摘要
研究旨在探讨肉桂醛协同恩诺沙星对鸭源多重耐药鸭源大肠杆菌抗菌作用及其潜在机制,为恩诺沙星临床应用提供新思路。试验采用K-B法测定鸭源大肠杆菌对9种抗菌药的敏感性;采用微量肉汤法测定肉桂醛和恩诺诺沙星对鸭源大肠杆菌的最小抑菌浓度(Minimum inhibitory concentration,MIC)和最小杀菌浓度(Minimum bactericidal concentration,MBC);通过棋盘法、生长曲线、时间杀菌曲线、药敏试验探究肉桂醛增强恩诺诺沙星抗菌作用;通过电导率、碱性磷酸酶(Alkaline phosphatase,AKP)活性测定、菌体内抗生素蓄积分析、荧光显微镜观察揭示肉桂醛联合恩诺沙星对鸭源大肠杆菌细胞壁和细胞膜影响。结果显示:肉桂醛对鸭源大肠杆菌的MIC和MBC分别为128~256μg/mL和128~256μg/mL;恩诺沙星对鸭源大肠杆菌的MIC和MBC分别为4~16μg/mL和4~16μg/mL。肉桂醛联合恩诺沙星抗鸭源大肠杆菌的FICI为0.25~0.38,呈现协同作用。肉桂醛联合恩诺沙星使大肠杆菌培养液电导率显著增加(P<0.05),核酸和蛋白质外泄显著增强(P<0.05),AKP外泄显著增加(P<0.05),菌液中恩诺沙星浓度显著降低(P<0.05);菌体细胞膜和细胞壁通透性增加。研究表明,肉桂醛联合恩诺沙星能破坏鸭源大肠杆菌细胞壁及细胞膜完整性,促进恩诺沙星进入细菌细胞,并呈现协同抗菌作用。
The experiment was aimed to study the antibacterial effect and mechanism of cinnamaldehyde combined with enrofloxacin on multidrug-resistant duck-derived Escherichia coli,providing new ideas for the clinical application of enrofloxacin.The susceptibility of duck-derived Escherichia coli to 9 antibiotics was determined by K-B method;The minimum inhibitory concentration(MIC)and minimum bactericidal concentration(MBC)of cinnamaldehyde and enrofloxacin against duck-derived Escherichia coli were determined by the micro broth method;The enhancement of enrofloxacin antibacterial effect was explored by cinnamaldehyde through chessboard method,growth curve,time-kill curve and drug sensitivity test;The effects of the combination of cinnamaldehyde and enrofloxacin on the cell wall and membrane of duck-derived Escherichia coli were revealed through conductivity,extracellular alkaline phosphatase(AKP)activity measurement,intracellular antibiotic accumulation analysis,and fluorescence microscopy observation.The results showed that the MIC and MBC of cinnamaldehyde against duck-derived Escherichia coli were 128 to 256μg/mL and 128 to 256μg/mL,respectively;The MIC and MBC of enrofloxacin against duck-derived Escherichia coli were 4 to 16μg/mL and 4 to 16μg/mL,respectively.The combined antibacterial index of cinnamaldehyde and enrofloxacin against duck-derived Escherichia coli ranged from 0.25 to 0.38,showing a synergistic or additive effect.Cinnamaldehyde could synergistically increase the conductivity of Escherichia coli bacterial culture medium with enrofloxacin(P<0.05),significantly enhance nucleic acid and protein leakage(P<0.05),significantly increase AKP leakage(P<0.05),and significantly decrease the concentration of enrofloxacin in the bacterial solution(P<0.05),which resulted in increasing permeability of bacterial cell membrane and cell wall.The results indicated that the cinnamaldehyde combined with enrofloxacin could disrupt the integrity of the cell wall and membrane of duck-derived Escherichia coli,promote the entry of enrofloxacin into bacterial cells,and exhibit synergistic and additive effects.
作者
马全朝
张晒
金银利
MA Quanchao;ZHANG Shai;JIN Yinli(Xinyang Agriculture and Forestry College,Xinyang,Henan 464000)
出处
《中国家禽》
北大核心
2025年第6期79-87,共9页
China Poultry
基金
河南省自然科学基金面上项目(212300410385)
2022信阳农林学院青年基金项目(QN2022006)。
关键词
鸭
肉桂醛
恩诺沙星
大肠杆菌
多重耐药
协同作用
duck
cinnamaldehyde
enrofloxacin
Escherichia coli
multi-drug resistance
synergistic effect
