COAGGREGATION OF CANDIDA-ALBICANS WITH ORAL ACTINOMYCES SPECIES

Eight strains of Actinomyces were examined for their ability to coaggr egate in vitro with four strains of Candida albicans. The Actinomyces coaggregated to various degrees with all of the Candida strains. Expos ure of the Candida but not the Actinomyces to heat, trypsin, proteinas e K, amphotericin B or trichodermin abolished coaggregation. All sugar s tested did not inhibit any of the reactions. All coaggregating pairs were disaggregated by the addition of SDS, but nonionic detergents ha d no effect. The addition of urea or EDTA completely reversed coaggreg ation. Actinomyces strains were sensitive to periodate oxidation, wher eas the Candida strains were unaffected. These data suggest that the c oaggregations involve a protein on the Candida surface that may intera ct with carbohydrates or carbohydrate-containing molecules on the surf ace of the Actinomyces. These observations expand the known range of i ntergeneric coaggregations occurring between human oral microbes and i ndicate that coaggregation of C. albicans and Actinomyces may be an im portant factor in oral colonization by this yeast.