Abstract：
Uropathogenic Escherichia coli (UPEC) is the most common pathogenic bacteria associated with urinary tract infection (UTI). UPEC can cause UTI by adhering to and invading uroepithelial cells. Fimbriae is the most important virulence factor of UPEC, and a potentially promising target in developing novel antibacterial treatments. In this study, the antibacterial properties and effects of the compound dictamnine, extracted from the traditional Chinese medicine Cortex Dictamni, on the bacterial morphology, cell adhesion, and invasion of UPEC were studied. Dictamnine exhibited no obvious antibacterial activity against UPEC, but significantly impeded the ability of UPEC to adhere to and invade uroepithelial cells. RT-qPCR analysis showed that treatment downregulated the expression of type 1 fimbriae, P fimbriae, and curli fimbriae adhesion genes, and also downregulated adhesion-related receptor genes of uroepithelial cells. Transmission electron microscopy showed that dictamnine destroyed the structure of the fimbriae and the surface of the bacteria became smooth. These results suggest that dictamnine may help to prevent UTI by simultaneously targeting UPEC fimbriae and urothelial adhesin receptors, and may have a potential use as a new anti-UPEC drug.
摘要：
尿路致病性大肠杆菌(UPEC)是与尿路感染(UTI)相关的最常见致病菌。UPEC可通过粘附和侵入尿路上皮细胞而引起UTI。菌毛是UPEC最重要的毒力因子,和开发新型抗菌治疗的潜在有希望的目标。在这项研究中,该化合物的抗菌性能和效果，从传统的中药CortexDictamni中提取，在细菌形态上，细胞粘附，并对UPEC的入侵进行了研究。对UPEC无明显抗菌活性,但明显阻碍了UPEC粘附和侵入尿路上皮细胞的能力。RT-qPCR分析表明，处理下调了1型菌毛的表达，P菌毛，和毛毛粘附基因，并下调尿路上皮细胞的粘附相关受体基因。透射电子显微镜显示，白菊碱破坏了菌毛的结构，细菌的表面变得光滑。这些结果表明，通过同时靶向UPEC菌毛和尿路上皮粘附素受体，可以帮助预防UTI。并且可能具有作为新型抗UPEC药物的潜在用途。
