摘要
伪中间葡萄球菌(Staphylococcus pseudintermedius)是犬脓皮病主要致病菌,具有多重耐药性,严重威胁犬及人类健康。本研究从脓皮病患犬中分离20株伪中间葡萄球菌,并揭示大黄酸对伪中间葡萄球菌的抗菌活性及抗菌机理。通过测定最小抑菌浓度、最低杀菌浓度、抑菌曲线和黏附抑制试验分析了大黄酸对伪中间葡萄球菌的抑菌活性;检测大黄酸对伪中间葡萄球菌细胞膜完整性、通透性,细胞活性氧(ROS)水平等,结合电镜观察细菌细胞形态和超微结构,从而探究大黄酸的抑菌机理。结果表明,大黄酸对伪中间葡萄球菌的最小抑菌浓度为12.5μg·mL^(-1),亚抑菌浓度能够显著抑制伪中间葡萄球菌生长和黏附;经大黄酸处理后,伪中间葡萄球菌细胞膜通透性改变,胞外β-半乳糖苷酶活性增加(P<0.05);ROS测定结果显示,大黄酸处理后细菌细胞ROS水平增高3.9倍(1×MIC)和6.4倍(2×MIC);大黄酸处理后,电镜观察伪中间葡萄球菌表面存在大量分泌物、皱缩,胞壁破裂、电子密度降低、内容物泄漏等。综上,大黄酸可通过改变细菌细胞膜通透性、破坏膜完整性,诱导细菌细胞产生大量ROS等作用机制达到抗菌目的。
Staphylococcus pseudintermedius is the main pathogenic bacterium of canine pyoderma,which has multi-drug resistance and serious threat to the health of dog and human.In this study,20 strains of Staphylococcus pseudintermedius were isolated from dogs with pyoderma,and the antibacterial activity and antibacterial mechanism of rhein against Staphylococcus pseudintermedius were revealed.In this study,the antibacterial activity of rhein against Staphylococcus pseudintermedius was determined by minimum inhibitory concentration,minimum bactericidal concentration,bacteriostatic curve and adhesion assay.The cell membrane integrity and permeability,ROS level of Staphylococcus pseudintermedius were detected after rhein treated.The morphology and ultrastructure of bacterial cells were observed by electron microscopy,so as to explore the antibacterial mechanism of rhein against Staphylococcus pseudintermedius.The results showed that the minimum inhibitory concentration of rhein against Staphylococcus pseudintermedius was 12.5μg·mL^(-1),and subinhibitory concentration could significantly inhibit the growth and adhesion.The permeability of bacterial cell membrane was changed and the activity ofβ-galactosidase was increased after treated with rhein(P<0.05).The results of ROS assay showed that the level of ROS increased by 3.9 times(1×MIC)and 6.4 times(2×MIC)after rhein treatment.Electron microscopy showed that the morphology was changed after rhein treatment,there was abundant secretions on the cell surface and it was shrunk,the cell wall was broken,electron density was reduced,and the contents was leaked.This study indicate that rhein can destroy cell membrane integrity and permeability,and induce bacterial cells to produce a lot of ROS to achieve antibacterial effect.
作者
宋军
周志新
付琳清
王晗晟
刘梦
孙东波
郑家三
SONG Jun;ZHOU Zhixin;FU Linqing;WANG Hansheng;LIU Meng;SUN Dongbo;ZHENG Jiasan(College of Animal Science and Veterinary Medicine, Heilongjiang Bayi Agricultural University, Daqing 163319,China)
出处
《畜牧兽医学报》
CAS
CSCD
北大核心
2021年第8期2275-2283,共9页
ACTA VETERINARIA ET ZOOTECHNICA SINICA
基金
国家自然科学基金青年科学基金项目(31802226)
黑龙江省政府博士后资助(LBH-Z17185)
黑龙江省农垦总局重点科研项目(HKKY190307)
黑龙江八一农垦大学三横三纵支持计划(TDJH201903)
黑龙江八一农垦大学引进人才启动项目(XYB201807)。
关键词
大黄酸
伪中间葡萄球菌
抗菌活性
抗菌机制
rhein
Staphylococcus pseudintermedius
antimicrobial activity
antimicrobial mechanism
