海南省2022年emm12型A族链球菌基因组及药物敏感性特征分析  

Analysis of genomic characteristics and drug sensitivities of group A Streptococcus emm12 in Hainan Province in 2022

作　　者：孙初阳 吴庆梓 蔡英桂 甘晓婷[1] 王素 王吉晓 张亚淋 遇晓杰 SUN Chuyang;WU Qingzi;CAI Yinggui;GAN Xiaoting;WANG Su;WANG Jixiao;ZHANG Yalin;YU Xiaojie(Hainan Provincial Center for Disease Control and Prevention,Hainan Academy of Preventive Medicine,Haikou,Hainan 571129,China)

机构地区：[1]海南省疾病预防控制中心,海南省预防医学科学院,海南海口571129

出　　处：《中国热带医学》2024年第6期659-663,共5页China Tropical Medicine

基　　金：海南省自然科学基金项目(No.821QN421)。

摘　　要：目的 了解海南emm12型A族链球菌(group A Streptococcus, GAS)基因组特征及对目前常用抗菌药物的敏感性,为猩红热等GAS相关疾病提供病原学数据。方法 基于2022年海南省呼吸道症候群监测获得的咽拭子分离GAS菌株,应用高通量测序技术对所分离菌株进行基因组测序和emm基因分型、基因多位点序列分型(multi-locus sequence typing, MLST)、耐药基因与毒力基因预测,利用MEGA 10.1.8最大似然法(maximum likelihood, ML)绘制系统进化树。采用微量肉汤稀释法测定最低抑菌浓度(minimum inhibitory concentration, MIC)进行药敏试验。结果 2022年海南呼吸道症候群监测分离的4株GAS分离株均为emm12/ST36型,毒力基因除emm基因外,共检测到7种超抗原基因speB(100%)、speI(75%)、speH(75%)、speC(100%)、ssa(100%)、sme Z(100%)、speG(100%)。所有菌株均携带大环内酯类耐药基因ermB和ermTM、四环素耐药基因tet(M),均不携带耐药基因mefA,对红霉素、克林霉素、四环素耐药率100%,对青霉素仍保持高度敏感。系统进化树分析显示,海南分离株均集中在同一分支上。结论 2022年海南GAS优势基因型为emm12型,MLST分型与emm分型具有一致性。携带的耐药基因与药敏实验结果一致,海南地区青霉素等β-内酰胺类药物可继续作为GAS临床治疗首选药物,需扩大菌株量进一步监测。Objective To understand the genomic characteristics and sensitivity to currently commonly used antibacterial drugs of group A Streptococcus(GAS)emm12 in Hainan,and to provide etiological data for GAS-related diseases such as scarlet fever.Methods Based on the throat swab isolates of GAS obtained from respiratory syndrome surveillance in Hainan Province in 2022,next-generation sequencing(NGS)was used to conduct genome sequencing,emm genotyping,gene multi-locus sequence typing(MLST),mobile genetic element annotation,drug resistance gene and virulence gene prediction.The phylogenetic tree was constructed using the maximum likelihood(ML)method of MEGA 10.1.8.Minimum inhibitory concentration(MIC)values were determined using the microbroth dilution method for antimicrobial susceptibility testing.Results The four GAS isolates from the 2022 Hainan respiratory syndrome surveillance were all emm12/ST36 types.In addition to the emm gene,a total of 7 superantigen genes were detected:speB(100%),speI(75%),speH(75%),speC(100%),ssa(100%),smeZ(100%),and speG(100%).All strains carried the macrolide resistance genes ermB and ermTM,and tetracycline resistance gene tet(M),none of them carried the resistance gene mefA.The resistance rates to erythromycin,clindamycin,and tetracycline were 100%,while high sensitivity to penicillin was maintained.The phylogenetic tree showed that the Hainan isolates clustered on the same evolutionary branch.Conclusions In 2022,the dominant genotype of GAS in Hainan is emm12 type,with consistency between MLST and emm typing.The carried resistance genes are consistent with the drug susceptibility test results.β-lactam drugs such as penicillin can continue to be the first choice for clinical treatment of GAS in Hainan,and further monitoring with an expanded number of strains is needed.

关 键 词：猩红热 A族溶血性链球菌 emm12型 超抗原 药物敏感性 

分 类 号：R378.12[医药卫生—病原生物学]