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 Suez Canal University Hospitals (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 were isolated from 36 Candida species. Nine 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.

Biofilm Formation and Aspartyl Proteinase Activity and Their Association with Azole Resistance Among Candida albicans Causing Vulvovaginal Candidiasis, Egypt

“… 53 The frequencies of ALS1 and HWP1 were 46.4% and 57.1% among 28 C. albicans causing catheter-associated candiduria in another study, where 32.1%, 21.4%, and 46.4% were strong, moderate, and weak biofilm producers, respectively. The authors documented that biofilm-forming isolates had a significantly higher prevalence of tested biofilm genes compared to the weak or non-biofilm-forming peers (P 0.049 and 0.001 for ALS1 and HWP1 , respectively), 54 which comes consistent with the current findings. Several factors could, however, influence in vitro biofilm production such as the isolation site of the tested strain, the initial inoculum size used in detection, and probably the substratum used whether silicone, polystyrene, polyvinyl chloride, or Teflon.…”

Antifungal and antibiofilm effects of probiotic Lactobacillus salivarius, zinc nanoparticles, and zinc nanocomposites against Candida albicans from Nile tilapia (Oreochromis niloticus), water and humans

“…In the current study, at least one of the virulence-associated genes ( ALS3 , HWP1 , RAS1 , and SAP4 ) was identified in all C. albicans isolates. Previous studies in Egypt have reported a higher prevalence of HWP1 and ALS1 genes in C. albicans isolates from patients ( Shrief et al., 2019 ; Hamady and Marei, 2021 ). Additionally, another study revealed that RAS1 and ALS1 were present in all Candida isolates, while HWP1 and SAP4 were found in half of the isolates ( Soliman et al., 2020 ).…”

Study of Azole Susceptibility and Virulence Patterns of Vulvovaginal Candida Species in Menoufia, Egypt

“…Furthermore, a significant shift in candidiasis etiology regarding non-albicans Candida (NAC) species (C. krusei, C. parapsilosis, C. tropicalis, and C. dubliniensis) has been reported 5 Specific virulence factors encoded by Candida genes attribute the pathogenicity of Candida spp. These virulence factors include, transition from the yeast to hyphal form, adhesions, biofilm formation and secretion of tissue-damaging hydrolytic enzymes such as proteases, phospholipases and hemolysins 6 .…”