医院相关性ST5型耐甲氧西林金黄色葡萄球菌ZJ5499的全基因测序及序列分析

Genomic analysis of healthcare-associated methicillin-resistant Staphylococcus aureus ZJ5499

目的对1例医院获得性耐甲氧西林金黄色葡萄球菌(MRSA)肺炎患者血中分离的1株MRSA(ZJ5499)进行基因组序列信息解析。方法采用Illumina平台高通量测序和Sanger测序相结合对ZJ5499菌株进行全基因组测序,并使用相关软件对序列进行拼接、基因预测、功能注释、直系同源簇注释(COG)及毒力因子和耐药基因分析;并与国内常见流行序列型(ST型)菌株进行进化关系分析、毒力因子和耐药基因比较。结果 ZJ5499菌株基因组大小为2 888 783bp,GC含量32.84%,序列已提交至GenBank数据库,登录号为CP011685。该菌株基因组中含有大量与致病性相关的毒力因子,并含有spc、aadD、mecA、norA和erm(A)五个耐药相关基因,与同一ST型菌株基本一致。进化关系分析显示该菌株与同一ST型菌株关系较近。毒力因子与ST5型菌株没有较大差异,而较其他ST型明显增多。结论本研究报道了临床MRSA菌株ZJ5499的全基因组序列。序列分析发现该菌株的毒力和耐药性与ST5型的菌株相近,而ST5型菌株较其他国内流行ST型菌株携带较多毒力基因。

Objective To analyze the genomic features of a healthcare-associated methicillin-resistant Staphylococcus aureus（MRSA）ZJ5499isolated from a patient with hospital acquired pneumonia.Methods The whole genome was sequenced by using Illumina sequencing combined with Sanger sequencing.Assembling,gene prediction,annotation,cluster of orthologous group,virulence and antibiotic resistance were analyzed by using relevant softwares respectively.The phylogenetic tree was constructed and compared with that of the prevalent sequencing type（ST）in China;comparation of virulence factors and antibiotic resistance genes was also conducted.Results The genome of ZJ5499 consists of a single circular DNA chromosome of2,888,783 bp with a GC content of 32.84%.The sequence were submitted to GenBank,and the accession number was CP011685.The strain had numerous virulence factors and 5antibiotic resistant genes,spc,aadD,mecA,norA and erm（A）,consistent with the strains of the same sequencing type.Phylogenetic tree analysis revealed that the strain was closely related to the strain of the same sequencing type,so were its virulence factors,but it had more virulence factors than the other sequencing types.Conclusion This present study reported the whole genome of a clinical isolate MRSA ZJ5499.Its virulence factors and antibiotic resistance genes are similar to those of the strains of same ST,according to comparative genomic analysis,but the number of virulence factors were more than the other prevalent MRSA sequencing types.