Evolution and molecular phylogeny of Listeria monocytogenes isolated from human and animal listeriosis cases and foods
Evolution and molecular phylogeny of Listeria monocytogenes isolated from human and animal listeriosis cases and foods
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DOI：
10.1128/jb.187.16.5537-5551.2005
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发表时间：
2005-08-01
影响因子：
3.2
通讯作者：
Wiedmann, M
中科院分区：
文献类型：
--
作者：
Nightingale, KK;Windham, K;Wiedmann, M
为了研究特定宿主物种和环境中单核细胞增生李斯特菌的进化和系统发育，从1999年至2001年在纽约州收集的大量分离株（n = 354）中随机抽取了人类（n = 60）和动物（n = 30）李斯特菌病例和食品样本（n = 30）分离株。4个管家基因（gap、prs、purM和ribC）、1个应激反应基因（sigB）和2个毒力基因（actA和in14）的部分测序结果显示，共有11个（gap）和33个（inlA）等位基因类型，以及52个序列类型（等位基因类型的独特组合）。actA、ribC和purM表现出最高的核苷酸多样性水平（pi > 0.05）。actA和inL4以及prs和高变管家基因ribC和purM显示了水平基因转移和重组的证据。actA和inL4在特定的氨基酸位点也显示出正选择的证据。所有7个基因的最大似然系统发育证实了单核增生乳杆菌包含两个深度分离的进化谱系。世系1具有高度克隆性，而世系2具有较高的多样性和水平基因转移的证据。除了单个间隙等位基因外，等位基因类型都是世系所独有的，而且世系之间的核苷酸距离远小于世系之间的核苷酸距离，表明世系之间的遗传交换是罕见的。我们的数据表明：(1)单核增生乳杆菌是一个高度多样化的物种，至少有两个不同的进化历史和种群结构的不同系统发育谱系；(2)水平基因转移和正选择有助于单核增生乳杆菌的进化。
To probe the evolution and phylogeny of Listeria monocytogenes from defined host species and environments, L. monocytogenes isolates from human (n = 60) and animal (n = 30) listeriosis cases and food samples (n = 30) were randomly selected from a larger collection of isolates (n = 354) obtained in New York State between 1999 and 2001. Partial sequencing of four housekeeping genes (gap, prs, purM, and ribC), one stress response gene (sigB), and two virulence genes (actA and inl4) revealed between 11 (gap) and 33 (inlA) allelic types as well as 52 sequence types (unique combination of allelic types). actA, ribC, and purM demonstrated the highest levels of nucleotide diversity (pi > 0.05). actA and inL4 as well as prs and the hypervariable housekeeping genes ribC and purM showed evidence of horizontal gene transfer and recombination. actA and inL4 also showed evidence of positive selection at specific amino acid sites. Maximum likelihood phylogenies for all seven genes confirmed that L. monocytogenes contains two deeply separated evolutionary lineages. Lineage I was found to be highly clonal, while lineage II showed greater diversity and evidence of horizontal gene transfer. Allelic types were exclusive to lineages, except for a single gap allele, and nucleotide distance within lineages was much lower than that between lineages, suggesting that genetic exchange between lineages is rare. Our data show that (i) L. monocytogenes is a highly diverse species with at least two distinct phylogenetic lineages differing in their evolutionary history and population structure and (ii) horizontal gene transfer as well as positive selection contributed to the evolution of L. monocytogenes.