泰安地区鸡源大肠杆菌的分离鉴定与耐药性分析

发布时间：2018-04-26 20:23

本文选题：鸡源大肠杆菌 + 血清型　；参考：《山东农业大学》2015年硕士论文

【摘要】：鸡大肠杆菌病是由大肠埃希氏杆菌某些血清型菌株引起的一类疾病的总称。常引起家禽胚胎死亡、脐炎、败血症、肝周炎、心包炎、卵黄性腹膜炎、输卵管炎等一系列疾病,对养鸡业的危害很大。大肠杆菌易产生耐药性,养殖过程中不规范用药进一步加剧了耐药性的发展。药物敏感性试验表明,鸡源大肠杆菌耐药菌株越来越多,耐药谱也越来越广,甚至有的分离株对尚未广泛用于兽医临床的新型抗生素也表现出很强的耐药性。本研究对泰安地区几个规模化养鸡场分离到的大肠杆菌耐药性情况开展了比较系统的研究,以期揭示该地区鸡源性大肠杆菌病的流行情况和细菌的耐药状况,为该地区鸡大肠杆菌病的发生流行的有效控制提供可靠的理论依据。本论文主要进行三个方面的研究:2013~2014年自山东省泰安地区的10个规模化鸡场采集的疑似鸡大肠杆菌病例的相关病料进行大肠杆菌的分离鉴定,共分离鉴定出14株鸡源大肠杆菌,以微量平板凝集试验鉴定分离菌株的O抗原血清型,分别属于O78、O2和O1等3个血清型,其中O78(6/14)、O2(6/14)为主要流行血清型,占分离菌株总数的85.71%。选取了20种常用治疗肠杆菌病的抗生素对14株鸡源大肠杆菌分离株进行药敏试验,结果显示:14株大肠杆菌对多种头孢菌素类抗生素如头孢噻肟、头孢噻吩、头孢呋辛、头孢曲松、头孢哌酮、头孢吡肟、头孢唑啉均具有极高的耐药性。此外,14株大肠杆菌对庆大霉素、链霉素、阿米卡星、卡那霉素、哌拉西林、氨苄西林等常用抗生素的耐药性也达到100%,对妥布霉素(92.9%)、氧氟沙星(85.7%)、氨曲南(85.7%)、头孢他啶(71.4%)及复方新诺明(64.3%)也具有较高的耐药性。这14株大肠杆菌仅对多粘菌素B(100%)、头孢西叮(100%)和复方新诺明(21.4%)的敏感性较高。对14株大肠杆菌的β-内酰胺类耐药基因TEM、SHV、CTX-M-1、CTX-M-8、0XA-2、OXA-10基因及氨基糖甙类耐药基因ant(3'')-Ia、acc(6')-Ib、aph(3')-IIa、armA、rmtA等11个耐药基因进行了PCR检测,结果表明,分离大肠杆菌耐药基因的携带率较高,所分离细菌全部携带CTX-M-1基因和acc(6')-Ib基因。此外,9株大肠杆菌携带?-内酰胺类耐药基因TEM(64.3%),2株大肠杆菌携带氨基糖苷类耐药基因aph(3')-IIa(14.3%),且存在同一菌株携带多种耐药基因的现象。这与药敏试验的结果基本对应,在分子水平上解释了本研究中14株大肠杆菌具有极广耐药谱的原因,为有效控制大肠杆菌感染提供了理论基础和科学依据。
[Abstract]:Escherichia coli is a kind of disease caused by some serotype strains of Escherichia coli. It often causes a series of diseases, such as death of poultry embryo, umbilical phlogistic, septicemia, pericarditis, pericarditis, yolk peritonitis, salpingitis and so on. Escherichia coli is susceptible to drug resistance, and the development of drug resistance is further aggravated by non-standard drug use in the breeding process. Drug sensitivity tests showed that more and more strains of Escherichia coli from chicken were resistant to drugs, and even some isolates showed strong resistance to new antibiotics which had not been widely used in veterinary clinic. The drug resistance of Escherichia coli isolated from several large-scale chicken farms in Tai'an area was systematically studied in order to reveal the prevalence of chicken Escherichia coli disease and the drug resistance of bacteria in this area. It provides a reliable theoretical basis for the effective control of the occurrence and prevalence of chicken E. coli disease in this area. In this paper, we mainly studied the isolation and identification of E. coli from 10 large scale chicken farms collected from 10 large-scale chicken farms in Shandong Province from 2013 to 2014. A total of 14 strains of Escherichia coli were isolated and identified. The O antigen serotypes of the isolated strains were identified by microplate agglutination test, belonging to three serotypes of O78 / O 2 and O 1 respectively, in which O786 / 14 / 14 / O2 / 14) was the main prevalent serotype, accounting for 85.71% of the total number of isolated strains. A total of 20 antibiotics used to treat Enterobacteriasis were selected to test 14 strains of Escherichia coli isolated from chicken. The results showed that 14 strains of Escherichia coli were resistant to various cephalosporins such as cefotaxime, cefothiophene, cefuroxime, cefuroxime and cefuroxime. Ceftriaxone, cefoperazone, cefepime and cefazolin are highly resistant. In addition, 14 strains of Escherichia coli were treated with gentamicin, streptomycin, amikacin, kanamycin, piperacillin, The resistance of ampicillin and other commonly used antibiotics to tobramycin 92.9m, ofloxacin 85.7am, amtreonam 85.7abong, ceftazidime 71.4) and compound sulfamethoxine 64.3cm) also showed higher resistance to tobramycin, ofloxacin, ampicillin and ceftazidime 71.4. These 14 strains of Escherichia coli were only sensitive to polymyxin B _ (100), cefaxil (100) and compound sulfamethasone (21. 4). The 尾 -lactam resistance gene (TEMN SHVCTX-M-1) CTX-8 0XA-2OXA-10 and the aminoglycoside resistance gene antnyclo-Iaanaccacc6HY-Ibapapam-IIaarmArmtA were detected by PCR. The results showed that the carrying rate of drug-resistant genes in E. coli was higher than that in Escherichia coli. All the isolated bacteria carried CTX-M-1 gene and acc(6')-Ib gene. In addition, 9 strains of Escherichia coli carrying Tem 64.3and 2 strains of Escherichia coli carrying the aminoglycoside resistance gene APHY3H3HY3, and the same strain carrying multiple drug resistance genes, also had the phenomenon that the same strain was carrying a variety of resistant genes, and the two strains carried the aminoglycoside resistance gene (APH3) and the second strain carried the amino glycoside resistance gene. This basically corresponds to the results of drug sensitivity test. It explains the reason why 14 strains of Escherichia coli in this study have a wide spectrum of drug resistance at the molecular level, which provides a theoretical and scientific basis for the effective control of E. coli infection.
【学位授予单位】：山东农业大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：S852.61

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