Shiga toxin-producing Escherichia coli (STEC) strains are important food-borne pathogens that can be transmitted through the consumption of food products derived from pigs. Moreover, antimicrobial resistance in STEC has been a matter of increasing concern. The aim of this study was to investigate the prevalence and antimicrobial characteristics of STEC isolates from pork in Korea. We isolated 131 isolates of E. coli from 334 pork samples collected from slaughterhouses and retail markets from 2008 to 2009. Among the 131 isolates, 6 (4.58%) were confirmed to belong to 6 different serotypes of STEC. All six STEC isolates contained stx1 and eaeA virulence genes, and four of them additionally carried the hly gene. The minimum inhibitory concentration (MIC) of 15 antibiotics (amoxicillin/clavulanic acid, ampicillin, cephalothin, cefoxitin, ceftiofur, gentamicin, neomycin, streptomycin, nalidixic acid, ciprofloxacin, colistin, chloramphenicol, florfenicol, tetracycline and sulfamethoxazole/trimethoprim) toward the STEC isolates was determined. As a result, three strains were associated with high MICs for florfenicol and chloramphenicol (64 μg/mL). Furthermore, all three strains were found to contain the florfenicol-resistant gene (floR) but not the chloramphenicol-resistant gene (cat). Sequence alignment and BLAST analysis of the polymerase chain reaction products of the floR gene indicated that they contained sequences with homology to the floR gene of E. coli or Salmonella enterica serovar, Heidelberg. This is the first report on the detection of floR in STEC isolated from pork obtained from retail markets in Korea.

中文翻译：

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韩国猪肉中产志贺毒素大肠杆菌的流行率和抗菌特性。

产志贺毒素大肠杆菌(STEC) 菌株是重要的食源性病原体，可通过食用源自猪的食品传播。此外，STEC 中的抗菌素耐药性已引起越来越多的关注。本研究的目的是调查韩国猪肉 STEC 分离株的流行情况和抗菌特性。我们从 2008 年至 2009 年从屠宰场和零售市场收集的 334 份猪肉样本中分离出 131 株大肠杆菌。在 131 株分离物中，有 6 株（4.58%）被确认属于 6 种不同的 STEC 血清型。所有 6 株 STEC 分离株均含有stx1和eaeA毒力基因，其中 4株还携带hly基因。15 种抗生素（阿莫西林/克拉维酸、氨苄西林、头孢噻吩、头孢西丁、头孢噻呋、庆大霉素、新霉素、链霉素、萘啶酸、环丙沙星、粘菌素、氯霉素、氟苯尼考、甲氧苄啶）对磺胺嘧啶/甲氧苄啶的最低抑菌浓度（MIC）分离株被确定。结果，三个菌株与氟苯尼考和氯霉素 (64 μg/mL) 的高 MIC 相关。此外，发现所有三个菌株都含有氟苯尼考抗性基因（floR），但不含氯霉素抗性基因（cat）。floR基因聚合酶链反应产物的序列比对和BLAST分析表明它们含有与floR同源的序列大肠杆菌或肠沙门氏菌血清型的基因，海德堡。这是关于从韩国零售市场获得的猪肉中分离出的 STEC 中检测出floR的第一份报告。