Escherichia coli O157:H7 is one of the major foodborne pathogenic bacterial that cause infectious diseases in humans.The previous found that a combination of kojic acid and tea polyphenols exhibited better activity ag...Escherichia coli O157:H7 is one of the major foodborne pathogenic bacterial that cause infectious diseases in humans.The previous found that a combination of kojic acid and tea polyphenols exhibited better activity against E.coli O157:H7 than using either alone.This study aimed to explore responses underlying the antibacterial mechanisms of kojic acid and tea polyphenols from the gene level.The functional enrichment analysis by comparing kojic acid and tea polyphenols individually or synergistically against E.coli O157:H7 found that acid resistance systems in kojic acid were activated,and the cell membrane and genomic DNA were destructed in the cells,resulting in“oxygen starvation”.The oxidative stress response triggered by tea polyphenols inhibited both sulfur uptake and the synthesis of ATP,which affected the bacteria's life metabolic process.Interestingly,we found that kojic acid combined with tea polyphenols hindered the uptake of iron that played an essential role in the synthesis of DNA,respiration,tricarboxylic acid cycle.The results suggested that the iron uptake pathways may represent a novel approach for kojic acid and tea polyphenols synergistically against E.coli O157:H7 and provided a theoretical basis for bacterial pathogen control in the food industry.展开更多
目的：了解2007年浙江省衢州地区产志贺毒素大肠埃希菌O157：H7在动物中的分布情况及其耐药性、PFGE分型及毒力基因携带状况。方法：按全国O157：H7监测方案于5～10月份肠道传染病高发季节，在衢州地区采集各种动物粪便／肛拭，用免疫...目的：了解2007年浙江省衢州地区产志贺毒素大肠埃希菌O157：H7在动物中的分布情况及其耐药性、PFGE分型及毒力基因携带状况。方法：按全国O157：H7监测方案于5～10月份肠道传染病高发季节，在衢州地区采集各种动物粪便／肛拭，用免疫磁珠富集后进行O157：H7分离培养、鉴定，可疑菌株以PCR法检测O、H抗原及志贺样毒素（SLT1和SLT2）、粘附抹平因子（eaeA）及溶血素（hly）4种毒力基因。用脉冲场凝胶电泳（pulse field gel electrophoresis，PFGE）方法进行同源性分析，同时选择14种抗生素进行药敏试验，分析分离所得菌株的耐药状况。结果：共监测动物粪便标本300份，分离得产志贺毒素大肠埃希菌O157：H7菌株16株，分离率为5．33％。16株O157：H7菌株，毒力基因Hly、eaeA、SLT2均阳性，SLT1均阴性。脉冲场凝胶电泳分型显示，16株O157：H7菌株可分2个PFGE基因型，型间差异较小。耐药性分析显示这些菌株对红霉素、利福平的耐药率最高，达100．0％，对其他受试抗生素均敏感。结论：该地区动物中产志贺毒素大肠埃希菌O157：H7带菌率较高，所分离菌株主要携带SLT2基因，因此推测该地区存在发生产志贺毒素大肠埃希菌O157：H7感染暴发或流行的潜在危险，需增加对动物源性O157：H7的监测力度。展开更多
基金supported by National Natural Science Foundation of China(31972021)R&D Projects in Key Areas of Guangdong Province(2019B020212003)+4 种基金the Science and Technology Program of Guangzhou,China(202206010177)Guangdong key research and development program(2021B0202060001)Foshan and agricultural academy cooperation projectGuangdong Modern Agriculture project(2022KJ117)Aquatic Products Center Project of GAAS。
文摘Escherichia coli O157:H7 is one of the major foodborne pathogenic bacterial that cause infectious diseases in humans.The previous found that a combination of kojic acid and tea polyphenols exhibited better activity against E.coli O157:H7 than using either alone.This study aimed to explore responses underlying the antibacterial mechanisms of kojic acid and tea polyphenols from the gene level.The functional enrichment analysis by comparing kojic acid and tea polyphenols individually or synergistically against E.coli O157:H7 found that acid resistance systems in kojic acid were activated,and the cell membrane and genomic DNA were destructed in the cells,resulting in“oxygen starvation”.The oxidative stress response triggered by tea polyphenols inhibited both sulfur uptake and the synthesis of ATP,which affected the bacteria's life metabolic process.Interestingly,we found that kojic acid combined with tea polyphenols hindered the uptake of iron that played an essential role in the synthesis of DNA,respiration,tricarboxylic acid cycle.The results suggested that the iron uptake pathways may represent a novel approach for kojic acid and tea polyphenols synergistically against E.coli O157:H7 and provided a theoretical basis for bacterial pathogen control in the food industry.
文摘目的：了解2007年浙江省衢州地区产志贺毒素大肠埃希菌O157：H7在动物中的分布情况及其耐药性、PFGE分型及毒力基因携带状况。方法：按全国O157：H7监测方案于5～10月份肠道传染病高发季节，在衢州地区采集各种动物粪便／肛拭，用免疫磁珠富集后进行O157：H7分离培养、鉴定，可疑菌株以PCR法检测O、H抗原及志贺样毒素（SLT1和SLT2）、粘附抹平因子（eaeA）及溶血素（hly）4种毒力基因。用脉冲场凝胶电泳（pulse field gel electrophoresis，PFGE）方法进行同源性分析，同时选择14种抗生素进行药敏试验，分析分离所得菌株的耐药状况。结果：共监测动物粪便标本300份，分离得产志贺毒素大肠埃希菌O157：H7菌株16株，分离率为5．33％。16株O157：H7菌株，毒力基因Hly、eaeA、SLT2均阳性，SLT1均阴性。脉冲场凝胶电泳分型显示，16株O157：H7菌株可分2个PFGE基因型，型间差异较小。耐药性分析显示这些菌株对红霉素、利福平的耐药率最高，达100．0％，对其他受试抗生素均敏感。结论：该地区动物中产志贺毒素大肠埃希菌O157：H7带菌率较高，所分离菌株主要携带SLT2基因，因此推测该地区存在发生产志贺毒素大肠埃希菌O157：H7感染暴发或流行的潜在危险，需增加对动物源性O157：H7的监测力度。
