Distribution and possible transmission of ampicillin- and nalidixic acid-resistant Escherichia coli within the broiler industry
Distribution and possible transmission of ampicillin- and nalidixic acid-resistant Escherichia coli within the broiler industry
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DOI：
10.1016/j.vetmic.2009.10.024
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发表时间：
2010-05-19
影响因子：
3.3
通讯作者：
Bojesen, Anders Miki
中科院分区：
文献类型：
--
作者：
Bortolaia, Valeria;Bisgaard, Magne;Bojesen, Anders Miki
本研究的目的是确定健康、未经处理的肉鸡群中耐β-内酰胺和（氟）喹诺酮的大肠杆菌的起源和传播。鉴于农场动物和人类中的抗菌药物耐药细菌之间可能存在联系，我们重点关注对公共和兽医健康至关重要的抗菌药物耐药细菌的动态。通过对用袜子法收集的肉鸡亲本和肉鸡群粪便样本进行处理，经常分离到对氨苄西林和萘啶酸耐药的大肠杆菌，而对环丙沙星的耐药率很低，未检测到对头孢菌素类的耐药。同样，对氨苄青霉素和萘啶酸的抗性是在与肉鸡亲代雏鸡第一周死亡率相关的临床大肠杆菌分离株中检测到的唯一表型。尽管通过扩增片段长度多态性 (AFLP) 分型，抗菌药物耐药性大肠杆菌具有遗传多样性，但不同鸡群中存在无法区分的分离株，包括来自肉鸡父母雏鸡、肉鸡父母和肉鸡的分离株。在没有明显的选择压力的情况下，我们描述的基因型异质性可能是生产系统中多次引入抗菌药物耐药细菌的结果。肉鸡饲养的限制限制了细菌在不同鸡群之间传播的可能性。我们的研究结果与耐氨苄西林和萘啶酸的大肠杆菌通过肉鸡生产系统的垂直传播一致。健康、未经处理的鸡群中抗菌药物耐药性大肠杆菌的持续存在强调了在肉鸡生产的任何水平上仔细评估治疗方案的必要性。 (C) 2009 Elsevier B.V. 保留所有权利。
This study was performed to determine the origin and transmission of beta-lactam- and (fluoro)quinolone-resistant Escherichia coli in healthy, untreated broiler flocks. We focused on the dynamics of bacteria resistant to critically important antimicrobials for public and veterinary health in view of the possible link between antimicrobial resistant bacteria in farm animals and humans. By processing faecal samples collected with the sock method in broiler parent and broiler flocks, E. coli resistant to ampicillin and nalidixic acid were frequently isolated, while resistance to ciprofloxacin was detected at a very low frequency, and resistance to cephalosporins was not detected. Similarly, resistance to ampicillin and nalidixic acid were the only phenotypes detected in a collection of clinical E. coli isolates associated with first-week-mortality in broiler parent chicks. Although antimicrobial resistant E. coli were genetically diverse by means of amplified fragment length polymorphism (AFLP) typing, indistinguishable isolates were present in different flocks, including isolates from broiler parent chicks, broiler parents and broilers. In the absence of apparent selective pressure, the genotypic heterogeneity that we describe is likely the consequence of multiple introductions of antimicrobial resistant bacteria into the production system. The confinement under which broilers are raised limits the possibilities of bacterial transmission among different flocks. Our findings are consistent with vertical transmission of ampicillin- and nalidixic acid-resistant E. coli through the broiler production system. The persistence of antimicrobial resistant E. coli in healthy, untreated chicken flocks emphasises the need of careful evaluation of therapeutic options at any level of the broiler production. (C) 2009 Elsevier B.V. All rights reserved.