Microtitration plate enzyme immunoassay to detect PCR-amplified DNA from Candida species in blood.

We developed a microtitration plate enzyme immunoassay to detect PCR-amplified DNA from Candida species. Nucleotide sequences derived from the internal transcribed spacer (ITS) region of fungal rDNA were used to develop species-specific oligonucleotide probes for Candida albicans, C. tropicalis, C. parapsilosis, and C. krusei. No cross-hybridization was detected with any other fungal, bacterial, or human DNAs tested. In contrast, a C. (Torulopsis) glabrata probe cross-reacted with Saccharomyces cerevisiae DNA but with no other DNAs tested. Genomic DNA purified from C. albicans blastoconidia suspended in blood was amplified by PCR with fungus-specific universal primers ITS3 and ITS4. With the C. albicans-specific probe labeled with digoxigenin, a biotinylated capture probe, and streptavidin-coated microtitration plates, amplified DNA from a few as two C. albicans cells per 0.2 ml of blood could be detected by enzyme immunoassay.     

Candidemia in pediatric outpatients receiving home total parenteral nutrition.

This is a cohort study of pediatric outpatients receiving total parenteral nutrition (TPN) and follow-up care in a Tennessee hospital between January and June 1999. The study was conducted following an increase in the incidence of candidemia. Of 13 children receiving home TPN, five had candidemia; three were due to Candida parapsilosis. Case patients were more likely to have an underlying hematologic disease (P = 0.02) as well as previous history of fungemia (P = 0.02). Two case patients had successive candidemia episodes 3 months apart; karyotypes and RAPD profiles of each patient's successive C. parapsilosis isolates were similar. Candida spp. were frequently detected in hand cultures from cohort members (four of 10) and family member caregivers (nine of 11); C parapsilosis was isolated from five caregivers. Our findings underscore the challenges of maintaining stringent infection control practices in the home health care setting and suggest the need for more intensive follow-up and coordination of home TPN therapy among pediatric patients.