Gao Shanjun, Liu Guangzhi, Li Jianguo, Chen Jing, Li Lina, Li Zhen, Zhang Xiulei, Zhang Shoumin, Thorne Rick Francis, Zhang Shuzhen
Microbiome Laboratory, Henan Provincial People's Hospital, People's Hospital of Zhengzhou University, Zhengzhou, China.
Department of Dermatology, Henan Provincial People's Hospital, People's Hospital of Zhengzhou University, Zhengzhou, China.
Front Cell Infect Microbiol. 2020 Dec 22;10:603858. doi: 10.3389/fcimb.2020.603858. eCollection 2020.
Compared to mono-species biofilm, biofilms formed by cross-kingdom pathogens are more refractory to conventional antibiotics, thus complicating clinical treatment and causing significant morbidity. Lemongrass essential oil and its bioactive component citral were previously demonstrated to possess strong antimicrobial efficacy against pathogenic bacteria and fungi. However, their effects on polymicrobial biofilms remain to be determined. In this study, the efficacy of lemongrass () essential oil and its bioactive part citral against dual-species biofilms formed by and species was evaluated . Biofilm staining and viability test showed both lemongrass essential oil and citral were able to reduce biofilm biomass and cell viability of each species in the biofilm. Microscopic examinations showed these agents interfered with adhesive characteristics of each species and disrupted biofilm matrix through counteracting nucleic acids, proteins and carbohydrates in the biofilm. Moreover, transcriptional analyses indicated citral downregulated hyphal adhesins and virulent factors of , while also reducing expression of genes involved in quorum sensing, peptidoglycan and fatty acids biosynthesis of . Taken together, our results demonstrate the potential of lemongrass essential oil and citral as promising agents against polymicrobial biofilms as well as the underlying mechanisms of their activity in this setting.
与单物种生物膜相比，由跨界病原体形成的生物膜对传统抗生素更具耐药性，从而使临床治疗复杂化并导致显著的发病率。柠檬草精油及其生物活性成分柠檬醛先前已被证明对病原菌和真菌具有强大的抗菌功效。然而，它们对多微生物生物膜的影响仍有待确定。在本研究中，评估了柠檬草（）精油及其生物活性成分柠檬醛对由 和 物种形成的双物种生物膜的功效。生物膜染色和活力测试表明，柠檬草精油和柠檬醛均能够减少生物膜中每个物种的生物膜生物量和细胞活力。显微镜检查表明，这些试剂干扰了每个物种的粘附特性，并通过对抗生物膜中的核酸、蛋白质和碳水化合物破坏了生物膜基质。此外，转录分析表明，柠檬醛下调了 的菌丝粘附素和毒力因子，同时也降低了参与 的群体感应、肽聚糖和脂肪酸生物合成的基因表达。综上所述，我们的结果证明了柠檬草精油和柠檬醛作为抗多微生物生物膜的有前景的试剂的潜力，以及它们在这种情况下的潜在作用机制。
