住院新生儿大肠杆菌分离株脉冲电场凝胶电泳分型

摘要： 目的 通过对新生儿临床分离的大肠杆菌菌株进行分型以示大肠杆菌菌株间的异质性和亲缘性,了解大肠杆菌感染的分子流行病学特征。方法 对2009年9月至2012年5月间北京儿童医院新生儿中心住院的102例患儿的110株大肠杆菌进行脉冲场凝胶电泳分型（PFGE）。结果 110株大肠杆菌临床分离株经PFGE共分65型,相似系数在47.3%～100%,条带在13～22条。优势基因型有13株,相似系数在80.4%～100%。有8对临床分离菌株分别来自于同一患儿,其中7对经PFGE分型方法证实它们属于同一型别（其中1对菌株来自于同一患儿的血液及脑脊液的标本,经PFGE分型证实属于同一基因型,相似系数为93.8%）;另1对显示不是同一型别,亲缘关系较远,故从同源性分析来看不除外不同菌株感染或污染的可能。5株菌株经PFGE证实菌株间亲缘关系较近,其中1株分离株来源的患儿曾与4株分离株来源的患儿同住一病房,考虑为院内获得性感染。结论 PFGE分型方法准确、可靠,可以协助临床明确和区分致病株与非致病株,追踪传染源,对于院内感染的防控起到重要的作用。     

住院新生儿大肠埃希菌分离株毒力因子研究

目的了解住院新生儿大肠埃希菌毒力因子的携带情况。方法收集2009年9月至2012年5月临床诊断为新生儿肺炎、败血症的连续病例,选择其中抗生素使用之前痰液、血液、脑脊液或脐分泌物培养为大肠埃希菌的病例。根据发病日龄不同,将菌株分为早发型及晚发型。根据标本来源不同,将菌株分为侵袭性感染和非侵袭性感染。选取11种最常见的毒力基因,应用PCR方法对大肠埃希菌菌株进行检测。采用Chromas软件进行读序,测序结果采用Chromas软件直接进行BLAST Search比对。结果 110株大肠埃希菌分离自102例住院新生儿,源于痰液79株(71.8%),血液18株(16.4%),脑脊液6株(5.4%),脐分泌物7株(6.4%);源于足月儿102株,早产儿8株。早发型27株,晚发型83株;侵袭性感染24株,非侵袭性感染86株。1Einv基因阳性91.8%,CNF1基因阳性21.8%,CNF2基因阳性12.7%,Eagg基因0.9%;共有7种毒力基因携带模式:单纯携带Einv基因66株,单纯携带CNF1基因1株,携带Einv-CNF1基因20株,携带Einv-CNF2基因11株,携带Einv-CNF1-CNF2基因3株,携带Einv-Eagg基因1株。8株(7.3%)11种毒力基因检测均阴性。2携带CNF1或CNF2菌株的37例患儿中22例合并呼吸衰竭,15例需予NCPAP呼吸支持,10例合并多脏器受损,3例肺出血。38对菌株分别来自同一患儿不同时期或不同部位,其中7对菌株经PFGE分型分别属于同一基因型。3对分别来源于同一患儿不同时期的痰液标本菌株,PFGE分型一致,但毒力基因携带模式不相同。结论本研究检测到4种大肠埃希菌毒力基因,以Einv基因携带率最高;共发现7种毒力基因携带模式,以单纯携带Einv基因最多见。CNF1及CNF2基因可能与肺部感染的严重性相关。     

新生儿大肠埃希菌感染的毒力因子基因检测研究

大肠埃希菌常在新生儿患者的血液甚至脑脊液和痰中分离到。为探索大肠埃希菌肠外感染的致病因素,2003年6月,我们对2001年2月-2003年2月,我们对从12例新生儿患儿临床标本分离的13株大肠埃希菌进行了毒力因子志贺样毒素(VT1、VT2、VT2e)、细胞坏死因子(CNF1、CNF2)、不耐热肠毒素(LTl)、耐热肠毒素(sTl、ST2)、肠侵袭因子(Einv)、肠聚集因子(Eagg)、A／E损伤因子(eaeA)基因检测,现报告如下：     

新生儿大肠杆菌脑膜炎

本文报告新生儿大肠杆菌脑膜炎为经脑脊液培养证实大肠杆菌引起的化脓性脑膜炎。患儿表现为体温低、或发热、嗜睡、前囟饱满、惊厥、皮肤与巩膜黄染等。见于未成熟儿与成熟儿。常有羊膜早破、胎儿宫内窘迫、急产或臀位产。免疫球蛋白测定IgA、IgM、IgG均降低。头孢噻肟钠治疗有效。     

