College of Natural Resources and Environment, Northwest A&F University, Yangling, Shaanxi 712100, China.
State Key Laboratory of Soil Erosion and Dryland Farming on the Loess Plateau, Northwest A&F University, Yangling 712100, China.
J Hazard Mater. 2024 Oct 5;478:135588. doi: 10.1016/j.jhazmat.2024.135588. Epub 2024 Aug 22.
The persistent emergence of multidrug-resistant bacterial pathogens is leading to a decline in the therapeutic efficacy of antibiotics, with Pseudomonas aeruginosa (P. aeruginosa) emerging as a notable threat. We investigated the antibiotic resistance and quorum sensing (QS) system of P. aeruginosa, with a particular focused on outer membrane vesicles (OMVs) and polymyxin B as the last line of antibiotic defense. Our findings indicate that OMVs increase the resistance of P. aeruginosa to polymyxin B. The overall gene transcription levels within P. aeruginosa also reveal that OMVs can reduce the efficacy of polymyxin B. However, both OMVs and sublethal concentrations of polymyxin B suppressed the transcription levels of genes associated with the QS system. Furthermore, OMVs and polymyxin B acted in concert on the QS system of P. aeruginosa to produce a more potent inhibitory effect. This suppression was evidenced by a decrease in the secretion of virulence factors, impaired bacterial motility, and a notable decline in the ability to form biofilms. These results reveal that OMVs enhance the resistance of P. aeruginosa to polymyxin B, yet they collaborate with polymyxin B to inhibit the QS system. Our research contribute to a deeper understanding of the resistance mechanisms of P. aeruginosa in the environment, and provide new insights into the reduction of bacterial infections caused by P. aeruginosa through the QS system.
耐多药细菌病原体的持续出现导致抗生素治疗效果下降，铜绿假单胞菌（P. aeruginosa）成为一个显著的威胁。我们研究了铜绿假单胞菌的抗生素耐药性和群体感应（QS）系统，特别关注外膜囊泡（OMVs）和多粘菌素 B 作为抗生素防御的最后一道防线。我们的研究结果表明，OMVs 增加了铜绿假单胞菌对多粘菌素 B 的耐药性。铜绿假单胞菌的整体基因转录水平也表明，OMVs 可以降低多粘菌素 B 的疗效。然而，OMVs 和亚致死浓度的多粘菌素 B 均抑制了与 QS 系统相关的基因转录水平。此外，OMVs 和多粘菌素 B 协同作用于铜绿假单胞菌的 QS 系统，产生更强大的抑制作用。这一抑制作用表现在毒力因子的分泌减少、细菌运动能力受损以及生物膜形成能力显著下降。这些结果表明，OMVs 增强了铜绿假单胞菌对多粘菌素 B 的耐药性，但它们与多粘菌素 B 合作抑制了 QS 系统。我们的研究有助于深入了解铜绿假单胞菌在环境中的耐药机制，并为通过 QS 系统减少铜绿假单胞菌引起的细菌感染提供了新的见解。
