PCR-mediated genotyping of Candida albicans strains from bone marrow transplant patients.

DNA amplification using polymerase chain reaction (PCR) primers aiming at eukaryotic or prokaryotic repetitive DNA motifs enables discrimination between individual Candida albicans isolates. This PCR-mediated DNA fingerprinting procedure was used to monitor yeast colonisation in immune-compromised leukaemia patients (n = 11) who were undergoing bone marrow transplantation (BMT). The leukaemia patients remained colonised by the same strain throughout a 5 month study period, irrespective of intermediate treatment with fungostatics or application of BMT-related therapies. All 11 strains could be identified separately by PCR fingerprinting. This implies that spreading of C. albicans from patient to patient does not seem to occur in this study group, despite the fact that medical employees frequently travel between wards which are in close proximity to other departments harbouring neutropenic patients. Several of the patients (n = 35) were also monitored for C. albicans colonisation and strain typing corroborated the lack of extensive cross-contamination during the study period. The application of PCR-mediated genotyping of fungi in epidemiological analyses and evaluation of hospital hygiene is discussed.