A Comparative Study between Invasive and Superficial Candida albicans Infections Regarding Biofilm Formation, ALS3 and SAP1-6 Genes Expression and Anti-Fungal Drug Susceptibility

Abstract

Background: Candida species are usually found as a component of individual's normal microflora. Candida albicans capable of causing opportunistic infections varying from superficial infections in immunocompetent people, to life-threatening systemic infections in immunocompromised persons. A variety of pathogenicity factors contribute to colonization and pathogenesis of C. albicans during superficial and systemic infections.Objective: The aim of this work is to compare between the expression of ALS3 and SAP1-6 genes among Candida albicans isolated from superficial versus invasive candidiasis. To study the antifungal susceptibility pattern of the collected isolates. Methodology: This study was conducted on 25 isolates of C. albicans isolated from superficial candida infection and 25 isolates from invasive infections, The isolates were assessed for their capability to form biofilm, measurement of quantitative gene expression of ALS3, SAP1-6 genes by real time reverse transcription -polymerase chain reaction (RT-PCR), and antifungal susceptibility using the disk diffusion method.Results: There had been a high statistically significant difference between the two groups regarding biofilm formation p value < 0.001. Also, there was a high statistically significant difference in the expression of SAP 1-6 and ALS3 genes between the two studied groups (P < 0.001) with higher expression levels in the systemic candidiasis group. Resistance to antifungals was more common in systemic isolates. Conclusion: This study has found a relationship between the biofilm development and fluconazole and itraconazole resistance in C. albicans isolates. Moreover, the present study detected a correlation between the expressions of ALS3 gene and biofilm development.