Study of Virulence Genes, Biofilm Formation and Antifungal Susceptibility of Medical Device Associated Candida Infection in ICU Hospitalized Patients

Background: Candida species are increasingly reported as a cause of hospital acquired infection. Biofilms play a role in Candida adherence to medical devices. Candida within biofilms is less susceptible to antifungal agents. HWP1, ALS1, ALS3, SAP1, PLB1 and INT1S are biofilm regulators genes. Objectives: the aim of the present work is to study medical device associated candida infection in ICU patients regarding virulence genes, biofilm formation and antifungal susceptibility. Methodology: Fifty candida isolates were identified by chromogenic media and VITEK 2 compact system and subjected to antifungal susceptibility test by modified disc diffusion method and VITEK -2. Biofilm study was carried out by microtiter plate method (MTP). Molecular study for virulence genes was done by conventional PCR. Results: Non albicans candida (NAC) were isolated at higher rate (64%) than candida albicans (36%). C. tropicalis was the commonest among non albicans. There was high agreement between Chromogenic media and VITEK -2 regarding identification of C.albicans and C.tropicalis. Kappa agreement was 0.87, 0.95 respectively. The resistance rates for candida isolates were as the followings: Fluconazole (28%), Amphotericin B (26%), Caspofungin (18%), Micafungin (16%), Voriconazole (14%) and (8%) for Flucytocine. HWP1, ALS1, ALS3 genes correlated with biofilm formation (p -values: 0.021, 0.001 and 0.014) respectively. Conclusion: Both NAC and Candida albicans are involved in device associated infection in ICU with higher resistance rate for Fluconazole and Amphotericin B. Drug resistance increases in isolates with biofilm forming capacity. Moreover, there was association between Virulence genes (HWP1, ALS 1 and ALS 3) and biofilm formation.