Escherichia coli O157:H7 Strains Isolated from High-Event Period Beef Contamination Have Strong Biofilm-Forming Ability and Low Sanitizer Susceptibility, Which Are Associated with High pO157 Plasmid Copy Number
Escherichia coli O157:H7 Strains Isolated from High-Event Period Beef Contamination Have Strong Biofilm-Forming Ability and Low Sanitizer Susceptibility, Which Are Associated with High pO157 Plasmid Copy Number
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DOI：
10.4315/0362-028x.jfp-16-113
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发表时间：
2016-11-01
影响因子：
2
通讯作者：
Arthur, Terrance M.
中科院分区：
文献类型：
--
作者：
Wang, Rong;Luedtke, Brandon E.;Arthur, Terrance M.
在肉类行业，高事件期（HEP）被定义为牛肉加工企业经历大肠杆菌O157：H7产品污染发生率增加的时间段。我们以前的研究表明，细菌生物膜的形成和消毒剂的耐药性可能有助于HEP。我们进行了本研究，以进一步表征E。大肠杆菌O157：H7菌株在HEP过程中分离的潜在造成污染，并调查其强大的生物膜形成能力和高消毒剂抗性的遗传基础。结果表明，与E. coli O157：H7多样性对照组菌株中，HEP菌株在接触表面上具有显著更高的生物膜形成能力，并且对常用消毒剂的敏感性较低。在HEP和对照菌株之间没有观察到消毒剂抗性基因的存在或抗生素抗性的流行率的差异。然而，HEP菌株保留了显著更高的pO157质粒拷贝数。在菌株的高质粒拷贝数、强生物膜形成能力、低消毒剂敏感性和消毒后的高存活和恢复能力之间观察到正相关性，这表明这些特定表型可以与pO157质粒上的基因表达直接相关，也可以通过受质粒存在影响的染色体基因表达间接调节。我们的数据突出了在HEP污染中由E.大肠杆菌O157：H7，我们的研究结果呼吁更加关注肉类加工设施中适当和有效的消毒措施。
In the meat industry, a high-event period (HEP) is defined as a time period when beef processing establishments experience an increased occurrence of product contamination by Escherichia coli O157:H7. Our previous studies suggested that bacterial biofilm formation and sanitizer resistance might contribute to HEPs. We conducted the present study to further characterize E. coli O157:H7 strains isolated during HEPs for their potential to cause contamination and to investigate the genetic basis for their strong biofilm-forming ability and high sanitizer resistance. Our results show that, compared with the E. coli O157:H7 diversity control panel strains, the HEP strains had a significantly higher biofilm-forming ability on contact surfaces and a lower susceptibility to common sanitizers. No difference in the presence of disinfectant-resistant genes or the prevalence of antibiotic resistance was observed between the HEP and control strains. However, the HEP strains retained significantly higher copy numbers of the pO157 plasmid. A positive correlation was observed among a strain's high plasmid copy number, strong biofilmforming ability, low sanitizer susceptibility, and high survival and recovery capability after sanitization, suggesting that these specific phenotypes could be either directly correlated to gene expression on the pO157 plasmid or indirectly regulated via chromosomal gene expression influenced by the presence of the plasmid. Our data highlight the potential risk of biofilm formation and sanitizer resistance in HEP contamination by E. coli O157:H7, and our results call for increased attention to proper and effective sanitization practices in meat processing facilities.