新生儿金黄色葡萄球菌皮肤和软组织化脓性感染临床分离株分子及毒力特征

目的 监测新生儿金黄色葡萄球菌（SA）皮肤和软组织化脓性感染（SSTIs）临床分离株的分子和毒力特征,为预防和治疗新生儿SSTIs提供理论依据。方法 收集2015年5月至2016年4月首都医科大学附属北京儿童医院NICU临床诊断为SSTIs的病例,对SA分离株进行agr、MLST、spa 和SCCmec 分型;通过PCR对SA菌株进行21种超抗原毒素基因、sasX、PVL基因检测。结果 44例SSTIs新生儿,男22例,中位年龄4.5（0～22）d,均为社区获得性感染。共分离出13例SA菌株,其中MRSA 7株,MRSA最常见的克隆是agrⅠ-MRSA-ST59-SCCmecⅣa,13株SA包含2～8种超抗原基因型,最常见的毒素基因型为sek-seb-seq,有6株SA PVL基因阳性,均不携带sasX基因。结论 新生儿SSTIs中,SA携带率较低, agrⅠ-MRSA-ST59-SCCmecⅣa-t437是MRSA最主要的流行克隆,SA分离株超抗原基因携带率高。     

致病性大肠杆菌致新生儿腹泻一次流行的临床分析

1989年月3底至4月中旬该院婴儿室暴发流行性新生儿腹泻计58例,占同期产婴总数39.2％。其中重型12例,死亡3例,死亡率5.2％。病原菌为致病性大肠杆菌O_(119)B_(14),大便培养阳性率为45％。药物敏感试验新霉素高度敏感。治疗选用新霉素,禁食、补液,尤注重纠正代谢性酸中中毒及支持疗法。中度脱水酸中毒患儿阴离子隙(AG)正常,而重度脱水酸中毒患儿AG均增高,提示AG可作为腹泻合并脱水酸中毒时观察病情的客观指标。     

暴发流行新生儿产肠毒素性大肠杆菌肠炎免疫状态探讨

本文对72例暴发流行新生儿产肠毒索性大肠杆菌(ETEC)肠炎患儿各项体液免疫指标进行了测定。结果ETEC阳性组血清IgG、IgA值显著高于ETEG阴性组;ST/LT型组血清IgA、IgM值显著高于单纯LT型组;中重度脱水及酸中毒组血清IgM、IgA值显著高于轻度组;恢复期组血清IgM显著高于急性期组。提示ETEG具有较强的抗原性;ST/LT混合毒素比LT单一毒素具有更强的致病性与抗原性。     

产科新生儿室一次埃希氏大肠杆菌呼吸道感染流行分析

我院于1994年12月20日至1995年2月10日在产科新生儿室发生一次埃希氏大肠杆菌呼吸道感染的流行,现报告如下。 临床资料 一、流行情况首发病例为一有上呼吸道感染的产妇入院分娩后为新生儿授乳,次日该新生儿出现鼻塞、流涕、咳嗽等上呼吸道感染症状。母、婴的咽     

幽门螺杆菌毒力基因与致病性研究进展

幽门螺杆菌(H. pylori)感染是人类最常见的慢性细菌感染,感染了全球超过50%的人口。大部分H. pylori感染是在儿童期获得,与慢性萎缩性胃炎、消化性溃疡、胃黏膜相关淋巴组织(MALT)淋巴瘤、胃癌等疾病密切相关。此外,还可能参与多种胃肠外疾病,如缺铁性贫血、生长发育迟缓、特发性血小板减少性紫癜等。H. pylori感染给儿童健康带来极大的危害,其致病性的差异主要与其毒力基因型的多态性有关。文章综述H. pylori毒力基因的特征与致病性。     

