Detachment activity of human saliva in vitro for Candida albicans cells attached to a plastic plate

Effect of Streptococcus salivarius K12 on the In Vitro Growth of Candida albicans and Its Protective Effect in an Oral Candidiasis Model

“…Saliva, which commonly contains S. salivarius, also has defensive effects and may play a key role in the process. Previous studies showed that adhesion of C. albicans germ tubes to polystyrene is decreased by saliva, whereas C. albicans yeast cell adhesion to the same material is enhanced (8,14). One may postulate that the possible action of S. salivarius K12 in vivo might involve the latter type of effect, whereby the rolled up Candida mycelial form prevents adhesion to mucosal surfaces of the oral cavity, resulting in the fungus then traveling harmlessly through to the esophagus and beyond.…”

“…The C. albicans strain TIMM1768 was isolated clinically from the blood of a candidiasis patient and maintained at Teikyo University Institute of Medical Mycology; this strain, which was shown to induce oral candidiasis in a murine model, has been used for animal experiments (12,14). Cultures were stored at Ϫ80°C in Sabouraud dextrose broth (Becton Dickinson, MD) containing 0.5% yeast extract (Becton Dickinson, MD) and 10% glycerol (vol/vol, final concentration) until use.…”

“…One hundred microliters of C. albicans cells was aliquoted into 96-well microtiter plates (1 ϫ 10 4 CFU per well for morphological analysis, 5 ϫ 10 5 CFU per well for crystal violet [CV] staining), 100-l serial dilutions of freeze-dried S. salivarius K12 powder were then added to the plates, which made final concentrations of 30 mg/ml (3.0 ϫ 10 9 CFU/ml) to 0.12 mg/ml (1.2 ϫ 10 7 CFU/ml), and the plates were incubated at 37°C in 5% CO 2 in air for 3 h. Germ tube formation was assessed microscopically: cells were fixed with 70% ethanol and stained with CV as described by Abe et al (1) and Kamagata-Kiyoura et al (14).…”

Reduced activity of Candida detachment factors in the saliva of the elderly

“…1 We previously demonstrated the existence of an active proteinaceous agent in human saliva that is capable of detaching Candida albicans hyphae from a substratum that had firmly attached to the bottom of a well in a plastic microplate. 3 This finding led us to the hypothesis that this agent constitutes the host defense against oral Candida infection. If this hypothesis is correct, we may conclude that the Candida-detaching activity is lowered in predisposed hosts (such as compromised patients).…”

“…In accordance with the conventional method, as reported previously, each subject was instructed to spit into a collection tube. 3 In accordance with the conventional method, the final concentration of saliva specimens was adjusted to 25%. 3 Briefly, C. albicans OH-1 cells that had been isolated from the oral cavities of the elderly subjects were suspended in RPMI 1640 medium (Nissui Pharmaceutical, Tokyo, Japan) containing 1% fetal calf serum (FCS; Bio West, Nuaille, France) at a density of 6.4 ϫ 10 6 cells per ml and used as inoculum.…”