粪肠球菌的临床分布及耐药性探讨

目的:本文旨在了解粪肠球菌在临床上分布特点,分析其对16种常用抗生素的耐药特点,指导临床合理选用抗生素。方法:采用全自动微生物鉴定仪VITEK-32鉴定系统,对临床标本中分离出的242株粪肠球菌进行鉴定,使用K-B法对242株粪肠球菌进行药敏试验,对其药敏数据进行统计分析。结果:在242株粪肠球菌中,泌尿系统感染最高(50.7%),其次为腹腔胆道感染(20.4%)、伤口感染(16.5%)、其他感染(12.4%);肠球菌耐药率最低者为替考拉宁(0%),其次为万古霉素(2%)、左旋氧氟沙星(11.1%)、呋喃妥因(11.5%);最高是头孢唑啉(100%),其次为复方新诺明(97.5%)、丁胺卡那霉素(95%)、克林霉素(94.6%)。结论:粪肠球菌是泌尿道、腹腔、胆道等感染的重要病原菌,且在医院感染的重要性越来越受到临床的重视,在抗感染治疗时应根据药敏试验的实际情况综合临床各方面资料,合理选用抗生素,减少耐药菌株的产生和耐药基因的传播。     

Real-time polymerase chain reaction quantification of specific butyrate-producing bacteria, Desulfovibrio and Enterococcus faecalis in the feces of patients with colorectal cancer

Background and Aim:  Bacterial metabolites produced in the bowel are potentially related to the genesis of colorectal cancer. Butyrate is protective against cancer, whereas hydrogen sulfide and oxygen free radicals can be toxic to the epithelium. The present study was designed to quantitate Eubacterium rectale , Faecalibacterium prausnitzii (both butyrate-producing bacteria), Desulfovibrio (sulfate-reducing bacteria), and Enterococcus faecalis (that produces extracellular superoxide) in the feces of patients with colorectal cancer.
Methods:  DNA was extracted from feces of 20 patients with colorectal cancer, nine patients with upper gastrointestinal cancer and 17 healthy volunteers. Real-time polymerase chain reaction using primers aimed at 16S rDNA was used to quantitate the above bacterial species or genus, and this was expressed relative to amplification of universal sequences conserved among all bacteria.
Results:  Levels of E. rectale and F. prausnitzii were decreased approximately fourfold ( P  = 0.0088 and 0.0028, respectively) in colorectal cancer patients compared to healthy control volunteers. Levels of Desulfovibrio were not significantly different between the three groups. E. faecalis populations were significantly higher in colorectal cancer patients compared to healthy volunteers ( P  = 0.0294).
Conclusions:  Butyrate producers were decreased and E. faecalis increased in the feces of colon cancer patients. These shifts in the colonic bacterial population could potentially lead to epithelial cell damage and increased turnover and may be a factor leading to colon cancer.     

Antiviral activity of enterocin CRL35 against herpesviruses

Enterocin CRL35 is an antibacterial polypeptide of 3.5×10³ Da produced by Enterococcus faecium CRL35. A series of experiments are described that show the enterocin also had antiviral activity against thymidine-kinase positive (tk⁺) and deficient (tk⁻) strains of herpes simplex (HSV) type 1 and 2 in Vero and BHK-21 cells. This activity was observed at 100 μg/ml, 15-fold lower than the cytotoxic concentration. In both cell lines there was a 2 log inhibition of infectivity. The compound inhibited viral multiplication in a dose-dependent manner and had no virucidal effect. Enterocin CRL35 also inhibited the virion-associated host shutoff in infected Vero cells showing that intracellular viral multiplication was affected.     

肠球菌感染的临床分布特点和耐药性分析

目的分析肠球菌在临床标本中的分布及对常用抗菌药物的耐药性,为临床治疗提供参考。方法应用Vitek微生物系统回顾性统计分析近3年我院肠球菌的分离及耐药情况。结果肠球菌的分离率为2.75%,分类以粪肠球菌为主,其次为屎肠球菌;肠球菌属对利福平、四环素、红霉素、莫西沙星、左氧氟沙星耐药率较高。而对万古霉素、利奈唑烷、替考拉宁仍然保持良好的敏感性。粪肠球菌对青霉素、氨苄西林、呋喃妥因、高浓度庆大霉素(GM500)、高浓度链霉素(S2000)的耐药率分别是23.3%,24.4%,12.2%,46.7%,38.8%,低于屎肠球菌的80%,84%,28%,68%,56%(p<0.05);屎肠球菌对四环素、氯霉素的耐药率分别为48%,28%低于粪肠球菌的85.6%,44.4%(p<0.05);结论临床标本中,肠球菌在泌尿生殖道标本中的分布最高,粪肠球菌和屎肠球菌的耐药谱明显不同,在重症感染时可选用万古霉素、替考拉宁、利奈唑烷进行治疗。     

