Alireza Khodavandi
1, Fahimeh Alizadeh
2* 
, Mahsa Jafarzadeh
21 Department of Biology, Gachsaran Branch, Islamic Azad University, Gachsaran, Iran.
2 Department of Microbiology, Yasooj Branch, Islamic Azad University, Yasooj, Iran.
Abstract
Background: Candidiasis has gained much attention in recent
decades due to its increasing prevalence in immunocompromised patients.
Usually, antifungals such as fluconazole and amphotricin B are used for
treatment of candidiasis, but one of the major clinical problems is the
emergence of antifungal resistance. Combination antifungal therapy is one of
the most commonly used methods to alleviate the problem of antifungal resistance.
Methods: The effect of fluconazole alone and in combination
with amphotericin B on C. tropicalis isolates were performed using the Clinical
and Laboratory Standards Institute (CLSI) reference method. Eventually hypha
formation, time kill study, proteinase and phospholipase activity and
expression of PLB and SAP2 genes
were carried out to investigate the enzymes inhibitory properties of antifungal
tested against C. tropicalis.
Results: Results showed the significant synergic effect of
fluconazole in combination with amphotericin B in inhibiting the growth of C. tropicalis
isolates, with fractional inhibitory concentration indices ranging from 0.06 to
0.5. The combination of fluconazole with amphotericin B reduced the number of
yeast form and inhibited the yeast to hyphae transition in C. tropicalis. The antifungals tested were able to show the effect
of down regulating expression of the selected genes significantly in
fluconazole/amphotericin B ranging from 1.42- to 2.27-fold.
Conclusion: Our results demonstrated that the synergistic
interaction of fluconazole/amphotericin B would be worth exploring for the
management of candidiasis. In addition, PLB and
SAP2 genes could be probable molecular targets in the synergistic
interaction of fluconazole/amphotericin B in C. tropicalis.