Akwar Holy T, Poppe Cornelis, Wilson Jeff, Reid-Smith Richard J, Dyck Monica, Waddington Josh, Shang Dayue, McEwen Scott A
Department of Population Medicine, University of Guelph, Guelph, Ontario N1G 2W1.
Can J Vet Res. 2008;72(2):195-201.
The main objectives of this study were to determine the prevalence and patterns of antimicrobial resistance in pigs on farms that medicated swine ration and those that did not. A total of 940 isolates of Escherichia coli from 188 pooled fecal samples obtained from weaner and finisher pigs on 47 farrow-to-finish swine farms (34 farms used in-feed medication and 13 did not) were tested for susceptibility to 21 antimicrobials using a breakpoint concentration method. The prevalence of resistance varied widely (0.0% to 81.3%) among the antimicrobials tested. Ninety percent of all the isolates tested were resistant to one or more antimicrobials. The most common multi-drug resistance patterns were to 2 to 6 antimicrobials. Resistance was significantly more frequent (P < 0.01) on farms that used in-feed medication compared to those that did not, and significantly more frequent (P < 0.01) in weaner pigs compared to finisher pigs. These findings indicate that resistance to a broad range of antimicrobials was prevalent among fecal E. coli isolates of pigs on study farms, and that this constitutes a potential reservoir for resistance genes that could spread to pathogens. The findings also provide further evidence that use of medication in swine rations provides selective pressure for antimicrobial resistance in E. coli in pigs.
本研究的主要目的是确定在使用猪用药物日粮的猪场和未使用的猪场中猪的抗菌药物耐药性流行情况及模式。使用断点浓度法对从47个全进全出养猪场（34个猪场使用饲料加药，13个未使用）的断奶仔猪和育肥猪采集的188份混合粪便样本中分离出的940株大肠杆菌进行了21种抗菌药物的敏感性测试。在所测试的抗菌药物中，耐药性流行率差异很大（0.0%至81.3%）。所有测试菌株中有90%对一种或多种抗菌药物耐药。最常见的多重耐药模式是对2至6种抗菌药物耐药。与未使用饲料加药的猪场相比，使用饲料加药的猪场耐药情况明显更频繁（P<0.01），与育肥猪相比，断奶仔猪的耐药情况明显更频繁（P<0.01）。这些发现表明，在研究猪场的猪粪便大肠杆菌分离株中，对多种抗菌药物的耐药性普遍存在，这构成了耐药基因可能传播到病原体的潜在储存库。这些发现还进一步证明，猪日粮中使用药物为猪大肠杆菌的抗菌药物耐药性提供了选择压力。
