F. Dalle et al., Comparative genotyping of Candida albicans bloodstream and nonbloodstream isolates at a polymorphic microsatellite locus, J CLIN MICR, 38(12), 2000, pp. 4554-4559
Molecular typing studies have shown that the predominant form of reproducti
on of Candida albicans is clonal and that, in a majority of situations, per
sistent or recurrent infections are due to a unique strain. Characterizatio
n of distinct subpopulations and correlation with clinical features may thu
s be important to understanding the pathogenesis of candidiasis. In a clona
l model, a unique polymorphic marker may identify populations with differen
t 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. Sizi
ng of the alleles was performed by automated capillary electrophoresis. A n
ew, 137 bp allele was characterized, and seven nondescribed combinations we
re observed, resulting in 15 and 11 distinct CEM profiles in bloodstream an
d control strains, respectively. Genotypes 126-135, 130-136, and 131-131 ac
counted 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 i
solates. Bloodstream and nonbloodstream strains of C. albicans thus have a
heterogeneous structure at the CEF3 locus, with three major and multiple mi
nor allelic combinations.