Comparison of molecular typing methods for Candida albicans strain delineation.

This paper compares the reproducibility and discriminatory power of pulse-field electrophoresis, randomly amplified polymorphic DNA and DNA fingerprinting in C. albicans strain delineation. Seven different karyotypic patterns were identified among 103 C. albicans strains isolated from the oral cavities of healthy carriers and from oral lesions of HIV-seropositive and seronegative patients by pulse-field electrophoresis. The randomly amplified polymorphic DNA technique turned out to be more discriminative than karyotyping, allowing further diversification within strains sharing the same karyotype. However, such a technique did not appear useful when employed as the only DNA typing method, since several strains, characterized by different karyotypes, showed indistinguishable electrophoretic amplification profiles. DNA fingerprinting with the 27A probe (S. Scherer, D. A. Stevens, Proc. Natl. Acad. Sci. USA 85 (1988) 1452-1456) yielded the most resolutive analysis, since about as many polymorphic patterns were obtained as the individual strains typed. Therefore, while C. albicans DNA typing by pulse-field electrophoresis followed by random amplification of polymorphic DNA appears to be adequate for discriminating C. albicans strains into distinct types and subtypes, DNA fingerprinting may be suitable for rapid identification of individual strains in fine epidemiological investigations.