Kim Shin-Hee, Wei Cheng-I, Tzou Ywh-Min, An Haejung
Department of Nutritional Sciences, College of Human Environmental Sciences, Oklahoma State University, Stillwater, Oklahoma 74078, USA.
J Food Prot. 2005 Oct;68(10):2022-9. doi: 10.4315/0362-028x-68.10.2022.
Multidrug-resistant enteric bacteria were isolated from turkey, cattle, and chicken farms and retail meat products in Oklahoma. Among the isolated species, multidrug-resistant Klebsiella pneumoniae was prevalently isolated from most of the collected samples. Therefore, a total of 132 isolates of K. pneumoniae were characterized to understand their potential roles in the dissemination of antibiotic-resistance genes in the food chains. Multidrug-resistant K. pneumoniae was most frequently recovered from a turkey farm and ground turkey products among the tested samples. All isolates were resistant to ampicillin, tetracycline, streptomycin, gentamycin, and kanamycin. Class 1 integrons located in plasmids were identified as a common carrier of the aadA1 gene, encoding resistance to streptomycin and spectinomycin. Production of beta-lactamase in the K. pneumoniae isolates played a major role in the resistance to beta-lactam agents. Most isolates (96%) possessed bla(SHV1). Five strains were able to express both SHV-11 (pI 6.2) and TEM-1 (pI 5.2) beta-lactamase. Transfer of these antibiotic-resistance genes to Escherichia coli was demonstrated by transconjugation. The bacterial genomic DNA restriction patterns by pulsed-field gel electrophoresis showed that the same clones of multidrug-resistant K. pneumoniae remained in feathers, feed, feces, and drinking water in turkey environments, indicating the possible dissemination of antibiotic-resistance genes in the ecosystem and cross-contamination of antibiotic-resistant bacteria during processing and distribution of products.
在俄克拉荷马州的火鸡、牛和养鸡场以及零售肉类产品中分离出了多重耐药性肠道细菌。在分离出的物种中，多重耐药性肺炎克雷伯菌在大多数采集样本中普遍被分离出来。因此，对总共132株肺炎克雷伯菌进行了特征分析，以了解它们在食物链中抗生素耐药基因传播中的潜在作用。在测试样本中，多重耐药性肺炎克雷伯菌最常从一个火鸡养殖场和火鸡碎肉产品中分离出来。所有分离株对氨苄青霉素、四环素、链霉素、庆大霉素和卡那霉素均耐药。位于质粒上的1类整合子被鉴定为aadA1基因的常见载体，该基因编码对链霉素和壮观霉素的耐药性。肺炎克雷伯菌分离株中β-内酰胺酶的产生在对β-内酰胺类药物的耐药性中起主要作用。大多数分离株（96%）具有bla(SHV1)。五株菌株能够同时表达SHV-11（pI 6.2）和TEM-1（pI 5.2）β-内酰胺酶。通过接合转移证明了这些抗生素耐药基因可转移至大肠杆菌。脉冲场凝胶电泳显示的细菌基因组DNA限制性图谱表明，在火鸡养殖环境中，羽毛、饲料、粪便和饮用水中存在相同的多重耐药性肺炎克雷伯菌克隆，这表明抗生素耐药基因可能在生态系统中传播，以及在产品加工和分销过程中耐药细菌的交叉污染。
