博落回提取物对猪场常见4种病原细菌的体外抗菌活性研究

The in vitro Antibacterial Activity of Macleaya cordata Extract against Four Common Pathogenic Bacteria in Pig Farms

【目的】研究博落回提取物(Macleaya cordata extract,MCE)的体外抗菌活性,为其在动物生产中的使用和添加提供试验依据。【方法】以金黄色葡萄球菌、猪霍乱沙门氏菌、大肠杆菌和铜绿假单胞菌为受试菌,采用抑菌圈法测定MCE对4种受试菌的抑制效果;运用微量稀释法测定MCE对4种受试菌的最小抑制质量浓度(MIC)和最小杀菌质量浓度(MBC);通过时间—杀菌曲线法,测定MCE对金黄色葡萄球菌和大肠杆菌的杀菌效果。【结果】MCE对4种革兰氏阳性和阴性受试菌均有一定的抑制作用,抑制能力由强到弱依次为金黄色葡萄球菌、大肠杆菌、猪霍乱沙门氏菌和铜绿假单胞菌,MIC分别为64、64、128和512μg/mL,MBC分别为128、128、256和>1024μg/mL;MCE对金黄色葡萄球菌和大肠杆菌的体外杀菌速率随质量浓度升高而增快,其中8、4、2倍于MIC的MCE分别在2、12、24 h可将2种受试菌完全清除,而1倍MIC的MCE在24 h后仍有少量细菌存活。【结论】MCE对受试菌均有一定的抑制效果,对金黄色葡萄球菌和大肠杆菌的体外杀菌速率呈现质量浓度依赖性。

[Purpose]The aim was to study the in vitro antibacterial activity of Macleaya cordata extract(MCE),and to provide experimental basis for its application and addition in animal industry.[Method]Staphylococcus aureus,Salmonella choleraesuis,Escherichia coli and Pseudomonas aeruginosa were selected as the test bacteria.The inhibition efficacy of MCE on 4 kinds of tested bacteria was measured by radial diffusion assay.Minimum inhibitory mass concentration(MIC)and minimum bactericidal mass concentration(MBC)of MCE against 4 different strains were determined by microdilution method.The dynamic bactericidal effects of MCE on S.aureus and E.coli were determined by time-killing curve.[Result]MCE has a certain inhibitory effect on the 4 gram-positive and negative bacteria,and the inhibition ability from strong to weak is S.aureus,E.coli,S.choleraesuis,P.aeruginosa successively.The MIC values of MCE against S.aureus,E.coli,S.choleraesuis and P.aeruginosa were 64,64,128 and 512μg/mL,respectively,and the MBC values were 128,128,256 and>1024μg/mL,respectively.The in vitro bactericidal rate of MCE against S.aureus and E.coli increased with the increase of concentration.Among them,MCE with concentration of 8,4 and 2×MIC could completely kill the two tested bacteria after 2,12 and 24 hours respectively,while a small amount of bacteria could still survive after the 24 hours treatment with concentration of 1×MIC MCE.[Conclusion]MCE had certain inhibitory effect on the tested bacteria,and its in vitro bactericidal rate against S.aureus and E.coli appeared to be concentration-dependent.