Cloning and characterization of a complex DNA fingerprinting probe for Candida parapsilosis

Candida parapsilosis accounts for a significant number of nosocomial fungem ias, but in fact, no effective and verified genetic fingerprinting method h as emerged for assessing the relatedness of independent isolates for epidem iological studies. A complex 15-kb DNA fingerprinting probe, Cp3-13, was th erefore isolated from a library of C. parapsilosis genomic DNA fragments. T he efficacy of Cp3-13 for DNA fingerprinting was verified by a comparison o f its clustering capacity with those of randomly amplified polymorphic DNA analysis and internally transcribed spacer region sequencing, by testing sp ecies specificity, and by assessing its capacity to identify microevolution ary changes both in vitro and in vivo. Southern blot hybridization of EcoRI /SalI-digested DNA with Cp3-13 provides a fingerprinting system that (i) id entifies the same strain in independent isolates, (ii) discriminates betwee n unrelated isolates, (iii) separates independent isolates into valid group s in a dendrogram, (iv) identifies microevolution in infecting populations, and (v) is amenable to automatic computer-assisted DNA fingerprint analysi s. This probe is now available for epidemiological studies.