围产期李斯特菌感染6例的临床及分子特征

Clinical and molecular characteristics of six cases of perinatal listeriosis

目的分析围产期李斯特菌感染6例的临床及其分子流行特征,为围产期李斯特菌感染的治疗、预防和控制提供参考依据。方法回顾性分析李斯特菌母婴感染病例的临床信息,对分离的病原菌进行血清学分型、脉冲场凝胶电泳分析、多位点序列分型及毒力基因检测。结果 6例孕妇出现发热、腹痛、胎动异常等症状;2例胎死宫内,4例新生儿出现胃肠炎、血流感染和脑膜炎等感染症状,其中1例新生儿出生2 d后死亡。6株产单核细胞李斯特菌有3种血清型(4b、1/2b和1/2a)、4种ST型(ST1、ST2、ST5和ST91)和5种PT型(pulsotype)。毒力基因(plcB、actA、hly、iap、prfA、inlA)检测均为阳性。结论 6例围产期李斯特菌感染病例症状较为严重,胎儿/新生儿预后差。分离的产单核细胞李斯特菌以血清型4b型和ST2型为主,携带6个毒力基因,致病力强。

Objective To analyze the clinical and etiological characteristics of six cases of perinatal listeriosis in our hospital from 2012 to 2017,so as to provide reference for prevention and control of perinatal listeriosis.Methods The clinical information of the patients was retrospectively analyzed.Listeria monocytogenes isolates were characterized by serotyping,pulsed-field typing (PFGE),multilocus sequence typing (MLST) and virulence factor assay.Results Six pregnant women experienced fever,abdominal pain and abnormal fetal movements.Of six cases,two fetuses died.Four newborn infants developed symptoms of gastroenteritis,septicemia and meningitis.One newborn infant died two days after birth.Six isolates of Listeria monocytogenes were classified into three serotypes (4b,1/2b and 1/2a),four STs (ST1,ST2,ST5 and ST91) and five pulsotypes (PTs).Virulence genes (plcB,actA,hly,iap,prfA,inlA) were positive in all isolates.Conclusions The symptoms are serious in all the six cases of perinatal listeriosis.The prognosis is poor for the fetuses/neonates.The predominant isolates were serotype 4b and ST2.All isolates carried 6 virulence genes,associated with strong pathogenicity.