ObjectivePasteurella multocida is a widespread zoonotic pathogen that causes severe damage to the poultry industry. This study focused on the antibacterial effects and mechanism of action of coptisine against P. multocida.MethodsThe minimum inhibitory concentration and half maximal inhibitory concentration of coptisine against P. multocida was measured. Additionally, the effect of coptisine on growth, cell wall, activity of respiratory enzymes, soluble protein content and DNA synthesis were also analyzed. Finally, the effect of coptisine on gene transcription was determined using RNA sequencing.ResultsWe demonstrated that coptisine has a strong antibacterial effect against P. multocida, with a minimum inhibitory concentration of 0.125 mg/mL. Moreover, the measurement of the half maximal inhibitory concentration confirmed that coptisine was safe for the pathogen. The growth curve showed that coptisine inhibited bacterial growth. Measurement of alkaline phosphatase activity in the culture solution showed that coptisine affected cell wall permeability. Transmission electron microscopy revealed that coptisine chloride destroyed the cell structure. In addition, coptisine blocked the respiratory system, as measured by the levels of critical enzymes of the tricarboxylic acid cycle and glycolysis, succinate dehydrogenase and lactate dehydrogenase, respectively. Similarly, coptisine inhibited the synthesis of soluble proteins and genomic DNA. The KEGG pathway analysis of the differentially expressed genes showed that they were associated with cellular, respiratory, and amino acid metabolism, which were downregulated after coptisine treatment. Additionally, genes related to RNA degradation and the aminoacyl-tRNA pathway were upregulated.ConclusionIn this study, we demonstrated that coptisine exerts an antibacterial effect on P. multocida. These findings suggest that coptisine has a multifaceted impact on various pathways, resulting in the inhibition of P. multocida. Thus, coptisine is a potential alternative to antibiotics for the treatment of P. multocida infections in a clinical setting.

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黄连碱对多杀性巴氏杆菌的抗菌作用机制

客观的多杀性巴氏杆菌是一种广泛传播的人畜共患病病原体，对家禽业造成严重损害。本研究主要探讨黄连碱的抗菌作用及其作用机制。多杀性巴氏杆菌方法测定黄连碱对黄连的最低抑菌浓度和半数抑菌浓度。多杀性巴氏杆菌被测量。此外，还分析了黄连碱对生长、细胞壁、呼吸酶活性、可溶性蛋白含量和DNA合成的影响。最后，通过RNA测序确定了黄连碱对基因转录的影响。结果我们证明黄连碱对细菌具有很强的抗菌作用。多杀性巴氏杆菌，最低抑菌浓度为 0.125 mg/mL。此外，半数抑制浓度的测量证实黄连碱对病原体是安全的。生长曲线表明黄连碱抑制细菌生长。培养液中碱性磷酸酶活性的测量表明黄连碱影响细胞壁通透性。透射电子显微镜显示氯化黄连碱破坏了细胞结构。此外，通过三羧酸循环和糖酵解的关键酶、琥珀酸脱氢酶和乳酸脱氢酶的水平分别测量，黄连碱会阻塞呼吸系统。同样，黄连碱抑制可溶性蛋白质和基因组 DNA 的合成。差异表达基因的KEGG通路分析表明，它们与细胞、呼吸和氨基酸代谢相关，黄连碱治疗后这些基因的表达下调。此外，与 RNA 降解和氨酰基-tRNA 通路相关的基因上调。结论在这项研究中，我们证明黄连碱对细菌具有抗菌作用。多杀性巴氏杆菌。这些发现表明黄连碱对多种途径具有多方面的影响，从而抑制多杀性巴氏杆菌。因此，黄连碱是治疗以下疾病的抗生素的潜在替代品：多杀性巴氏杆菌临床环境中的感染。