1例产后哺乳期腹泻患者分离单增李斯特菌的生物学特征分析

Biological characteristics of Listeria monocytogenes ST145 strain isolated from of a lactation diarrhea case

目的分析1例单增李斯特菌所致产后哺乳期腹泻患者的临床特征、病原学、菌株的毒力基因携带及分子特征。方法搜集病例的临床相关信息;采用选择性增菌和显色培养基分离单增李斯特菌,用VITEK-2 COMPACT30全自动细菌分析仪鉴定分离菌株,采用单增李斯特菌诊断血清对分离株进行血清分型,使用脉冲场凝胶电泳技术及多位点序列分型技术进行分子分型,应用PCR检测毒力基因,并用E-test方法检测分离菌株对5种抗生素的药物敏感性。结果产后哺乳期患者食用甜瓜和冰箱冷藏的酸奶后引起不能自限的腹泻,检测结果证实病原为4b血清型、ST145序列型单增李斯特菌。分离菌株携带毒力基因plcB、act、hly、iap、prfA、inlA,对青霉素、氨苄西林、美罗培南、红霉素和复方磺胺均敏感。结论单增李斯特菌引起的腹泻患者容易漏诊,加强孕妇等高危人群腹泻患者粪便标本中单增李斯特菌的检测,对于单增李斯特菌病病人的及时治疗,预防不良预后具有重要的公共卫生意义,尤其对这一特殊型别单增李斯特菌在我国引起的病例感染应引起重视,其可能的感染来源和致病风险值得进一步的研究。

We aim to investigate the biological characteristics of the Listeria monocytogenes from a case of lactation diarrhea,including molecular characteristics and virulence gene carrying the strain.The clinical information of patient was collected.The isolated strain was identified by VITEK-2 COMPACT30 automatic bacterial analyzer identification system,and characterized by serotyping,pulsed-field gel electrophoresis(PFGE)and multi locus sequence typing(MLST).The virulence genes was detected by PCR method.The five antibiotics susceptibility of the strain was tested by E-test method.Results showed that postpartum lactation patient with unrestricted diarrhea was caused by L.monocytogenes,who had eaten muskmelon and refrigerated yogurt.The isolate was belonged to serotype 4b and ST145,carrying the main virulence genes(plcB,act,hly,iap,prfA and inlA)and was sensitive to penicillin,ampicillin,mer openem,erythromycin and cotrimoxazol.The detection of L.monocytogenes in stool samples from patients with diarrhea in high-risk populations is important,which would be helpful for the timely treatment and prevention of poor prognosis.Further study about the listeriosis caused by this particular type strain is needed to be carried in China,including its possible source and infection risk.