Genetic relationship between human and animal isolates of Candida albicans

Abstract

Analyzing Candida albicans isolates from different human and animal individuals by Ca3 fingerprinting, we obtained no evidence for host-specific genotypes and for the existence of species-specific lineages, even though a certain degree of separation between human and animal isolates was found. Therefore, animals could potentially serve as reservoirs for human Candida infection.

FIG. 1.

Ca3 fingerprints of Candia albicans isolates. EcoRI-digested genomic DNA from eight animal and human C. albicans isolates was subjected to Southern blot analysis applying a digoxigenin-labeled Ca3 sequence. DNA from C. albicans strain 3153A (13) was included as a molecular weight and band intensity standard.

FIG. 2.

Genetic relations of Candia albicans isolates from humans and animals. A neighbor-joining tree was calculated from Ca3 fingerprint results for 45 C. albicans isolates from humans (H1 to H42) and from various animal species. Curved arrows indicate cases where an animal isolate was the closest relative to a human isolate. Two groups of isolates are also marked in which a human isolate was as close to an animal isolate as to other human isolates (triangles, H7 plus its closest isolates: chicken, H24, and H42; circles, H12 plus its closest isolates: rabbit, H2, and H14). To assess the phylogenetic support for groupings on the tree, we performed a bootstrap resampling analysis. Bootstrap support values higher than 50% are indicated next to the appropriate nodes.