Lee J-H, Kim Y-G, Lee J
School of Chemical Engineering, Yeungnam University, Gyeongsan, Korea.
J Appl Microbiol. 2017 Dec;123(6):1420-1428. doi: 10.1111/jam.13602. Epub 2017 Nov 2.
Urinary tract infections are caused primarily by uropathogenic Escherichia coli (UPEC), and indwelling catheters are usually colonized by UPEC biofilms tolerant to common antibiotics. Hence, UPEC biofilms pose a substantial challenge, and there is an urgent need for effective control strategies.
In this study, 79 essential oils were screened for antibiofilm ability against UPEC. Components of active oils were identified, and their antibiofilm activities were also investigated using 96-well plates with crystal violet assay, scanning electron microscopy, and confocal laser scanning microscopy. Oregano oil and thyme red oil and their major common constituents, carvacrol and thymol, significantly inhibited UPEC biofilm formation at subinhibitory concentrations (<0·01%). These findings were supported by observations that carvacrol and thymol reduced fimbriae production and the swarming motility of UPEC. Furthermore, carvacrol and thymol markedly decreased the hemagglutinating ability of UPEC, and UPEC was more easily killed by human whole blood in the presence of carvacrol and thymol.
Carvacrol-rich oregano oil and thymol-rich thyme red oil have high antibiofilm and antivirulence activities against UPEC.
In the wake of rising antimicrobial resistance, we envisage that carvacrol and thymol could be used to prevent biofilm formation by UPEC and to reduce its virulence.
尿路感染主要由尿路致病性大肠杆菌（UPEC）引起，留置导管通常会被对常用抗生素耐受的UPEC生物膜定植。因此，UPEC生物膜构成了重大挑战，迫切需要有效的控制策略。
在本研究中，筛选了79种精油对UPEC的抗生物膜能力。鉴定了活性精油的成分，并使用96孔板通过结晶紫测定、扫描电子显微镜和共聚焦激光扫描显微镜研究了它们的抗生物膜活性。牛至油和百里香红油及其主要共同成分香芹酚和百里酚在亚抑菌浓度（<0·01%）下显著抑制UPEC生物膜形成。香芹酚和百里酚减少UPEC菌毛产生和群集运动的观察结果支持了这些发现。此外，香芹酚和百里酚显著降低了UPEC的血凝能力，并且在香芹酚和百里酚存在的情况下，UPEC更容易被人全血杀死。
富含香芹酚的牛至油和富含百里酚的百里香红油对UPEC具有高抗生物膜和抗毒力活性。
鉴于抗菌药物耐药性不断上升，我们设想香芹酚和百里酚可用于预防UPEC生物膜形成并降低其毒力。
