AN EXPERIMENTAL-MODEL FOR STUDY OF CANDIDA SURVIVAL AND TRANSMISSION IN HUMAN VOLUNTEERS

In order to determine the potential for cross-transmission of Candida spp. between health-care workers and patients, the survival of clinica l isolates of five species of Candida on the palms of human volunteers was tested. One hundred mu l of a McFarland 1.0 density suspension (5 x10(5) cfu) from an overnight culture of Candida albicans, Candida kru sei, Candida parapsilosis, Candida tropicalis and Candida glabrata was used as inoculum. The degree of hydrophobicity of the different Candi da species was also tested and did not influence the survival. The hal f-lives were brief, being 9.5, 12.4, 7.4, 12.8, 9.6 min for Candida al bicans, Candida krusei, Candida glabrata, Candida parapsilosis, and Ca ndida tropicalis, respectively, but at 45 min 2.6 x 10(3) to 3 x 10(4) organisms remained on the hands. Survival of Candida albicans for as long as 24 h on inanimate surfaces was observed. Transmission from one hand to a second hand occurred in 69 % of the experiments and from th e first to a third hand in 38 %. Transmission to and from inanimate su rfaces was successful in most of the experiments (90 %). This experime ntal model aids in the biological study of Candida spp. and suggests s ome of the potential mechanisms of transmission.