Open Access Research article

Effects of salivary protein flow and indigenous microorganisms on initial colonization of Candida albicans in an in vivo model

Norihiko Kanaguchi13, Naoki Narisawa3, Tatsuro Ito23, Yosuke Kinoshita13, Yasuka Kusumoto13, Osamu Shinozuka1 and Hidenobu Senpuku3*

Author Affiliations

1 Dentistry for Persons with Disabilities, Tokyo Medical & Dental University, Tokyo, Japan

2 Department of Pediatric Dentistry, Nihon University Graduate School of Dentistry at Matsudo, Chiba, Japan

3 Department of Bacteriology, National Institute of Infectious Diseases, 1-23-1 Toyama, Shinjuku-ku, Tokyo, 162-8640, Japan

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BMC Oral Health 2012, 12:36  doi:10.1186/1472-6831-12-36

Published: 31 August 2012



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.


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.


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.


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.

Candida albicans; NOD/SCID.e2f1- mice; Saliva; Colonization; Sucrose