艰难梭菌感染防治措施的研究进展

艰难梭菌是革兰阳性厌氧芽孢杆菌,芽孢位于菌体次极端,可在体外存活数月以上[1].艰难梭菌可在人体肠道无症状定植,也可引发轻度至重度腹泻、伪膜性肠炎(PMC),严重者可导致死亡.艰难梭菌通过产生肠毒素A(TcdA)和细胞毒素B(TcdB)这两种毒素致病,TcdA 和 TcdB 是导致上皮细胞坏死和炎症的主要原因[2].抗菌药物是艰难梭菌感染(CDI)的首选治疗手段,也是公认的艰难梭菌相关性腹泻(CDAD)的危险因素,长期使用抗菌药物会导致肠道菌群失调,引起芽孢萌发[3].     

抑郁、焦虑状态人群的肠道菌群构成

目的:探讨抑郁、焦虑状态人群与健康人群肠道菌群组成的差异.方法:选择2017年5月至2018年4月复旦大学附属中山医院全科和心理门诊收治的237例就诊者,根据抑郁症筛查量表(patien health questionnare,PHQ-9)和广泛性焦虑障碍量表(generalized anxiexy disorde-7...     

重症监护室肺部感染患者肠道菌群特征分析

目的 探究重症监护室(ICU)肺部感染患者的肠道菌群特征,为肺部感染的危重症患者微生态靶向治疗提供借鉴。方法 收集2021年3-9月入住重庆高新区人民医院ICU的肺部感染患者粪便样本78例,ICU非肺部感染患者粪便样本22例,健康人群的粪便样本40例,采用16S rRNA测序技术对粪便菌群进行检测鉴定,通过生物信息学方法比较并分析ICU肺部感染患者肠道菌群结构特征。结果 ICU肺部感染患者的肠道微生物与健康人群相比,alpha多样性显著降低。ICU肺部感染患者肠道菌群以厚壁菌门、拟杆菌门、普雷沃菌属和拟杆菌属为主。处于极度失调(单一菌群丰度>50%)的ICU肺部感染患者的肠道菌群主要富集了普雷沃菌属、拟杆菌属、肠球菌和埃希菌等细菌。LEfSe分析提示,疣微菌科是ICU肺部感染患者肠道菌群中的标志性微生物。ICU肺部感染患者与健康人群相比,糖类和氨基酸代谢通路有所降低。另外,患者年龄结构、体质量指数、急性生理与慢性健康评分系统Ⅱ评分和住院时间与部分肠道菌群存在紧密联系。结论 ICU肺部感染患者与健康人群相比,肠道菌群多样性显著降低。ICU肺部感染患者中肠道菌群极度失调者,可能由于感...     

艰难梭菌肠炎的诊疗进展

由于抗生素不合理使用,抗生素相关性肠炎(AAC)的发病有日益增多的趋势,已引起了广大医务工作者的高度重视.而引起AAC的主要病原菌是艰难梭菌(CD)[1],CD是一种条件致病菌,约占正常人肠道菌的3%,为革兰阳性厌氧杆菌,易产生耐药性.国内外很多学者做了相关临床研究和动物实验学研究,探索了一些效价比较好的治疗方法,取得了一定进展,本文就其治疗进展进行综述.     

