Comparison of expression level of CDR1 and MDR1 genes in stages of biofilm formation of Candida albicans and Candida tropicalis

Abstract

Introduction: Opportunistic fungi create biofilm resistant to active antifungal drugs in immunocompromised people. The present study aimed to assess the expression of CDR1 and MDR1 genes in the stages of biofilm formation by candidate species isolated from clinical samples. Material & Methods: 100 oral, vaginal, and fecal swabs were sampled from people with immune and physiological defects and normal people. The isolates were identified by laboratory tests and specific Candida chrome agar culture medium, and the presence of resistance genes was proved by molecular method. The formation of biofilm in the presence and absence of amphotericin B- in the strains was investigated using the crystal violet test and scanning electron microscope photo. The expression level of CDR1 and MDR1 genes was determined using the real-time polymerase chain reaction (PCR) technique. Results: More than 50% of isolated strains were Candida albicans, and the frequency of other strains was 8.33%. Among the 60 strains that were investigated in terms of genotype, only 48 Candida strains had both CDR1 and MDR1 genes. The statistical analysis of the results demonstrated that the amphotericin B-drug during 30 hours after biofilm formation significantly reduced the expression of resistance genes compared to the control group (P<0.05). Discussion & Conclusion: The expression of resistance genes in Candida albicans and Candida tropicalis is effective in increasing biofilm formation and the occurrence of candidiasis. Simultaneous expression of resistance genes is effective in increasing Candida albicans pathogenicity. The sub-MIC concentration of amphotericin B significantly reduces the expression of resistance genes and biofilm formation in Candida strains.

Keywords

• biofilms
• candida albicans
• candidiasis
• cdr1
• mdr1
• multiplex pcr