2019年湖南省部分地区鸡、鸭、猪源大肠杆菌耐药性调查

旨在调查2019年湖南省部分地区不同来源的大肠杆菌对抗生素的耐药水平,为养殖合理用药提供参考。从4个市畜禽养殖场采集猪、鸡和鸭粪便285份,使用麦康凯琼脂培养基和伊红美蓝培养基对大肠杆菌筛选,利用基质辅助激光解析电离飞行时间质谱进行鉴定,采用微量肉汤稀释法检测16种抗生素对大肠杆菌的最小抑菌浓度(MIC)。共分离出203株大肠杆菌(鸡源146株、鸭源20株和猪源37株),对四环素和氨苄西林耐药率最高,分别达到89.2%和84.7%;对头孢他啶、奥格门丁、黏菌素耐药率较低,分别为2.5%、2.0%和0.5%;所有菌株均对美罗培南敏感。抗3种及以上抗生素的菌株数目占比为87.7%,而仅5.42%的菌株对所有检测的抗生素敏感。另外,来源于减抗示范养殖场的大肠杆菌对大部分抗生素的耐药率,与来源于非减抗养殖场大肠杆菌相比未见显著差异。上述结果表明,湖南省动物源大肠杆菌的耐药水平仍处在较高水平,重视兽药使用管理并持续开展对大肠杆菌的耐药性监测十分必要。

Investigation of antimicrobial resistance of Escherichia coli from chickens,ducks and pigs in some areas of Hunan Province in 2019

The purpose of this study was to investigate the antibiotic resistance level of Escherichia coli from different sources in Hunan Province in 2019,and to provide reference for rational antibiotic use in livestock and poultry.A total of 285 fecal samples were collected from livestock and poultry farms(pig,chicken and duck)in four cities.E.coli strains were screened by MacConkey agar medium and eosin-methylene blue medium.Matrix assisted laser desorption ionization time-of-flight mass spectrometry(MALDI-TOF-MS)was used to identify isolates.The minimal inhibitory concentration(MIC)of E.coli isolates against 16 antibiotics was determined using the microdilution broth method.A total of 203 strains of E.coli(146 strains from chickens,20 strains from ducks and 37 strains from pigs)were isolated.The resistance rates of the strains to tetracycline and ampicillin were the highest at 89.2% and 84.7%,respectively;their resistance rates to ceftazidime,amoxicillin/clavulanate and colistin were 2.5%,2.0% and 0.5%,respectively.And,all the strains were sensitive to meropenem.In addition,87.7% of the strains were resistant to three or more tested antibiotics,and only 5.42% were sensitive to all the tested antibiotics.Significant difference was observed in the resistance rates of the E.coli isolates obtained from the model farms with reduced antibiotics usage and the other farms.These results indicated that the antimicrobial resistance of E.coli from chickens,ducks and pigs in Hunan Province was still at a high level.Therefore,it is still necessary to pay attention to the use and management of veterinary drugs and to carry out continuous monitoring of antimicrobial resistance of E.coli in the area.