Comparative genotyping of Candida albicans bloodstream and nonbloodstream isolates at a polymorphic microsatellite locus.
Molecular typing studies have shown that the predominant form of reproduction of Candida albicans is clonal and that, in a majority of situations, persistent or recurrent infections are due to a unique strain. Characterization of distinct subpopulations and correlation with clinical features may thus be important to understanding the pathogenesis of candidiasis. In a clonal model, a unique polymorphic marker may identify populations with different biological properties. We therefore compared 48 bloodstream isolates and 48 nonbloodstream matched strains of C. albicans at the elongation factor 3-encoding gene (CEF3) polymorphic microsatellite locus of C. albicans. Sizing of the alleles was performed by automated capillary electrophoresis. A new, 137-bp allele was characterized, and seven nondescribed combinations were observed, resulting in 15 and 11 distinct CEF3 profiles in bloodstream and control strains, respectively. Genotypes 126-135, 130-136, and 131-131 accounted for 60.4% of both bloodstream and control strains. Four bloodstream isolates but no control strains displayed the 135-135 combination. None of the other genotypes was present at an increased frequency in bloodstream isolates. Bloodstream and nonbloodstream strains of C. albicans thus have a heterogeneous structure at the CEF3 locus, with three major and multiple minor allelic combinations.
Dalle
F
F
Laboratoire de Parasitologie et Mycologie, and Laboratoire de Génétique Moléculaire, Centre George François Leclerc, Dijon, France.
Franco
N
N
Lopez
J
J
Vagner
O
O
Caillot
D
D
Chavanet
P
P
Cuisenier
B
B
Aho
S
S
Lizard
S
S
Bonnin
A
A
D000483:Alleles; D002176:Candida albicans / Q000145:classification* / Q000235:genetics; D002874:Chromosome Mapping; D016469:Fungemia / Q000382:microbiology*; D005838:Genotype; D006801:Humans; D018895:Microsatellite Repeats; D016533:Mycological Typing Techniques; D015203:Reproducibility of Results