摘要
克罗诺杆菌(Cronobacter)是一种急性细菌病原体,最初因与新生儿重症监护室爆发的几起致死性疾病(脑膜炎,坏死性小肠结肠炎)相关而受到人们广泛关注。目前Cronobacter PubMLST基因组和序列定义数据库(http://pubmlst.org/cronobacter/)中已包含超过2400多株克罗诺杆菌分离菌株的序列信息,阪崎克罗诺杆菌1774株,丙二酸盐阳性克罗诺杆菌295株是其中的优势菌种,这些菌株共分离自40多个国家和地区。通过将7个位点的多位点序列分型(7-loci multilocus sequence typing,7-lociMLST)方案应用于2438株克诺罗菌株,共揭示了591种可定义的序列型(sequencetype,ST),其中ST4(334株)、ST1(280株)、ST7(78株)和ST13(67株)为主要序列型。7-lociMLST对于克罗诺杆菌的致病型分型鉴定有很大帮助,但由于MLST所针对的七个基因位点在基因组总量中占比较小,导致同一ST型中包含地理来源,分离时间,宿主等不相关的菌株,而对菌株溯源结果适得其反。为了解决这一问题,本研究进一步采用基于直系同源基因簇的多位点序列分析方法(Clusters of Orthologous Genes MLST, cogMLST(1865-loci)),对PubMLST中240株已完成全基因组测序的菌株,包括阪崎克罗诺杆菌ST1(67株),ST4(95株),ST13(43株)和丙二酸盐阳性克罗诺杆菌ST7(35株)进行了全基因组序列分析。结果显示,cogMLST可对ST型相同,但无相关性的菌株进行进一步分型,且不同聚类与菌株分离国家及来源之间存在一定相关性。这或许对于相同ST克罗诺杆菌属菌株的全球溯源分析及食源性疾病监测有较大帮助。
Cronobacter, as an emergent bacterial pathogen, has attracted extensive attention for causing several fatal outbreaks in neonatal intensive care units including meningitis and necrotising enterocolitis. There are over 2 400 isolates so far with metadata contained in the Cronobacter PubMLST genome and sequence definition database (http://pubmlst.org/cronobacter/). Among them, C. sakazakii (1 774 isolates) and C. malonaticus (295 isolates) were the dominant species. These strains were isolated from more than 40 countries and regions. 7-loci MLST (multilocus sequence typing) scheme were applied to 2 438 strains and revealed 591 definable sequence types. Among them, ST4 (334 strains), ST1 (280 strains), ST7 (78 strains), and ST13 (67 strains) were the main sequence types. Although the 7-loci MLST clonal recognition is useful for the identification of Cronobacter pathovars, it is counter-productive for microbial source tracking. Since the seven loci targeted by MLST are relatively small in the total genome, unrelated strains (geographic source, separation time, host, etc.) would occur with the same ST. To adress this issue, the whole genome-MLST based on Clusters of Orthologous Genes (COG-MLST, 1865 loci) has been used to analyse 240 whole genomes of Cronobacter, including C. sakazakii ST1 (67 isolates), ST4 (95 isolates), ST13 (43 isolates) and C. malonaticus ST7 (35 isolates). The results showed that the cogMLST could further classify unrelated strains of the same ST and there were some correlation between different clusters and the countries and sources of the strains. This may be helpful for global traceability analysis and foodborne disease surveillance of the Cronobacter strains occur with the same ST.
作者
闫瑞
杨捷琳
陈翠玲
钮冰
徐之雯
蒋原
YAN Rui;YANG Jielin;CHEN Cuiling;NIU Bing;XU Zhiwen;JIANG Yuan(School of Life Science, Shanghai University, Shanghai 200444, China;Shanghai Entry-Exit Inspection and Quaran?tine Bureau, Shanghai 200135, China)
出处
《中国乳品工业》
CAS
北大核心
2019年第9期9-14,共6页
China Dairy Industry
基金
国家自然科学基金项目(31671936)
上海市自然科学基金项目(16ZR1410900)
中央引导地方发展专项(YDZX20173100004528)
江苏省肉类生产与加工质量安全控制协同创新心
关键词
克罗诺杆菌
多位点序列分型
全基因组分型
溯源分析
Cronobacter
Multilocus sequence typing (MLST)
Whole genotyping
Traceability analysis
