Listeria monocytogenes is a foodborne pathogen causing systemic infection with high mortality. To allow efficient tracking of outbreaks a clear definition of the genomic signature of a cluster of related isolates is required, but lineage‐specific characteristics call for a more detailed understanding of evolution. In our work, we used core genome MLST (cgMLST) to identify new outbreaks combined to core genome SNP analysis to characterize the population structure and gene flow between lineages. Whilst analysing differences between the four lineages of L. monocytogenes we have detected differences in the recombination rate, and interestingly also divergence in the SNP differences between sub‐lineages. In addition, the exchange of core genome variation between the lineages exhibited a distinct pattern, with lineage III being the best donor for horizontal gene transfer. Whilst attempting to link bacteriophage‐mediated transduction to observed gene transfer, we found an inverse correlation between phage presence in a lineage and the extent of recombination. Irrespective of the profound differences in recombination rates observed between sub‐lineages and lineages, we found that the previously proposed cut‐off of 10 allelic differences in cgMLST can be still considered valid for the definition of a foodborne outbreak cluster of L. monocytogenes.

中文翻译：

---

单核细胞增生李斯特氏菌的谱系特异性进化和基因流独立于噬菌体。

单核细胞增多性李斯特菌是一种食源性病原体，可引起全身感染，死亡率很高。为了有效跟踪疫情爆发，需要对一组相关分离株的基因组特征进行明确定义，但谱系特异性特征需要对进化有更详细的了解。在我们的工作中，我们使用核心基因组 MLST (cgMLST) 来识别新的疫情，并结合核心基因组 SNP 分析来表征种群结构和谱系之间的基因流。在分析L的四个谱系之间的差异时。对于单核细胞增多症，我们检测到了重组率的差异，有趣的是，亚谱系之间的 SNP 差异也存在差异。此外，谱系之间核心基因组变异的交换表现出独特的模式，谱系III是水平基因转移的最佳供体。在试图将噬菌体介导的转导与观察到的基因转移联系起来时，我们发现谱系中噬菌体的存在与重组程度之间存在负相关。不管亚谱系和谱系之间观察到的重组率存在巨大差异，我们发现之前提出的 cgMLST 中 10 个等位基因差异的截止值对于 L 食源性暴发集群的定义仍然可以被认为是有效的。单核细胞增多症。