利福喷丁联合氟康唑对耐药白念珠菌感染小鼠的作用及免疫机制分析

Effect of Rifapentine Combined with Fluconazole on Drug-resistant Candida Albicans in Mice and Underlying Immunologic Mechanism

目的:观察利福喷丁联合氟康唑对耐药白念珠菌感染小鼠的保护作用,并探讨其作用机制。方法:100只ICR小鼠随机分为5组:空白对照组、模型组、利福喷丁组(0. 9 mg·kg^(-1))、氟康唑组(0. 5 mg·kg^(-1))、利福喷丁+氟康唑组(0. 9 mg·kg^(-1)+0. 5 mg·kg^(-1))。除空白对照组外,给予各组小鼠尾静脉注射耐药白念珠菌100悬液处理,构建真菌感染模型。感染2h后,利福喷丁组、氟康唑组、利福喷丁+氟康唑组分别腹腔注射给药,空白对照组和模型组腹腔注射等体积生理盐水,1次/d,连续给药7 d。真菌感染后连续观察30 d,统计各组大鼠生存情况,检测Th1、Th17、Th2细胞比例,观察肾脏组织病变情况及肾脏载菌量。结果:与空白对照组比较,模型组小鼠平均存活时间明显缩短,肾脏组织现大量真菌菌丝、孢子和炎症性病变,肾脏载菌量明显增多,外周血Th1、Th17细胞比例明显降低,Th2细胞比例明显增高(P <0. 05)。与模型组比较,利福喷丁组小鼠平均存活时间、肾脏组织病变程度及肾脏载菌量差异均无统计学意义(P> 0. 05);氟康唑组及利福喷丁+氟康唑组小鼠平均存活时间显著延长,肾脏组织中菌丝和孢子减少,肾脏组织病变程度减轻,肾脏载菌量显著减少,外周血Th1、Th17细胞比例显著升高,Th2细胞比例显著降低(P <0. 05);且联合作用效果显著优于氟康唑单独作用(P <0. 05)。结论:利福喷丁联合氟康唑可增强氟康唑对耐药白念珠菌的抗菌作用,其机制可能与调节Th1、Th17、Th2细胞分化有关。

Objective: To observe the protective effect of rifapentine combined with fluconazole in mice infected with drug-resistant Candida albicans,and explore the underlying mechanism. Methods: Totally 100 ICR mice were randomly divided into 5 groups: the blank control group,the model group,rifapentine group(0. 9 mg·kg^-1),fluconazole group(0. 5 mg·kg^-1),rifapentine + fluconazole group(0. 9 mg·kg^-1+ 0. 5 mg·kg^-1). Except for the blank control group,the mice in the other groups were injected with drug-resistant Candida albicans 100 suspension via tail vein,and a fungal infection model was established. After 2-hour infection,rifapentin group,fluconazole group and rifapentin + fluconazole group was given 0. 9 mg·kg^-1 rifapentin,0. 5 mg·kg^-1 fluconazole and0. 9 mg·kg^-1 rifapentin + 0. 5 mg·kg^-1fluconazole,respectively. The blank control group and the model group were injected with saline at the same volume,once a day for 7 days. After the fungal infection,the mice were under 30-day continuous observation,the survival time in each group was statistically analyzed,the proportions of Th1,Th17 and Th2 cells were detected,and the renal tissue lesion and the loaded amount of bacteria were observed. Results: Compared with that in the blank control group,the average survival time of the mice in the model group was significantly shortened,a large number of fungal hyphae and spores and inflammatory lesions were presented in kidney,the amount of bacteria loaded in kidney was significantly increased,and the proportions of Th1 and Th17 cells in peripheral blood decreased significantly,the proportion of Th2 cells increased significantly( P < 0. 05). Compared with the model group,there were no significant differences in the average survival time,the degree of renal tissue lesion and the renal bacteria carrying capacity in rifapentine group( P > 0. 05). The average survival time of fluconazole group and rifapentine + fluconazole group was significantly prolonged,mycelium and spores decreased in renal tissue,the degree of renal tissue lesion was relieved,the amount of bacteria loaded in kidney decreased significantly,the proportions of Th1 and Th17 cells in peripheral blood significantly increased,and the proportion of Th2 cells decreased significantly( P < 0. 05). The combined effect was significantly better than that of fluconazole alone( P < 0. 05). Conclusion: Rifapentin combined with fluconazole can enhance the antibacterial effect of fluconazole on drug-resistant Candida albicans,and the mechanism may be related to regulating the differentiations of Th1,Th17 and Th2 cells.