Coaggregation of Candida albicans with oral Fusobacterium species

Abstract

Nine strains of oral Fusobacterium were examined for their ability to coaggregate in vitro with four strains of the oral yeast. Candida albicans. All of the Fusobacterium nucleatum strains and Fusobacterium periodontium and Fusobacterium sulci coaggregated to various degrees with all of the Candida strains. Fusobacterium alocis, Fusobacterium mortiferum and Fusobactrium simiae strains did not coaggregate with any of the Candida strains. Exposure of the coaggregating Fusobacterium strains but not the Candida strains to heat, trypsin, and proteinase K eliminated coaggregation. Amphotericin B or trichodermin treatment of the yeast species had no effect. The reactions were inhibited by addition of 0.1 M mannose, glucosamine and alpha-methyl mannoside. All coaggregating pairs were disaggregated by the addition of sodium dodecyl sulfate, but nonionic detergents had no effect. The addition of 2.0 M urea completely reversed coaggregation. Candida strains were sensitive to periodate oxidation, whereas the Fusobacterium strains were stable to this treatment. All coaggregations occurred in the presence of saliva and appeared stronger than in buffer. These data suggest that the coaggregations involve either a protein or glycoprotein on the Fusobacterium surface, which may interact with carbohydrates or carbohydrate-containing molecules on the surface of the Candida. These observations expand the known range of intergeneric coaggregations occurring between human oral microbes and indicate that coaggregation of C. albicans and Fusobacterium species may be an important factor in oral colonization by this yeast. The authors believe this to be the first description of coaggregation concerning a carbohydrate component on the yeast cell and a protein component on the oral bacterial cell.

New Assay for Measuring Cell Surface Hydrophobicities of Candida dubliniensis and Candida albicans

“…A 100-l aliquot of yeast suspension (10%) was mixed with 200 l of the bacterial suspension (1%) and 100 l of CoAg buffer, or as a control each CoAg partner was mixed with just the CoAg buffer (7,14). The mixtures were vortexed for 10 s, shaken on a rotary platform shaker for 3 min, and left undisturbed at room temperature for an additional 2 min.…”

Polymicrobial Interactions: Impact on Pathogenesis and Human Disease

“…Although streptococcal species, namely, Streptococcus gordonii, Streptococcus oralis, and Streptococcus sanguinis, exhibit the highest affinities for C. albicans, C. albicans as well as Candida dubliniensis have been shown to coaggregate with Fusobacterium species in suspension (75,76). The latter interactions were inhibited by mannose and therefore were thought to involve a protein component of Fusobacterium binding to a carbohydrate (mannan) receptor on the Candida cell surface (96).…”

Fap2 of Fusobacterium nucleatum Is a Galactose-Inhibitable Adhesin Involved in Coaggregation, Cell Adhesion, and Preterm Birth

“…nucleatum exhibits different types of adhesions and harbors several adhesins, including an arginine-inhibitable adhesin (20,33), a mannose-sensitive lectin involved in fusobacterial coaggregation with Candida species (34,35), and Fad, which is required for cell attachment and invasion (36)(37)(38) and was recently shown to bind E-cadherin on colorectal cancer cells and promote carcinogenesis (39). FadA was also shown to be involved in F. nucleatum 12230 colonization of the mouse placenta (36,39,40).…”