儿童不同标本来源分离的大肠埃希菌耐药性分析

目的：对儿童不同标本进行大肠埃希菌分离培养,了解不同标本大肠埃希菌分离株的耐药率差异,以便指导临床合理使用抗菌药物。方法：收集629份2004年6月至2009 年5月儿童尿液、痰液、血液、分泌物等标本,采用VITEK-32全自动微生物鉴定药敏仪进行细菌鉴定,药敏测定采用K-B法,并比较不同标本所检出大肠埃希菌对抗菌药物的耐药率差异。结果：共检出大肠埃希菌260株,其中尿108 株,痰64株,分泌物54株,血液23株。大肠埃希菌株ESBLs、AmpC、同产ESBLs+AmpC检出率分别为36.9%、12.3%和3.1%,其中痰液大肠埃希菌分离株ESBLs检出率明显高于其他标本（P<0.05）,不同标本的大肠埃希菌分离株对阿莫西林/克拉维酸、替卡西林/克拉维酸、哌拉西林、头孢噻肟、头孢呋辛、头孢吡肟、庆大霉素、复方新诺明、呋喃妥因的耐药率不同,其中痰液分离株的耐药率明显高于其他标本（P<0.05）。结论：儿童不同标本分离的大肠埃希菌对多种抗菌药物耐药率不同,建议临床医师在治疗不同标本来源分离培养的大肠埃希菌引起的感染时,应根据药敏结果合理使用抗菌药物。［中国当代儿科杂志,2010,12（5）：348-350］     

Cerebral venous thrombosis and Escherichia coli infection in neonates

AIM: To present a possible association between cerebral venous thrombosis (CVT) and infection with Escherichia coli. METHODS: Four neonates with deep CVT occurring during an E. coli infection are presented. RESULTS: In these patients the thrombotic disease was found by Doppler ultrasonography. The thrombosis involved at least the sagittal sinus and the transverse sinus according to subsequent MRI scans. The E. coli strains did not produce verotoxin or haemolysin. Disseminated intravascular coagulation was not demonstrated. Three patients presented with seizures. At discharge, all of the patients had signs of neurological damage, but two of them have improved significantly since then. None of the patients has had recurrent (venous) thrombosis. CONCLUSION: E. coli infections in neonates may predispose to CVT, a finding that has clinical implications.     

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??Abstract??Objective To investigate the molecular epidemiology of Escherichia coli isolated from neonates in Bejing Children’s Hospital. Methods Pulsed field gel electrophoresis??PFGE?? typing was conducted for 110 strains of Escherichia coli clinical isolates from 102 neonates hospitalized at the Neonatal Center of Beijing Children's Hospital from September 2009 to May 2012. Results Totally 110 strains of Escherichia coli isolated by PFGE typing were divided into 65 types??the similarity coefficient between 47.3%??100%.Dominant gene type contained 13 stains??similarity coefficient between 80.4%??100%. There were 8 pairs of clinical isolates strains from the same neonatal patient??7 pairs of which were confirmed by PFGE typing methods that they belonged to the same type??1 of which isolated from the same neonatal patient with cerebrospinal fluid and blood??belonging to the same genotype??the similarity coefficient being 93.8%??. The other 1 pair of strains?? typed by PFGE method?? showed that they were not the same type and were distantly related. It meant that they were different strains infection or contamination. Five of strains by PFGE typing confirmed that genetic relationship was close??and 1 of them had ever shared the same ward with the other 4 strains. Conclusion PFGE technique is accurate and reliable??PFGE study is helpful for clinicians to confer and distinguish the pathogenic strains?? and trace the source of infection. It plays an important role in preventing the occurrence of nosocomial infections.     

新生儿大肠埃希菌化脓性脑膜炎临床特点及耐药性分析

目的了解新生儿大肠埃希菌化脓性脑膜炎的临床特点及耐药性情况。方法回顾性分析2004年6月—2014年6月收治的46例新生儿大肠埃希菌化脓性脑膜炎的临床资料,46例新生儿分为社区感染组和院内感染组,以及2004年6月—2009年5月的早期组和2009年6月—2014年6月的晚期组,分别比较临床表现及产超广谱β内酰胺酶(ESBLs)检出率和药敏试验结果。结果患儿均以发热或体温不升,反应差,少吃或拒乳,呼吸、心率增快为临床表现。院内感染组ESBLs检出率明显高于社区感染组,晚期组ESBLs检出率明显高于早期组,差异均有统计学意义(P??0.05)。院内感染组对常用的头孢菌素类抗生素耐药性明显高于社区感染组,晚期组对常用的青霉素类、头孢菌素类抗生素耐药性明显高于早期组,差异均有统计学意义(P??0.05)。结论新生儿大肠埃希菌化脓性脑膜炎临床表现不典型,近年来大肠埃希菌对青霉素类及头孢菌素类抗生药物的耐药性显著上升,院内感染是获得ESBLs的高危因素。     

Neonatal escherichia coli infections: concerns regarding resistance to current therapy

