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单增李斯特菌是一种重要的人畜共患病原菌,对食品安全和人类健康造成了严重威胁,但现阶段对其进化规律的研究仍相对较少。本研究运用Illumina测序技术对一株中国单增李斯特菌WaX12的基因组进行了测定,并通过比较基因组学分析了该菌的微进化规律。结果表明:WaX12的基因组与Finland 1998相似度最高,但两者基因组间存在135个基因的差异,主要集中在WaX12的原噬菌体上。进一步分析可知,WaX12的基因组携带5个原噬菌体,除原噬菌体1外,其余4个原噬菌体均未存在于Finland 1998中。原噬菌体3和原噬菌体5来源于其他单增李斯特菌的基因组,而原噬菌体2和原噬菌体4则分别来自于大肠杆菌和粪球菌。由此可见,原噬菌体是该单增李斯特菌微进化的主要原因,而这种微进化的发生不仅限于同一种属的细菌之间,还可能源于不同种属细菌间的基因转移。
Listeria monocytogenes is an important zoonotic pathogen, posing a serious threat to food safety and human health. However, the research on its evolutionary law is still relatively few. In this study, we sequenced the genome of a Chinese Listeria monocytogenes WaX12 by Illumina sequencing and analyzed the micro-evolution of this strain by comparative genomics. The results showed that the genome of WaX12 had the highest similarity with Finland 1998, but there were 135 differences between the two genomes, which mainly focused on the original phage of WaX12. Further analysis showed that the genome of WaX12 carries 5 prophages, except for prophage 1, the other 4 prophases are not present in Finland 1998. Prophage 3 and prophage 5 are derived from other Listeria monocytogenes, while prophage 2 and prophage 4 are from Escherichia coli and from fecal bacteria. Thus, prophage is the main reason for the micro-evolution of Listeria monocytogenes, and this micro-evolution occurs not only between the same species of bacteria, but also from the gene transfer between different species of bacteria.