四株ST9型耐甲氧西林金黄色葡萄球菌的全基因组序列分析  

Whole-genomes sequence analysis of four ST9 methicillin-resistant Staphylococcus aureus

作　　者：陈怡文 王珊珊[1] 石继春[1] 徐颖华[1] 崔生辉[1] CHEN Yiwen;WANG Shanshan;SHI Jichun;XU Yinghua;CUI Shenghui(National Institute for Food and Drug Control,Beijing 100050,China)

机构地区：[1]中国食品药品检定研究院,北京100050

出　　处：《中国食品卫生杂志》2022年第6期1135-1140,共6页Chinese Journal of Food Hygiene

基　　金：国家重点研发计划(2018YFC1603900)。

摘　　要：目的 了解不同来源ST9耐甲氧西林金黄色葡萄球菌(MRSA)的全基因组特征。方法 对收集的4株分离自猪胴体和屠宰工作人员的ST9 MRSA菌株进行全基因组序列测序,分析ST9 MRSA的基因特征、耐药基因和毒力基因携带情况,利用比较基因组学筛选单核苷酸多态性(SNP),并与NCBI收录的11株不同ST型的MRSA和甲氧西林敏感金黄色葡萄球菌菌株进行核心基因分析,构建系统发育树。结果 4株不同来源ST9 MRSA全基因组序列全长约为2.6 Mbp,共含有2 122~2 494个基因,基因组的平均GC含量为32.8%。不同来源菌株基因组中均含有26~31种耐药基因、44~56种毒力基因。4株ST9 MRSA与欧洲主要流行的ST398代表性菌株比较,核苷酸同源性高,菌株之间SNP数量少于300个。系统进化发育树分析结果显示ST9和ST398 MRSA在分子进化过程中分成了不同独立进化分支,家畜和人来源的MRSA菌株在分子进化中没有明显相关性。结论 本研究获得了不同来源ST9 MRSA全基因组基本特征的背景材料,了解了不同ST型MRSA分子进化溯源关系,为后续ST9 MRSA的分子流行病学和致病性机制研究提供科学指导。Objective To explore the whole-genome characteristics of methicillin-resistant Staphylococcus aureus(MRSA).Methods Four ST9 MRSA strains isolated from pig carcasses and slaughter workers were collected and sequenced.The genetic characteristics,resistance genes and virulence genes of their genomes were analyzed.Single nucleotide polymorphism(SNPs) were screened by comparative genomics,and the comparisons with the core genes of 11MRSA and methicillin sensitive Staphylococcus aureus(MSSA) with different ST type from NCBI were analyzed to construct a phylogenetic tree.Results The results showed that the full-length genomic sequence of the four ST9 MRSA strains from different sources was about 2.6 Mbp,of which contained 2 122-2 494 genes,and the average GC content of the genes in the four genomes was 32.8%.The genomes from different sources contained 26-31 drug resistance genes and 44-56virulence genes.Compared with ST398 MRSA which was popular in Europe and other countries,the four ST9 MRSA strains had high nucleotide homology,and the numbers of SNPs between strains were less than 300.The phylogenetic tree analysis showed that ST9 and ST398 MRSA had been divided into different independent evolutionary branches in the molecular evolutionary courses.MRSA strains from animal and human origin had no obvious correlation in molecular evolution.Conclusion This study obtained background materials on the basic characteristics of the ST9 MRSA genome from different sources,which could help understand the molecular evolutionary traceability of different ST-type MRSAs.These data will provide scientific guidance for subsequent studies on the molecular epidemiology and pathogenic mechanism of ST9 MRSA.

关 键 词：耐甲氧西林金黄色葡萄球菌 ST9 全基因组测序 系统发育分析 比较基因学分析 

分 类 号：R155[医药卫生—营养与食品卫生学]