引起非妊娠成年患者血流感染的无乳链球菌毒力基因及分子分型研究  

Virulence gene and molecular typing of group B Streptococcus causing bloodstream infection in non-pregnant adult patients

作　　者：陈星月 刘婧娴[1] 刘瑛[1] Chen Xing-yue;Liu Jing-xian;Liu Ying(Department of Clinical Laboratory,Xin Hua Hospital,Shanghai Jiao Tong University School of Medicine,Shanghai 200092)

机构地区：[1]上海交通大学医学院附属新华医院检验科,上海200092

出　　处：《中国抗生素杂志》2023年第1期107-114,共8页Chinese Journal of Antibiotics

摘　　要：目的对上海交通大学医学院附属新华医院引起非妊娠成人患者血流感染的无乳链球菌进行毒力基因检测和分子分型研究。方法收集上海市某三甲医院2012—2020年分离的引起非妊娠成人患者血流感染的无乳链球菌(group B Streptococcus,GBS)临床菌株,通过病例系统收集相应患者的临床资料进行统计分析。采用MALDI-TOFMS对菌株进行鉴定;采用Vitek-2 Compact联合纸片扩散法(K-B法)进行药物敏感试验;采用PCR方法和琼脂糖凝胶电泳方法进行与菌株黏附、侵袭和免疫逃逸相关的毒力基因检测;采用多重PCR方法进行血清学分型;采用MLST方法进行分子分型研究,分型结果采用Bionumeric8.0软件分析菌株间亲缘关系。结果2012—2020年共分离到13株符合入组条件的GBS菌株,相应患者人群以中老年为主,占92.4%;男女比例为3.3:1,且大部分患者有心律失常、糖尿病或肝硬化等基础疾病。药敏结果提示菌株对氨苄西林、万古霉素、利奈唑胺、青霉素、头孢曲松、替加环素等抗菌药物仍然保持高度敏感,对克林霉素耐药率最高达84.6%,其次是四环素(61.5%)和红霉素(53.8%)。黏附作用相关基因中fbsB、pavA基因携带率100%,而菌毛编码基因gbsPC1的携带率最低(46.15%);侵袭力相关基因中cylX、cylD、cylG、acpC、cylZ、cylA、cylB、cylE、cylF、cylI、cylJ、cfb、hylB和bca基因的携带率100%,cylK和spb1的携带率较低分别为7.69%和38.45%,rib基因在13株菌种均未检出。免疫逃避相关基因中cpsF、cpsE、cpsD、cpsB、neuA、neuD、neuC、neuB和pbp1A的基因携带率为100%,bac、cpsJ、cpsI、cpsG的携带率较低。菌株的血清学分型以Ⅰb型为主,占38.5%(5/13);13株菌共分为10种ST型,同源性分析显示菌株亲缘关系较远。结论无乳链球菌引起非妊娠成人患者血流感染的危险因素可能为高龄、男性以及心律失常等基础疾病,菌株对克林霉素、四环素耐药率较高,且携带较多Objective To investigate the virulence genes and molecular typing of Streptococcus agalactiae which caused bloodstream infection in non-pregnant adult patients in Xin Hua Hospital,Shanghai Jiao Tong University School of Medicine.Methods The Streptococcus agalactiae(GBS)isolated from blood culture in non-pregnant adult patients,were collected from 2012 to 2020 in Xinhua Hospital,clinical data of the patients were collected from medical records for statistical analysis.The strains were identified by MALDI-TOF MS.The drug sensitivity test was performed by VITEK-2 Compact combined with paper diffusion method(K-B method).The virulence genes related to adhesion,invasion and immune escape were detected by PCR and agarose gel electrophoresis.The serotyping was performed by multiplex PCR.MLST method was used for molecular typing study,and Bionumeric 8.0 software was used to analyze the relationship among the strains.Results From 2012 to February 2020,a total of 13 strains of GBS met the inclusion criteria were collected.The majority of patients were middle-aged and elderly,accounting for 92.4%.The male-female ratio was 3.3:1,and most patients had underlying diseases such as arrhythmias,diabetes or cirrhosis of the liver.The strains were still highly sensitive to ampicillin,vancomycin,linezolid,penicillin,ceftriaxone,tigecycline and other antibiotics,but the resistance rate of clindamycin was up to 84.6%,followed by tetracycline(61.5%)and erythromycin(53.8%).In adhesion related genes,the positive rate of fbsB and pavA genes was 100%,while gbsPC1 was low(46.15%).Among the invasiveness related genes,the positive rate of cylX,cylD,cylG,acpC,cylZ,cylA,cylB,cylF,cylI,cylJ,cfb,hylB,and bca genes were 100%,while for cylK and spb1 were 7.69%and 38.45%,respectively.rib gene was not detected in 13 strains.Among the genes related to immune evasion,the positive rate of cpsF,cpsE,cpsD,cpsB,neuA,neuD,neuC,neuB and pbp1A was 100%,while for bac,cpsJ,cpsI and cpsG the positive rate was low.The main serotype in these strains wasⅠb,account

关 键 词：无乳链球菌 成人 血流感染 荚膜血清型 毒力基因 多位点序列分型 

分 类 号：R978[医药卫生—药品]