GeneXpert实时荧光定量PCR快速检测艰难梭菌的临床评估

目的对GeneXpert实时荧光定量聚合酶链反应(PCR)在快速检测临床粪便标本中艰难梭菌的应用进行评估。方法采用双拭子蘸取临床未成形粪便标本,一支拭子用于GeneXpert实时荧光定量PCR检测艰难梭菌毒素基因tcdB,另一支用于常规厌氧菌培养检测;对GeneXpert实时荧光定量PCR检测结果与常规厌氧菌培养结果的一致性进行统计学分析,并计算GeneXpert实时荧光定量PCR的敏感性、特异性、阳性预测值和阴性预测值等参数。结果临床收集到141例未成形粪便标本,GeneXpert实时荧光定量PCR检出艰难梭菌毒素基因tcdB阳性42例,其中常规厌氧菌培养阳性34例,两者一致性较好(Kappa=0.775 0,P0.01),GeneXpert实时荧光定量PCR的敏感性、特异性、阳性预测值和阴性预测值分别为87.2%、92.2%、81.0%和94.9%。结论 GeneXpert实时荧光定量PCR直接检测粪便标本中的艰难梭菌具有检测快速、操作简便等优点,有重要的临床应用价值。     

16S rRNA基因和ERIC指纹图谱技术对溃疡性结肠炎肠道菌群的分析研究

溃疡性结肠炎是一种反复发作、病因和发病机制尚不十分明确的慢性非特异性炎症性肠病。肠道菌群的变化在其发病中起重要作用。随着微生态学及分子生物学发展,以16SrRNA、肠道细菌基因间重复序列(enterobacterial repetitive intergenic consensus,ERIC)为基础的PCR扩增技术已经应用于溃疡性结肠炎肠道菌群的分析。本文就近年来16S rRNA和ERIC指纹图谱技术对溃疡性结肠炎肠道菌群的分析研究进展作一综述。     

艰难梭菌在肠道不同状态下危险因素分析

目的 分析艰难杆菌在肠道不同状态下的危险因素.方法 回顾性分析2019年3月至2019年5月首都医科大学附属北京友谊医院进行粪便检查的432例住院患者的临床资料,均取粪便标本进行艰难杆菌培养,统计艰难杆菌感染患者腹泻的发生率,将有腹泻症状患者设为艰难杆菌腹泻组(29例),将无腹泻症状患者设为艰难杆菌无症状定植组(25例...     

脓毒症患者肠道菌群多样性和结构变化分析北大核心CSCD

目的探讨脓毒症患者发病过程中肠道菌群多样性和结构变化情况。方法对2015年11月至2016年3月期间于北京市多家三甲医院急诊科就诊并符合Sepsis3.0诊断标准的脓毒症患者25例和同时期30例非脓毒症患者的粪便样本进行检测,利用16S rRNA(16S ribosomal RNA)测序技术对肠道菌群进行测序,使用Uparse、Qiime、R及LEfSe软件等分析菌群多样性及其结构变化。结果脓毒症组和非脓毒症组患者在性别、年龄以及慢性基础疾病方面比较差异无统计学意义。两组在肠道菌群多样性方面比较差异无统计学意义(P>0.05)。两组在肠道菌群结构方面比较,差异有统计学意义(P<0.05),即脓毒症组患者肠道菌群中Negativicutes纲、Selenomonadales目、Veillonellaceae科、Lachnospiraceae科、Faecalibacterium属、Hafnia属、Lachnoclostridium属、Blautia属及Ruminococcus种的菌群丰度明显降低;而Bacilli纲、Coriobacteriia纲、Lactobacillales目、Coriobacteriales目、Clostridiaceae科、Coriobacteriaceae科、Clostridium_sensu_stricto属、Collinsella属及Collinsella_aerofaciens种的菌群丰度明显增加。结论脓毒症组与非脓毒症组患者相比较,肠道菌群多样性无改变;而脓毒症组的患者存在肠道菌群组成结构改变。     

