Proteomics and Transcriptomics Analysis of  Emilia sonchifolia (L.) DC Antibacterial Activity against Methicillin-resistant Staphylococcus epidermidis

Background: Bloodstream infections (BSIs) are a public health concern and cause substantial morbidity and mortality. The pathogen Staphylococcus epidermidis causes a significant number of BSIs. Antibiotics targeting Staphylococcus epidermidis have been the mainstay in BSIs. However, conventional antibiotics have been eclipsed in combating with drug-resistant bacteria. Alternate ways of treating these antibiotic-resistant infections are thus urgently needed. Numerous studies have demonstrated that certain traditional Chinese medicine(TCM) exhibit notable antimicrobial activity and possess the ability to impede the development of bacterial resistance. Based on an extensive body of research in the field of TCM, it has been determined that the compositae plant exhibits a noteworthy anti -Methicillin-Resistant Staphylococcus Epidermidis (MRSE) effect. Thus, Emilia sonchifolia was used to explore the antibacterial activity againse MRSE. Methods : Here, the objective of this study was to examine the antibacterial efficacy and underlying antibacterial mechanism of Emilia sonchifolia against methicillin-resistant Staphylococcus epidermidis ( MRSE ). The antibacterial activity of Emilia sonchifolia against MRSE was assessed through in vitro tests measuring minimum inhibitory concentration(MIC) and minimum bactericidal concentration(MBC).On the other hand, a mouse bloodstream infections of MRSE was used to evaluate the antibacterial activity of Emilia sonchifolia against MRSE in vivo . Furthermore, based on proteomics and transcriptomics were investigated to explore the underlying antibacterial mechanisms of Emilia sonchifolia against MRSE. Results: The results showed that MIC and MBC values of Emilia sonchifolia against MRSE were 5mg/mL and 20mg/mL, respectively. Meanwhile, Emilia sonchifolia can effectively treat MRSE induced bloodstream infections.In addition, proteomic and transcriptomic data revealed a significant down-regulation of purine metabolism,which were associated with oxidative stress and cell wall synthesis. Furthermore,We determined imp, AMP and GMP by Elisa. The results showed that the contents of these enzymes all decreased, indicating that purine metabolism was inhibited. At the same time, SEM results showed that bacterial cell wall was destroyed. Conclusions: Emilia sonchifolia exerts antibacterial effects by affecting purine metabolism, promoting bacterial oxidative stress and inhibiting bacterial cell wall synthesis. Thus, the aforementioned observations have contributed novel insights into the mechanistic understanding of Emilia sonchifolia 's efficacy against MRSE , thereby offering potential strategies for managing MRSE infections.