A novel animal model for dry mouth: E2f1-deficient NOD/SCID mice

Persistent colonization of Candida albicans yeast on the tongue in NOD/SCID.e2f1-/- mice

Candida albicans is a commensal fungus that commonly colonizes as opportunistic pathogens human mucosal surfaces. Our aim was to observe persistent infection of C. albicans on the tongue in NOD/SCID.e2f1(-/-) mice, which naturally was decreased saliva and undeveloped T and B cells. Using a cotton swab, a C. albicans suspension was applied to the tongue of wild type and mutant mice after disinfection using 0.2% Chlorhexidine (CHX). In our earlier report, it was found that many times inoculation per day and consecutive day inoculations without disinfection of indigenous microorganisms did not induce significant C. albicans infection for 48 h in the oral cavity. In this study, using inoculation of four sets {one inoculation after disinfection by CHX + interval (3 or 4 d)} induced longer term and higher numbers infection for 4 days on the tongue than results in a previous report in both NOD/SCID.e2f1(+/+) and NOD/SCID.e2f1(-/-) mice. Repeat of disinfection to indigenous microorganisms and inoculation with interval established and realized a new model for persistent infection of C. albicans yeast. However, decreased saliva and consecutive inoculations per day did not contribute to the persistent colonization on the tongue in the mice. It is suggested that the interaction between C. albicans and indigenous microorganisms is important for persistent colonization of C. albicans yeast on the tongue rather than decreased saliva in the oral cavity.