膀胱上皮细胞对大肠杆菌抗菌作用观察

目的：了解膀胱上皮细胞和大肠杆菌的相互作用，观察其对大肠杆菌杀菌作用的动态变化。方法：采用人膀胱上皮细胞株T24和大肠杆菌标准株K12共同孵育，分别与作用后的15分钟、30分钟、60分钟、90分钟、120分钟，用Triton X-100释放粘附在细胞上及细胞内的活菌，用平板菌落计数法计数活菌数。结果：T24对大肠杆菌K12有杀菌作用，在相互作用15分钟时即表现出来，且在30分钟时杀菌作用最强，与对照组相比细菌减少53％。结论：膀胱上皮细胞对大肠杆菌有杀菌作用，这可能是泌尿道抵抗外来细菌感染的一种天然防御机制。

Antibacterial effect of urinary bladder epithelial cells against Escherichia coli

Objective： Epithelial ceils are the first barrier to protect the host from mucosal pathogens. In this study we examined antibacterial capacities of urinary epithelial cell line T24 against Escherichia coll. Methods： E, coli K12 strain and T24 cells were suspended in 1640 medium for the experiment（approximately 100 bacteria per epithelial cell）, added to eppendorf tubes and then put in CO2 incubator at 37℃. The growth of bacteria was detected at different time points from 15 min to 120 min by the quantitative colony counting method. Results： Antibacterial effects of T24 cells against E. coli K12 strain at 15,30 and 60 rain were 19. 4%, 53. 0%, 39.2% respectively. Conclusion：The direct antibacterial activities of epithelial cells may be a host defense factor to maintain the urinary bladder in a sterile situation.