畜牧兽医学报 ›› 2014, Vol. 45 ›› Issue (11): 1858-1865.doi: 10.11843/j.issn.0366-6964.2014.11.017

• 预防兽医 • 上一篇    下一篇

免疫抑制性病毒感染肉鸡群继发大肠杆菌的分离鉴定及多样性研究

琚思迪1,董宣1,赵鹏1,李阳1,孟凡峰1,孙鹏1,董向磊2,高崧2,崔治中1*   

  1. (1.山东农业大学动物科技学院,泰安 271018;2.扬州大学兽医学院,扬州 225009)
  • 收稿日期:2014-04-08 出版日期:2014-11-23 发布日期:2014-11-23
  • 通讯作者: 崔治中,教授,E-mail:zzcui@sdau.edu.cn
  • 作者简介:琚思迪(1990-),女,山东诸城人,硕士生,主要从事分子病毒学的研究,E-mail:jusidiapple@163.com
  • 基金资助:

    公益性行业(农业)科研专项(201203055)

Isolation,Identification and Diversity Study of Escherichia coli from Broilers Infected with Immunosuppressive Viruses

JU Si-di1,DONG Xuan1,ZHAO Peng1,LI Yang1,MENG Fan-feng1,SUN Peng1,DONG Xiang-lei2,GAO Song2,CUI Zhi-zhong1*   

  1. (1.College of Animal Science and Technology,Shandong Agricultural University,Taian 271018,China;2.College of Veterinary Medicine,Yangzhou University,Yangzhou 225009,China)
  • Received:2014-04-08 Online:2014-11-23 Published:2014-11-23

摘要:

旨在了解免疫抑制性病毒感染肉鸡群后继发大肠杆菌的血清型及其耐药性的多样性。用J亚群禽白血病病毒与禽网状内皮增生症病毒感染或共感染1日龄商品代肉鸡,对两次重复试验中发生细菌感染而导致死亡的鸡进行麦康凯培养基分离培养。每个病变脏器各随机挑取5个红色菌落或(及)白色菌落,并分别进行生化试验、血清型鉴定和药敏试验。结果从58只呈现肝周炎或(和)心包炎的死亡鸡中分离到典型的红色菌落445个,白色菌落71个。经生化试验鉴定,516个菌落均为大肠杆菌。O抗原血清型鉴定结果表明,这些菌落分别属于12个不同的血清型。对12种常用抗生素的药敏试验(药敏片法和试管稀释法)结果表明,共感染能在较短时间内引起典型的大肠杆菌病,并引起较高的死亡率。从516个大肠杆菌中挑选的17组菌落(来自同一病鸡、同一脏器且经鉴定为同一血清型的5个菌落定义为一组菌落)的试管药敏试验的比较表明,第3组的5个菌落对黏杆菌素的最小抑菌质量浓度的范围为0.05~51.20 mg•mL-1;第17组菌落对丁胺卡那的最小抑菌质量浓度从0.05到51.20 mg•mL-1,均相差1 000倍。同一群鸡肝周炎和心包炎的大肠杆菌分离株的高度多样性,证明这是在病毒感染诱发免疫抑制状态下发生条件性致病菌的继发性细菌感染。鸡群中大肠杆菌在耐药性上的多样性,是鸡群在不合理应用抗生素的条件下体内大肠杆菌迅速产生耐药菌株的遗传基础。

Abstract:

This study aimed to investigate the diversity of serotype and drug resistance of E.coli from the secondary infection of broilers that primarily infected by immunosuppressive viruses.E.coli isolates derived from one-day-old broilers single-infected or co-infected with avian leukosis virus subgroup J (ALV-J) and reticuloendotheliosis virus (REV) were isolated,identified and used for drugs sensitivity experiment.Five red or (and) white clones were picked from the diseased organs.Results showed that 516 E.coli isolates were isolated from 58 diseased chickens and identified from two repeated experiments including 445 red colonies and 71 white colonies.Results also reveal that the co-infection could infect more serious mortality and among these 516 tested E.coli colonies,12 serotypes of O-antigen were identified.E.coli of different serotypes was even isolated from the same organ in the same bird.Then 17 groups of colonies (5 same O-serotype colonies isolated from the same organ in the same bird were identified as a group of colonies) were selected to drug susceptibility test for 12 kinds of common antibiotics.The results showed that the minimum inhibitory concentration was from 0.05 to 51.20 mg•mL-1 in the third group to colimycin and from 0.05 to 51.20 mg•mL-1 in the seventeen group to amikacin.However,differences in the other groups were not significant.The high-degree diversity of E.coil isolated from our experiments proved that the infection was the secondary E.coil infection.It was happened in the immunosupression condition under the viruses infection.At the same time,the diversity of drug resistance is the genetic basis for resistant strains rapidly generated from the E.coil in vivo under the condition of irrational use of antibiotics.

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