基于PasteurMLST网站分析中国单增李斯特菌克隆复合体的多样性

摘要

To understand the diversity of clone complexes in Chinese Listeria monocytogenes,the data of 53 Chinese L.monocytogenes strains having sequence types (ST) in 1987-2015 were obtained by using the PasteurMLST database,and their clone complexes' diversity was analyzed.The results showed that the 53 strains could be divided into 44 sequence types,and the number of strains with ST 705 was the most (being 6 and accounting for 11.3％ of the total number);All the strains' sources were widespread,a majority of those strains were of 1/2a serotype,and the strain number and ST number from the south region were more than those from the north region.The bulk analysis of data by the eBURST software indicated that the strains of single sequence type was 18,and the clone complexes of two,four,five and seven sequence types were 5,1,1 and 1 respectively;The CC155 was the largest clone complex (accounting for 24.5％ of the total strains).The further analysis showed that there was a close relation between the clone complexes and the strain sources.The phylogenetic analysis showed that the CC9 and the CC155 had a close evolutionary relationship,and the phylogenetic tree constructed by amino acid sequences was more accurate than that by nucleotide sequences.From the above results it was concluded that the Chinese L.monocytogenes had a high genetic diversity based on the PasteurMLST database,the ST 705 was more in multilocus sequence typing,and the CC155 was a major clone complex,which laid a theoretical foundation for further research on the origin and evolution of L.monocytogenes.%为了了解中国分离的单增李斯特菌克隆复合体的多样性,利用了PasteurMLST网站上公布的数据,获得了1987-2015年具有序列型(Sequence type,ST)的来自中国的单增李斯特菌53条菌株数据,进行了克隆复合体的多样性分析.结果表明:53条菌株数据中可分为44个ST型,以ST 705型居多(共6株,占总数的11.3％);所有提交菌株的来源广泛,以1/2a血清型为主,南方地区的菌株数与ST型数均多于北方地区.利用eBURST软件对数据进行总体分析,共发现了单个ST型18个,2个ST型的克隆复合体5个,4个ST型的克隆复合体1个,5个ST型的克隆复合体1个,7个ST型的克隆复合体1个,其中CC155是最大的克隆复合体(占总菌株的24.5％).进一步分析得知克隆复合体与菌株来源关系密切.系统发育树分析得出CC9与CC155存在较近的进化关系,并且氨基酸序列构建的系统发育树比核苷酸更加准确.由此可见,基于PasteurMLST网站分析的中国单增李斯特菌具有较高的遗传多样性,MLST分型以ST 705为多,克隆复合体以CC155为主,这为进一步研究单增李斯特菌的溯源以及进化关系奠定了理论基础.