The nucleotide sequence determination of catalases of three medically important yeasts using newly designed degenerated primers.

We have developed degenerated primers for the isolation of several fungal species catalases, based on the known catalase genes of several yeast species. Using a combination of degenerated primers and the nested polymerase chain reaction (PCR) method, we were able to obtain PCR products from Candida dubliniensis, C. tropicalis, and C.

Disruption of the human pathogenic yeast Candida albicans catalase gene decreases survival in mouse-model infection and elevates susceptibility to higher temperature and to detergents.

Catalase-deficient strains of the human pathogenic yeast Candida albicans were constructed using the URA-blaster method. The disruptant was viable and grew normally in an ordinary culture condition, but became extremely sensitive to treatment with hydrogen peroxide. No catalase activity was observed in a catalase (CCT)-gene-disrupted strain, 1F5-4-1, suggesting that there were no other catalase or catalase-like enzymes in this yeast.

Repetitive sequences (RPSs) in the chromosomes of Candida albicans are sandwiched between two novel stretches, HOK and RB2, common to each chromosome.

A novel sequence designated HOK, which is next to the RPS, a repetitive sequence specific to Candida albicans, was cloned and sequenced. HOK hybridized with all of the chromosomes on which the RPSs were located, but did not hybridize with chromosome 3, which does not harbour any RPSs. Sequence determination revealed that a portion of HOK has significant homology with the B and C1 fragments of Ca3, which is used as a molecular epidemiological probe.