TaqMan实时荧光定量PCR检测艰难梭菌

目的 建立特异敏感的实时荧光定量PCR方法,用于艰难梭菌的快速检测;评价基于纯培养艰难梭菌和粪便中艰难梭菌的2种标准曲线;并应用该荧光定量PCR法对急性艰难梭菌感染（CDI）的小鼠进行粪便含菌量检测评价。方法 针对艰难梭菌基因组中16S rRNA序列设计特异性引物和探针,建立一套快速检测艰难梭菌含量的实时荧光定量PCR方法,验证方法的特异性、灵敏性;绘制艰难梭菌纯菌浓度梯度稀释标准曲线和粪便中同浓度梯度艰难梭菌的标准曲线,比较两者的差异;用艰难梭菌高毒株NAP1/027感染用抗生素处理的C57BL/6小鼠,建立CDI小鼠模型,同时应用该荧光定量PCR和活菌培养法定量检测小鼠粪便中的艰难梭菌含量变化。结果 建立的TaqMan实时荧光定量PCR具有较高的灵敏性和特异性,生成标准曲线的相关系数为0.999 8,斜率为-3.400 4;用纯培养艰难梭菌和粪便中艰难梭菌分别制备标准曲线,结果表明2种标准曲线定量检测结果差异无统计学意义。建立CDI小鼠模型,应用该荧光PCR能有效、准确的检测出粪便中艰难梭菌的含量,可替代费时费力的活菌培养计数法。结论 用纯培养艰难梭菌来制备标准曲线不影响对含菌粪便标本的准确定量检测,荧光定量PCR能准确快捷地检测CDI小鼠粪便中的艰难梭菌含量,比活菌计数更快速和方便,可用于艰难梭菌感染小鼠模型中小鼠肠道内艰难梭菌定植的定量检测。     

Influence of various antimicrobial agents on the intestinal flora in an intestinal MRSA-carrying rat model

Using an intestinal methicillin-resistant Staphylococcus aureus (MRSA)-carrying rat model, we compared the influence of piperacillin (PIPC) on the intestinal flora to those of cefazolin (CEZ), cefmetazole (CMZ), and flomoxef (FMOX). The number of MRSA did not increase after PIPC and CEZ administrations compared with the nontreated group. However, it significantly increased in the cases of FMOX and CMZ administration (P < 0.01). In the FMOX- and CMZ-treated groups, the intestinal flora was severely disrupted and the recovery of the number of Escherichia coli and Bacteroides spp. cells was delayed. On the other hand, in the PIPC- and CEZ-treated groups, the rapid recovery of bacteria that composed the intestinal flora was observed. The C_max/MIC₅₀ and C_trough/MIC₅₀ ratios in E. coli and Bacteroides spp. in the case of FMOX and CMZ were relatively higher than those in the case of the PIPC- and CEZ-treated groups.     

Changes in intestinal flora after administration of panipenem/betamipron or sulbactam/cefoperazone for treatment of postoperative infections in gastrectomy patients

To determine the effect of antibiotics used for the treatment of postoperative infections on the normal intestinal flora in patients who have undergone gastroenterological surgery, we performed a prospective randomized study in patients who had undergone distal gastrectomy. Cefazoline was administered up to postoperative day 3 for prophylaxis. For the treatment of postoperative infections, either panipenem/betamipron (PAPM/BP; n = 5) or sulbactam/cefoperazone (SBT/CPZ; n = 5) was adminstered to ten patients with signs of postoperative infections. Feces were examined for bacteria before and 4 and 7 days after the commencement of administration of these therapeutic antibiotics. The anaerobic bacterial count decreased significantly in four of five patients treated with SBT/CPZ, from 10^10.2±0.36/g before treatment to 10^5.22±3.51/g. In the PAPM/BP-treated group, the anaerobic bacterial count did not change after antibiotic therapy. We also investigated the major genera of colonic anaerobes, and found that the numbers of bifidobacteria were maintained during PAPM/BP administration. However, in the SBT/CPZ group, the number of bifidobacteria decreased to below the detection limit in four of five patients. Little change was observed in the aerobic bacterial count in either group. However, Enterobacteriaceae were replaced by enterococcus or candida in all patients from the SBT/CPZ group and in one of five patients from the PAPM/BP group. Physicians should be alert for the possible clinical consequences of changes in intestinal microflora after antibiotic treatment of postoperative infections. Received: June 29, 1998 / Accepted: November 5, 1998     