Currently recommended antibiotic treatment of suspected neonatal sepsis is ampicillin and an aminoglycoside. Recently, we observed increasing ampicillin and gentamicin resistance in strains of Escherichia coli isolated from neonates at our institution. We therefore reviewed clinical and laboratory records of all neonates with systemic infection, hospitalized from 1994 through 1998, from whom E. coli was isolated from blood and/or cerebrospinal fluid. The influence of perinatal variables (e.g. rupture of foetal membranes > 24h, group B Streptococcus (GBS) colonization, urinary tract infection during pregnancy and the use of antepartum and/or intrapartum antibiotics), and neonatal variables (e.g. gestational age, age at onset of sepsis (early: < or = 72 h, late: >72 h), number of E. coli septic recurrences, and associated underlying medical and/or surgical conditions) on antimicrobial susceptibilities of invasive E. coli isolates was studied. Twenty-three neonates with invasive E. coli infection were identified; most [19 (83%)] presented as late-onset sepsis (LOS). Ampicillin-resistant E. coli were isolated in 75% and 53% of neonates in the early- and late-onset groups, respectively. Gentamicin resistance was found in 50% of early-onset sepsis (EOS) isolates compared with 16% in the late-onset group. Isolates from two neonates with EOS were resistant to both ampicillin and gentamicin. One neonate with EOS and three with LOS had recurrent E. coli sepsis; all isolates were ampicillin-resistant and one was gentamicin-resistant. All these neonates were initially treated with ampicillin and gentamicin. Both groups had associated underlying medical and/or surgical conditions (50% early-onset, 47% late-onset). Maternal GBS colonization occurred in 2 (50%) versus 3 (16%) of EOS and LOS cases, respectively. All GBS colonized women received intrapartum ampicillin prior to delivery. CONCLUSIONS: Ampicillin and gentamicin resistance is emerging in neonatal E. coli isolates from invasive infection. Current- empiric management of neonatal sepsis requires re-evaluation given changing antimicrobial susceptibilities.     

Factors influencing the development of hemolytic uremic syndrome caused by enterohemorrhagic Escherichia coli infection: From a questionnaire survey to in vitro experiment

Enterohemorrhagic Escherichia coli (EHEC) is known as an etiological agent of not only hemorrhagic colitis, but also hemolytic uremic syndrome (HUS) and other serious complications. In this paper, a summary of the results, especially in relation to possible factors involving HUS complication, of a questionnaire survey conducted on the occasion of the massive EHEC outbreak in Sakai city in 1996, is presented. A brief review of the virulence factors and pathogenic mechanism involved in the development of HUS in EHEC infection is also described.     

Enteroinvasive Escherichia coli (EIEC) in sporadic diarrhea in Delhi

Rectal swab/stool specimens of 104 children with diarrhea and 31 healthy controls were processed by routine bacteriological methods. Escherichia coli was grown as predominant flora on primary culture in 32 patients and 7 controls. Three representative colonies from each of these were selected at random and tested for invasive character by their ability to produce keratoconjunctivitis in guinea-pig eye and invasion of HeLa cells. Isolates from only 2 patients and none of the controls were found to be invasive. Enteroinvasive E. coli (EIEC) appear to be a relatively uncommon cause of sporadic diarrhea among children in this region.     

Escherichia coli brain abscess in a twin pair associated with TLR4 gene mutation

Brain abscesses are uncommon complications of bacterial meningitis or sepsis in neonates and infants. The causative pathogens of brain abscess in newborns are various. Of those, Escherichia coli is rarely seen as a pathogen in brain abscess at this age. Herein we reported brain abscesses in twin infants caused by E. coli sepsis. Interestingly, genetic analysis identified heterozygous Toll‐like receptor 4 (TLR4) gene mutation in the twins. Because TLR plays an important role in the natural response to bacterial products and initiates specific immune response against these pathogens, this may explain the development of brain abscess in the present case.     

Molecular analysis of enterohemorrhagic Escherichia coli isolates in Japan and its application to epidemiological investigation

Many outbreaks of enterohemorrhagic Escherichia coli (EHEC) O157 infections occurred in Japan in 1996. Molecular epidemiological analyses of the isolates by methods such as XbaI-digested, pulsed-field gel electrophoresis (PFGE), revealed that a variety of PFGE type strains have spread all over Japan. They also showed that such molecular methods are very useful for confirming the epidemiologically related isolates and in assisting the epidemiological investigation. Recent characteristic features of the infection are that the incidence of patients experiencing symptoms such as abdominal cramps, diarrhea and hemorrhagic colitis is higher in children younger than 9 years old; however, that of asymptomatic carriers seems to be higher in adults; and that EHEC O157:H7-serotyped strains are still the main isolates, while the isolation frequency of other serotype strains, such as O26 and O111, is increasing.