Objective To explore the relationship between ERG4
gene overexpression and
azole resistance in clinical
Candida albicans strains.
Methods The National Committee for
Clinical Laboratory Standards (NCCLS)M27-A2 broth microdilution
method was conducted to evaluate antifungal susceptibility of 34 clinical
Candida albicans isolates
in vitro. Total
RNA was extracted from these
Candida albicans strains and transcribed into
cDNA. Real-
time fluorescence-based quantitative
PCR was performed to determine the
mRNA expression of ERG4
gene.
Statistical analysis was carried out by a two-sample t-test. Results The expression level of ERG4
mRNA was significantly higher in
fluconazole-resistant than in -sensitive
Candida albicans strains (4.20 ± 2.56 vs. 1.72 ± 1.33, t = 3.99, P < 0.05), higher in
itraconazole-resistant than in -sensitive
Candida albicans strains (3.60 ± 2.47 vs. 1.66 ± 1.61, t = 3.71, P < 0.05), and higher in
voriconazole-resistant than in -sensitive
Candida albicans strains (3.99 ± 2.72 vs. 2.07 ± 1.58, t = 2.91, P <0.05). Further more, increased ERG4
mRNA expression was also observed in isolates cross-resistant to all the three
azole antifungal agents compared with those susceptible to all of them (4.49 ± 2.73 vs. 1.69 ± 1.82, t = 3.81, P < 0.05). Conclusions The overexpression of ERG4
gene may be associated with cross resistance to
fluconazole,
itraconazole and
voriconazole in clinical
Candida albicans strains, but its exact
role is expected to be investigated through
downregulation of the ERG4
gene.