实时荧光定量PCR在测定艾滋病患者肠道菌群量变化中的应用及意义

目的:应用实时荧光定量PCR观察艾滋病患者肠道菌群量的变化,研究艾滋病对肠道微生态的影响及其在发病中的作用。方法:分别设计双歧杆菌属、乳酸杆菌属、大肠杆菌、粪肠球菌及屎肠球菌的特异性引物。收集艾滋病患者粪便标本30份及正常对照标本30份,提取细菌基因组DNA,应用实时荧光定量PCR反应测定5种细菌的数量。结果:艾滋病患者组双歧杆菌属、乳酸杆菌属的数量较正常对照组明显减少;大肠杆菌、粪肠球菌、屎肠球菌数量明显增多,差异有统计学意义(P<0.05)。结论:艾滋病患者肠道微生态发生了明显变化,提示艾滋病患者肠道微生态紊乱。     

口服微生态制剂对直肠癌患者术后肠道菌群分布及SIgA的影响

目的探讨低位直肠癌患者行腹、会阴联合直肠癌根治术(Miles术)术后口服微生态制剂对肠道菌群及粪便分泌型免疫球蛋A(SigA)含量的影响。方法将126例Miles术后患者采用随机化原则分成观察组和对照组,每组各63例。观察组患者术后给予口服双歧三联活菌胶囊(培菲康胶囊),对照组常规治疗。分别于入院时、术后第一次排便、术后1个月收集两组患者的新鲜大便,比较两组患者的肠道菌群的改变及粪便SIgA含量。结果术后第一次排便及术后1月观察组双歧杆菌、乳酸杆菌、拟杆菌数量显著高于对照组(P0.05),而肠球菌、肠杆菌数量均显著低于对照组(P0.05)。术后1个月,观察组患者的肠道菌群与手术前相比,基本恢复(P0.05)。术前及术后第一次排便,两组患者粪便中的SIgA水平无显著差异(P0.05);而术后1个月,观察组粪便SIgA含量均显著高于对照组(P0.05),且恢复至术前水平,而对照组仍低于术前水平。结论直肠癌Miles手术后口服微生态制剂可有效纠正患者肠道菌群失调,并通过升高粪便SIgA含量恢复肠道屏障功能和局部免疫力。     

低聚果糖对双歧杆菌增殖效果及肠道菌群的影响

目的　分析低聚果糖体外对双歧杆菌的增殖效果,及体内对肠道菌群的影响。方法　在厌氧菌液体 培养基中加入低聚果糖,观察双歧杆菌的增殖情况;用培养方法检测肠道菌群。结果　在厌氧菌液体培养基中 加入低聚果糖前后双歧杆菌菌数分别为1.5亿/ml和3亿/ml;服用低聚果糖后,35～50患者肠道内肠杆菌及类 杆菌显著减少,50岁以上者肠道内双歧杆菌显著增多。结论　低聚果糖对双歧杆菌有增殖效果,对人体肠道菌 群具有一定的调节作用。     

Impact of toxigenic Clostridium difficile polymerase chain reaction testing on the clinical microbiology laboratory and inpatient epidemiology

Conversion from Clostridium difficile toxin A/B EIA to tcdB polymerase chain reaction for diagnosis of C. difficile infection (CDI) resulted in significant decreases in laboratory testing volume and largely unchanged C. difficile toxin detection rates. Decreases in healthcare-associated CDI rates (P ≤ 0.05) reflected a clinical practice benefit of this conversion.     

