ABSTRACT
Objective:To study the antimicrobial activity of diacerein on common pathogens of the ocular surface in vitro.Methods:Pathogens were collected from patients with ocular surface infections in Henan Eye Hospital, including Gram-positive cocci and bacilli, Gram-negative bacilli, filamentous fungi, and Candida.The antimicrobial activity of diacerein was determined by the K-B agar diffusion method, and its minimum inhibitory concentration (MIC) was determined by the micro-liquid method.Levofloxacin and voriconazole were used as the control of antibacterial and antifungal drug, respectirely.Results:Diacerein showed antibacterial activity against 42 strains of Gram-positive cocci and 10 strains of Gram-positive bacilli, its inhibition zone diameters for Staphylococcus epidermidis, S.aureus, S.intermedius and Gram-positive Corynebacterium were not significantly different from those of levofloxacin (all at P>0.05). Its MIC range of diacetate against Staphylococcus epidermidis, S. aureus, S. intermedius and other Staphylococci was 1-32 μg/ml, and its respective MIC 90 was 16, 8, 16, and 32 μg/ml.Diacerein had no bacteriostatic effect on 23 strains of Gram-negative bacilli, 10 strains of filamentous fungi and 3 strains of candida. Conclusions:Diacerein has antibacterial effects against Gram-positive Staphylococcus and Corynebacterium isolated from the ocular surface, but shows no antimicrobial activity against Gram-negative bacilli and fungi.Diacerein offers a new drug option and method for the treatment of bacterial keratitis.
ABSTRACT
Objective@#To study the effects of platelets on macrophages phagocytosis and inhibition of fungi.@*Methods@#Macrophages were cultured, Fusarium Pythium spores were extracted and platelets were isolated from blood of mouse.Simple spore group, spore+ macrophage group and mixed platelet group were set, and were inoculated with fungal spore, equal proportion spore+ macrophage and platelet+ spore+ macrophage, respectively.The prepared plate was placed on a spinning disk laser scanning confocal microscope at 1 hour, 2, 3 and 4 hours after culture, five visual fields were randomly selected at the corresponding time points for photography.The phagocytic rate, phagocytic index and fungal spore germination rate were calculated.Fungal hyphae length of each group at 4, 6 and 8 hours after culture were calculated.The single macrophage group, spore+ macrophage group and mixed platelet group were set and the cytotoxicity was measured by real-time cell analyzer.The breeding and use of mice was in according with the ARVO statement.This study was approved by the Experimental Animal Ethics Committee of Henan Eye Institute (HNEECA-2017-04).@*Results@#The phagocytic rate and phagocytic index of macrophages in mixed platelet group at 1 hour, 2, 3 and 4 hours after culture were significantly higher than those in spore+ macrophage group at corresponding time point (all at P<0.05). There were significant differences in spore germination rate at 1 hour, 2, 3 and 4 hours after culture among different groups (H=60.05, 37.89, 55.15, 60.52; all at P<0.001). The spore germination rates of spore+ macrophage group at 1 hour, 2, 3 and 4 hours after culture were lower than those of simple spore group, while the spore germination rates of mixed platelet group at 1 hour and 3, 4 hours after culture were lower than that of spore+ macrophage group, the differences were statistically significant (all at P<0.01). There were significant differences in fungal hyphae length at 4, 6 and 8 hours after culture among the three groups (H=13.76, 43.57, 60.87; all at P≤0.001). The fungal hyphae lengths of spore+ macrophage group at 4, 6 and 8 hours after culture were lower than those of simple spore group, and the fungal hyphae lengths of mixed platelet group at 6 and 8 hours after culture were lower than those of spore+ macrophage group at the corresponding time point.The differences were statistically significant (all at P<0.05). There was no significant difference in cell index between 0 hour, 6, 12, 18 and 24 hours after culture (F=0.02, 1.08, 1.61, 1.58, 2.52; all at P>0.05). There were significant differences in cell index among different groups at 30, 36, 42 and 48 hours after culture (F=10.81, 8.08, 5.61, 5.72; all at P<0.05). The cell indexes in spore+ macrophage group at different time points were significantly lower than those in simple macrophage group (all at P<0.01).@*Conclusions@#Platelets can promote the phagocytosis and inhibition of macrophages on fungi, and platelets may have antagonistic effect on fungal cytotoxicity.