摘要
采集36头腹泻犊牛的新鲜粪样,进行细菌的分离培养、生化和PCR鉴定,并进行致病性试验、血清型鉴定、药敏试验、耐药基因检测和治疗试验。结果显示,初步分离到25株疑似大肠杆菌菌株,经16S rDNA鉴定全部为大肠杆菌。致病性试验显示,分离株有较强的致病性,取死亡小鼠实质器官进行病原鉴定,均分离到大肠杆菌。25株分离株共覆盖6种血清型,其中O157和O152为优势血清型。25株分离菌对强力霉素、复方新诺明耐药率最高,达88%;对氨苄西林、链霉素、环丙沙星的耐药率分别为76%,72%,56%。所有分离株均携带大环内酯类ermB基因和四环素类tetB基因,大部分携带blaTEM(72%)、aaC2(64%)、aaC4(68%)和qnrB(60%)基因。治疗试验表明,新霉素与白头翁散结合治疗大肠杆菌所致犊牛腹泻的效果最佳。结果表明,犊牛源腹泻大肠杆菌菌株对临床常见抗生素产生了不同程度的耐药,并携带多种耐药基因,建议采用中西药结合治疗该病。本研究为大肠杆菌所致犊牛腹泻的合理用药和有效防治提供了依据。
In order to determine the pathogenicity and drug resistance of Escherichia coli causing calf diarrhea and take timely and effective treatment measures, 36 fresh fecal samples from calves with diarrhea were selected, and the bacteria were isolated and cultured, identified by biochemical and PCR methods, the pathogenic trial, serotype identification, drug sensitivity test and drug resistance gene detection were carried out.The results showed that 25 suspected Escherichia coli strains were isolated initially and identified finally as Escherichia coli by 16 S rDNA gene analysis.The results of pathogenic trial showed that the isolated strains had high pathogenicity, and Escherichia coli was isolated from the parenchymal organs of dead mice. The 25 isolates covered a total of 6 serotypes, of which O157 and O152 were the dominant serotypes.The drug resistance rates of 25 isolates to doxycycline and cotrimoxazole were the highest(88%),and to ampicillin, streptomycin and ciprofloxacin were 76%,72% and 56%,respectively.All the isolates carried macrolide ermB gene and tetracycline tetB gene, and most of them carried blaTEM(72%),aaC2(64%),aaC4(68%) and qnrB(60%) genes.The treatment experiment showed that the combination of neomycin with Baitouweng powder has the best effect on calves with caused by Escherichia coli.The above results showed that the Escherichia coli strains from calves with diarrhea had different degrees of resistance to common clinical antibiotics, and carried a variety of drug resistance genes, and it is suggested that Chinese and western medicine should be combined to treat diarrhea of calves caused by Escherichia coli.This study provides a basis for rational drug use and effective prevention and treatment of diarrhea in calves caused by Escherichia coli.
作者
梁艳艳
李可
贾丽
侯铭源
田梦悦
张婷
马玉忠
LIANG Yanyan;LI Ke;JIA Li;HOU Mingyuan;TIAN Mengyue;ZHANG Ting;MA Yuzhong(College of Veterinary Medicine,Hebei Agricultural University,Baoding,Hebei 071001,China)
出处
《中国兽医学报》
CAS
CSCD
北大核心
2022年第3期477-482,495,共7页
Chinese Journal of Veterinary Science
基金
河北省重点研发计划资助项目(19226611D)。
关键词
犊牛腹泻
致病性大肠杆菌
病原分析
治疗
calf diarrhea
pathogenic Escherichia coli
pathogenic analysis
treatment
