• 主题
高级搜索  >
历史搜索 清空历史
首页> 外文期刊>Applied Microbiology >Evolution of Listeria monocytogenes in a Food Processing Plant Involves Limited Single-Nucleotide Substitutions but Considerable Diversification by Gain and Loss of Prophages
【24h】

Evolution of Listeria monocytogenes in a Food Processing Plant Involves Limited Single-Nucleotide Substitutions but Considerable Diversification by Gain and Loss of Prophages

机译：食品加工厂中Histeria单核细胞增生的演变涉及有限的单核苷酸取代，但通过增益和丧失的损失相当多样化

获取原文
           
页面导航
  • 摘要
  • 著录项
  • 相似文献
  • 相关主题

摘要

Whole-genome sequencing (WGS) is becoming the standard method for subtyping Listeria monocytogenes . Interpretation of WGS data for isolates from foods and associated environments is, however, challenging due to a lack of detailed data on Listeria evolution in processing facilities. Here, we used previously collected WGS data for 40 L. monocytogenes isolates obtained from a cold-smoked salmon processing facility between 1998 and 2015 to probe the L. monocytogenes molecular evolution in this facility, combined with phenotypic assessment of selected isolates. Isolates represented three clusters (1, 2, and 3); cluster 3 isolates ( n ?=?32) were obtained over 18?years. The average mutation rate for cluster 3 was estimated as 1.15 ×?10~(?7) changes per nucleotide per year (～0.35 changes per genome per year); the most recent common ancestors (MRCAs) of subclusters 3a and 3b were estimated to have occurred around 1958 and 1974, respectively, within the age of the facility, suggesting long-term persistence in this facility. Extensive prophage diversity was observed within subclusters 3a and 3b, which have one shared and six unique prophage profiles for each subcluster (with 16 prophage profiles found among all 40 isolates). The plasmid-borne sanitizer tolerance operon bcrABC was found in all cluster 2 and 3 isolates, while the transposon-borne sanitizer tolerance gene qacH was found in one cluster 1 isolate; presence of these genes was correlated with the ability to survive increased concentrations of sanitizers. Selected isolates showed significant variation in the ability to attach to surfaces, with persistent isolates attaching better than transient isolates at 21°C.IMPORTANCE Knowledge about the genetic evolution of L. monocytogenes in food processing facilities over multiple years is generally lacking. This information is critical to interpret WGS findings involving food or food-associated isolates. This study suggests that L. monocytogenes that persists in processing facilities may evolve with a low single-nucleotide mutation rate mostly driven by negative (i.e., purifying) selection but with rapid diversification of prophages. Hence, isolation of L. monocytogenes with few single-nucleotide polymorphism (SNP) differences in different locations (e.g., supplier plants and receiving plants) is possible, highlighting the importance of epidemiological and detailed isolate metadata for interpreting WGS data in traceback investigation. Our study also shows how advanced WGS data analyses can be used to support root cause analysis efforts and may, for example, pinpoint the time when a persistence event started (which then potentially could be linked to facility changes, introduction of new equipment, etc.).
机译：全基因组测序（WGS）正成为亚细胞李斯特菌单核细胞增生的标准方法。然而，由于在加工设施中缺乏关于Listeria演化的详细数据，对食物和相关环境的分离株的WGS数据的解释是具有挑战性的。这里，我们使用先前收集了从1998年和2015年间的冷熏鲑鱼处理设施获得的40万的WGS数据，以探测该设施中的L.单核细胞化分子演进，结合所选分离株的表型评估。分离株代表三簇（1,2和3）;群集3分离物（n？= 32），超过18年获得。簇3的平均突变率估计每年每年核苷酸的1.15×10〜（？7）变化（每年/每年〜0.35变化）;估计在该设施的年龄左右，估计，估计了2岁的常见祖先（MRCAS）左右发生在1958年和1974年，建议在该设施中长期持久性。在Sublustrers 3a和3b中观察到广泛的前进分集，其为每个子簇具有一个共享和六个独特的ProMhage曲线（在所有40个分离株中发现了16个Prophage型材）。在所有簇2和3个分离物中发现了质粒传播的消毒剂耐受性术语BCRABC，而转座子传播的消毒剂耐受性基因QACH被发现在一个簇1中存在;这些基因的存在与存活浓度的消毒剂浓度增加的能力相关。所选分离物显示出连接到表面的能力的显着变化，持续的分离物在21°C的瞬态分离物上效果更好地附着在多年来食品加工设施中L.单核细胞增生的遗传演化。该信息对于解释涉及食物或食物相关的分离株的WGS发现至关重要。该研究表明，在加工设施中持续存在的L.单核细胞增生可以随着低单核苷酸突变速率而发展，其主要由负（即净化）选择，但随着预测的快速多样化。因此，可以分离不同位置的单核苷酸多态性（SNP）差异（例如供应商植物和接收植物）的单核细胞增生，突出了流行病学和详细分离元数据的重要性，以解释在回溯调查中的WGS数据。我们的研究还显示了先进的WGS数据分析如何用于支持根本原因分析工作，并且例如可以针对持久事件启动的时间（其中可能与设施变化相关联，引入新设备等。 ）。

著录项

相似文献

  • 外文文献
  • 中文文献
  • 专利
获取原文

客服邮箱：kefu@zhangqiaokeyan.com

京公网安备：11010802029741号 ICP备案号：京ICP备15016152号-6 六维联合信息科技 (北京) 有限公司©版权所有

  • 客服微信

  • 服务号