D006801:Humans; D008297:Male; D008875:Middle Aged; D009666:Nose / Q000382:microbiology*; D013211:Staphylococcus aureus / Q000235:genetics*