乔治亚大学的研究人员抽样了14000多只，于不同条件下饲养的鸡只后发现，即使抑制了家禽饲养场的抗生素使用，对于减少威胁人类健康之抗药性细菌的效果仍然不大。
这四种不同的养殖条件包括给予抗生素的商用鸡只、未给与抗生素的商用鸡只、给予抗生素的实验室养殖用鸡只及未给予抗生素的实验室用鸡只。
乔治亚大学兽医学院的教授Margie Lee发现，养殖于无抗生素农场甚至是实验室中的鸡，也含有大量的抗药性细菌。抗药性细菌不一定来自使用抗生素的家禽，而且取缔抗生素的使用事实上是没有帮助的。
这项研究结果刊载于3月号的Applied and Environmental Microbiology中，研究作者建议家禽来到农场时体内就带有抗药性细菌了，这可能从牠们发育的蛋里就携带着这些细菌。因此必需从引进的家禽来源就开始控管，而不只是管理养鸡场的饲养条件就可以抑制抗药性细菌的生成。此外，消费者也应重视烹调的方式，必需食用煮熟的肉，而且接触到生的鸡肉后，一定要洗手后再接触其它食物。
(资料来源 : Bio.com)
部分英文原文：
Applied and Environmental Microbiology, March 2007, p. 1404-1414, Vol. 73, No. 5
0099-2240/07/$08.00+0 doi:10.1128/AEM.01193-06
Copyright © 2007, American Society for Microbiology. All Rights Reserved.
Impact of Antimicrobial Usage on Antimicrobial Resistance in Commensal Escherichia coli Strains Colonizing Broiler Chickens
J. L. Smith,1 D. J. V. Drum,1 Y. Dai,1 J. M. Kim,1 S. Sanchez,2 J. J. Maurer,1,3 C. L. Hofacre,1,3 and M. D. Lee1,3*
Poultry Diagnostic and Research Center,1 Athens Diagnostic Laboratory, College of Veterinary Medicine, University of Georgia, Athens, Georgia 30602,2 Center for Food Safety, College of Agriculture and Environmental Sciences, University of Georgia, Griffin, Georgia 302233
Received 23 May 2006/ Accepted 19 December 2006
Escherichia coli strains isolated from commercial broilers and an experimental flock of chickens were screened to determine phenotypic expression of antimicrobial resistance and carriage of drug resistance determinants. The goal of this study was to investigate the influence of oxytetracycline, sarafloxacin, and enrofloxacin administration on the distribution of resistance determinants and strain types among intestinal commensal E. coli strains isolated from broiler chickens. We detected a high prevalence of resistance to drugs such as tetracycline (36 to 97%), sulfonamides (50 to 100%), and streptomycin (53 to 100%) in E. coli isolates from treated and untreated flocks. These isolates also had a high prevalence of class 1 integron carriage, and most of them possessed the streptomycin resistance cassette, aadA1. In order to investigate the contribution of E. coli strain distribution to the prevalence of antimicrobial resistance and the resistance determinants, isolates from each flock were DNA fingerprinted by enterobacterial repetitive intergenic consensus sequence (ERIC) PCR. Although very diverse E. coli strain types were detected, four ERIC strain types were present on all of the commercial broiler farms, and two of the strains were also found in the experimental flocks. Each E. coli strain consisted of both susceptible and antimicrobial agent-resistant isolates. In some instances, isolates of the same E. coli strain expressed the same drug resistance patterns although they harbored different tet determinants or streptomycin resistance genes. Therefore, drug resistance patterns could not be explained solely by strain prevalence, indicating that mobile elements contributed significantly to the prevalence of resistance.
