Investigation of phospholipase activity in candida albicans strains isolated from blood and oral cavity specimens

Objective: An opportunistic pathogen, Candida spp, cause invasive and mucosal infections with its important virulence factor, phospholipase enzymes which break down and lyse the phospholipids of the host cell membranes. In our study, investigation of phospholipase B1 and C1 activities of C. albicans strains isolated from blood and oral cavity specimens and comparison of the two groups were aimed. Methods: A total number of 60 C. albicans strains isolated from blood culture (n=30) and oral cavity specimens (n=30) in Dokuz Eylul University Hospital Mycology laboratory between January 2015-December 2015 were included. Phospholipase activity of the strains were investigated by plate method using egg yolk agar and PLB1 and PLC1 genes encoding phospholipase B1 and C1 enzymes in C. albicans were examined by reverse transcriptase polymerase chain reaction (RT-PCR). The data obtained for two groups were compared statistically. Results: Twenty six (86.7%) and 24 (80.0%) of the strains isolated from blood and oral cavity specimens had phospholipase activity by plate method, respectively. When the positivity rates of the groups were compared, no statistically important difference was observed (χ2=0.48; p=0.49). There was an important difference between the average Pz values (0.6138±0.9823 and 0.6988±0.9910) of the groups (Mann Whitney U=173.500; p=0.007). All blood and oral cavity isolates expressed PLB1 and 27 (90.0%) and 22 (73.3%) of the strains isolated from blood and oral cavity, respectively expressed PLC1. When the results of RT-PCR test were quantitated, PLB1 expression was found to be between 0.52-1.05 for blood and 0.70-1.33 for oral cavity isolates. No statistically important difference was detected between the PLB1 expression values of two groups. PLC1 expression values were determined to be between 0.35-1.04 and 0.75-1.33 for blood and oral cavity strains, respectively. PLC1 expression values of the oral cavity isolates were statistically higher when compared with the values of blood strains (Mann Whitney U=103.500; p<0.001). Conclusion: Determination of high phospholipase activity of C. albicans strains isolated from oral cavity and blood samples; support that the production of these enzymes play an important role in virulence and from the results of our study it can be concluded that PLC1 enzymes have an important role in mucosal infections however more comprehensive studies are required. Key words: Candida albicans, phospholipase B1, phospholipase C1, RT-PCR