Genotyping of Candida albicans on the basis of polymorphisms of ALT repeats in the repetitive sequence (RPS).
BACKGROUND
Candida albicans is one of the most important etiologic agents causing superficial and deep fungal infections. For prevention of candidiasis, it is important to develop a rapid system that discriminates C. albicans at the strain level.


OBJECTIVE
To develop a system that can identify C. albicans at the strain level.


METHODS
Genomic DNAs were purified from 179 clinical isolates of C. albicans, and were used as templates for PCR amplification of 25S rDNA and ALT repeats in repetitive sequences (RPSs). PCR products generated from ALT repeats were digested with EcoRI and/or ClaI in order to study the relationships between restriction profiles and amplification profiles.


RESULTS
One hundred and seventy nine clinical isolates were grouped into genotypes A (92 isolates), B (38 isolates) and C (49 isolates) on the basis of their 25S rDNA, and each was further classified into five types (types 3, 4, 3/4, 2/3/4 and 3/4/5) by PCR amplification targeting ALT repeats. Type 3 C. albicans constituted the majority of isolates in any genotypes (66.3% for genotype A, 76.3% for genotype B and 73.4% for genotype C). Each C. albicans type showed several amplification patterns, indicating the existence of subtypes. RFLP analysis revealed that restriction profiles of PCR products corresponded to amplification patterns from PCR.


CONCLUSIONS
The present results indicate that PCR amplifications targeting 25S rDNA and ALT repeats are useful for rapid genotyping and distinction of C. albicans involved in superficial candidiasis.
Iwata
Takako
T
Department of Dermatology, Nagoya University Graduate School of Medicine, 65 Tsurumai, Nagoya-shi, Aichi 466-8550, Japan.
Hattori
Hisao
H
Chibana
Hiroji
H
Mikami
Yuzuru
Y
Tomita
Yasushi
Y
Kikuchi
Akihiko
A
Kanbe
Toshio
T
D002176:Candida albicans / Q000145:classification* / Q000235:genetics*; D002177:Candidiasis / Q000382:microbiology*; D015825:Chromosomes, Fungal; D004271:DNA, Fungal / Q000032:analysis; D004275:DNA, Ribosomal / Q000032:analysis; D005838:Genotype; D006801:Humans; D016133:Polymerase Chain Reaction / Q000379:methods; D012150:Polymorphism, Restriction Fragment Length; D012091:Repetitive Sequences, Nucleic Acid; D012680:Sensitivity and Specificity; D012871:Skin Diseases / Q000382:microbiology*
D004271:DNA, Fungal; D004275:DNA, Ribosomal