The adherence and dissociation of Candida albicans, C. tropicalis, Streptococcus mutans and S. sanguis to six substrates including hydroxylapatite (HAP) which exhibit various hydrophobicity, was examined by the use of a bioluminescent adenosine triphosphate (ATP) assay. Dissolution of HAP by C. albicans or S. mutans was determined spectrophotometrically by the use of o-cresolphthalein complexone. In the adherence of C. tropicalis, S. mutans and S. sanguis, the amount of adherent cells correlated with the hydrophobicity of the substrates. In contrast, the adherence of C. albicans to HAP was extraordinary high, although the adherence of the fungi also correlated with the hydrophobicity of the substrates, except for HAP. The yeasts attached to HAP was effectively removed by high concentration of either phosphate or calcium ions. The amount of calcium-release from HAP caused by C. albicans and S. mutans was 113 microg ml(-1) (final pH = 3.45), and 5.4 microg ml(-1) (final pH 4.81), respectively and the maximum growth of C. albicans and S. mutans was 10(7) cfu ml(-1) and 7.4 x 10(12) cfu ml(-1), respectively. The results, taken together, suggest that C. albicans adhere to HAP specifically through electrostatic interaction, and that, in a much smaller number (1.0/7.4 x 10(5)), C. albicans possesses the ability to dissolve HAP to a greater extent (approximately 20-fold) when compared with S. mutans.

No abstract

Interactions between bacterial oral flora and Candida albicans are important in denture plaque formation. This study therefore first aimed to quantify the coadherence of C. albicans and bacteria by the use of a bioluminescent adenosine triphosphate (ATP) assay based on the firefly luciferase-luciferin system. The second aim was to examine the effect of i) dietary sugars (used for preculture) and ii) enzymatic digestion of fungi on the coadherence. When yeast was preincubated in yeast nitrogen base medium (YNB) supplemented with 250 mM glucose, the yeast coadhered with all isolates of Streptoccus mutans and Streptococcus sanguis, and no significant coadhesion was observed with the isolates of Streptococcus sobrinus, Streptococcus salivarius, Lactobacillus and Actinomyces. However, when the yeast was precultured in YNB supplemented with 500 mM galactose, the yeast coadhered with S. salivarius and Actinomyces, which was not observed when the yeast was grown in YNB with glucose. In addition, the coadherence of the yeast with the isolates of S. sanguis was significantly reduced. Enzymatic digestion of yeast and a reverse transcription polymerase chain reaction assay revealed that expression of at least two types of proteinaceous adhesins are involved in these phenomena.

No abstract

No abstract

The role of saliva or serum proteins, such as mucin, fibronectin (FN) and mannan-binding protein, on Candida biofilm formation was investigated. Supplementation of saliva with FN had no significant effect on biofilm formation. In contrast, biofilm formation on either mucin-coated or FN-coated acrylic surfaces was significantly less than that of the control. These results suggest that salivary mucin or FN alone does not facilitate biofilm formation of Candida. Supplementation of serum with FN increased biofilm formation of C. glabrata compared with the control. Pretreatment of serum with anti-FN monoclonal antibody significantly reduced biofilm formation, as did pretreatment of serum with anti-mannan-binding protein monoclonal antibody or Con-A. Therefore, Candida biofilm formation on acrylic surfaces appears to be a complex phenomenon involving a multiplicity of proteins operating intraorally.

Abstract. Plasma concentrations of estrone sulfate in different breeds of Japanese beef cattle and the relationship between those concentrations and feto-placental growth were examined in order to assess the possibility of monitoring abnormal growth of the fetus. Blood samples were obtained from cows from day 90 of gestation to parturition. The plasma concentration of estrone sulfate was measured by direct enzyme immunoassay. From day 180 of gestation, the mean concentration of estrone sulfate increased gradually and it was drastically elevated after day 240 of gestation with the maximum at day 285. Plasma concentrations of estrone sulfate on day 240 of gestation was significantly increased in F1 cows (Holstein Friesian and Japanese Black) compared with those in other breeds of cow. From day 270 to 278 of gestation, estrone sulfate concentrations of Holstein Friesian cows inseminated by Holstein Friesian differed from those inseminated by Japanese Black. In the cow with retained placenta, the plasma concentration of estrone sulfate reached plateau at day 240 of gestation and did not increase thereafter. There was no significant relationship between estrone sulfate concentration and duration of gestation, calf birth weight, weight of placenta or viability of newborn calves. These results indicate that changes of plasma estrone sulfate concentration in Japanese beef cattle are very similar to those in Holstein dairy cattle. They also suggest that the plasma concentration of estrone sulfate is associated with the breed of pregnant cow and that its concentration is also affected by calf birth weight depending on the breed of bull. It seems possible to predict the incidence of retained placenta but not the calf birth weight and viability of newborn calves in Japanese beef cattle.

No abstract