Investigation of virulance factors of candida species from the blood cultures

Candida species are opportunistic fungal pathogens that are normal members of the skin and mucosal flora, but can cause superficial and invasive infections with disruption of skin and mucosal integrity. It is seen that the most important virulence factors of Candida species are hyphae formation, dimorphism, hydrolytic enzymes and biofilm formation. In our study, it is aimed to investigate acid proteinase, phospholipase, esterase activities and biofilm formation of Candida isolates isolated from blood culture samples. In the study were included 90 Candida isolates isolated from blood culture samples sent from various services. Identification of the isolates was carried out using conventional methods and automated systems. The acid proteinase groups of the isolates included in the study were studied using 1% bovine serum albumin thawed agar medium, phospholipase weights were studied on egg yolk agar medium, esterase operations were studied using the plate method using Tween 80 agar medium and each isolate was evaluated by comparing it with a positive standard strain. The biofilm forming abilities of the isolates were studied with the microtitration plate method and the absorbance values obtained were quantitatively graded by comparing the absorbance values of the standard strains. Of the studied isolates, 35 (38.8%) were C. albicans, 29 (32.2%) were C. parapsilosis, 17 (18.9%) were C. glabrata, 6 (6.7%) were C. krusei and 3 (3.4%) were identified as C. tropicalis. It was observed that 35 (100%) of the 35 C. albicans isolates whose enzymatic activities were investigated had proteinase activity, 29 (82.8%) had phospholipase activity, and 33 (94.2%) had esterase activity. It was determined that 54 (98%) of the non-albicans isolates (n:55) had proteinase activity, 8 (14.5%) had esterase activity and had no phospholipase activity. It was observed that 4 (11.4%) of 35 C. albicans isolates, whose biofilm forming abilities were investigated, formed a weak biofilm and 1 (2.8%) formed a moderate biofilm. It was observed that 7 (12.7%) of the non-albicans isolates (n:55) formed weak biofilms, 2 (3.6%) moderate biofilms, and 16 (29%) strong biofilms. As a result, it was observed that the phospholipase and esterase activities of C.albicans isolates included in our study were higher than non-albicans. It was determined that non-albicans isolates formed a higher degree of biofilm compared to C. albicans.