Clinical characteristics of infections caused by Roseomonas species and antimicrobial susceptibilities of the isolates

Human infections due to Roseomonas species are uncommon and the vast majority of reported infections are opportunistic and easy to treat. We retrospectively reviewed the computerized database of the Bacteriology Laboratory at the National Taiwan University Hospital to identify patients with infections caused by Roseomonas species during the period January 2000 to December 2010. Isolates of Roseomonas species were confirmed by 16S rRNA gene sequencing analysis. During the study period, 20 patients had cultures positive for Roseomonas species. R. mucosa was the most prevalent isolate (n = 18), followed by 1 each of R. gilardii and Roseomonas genomospecies 5. True infection caused by Roseomonas species was confirmed in 17 (85%) patients. Most (n = 12, 71%) of these infections were health care-associated infection. The majority of the patients (n = 12, 71%) had underlying diseases. Malignancy was the most common underlying disease, and catheter-related bloodstream infection was the most common type of infection. The antimicrobial susceptibility patterns varied among the different Roseomonas species. In conclusion, Roseomonas species can cause infection in children and adults regardless of immune status. Because different Roseomonas species may have different clinical features and susceptibility profiles, molecular studies are necessary to identify Roseomonas isolates to the species level.     

中国麻风分枝杆菌种型分布与特征

目的了解中国目前传播的麻风分枝杆菌(M.leprae)菌种及单核苷酸多态性(SNPs)型分布与特征。方法对来自中国22个省市171例麻风患者皮损组织样本,采用巢式PCR扩增麻风分枝杆菌特异16S rRNA保守片段,并对PCR阳性产物直接测序,经BLAST进行序列比对;采用PCR产物限制性酶切基因多态性方法对麻风分枝杆菌进行SNP分型。结果 171例标本扩增片段与来自巴西的麻风分枝杆菌Br4923相似性达99%,均为M.leprae,未检出M.lepromatosis。在85例SNP分型标本中,SNP3型、SNP1型和SNP2型分别占78.8%(67/85)、20%(17/85)和1.2%(1/85),未检出SNP4型。130例16S rRNA序列存在C251T位碱基变异,不同临床型别标本中16S rRNA序列突变及SNP型别分布差异无统计学意义;16S rRNA基因C251T突变与麻风分枝杆菌菌株的SNP分型有一定的关联,存在突变的菌株多为SNP3型,少见SNP1型,未见SNP2型;不同地区的SNP型别分布之间差异有统计学意义,内陆地区的SNP3型菌株分布率97.1%(34/35)显著高于沿海66%(33/50)(χ~2=11.96,P0.01)。不同地区的16S rRNA序列突变率差异也有统计学意义,内陆地区的16S rRNA突变率94.8%(92/97)显著高于沿海51.4%(38/74)(χ~2=43.56,P0.01)。结论麻风分枝杆菌16S rRNA基因序列突变C251T与SNP分型有关,可提示不同基因型麻风分枝杆菌的地理分布。未发现麻风分枝杆菌M.lepromatosis菌种。     

溃疡性结肠炎患者及其配偶的肠道菌群构成与多样性分析

目的比较同一生活环境下溃疡性结肠炎(UC)患者与其配偶(UF),及健康人群的肠道菌群差异,探讨生活环境对UC患者肠道菌群的影响。方法招募UC患者8例、同一生活坏境下患者配偶8例及普通健康人群8例,分为UC组、UC配偶组(UF组)、健康人群组(ZC组)。分别收集三组人群的粪便样本,通过16SrRNA基因测序技术进行菌群分析,比较三组样本间肠道菌群的差异性。结果肠道菌群多样性分析表明三组间菌群丰富度及群落多样性差异无统计学意义(P>0.05)。肠道菌群构成分析表明在属分类水平上,ZC组及UF组中考拉杆菌属的相对丰度比UC组增高(P<0.05);ZC组及UC组中锥形杆菌属的相对丰度比UF组降低(P<0.05);UC组及UF组中奥尔森菌属、霍尔德曼菌属、克雷伯菌属的相对丰度比ZC组增高(P<0.05)。结论考拉杆菌属、奥尔森菌属及克雷伯菌属可能是预测UC肠道菌群失调及疾病预后的生物学标志物。生活环境会影响UC患者肠道菌群变化,但并不是UC发病的决定性因素。