肠球菌的耐药性及脉冲场凝胶电泳分型研究

目的研究临床分离的肠球菌对常用抗生素的耐药性及肠球菌与感染性疾病的关系。方法应用纸片扩散法检测从临床标本中分离的３１１株肠球菌的耐药性；脉冲场凝胶电泳（ＰＦＧＥ）对细菌分型；病例回顾性分析。结果肠球菌对临床常用的１５种抗生素的耐药率以万古霉素最低；其次为氨苄西林／舒巴坦耐药率为１７．４％；亚胺硫霉素耐药率为１８．３％。粪肠球菌与屎肠球菌对抗生素的耐药率有明显差异。应用ＰＦＧＥ法将粪肠球菌分为Ａ型及亚型、Ｂ型、Ｃ型及亚型、Ｄ型，屎肠球菌分为Ａ、Ｂ、Ｃ型。结论肠球菌对临床常用的１５种抗生素的敏感性以万古霉素最敏感。肠球菌引起的不同系统感染，以泌尿系统最常见。ＰＦＧＥ对肠球菌感染流行监测是一个有力的工具。     

杭州市五家医院万古霉素耐药肠球菌耐药转座子结构及分子分型

目的 明确万古霉素耐药肠球菌(VRE)耐药转座子结构及分子分型.方法 收集2006年4月至2007年4月杭州市5家医院21株VRE菌株,用Etest法进行抗菌药物的药敏试验,并通过PCR、接合试验、质粒提取、耐药转座子结构、脉冲凝胶电泳(PFGE)、多位点序列分型(MIST)及多位点串联重复序列分型(MLVA)进行研究.结果 21株VRE基因型及表型均符合vanA.属于10个不同的PFGE型,7个不同的MLST分型,4个不同的MLVA分型,其中18株属于克隆复合体CC17,另外3株为ST343与CC17接近.所有VRE菌株均对利奈唑胺及替加环素敏感.多对引物对转座子的不同区域的PCR扩增并进行序列拼接、比对,发现其中2株VRE菌株携带典型的耐药转座子Tn1546,其余19株VRE菌株均携带一种新的与Tn1546相似耐药转座子,均在vanXY之间反向插入IS1485.18株VRE菌株均可通过滤膜接合试验进行万古霉素耐药转移,接合菌均含有约54 000 bp大小的质粒.结论 杭州市5家医院21株VRE菌株均为vanA表型及基因型,发现了一种新的万古霉素耐药转座子结构.21株VRE菌株经MLST分型属于7个不同的序列分型,属于或接近易在医院环境里生存并在近年来迅速造成了全球播散的克隆复合体CC17.     

儿童患者中分离的746株肠球菌耐药性分析

目的分析我院2001-2005年儿童患者临床标本中分离的肠球菌对10种常用抗菌药物的耐药性。方法药敏试验采用Kirby—Bauer琼脂扩散法，Nithocefin纸片检测β内酰胺酶，数据处理采用WHONET5．3软件。结果746株肠球菌中粪肠球菌、屎肠球菌和坚韧肠球菌分别占47．8％、47．2％和2．1％。未出现对万古霉素和替考拉宁耐药株，住院标本中分离的粪肠球菌对氨苄西林、环丙沙星、高浓度庆大霉素和高浓度链霉素的耐药率高于门诊标本分离株（P〈0．01），住院标本中屎肠球菌对氨苄西林的耐药率高于门诊标本（P〈0．05）；除万古霉素、替考拉宁、红霉素、高浓度链霉素外，屎肠球菌对其他常用抗菌药的耐药率明显高于粪肠球菌（P〈0．01）。结论儿科肠球菌感染以医院感染为主，菌株对氨苄西林、高浓度庆大霉素和红霉素有较高耐药性，对万古霉素和替考拉宁均未出现耐药株。     

301株肠球菌的分布和药敏分析

[目的]探论301株肠球菌标本的分布，了解其对12种抗生素的药敏情况。[方法]选取2004年报月-2005年12月院内感染患者分离标本，采用杭州天和公司的生化管鉴定，采用天津高达公司的药敏板进行药敏实验。[结果]301株肠球菌中粪肠菌237株（78．7％），屎肠菌61株（20．3％），其它3株（1．0％）粪肠球菌对12种抗生素呈多重耐药，61株对12种抗生素呈多重耐药，较粪肠球菌更为严重，未发现耐万古霉素肠球菌。[结论]肠球菌是重要的院内感染病原菌，由于其多重耐药越来越来成为临床治疗的难题，需要引起我们的重视。     

屎肠球菌对氨苄西林耐药pbp5基因突变的研究

目的 研究屎肠球菌对氨苄西林耐药与β内酰胺酶、pbp5基因突变的关系。方法 用硝基噻吩（nitrocefin）法检测β内酰胺酶的产生，聚合酶链反应扩增pbp5基因片段，单链构像多态性分析检测pbp5扩增片段的基因突变，测序确定突变的具体位点。结果 57株对氨苄西林耐药的屎肠球菌β内酰胺酶阴性；pbp5基因片段均有3至6个位点发生突变，485和499位点突变、466’位插入突变最为常见。结论 pbp5基因突变在屎肠球菌对氨苄西林耐药中起着重要作用。