2007至2019年儿童脑脊液培养菌种分析

Distribution of pathogen species in cerebrospinal fluid culture from 2007 to 2019

目的了解儿童脑脊液培养常见菌及其体外耐药性,为其结果解读和临床经验性治疗提供参考。方法查询实验室信息系统,回顾分析浙江大学医学院附属儿童医院2007至2019年所有脑脊液的培养结果,并通过电子病历系统追溯患儿的临床特点。结果共分离到菌株1312株(细菌1294株,真菌18株),致病菌497株(37.9%,497/1312),其中革兰阳性菌288株(57.9%),革兰阴性菌200株(40.3%),真菌9株(1.8%),前5位细菌为大肠埃希菌(20.5%,102/497)、肺炎链球菌(12.9%,64/497)、无乳链球菌(10.5%,52/497)、屎肠球菌(6.6%,33/497)和金黄色葡萄球菌(5.6%,28/497),研究年限内致病菌的分离率有逐年增高趋势(χ^(²)=34.84,P<0.001)。除肺炎链球菌感染者主要为1岁以上儿童外(76.6%,49/64),其他4种菌主要见于1岁以下婴儿[大肠埃希菌(95.1%,97/102)、无乳链球菌(98.1%,51/52)、屎肠球菌(81.8%,27/33)和金黄色葡萄球菌(71.4%,20/28)]。815株(62.1%,815/1312)为污染菌,以凝固酶阴性葡萄球菌(680株)、微球菌(50株)、棒状杆菌(28株)和屎肠球菌[23株,占屎肠球菌总数的41.1%(23/56)]为主,污染菌分离率在夏秋季较高,研究年限内其污染菌分离率逐年下降趋势明显(χ^(²)=13.26,P<0.001)。结论儿童脑脊液培养致病菌以大肠埃希菌、肺炎链球菌、无乳链球菌、屎肠球菌和金黄色葡萄球菌为主,而凝固酶阴性葡萄球菌、微球菌、棒状杆菌、屎肠球菌是脑脊液培养常见污染菌,临床医师应结合菌种类型和临床特点分析脑脊液培养的意义。

Objective To investigate the distribution of pathogen species isolated from cerebrospinal fluid culture(CSF)in children and analyze the antibiotic-resistance of the main isolates in vitro,which provides reference for interpreting the pathogens and choosing antibiotics in empiric therapy for pediatric patients.Methods The results of cerebrospinal fluid culture were collected by checking laboratory information system of the Children′s Hospital of Zhejiang University and the clinical characteristics of these children were analyzed retrospectively by checking electronic medical record system.Results A total of 1312 isolates were detected,including 1294 isolates of bacteria and 18 isolates of fungi.A total of 497(37.9%)isolates were pathogenic microorganisms,of which 288(57.9%)isolates were gram-positive,200(40.3%)isolates were gram-negative,and 9(1.8%)isolates were fungi.The top 5 pathogens were Escherichia coli(102 isolates,20.5%),Streptococcus pneumoniae(64 isolates,12.9%),Streptococcus agalactiae(52 isolates,10.5%),Enterococcus faecium(33 isolates,6.6%)and Staphylococcus aureus(28 isolates,5.6%).Most of the Streptococcus pneumoniae strains were isolated from children more than 1 year old(76.6%,49/64),while the other top 4 bacteria were mainly isolated from infants less than 1 year old,with the rate of 95.1%(97/102)for Escherichia coli,98.1%(51/52)for Streptococcus agalactiae,81.8%(27/33)for Enterococcus faecium and 71.4%(20/28)for Staphylococcus aureus.A total of 815(62.1%)isolates were considered to be contaminated pathogens according to the analysis on clinical manifestations and other laboratory findings in CSF,and coagulase-negative Staphylococcus(680 isolates),Micrococcus(50 isolates),Corynebacterium(28 isolates)and Enterococcus faecium(23 isolates),which accounted for 41.1%(23/56)of the total detected Enterococcus faecium,were the top 4 contaminated bacteria.During the study period,the isolation rate of the pathogenic microorganisms increased year by year(χ^(²)=34.84,P<0.001),while the isolation rate of the contaminated pathogens,which detected mainly in summer and autumn,decreased year by year(χ^(²)=13.26,P<0.001).Conclusions The predominant bacteria causing pediatric purulent meningitis were Escherichia coli,Streptococcus pneumoniae,Streptococcus agalactiae,Enterococcus faecium and Staphylococcus aureus.Coagulase-negative Staphylococcus,Micrococcus,Corynebacterium and Enterococcus faecium were common contaminated bacteria in CSF culture,therefore clinicians should interpret the results of CSF culture cautiously according to the bacterial species and clinical manifestations.