Detection of als1 and hwp1 genes involved in biofilm formation in Candida albicans isolated from catheter associated candiduria.

Abstract

Background: Candida species are opportunistic fungal pathogens that can affect immune compromised patients and may cause life threatening infections. Biofilm formation is an important virulence factor that enables Candida species to invade the host tissues. This study aimed to assess the ability of Candida albicans to form biofilm in patients with catheter associated candiduria and to determine the presence of some genes involved in biofilm formation at the molecular level. Methods: This cross-sectional descriptive study was carried out from June 2019 to June 2020 on 93 catheterized patients admitted to different wards at SCUHs, Ismailia. Candida albicans strains were identified phenotypically by their growth on sabouraud dextrose agar, Gram staining, growth on hypertonic sabouraud broth, chlamydospore formation and germ tube formation test. Biofilm formation was detected by tissue culture plate method. Detection of the genes involved in biofilm formation was done by PCR. Results: Twenty eight Candida albicans strains wereisolated from 36 Candida species. 9 isolates (32.1%) were strong biofilm producers, 6 isolates (21.4%) were moderate biofilm producers and 13 isolates (46.4%) were weak or non-biofilm producers. ALS1 gene was detected in 13 isolates (46.4%), while HWP1 gene was detected in 16 isolates (57.1 %). Conclusion: This study documented the prevalence of candiduria in catheterized patients and found a statistically significant higher prevalence of the tested biofilm forming genes among biofilm forming isolates as compared to the weak or non-biofilm forming ones; but additional studies should be carried out as the management of catheter associated caniduria is still controversial.