title: Effects of salivary protein flow and indigenous microorganisms on initial colonization of Candida albicans in an in vivo model.
abstract: BACKGROUND
  Candida albicans is a dimorphic fungus that is part of the commensal microbial flora of the oral cavity. When the host immune defenses are impaired or when the normal microbial flora is disturbed, C. albicans triggers recurrent infections of the oral mucosa and tongue. Recently, we produced NOD/SCID.e2f1-/- mice that show hyposalivation, decrease of salivary protein flow, lack IgA and IgG in saliva, and have decreased NK cells. Our objective was to characterize C. albicans infection and biofilm formation in mice.
  
  
  METHODS
  NOD/SCID.e2f1-/- mice were used as an animal model for C. albicans infection. C. albicans yeast and hyphal forms solutions were introduced in the oral cavity after disinfection by Chlorhexidine.
  
  
  RESULTS
  The numbers of C. albicans colonized and decreased in a time-dependent manner in NOD/SCID.e2f1+/+ after inoculation. However, the colonization levels were higher in NOD/SCID.e2f1+/+ than NOD/SCID.e2f1-/- mice. In the mice fed 1% sucrose water before inoculation, C. albicans sample was highly contaminated by indigenous microorganisms in the oral cavity; and was not in the mice fed no sucrose water. The colonization of C. albicans was not influenced by the contamination of indigenous microorganisms. The hyphal form of C. albicans restricted the restoration of indigenous microorganisms. The decreased saliva in NOD/SCID.e2f1-/- did not increase the colonization of C. albicans in comparison to NOD/SCID.e2f1+/+ mice. We suggest that the receptor in saliva to C. albicans may not be sufficiently provided in the oral cavity of NOD/SCID.e2f1-/- mice.
  
  
  CONCLUSIONS
  The saliva protein flow may be very important for C. albicans initial colonization, where the indigenous microorganisms do not affect colonization in the oral cavity.
authors.affiliation: Dentistry for Persons with Disabilities, Tokyo Medical & Dental University, Tokyo, Japan.
authors.forename: Norihiko
authors.initials: N
authors.lastname: Kanaguchi
authors.forename: Naoki
authors.initials: N
authors.lastname: Narisawa
authors.forename: Tatsuro
authors.initials: T
authors.lastname: Ito
authors.forename: Yosuke
authors.initials: Y
authors.lastname: Kinoshita
authors.forename: Yasuka
authors.initials: Y
authors.lastname: Kusumoto
authors.forename: Osamu
authors.initials: O
authors.lastname: Shinozuka
authors.forename: Hidenobu
authors.initials: H
authors.lastname: Senpuku
mesh_terms: D000818:Animals; D018441:Biofilms / Q000187:drug effects; D002176:Candida albicans / Q000187:drug effects / Q000302:isolation & purification / Q000502:physiology*; D002180:Candidiasis, Oral / Q000503:physiopathology; D015169:Colony Count, Microbial; D004195:Disease Models, Animal; D005260:Female; D025301:Hyphae / Q000302:isolation & purification / Q000502:physiology; D007071:Immunoglobulin A, Secretory / Q000032:analysis; D007074:Immunoglobulin G / Q000032:analysis; D007694:Killer Cells, Natural / Q000473:pathology; D051379:Mice; D016688:Mice, Inbred NOD; D008815:Mice, Inbred Strains; D016513:Mice, SCID; D009061:Mouth Mucosa / Q000382:microbiology; D012463:Saliva / Q000382:microbiology*; D012471:Salivary Proteins and Peptides / Q000378:metabolism*; D012636:Secretory Rate / Q000502:physiology; D013395:Sucrose / Q000494:pharmacology; D014059:Tongue / Q000382:microbiology; D014987:Xerostomia / Q000382:microbiology
chemical_list: D007071:Immunoglobulin A, Secretory; D007074:Immunoglobulin G; D012471:Salivary Proteins and Peptides; D013395:Sucrose