Investigation Of Gelatinase Gene Expression And Growth Of Enterococcus Faecalis Clinical Isolates In Biofilm Models

Objectives: Enterococcus faecalis is the major reason for biofilm-related infections and it also interacts with Staphylococcus aureus in biofilms. Gelatinase (gelE) enzyme is an important virulence factor of E. faecalis for biofilm formation. This study aimed to compare the biofilm producing E. faecalis isolates from urine and urinary catheters. The influence of S. aureus on the growth of E. faecalis biofilm cells was also investigated in a dual biofilm model in vitro. Another aim was to evaluate E. faecalis gelE gene expression during biofilm formation. Materials and Methods: Firstly, crystal violet staining was used to measure the total biofilm biomass of the isolates. Secondly, plate counting was performed to determine the biofilm formation ability of E. faecalis isolates and the effect of S. aureus on E. faecalis biofilm formation. Finally, the gelE expression profile of the isolates was assessed by quantitative real time-polymerase chain reaction. Results: According to crystal violet staining and plate counting, all E. faecalis isolates were biofilm producers and the number of E. faecalis sessile cells increased in the presence of S. aureus. Among the 21 E. faecalis isolates, ten expressed high levels of the gelE gene, while eight of them had low expression profiles (p<0.05). Conclusion: When they grow together, S. aureus may give some advantages to E. faecalis such as increasing sessile cell growth. The expression of the gelE gene was not affected by E. faecalis biofilm formation of the isolates collected from the patients with urinary tract infections.WoSScopu

Evaluation of the natural killer cytotoxicity and the levels of cytokines in rats with type I diabetes mellitus

Type I diabetes mellitus (insulin-dependent DM = IDDM) is a chronic disease characterized by specific destruction of pancreatic β cells, resulting in an absolute lack of insulin. Immune mechanisms, genetic susceptibility, and environmental factors are all implicated in the pathogenesis of Type 1 diabetes. This study was aimed at determining the efficiency of cytokines, natural killer (NK) cells in the pathophysiology of IDDM. Therefore, we evaluated the plasma levels of cytokines by specific enzyme-linked immunosorbent assay (ELISA) and the cytotoxicity activity of NK cells by anti-candididal index in rats with type I diabetes. We found that the cytotoxicity activity of NK cells in IDDM groups significantly decreased compared to the control groups. The levels of interferon-γ (IFN-γ) in IDDM groups were slightly higher than in healthy controls. These results indicate that the changes of TH1 type cytokines such as IFN-γ and NK cell activity can play a role in the etiology of IDDM. The data may provide new strategies for the treatment of IDDM

Slime production and proteinase activity of Candida species isolated from blood samples and the comparison of these activities with minimum inhibitory concentration values of antifungal agents

Slime and proteinase activity of 54 strains consisting of 19 Candida parapsilosis and 35 Candida albicans strains isolated from blood samples were investigated in this study. Ketoconazole, amphothericin B, and fluconazole susceptibility of Candida species were compared with slime production and proteinase activity of these species. For both Candida species, no correlation was detected between the slime activity and minimum inhibitory concentration (MIC) values of the three antifungal agents. For both Candida species no correlation was detected between the proteinase activity and the MIC values of amphothericin B, and fluconazole however, statistically significant difference, was determined between the proteinase activity and MIC values of ketoconazole (p = 0.007). Slime production was determined by using modified Christensen macrotube method and proteinase activity was measured by the method of Staib. Antifungal susceptibility was determined through the guidelines of National Committee for Laboratory Standards (NCCLS M27-A)

The effects of fluconazole and cytokines on human mononuclear cells

Candida infections are common infections and fluconazole is one of the most frequently administered antifungal agents in their treatment. The resistance developed against antifungal agents has necessitated the improvement of new treatments. This study focuses on the investigation of the effect of fluconazole and cytokines such as interferon-gamma (IFN-γ), tumor necrosis factor-alpha (TNF-α), granulocyte-macrophage colony-stimulating factor (GM-CSF) on chemokine production and anticandidal activity of human monocytes. In the study it was observed that GM-CSF caused an increase in candidacidal activity of monocytes. Anticandidal activity of GM-CSF + IFN-γ combination was not found to be more effective than GM-CSF or IFN-γ alone. The presence of cytokine and fluconazole caused an increase in the levels of CCL3 and CCL4 chemokines. Accordingly, it was considered that chemokines could contribute to the efficacy of fluconazole in C. albicans infections. Besides, in order to strengthen the immune system some cytokines might be used in addition to antifungal agents for the treatment