首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 93 毫秒
1.
目的 探讨上海交通大学医学院附属瑞金医院分离的5株泛耐药阴沟肠杆菌产碳青霉烯酶及16S rRNA甲基化酶的情况及两者之间的相关性.方法 用E test法检测5株泛耐药阴沟肠杆菌对10种抗菌药物的MIC值.PCR扩增16S rRNA甲基化酶基因armA、mtA、rmtB、rmtC、rmtD、npmA,β-内酰胺酶基因TEM、SHV、CTX-M-1、CTX-M-2、CTX-M-8、CTX-M-9、CTX-M-25、PER-1、VEB-1.鸟枪克隆法克隆碳青霉烯酶基因,并对克隆片段进行测序.质粒接合试验验证碳青霉烯酶基因及16S rRNA甲基化酶基因是否具有转移性.脉冲场凝胶电泳(PFGE)法对5株菌进行分子分型.等电聚焦电泳法检测β-内酰胺酶等电点.Southern杂交法对耐药决定因子进行定位.结果 5株阴沟肠杆菌对10种抗菌药物的MIC值均>32 mg/L.克隆的碳青霉稀酶基因为blaKPC-2,酶编码基因上游为一转座酶基因,两侧为复制靶位,下游为ISKpn6的插入序列,该序列包括一个重复序列和tnpA转座子,酶编码基因位于54.2 kb的一个非接合性大质粒上.等电聚焦电泳显示5株菌均产4种β-内酰胺酶(TEM-1,pI5.4;KPC-2,pI6.7;SHV-12,pI8.2;CTX-M-14,pI8.4).16S rRNA甲基化酶基因位于接合性质粒上,而blaKPC-2基因则位于非接合性质粒上,5株菌PFGE型别一致.结论 5株泛耐药阴沟肠杆菌对碳青霉烯类耐药由产碳青霉烯酶KPC-2所介导.blaKPC-2与armA型16S rRNA甲基化酶基因由两条不同的质粒编码,不存在相关性.临床医院应加强监控,以防止交叉感染.  相似文献   

2.
目的 研究碳青霉烯类耐药肺炎克雷伯菌临床儿童分离株的耐药特点及分子流行病学特征.方法 收集温州医学院附属第二医院2010年7月-2011年6月从儿童标本中分离的耐碳青霉烯类肺炎克雷伯菌12株,所有菌株为非重复菌株,菌种鉴定采用全自动微生物分析仪.改良的Hodge试验筛选产碳青霉烯酶阳性菌株,采用PCR法检测KPC、IMP、bla(s)、VIM、SPM和整合酶基因,测序确定基因型.对菌株进行质粒结合试验、质粒消除试验检测质粒的转移性.脉冲场凝胶电泳(PFGE)分析耐药菌株的同源性.结果 12株耐碳青霉烯类肺炎克雷伯菌对庆大霉素、妥布霉素、阿米卡星、环丙沙星、左氧氟沙星、复方磺胺甲噁唑的敏感率分别为8.3%、41.7%、58.3%、8.3%、8.3%、33.3%;12株菌均携带有KPC-2基因,且同时携带有TEM-1和SHV型β-内酰胺酶基因,其中SHV-11-like和SHV-1 2-like各6株;11株携带CTX-M型基因,其中4株为CTX-M-14-like基因,6株CTX-M-15-like基因;2株携带有OXA-10型基因,1株携带有PER-1基因.未检出NDM-1、GIM、SPM、SIM、VIM型碳青霉烯酶基因.12株均为Ⅰ类整合酶基因(int1)阳性.2株通过接合试验把质粒传递给受体菌EC600.所有接合子blaTEM-1基因阳性、超广谱β-内酰胺酶(ESBL)基因阳性及对亚胺培南、庆大霉素、阿米卡星、妥布霉素和头孢噻肟耐药,接合子ESBL基因型与供菌一致.2株菌经质粒消除后对亚胺培南的MIC值均有较大程度降低,消除后KPC-2基因扩增为阴性.12株KPC-2基因阳性菌株经PFGE分成5个基因型,主要为B型和C型.结论 KPC-2型碳青霉烯酶基因已经在儿童肺炎克雷伯菌中播散,常伴随携带多种类型的ESBL基因和Ⅰ类整合酶基因,部分耐药基因可通过质粒播散.  相似文献   

3.
目的研究大肠埃希菌和肺炎克雷伯菌同时产超广谱β内酰胺酶(ESBL)及质粒型Ampc酶菌株的比率及其基因型。方法收集北京两家教学医院2001--2002年产ESBL且对头孢西叮耐药的59株大肠埃希菌和21株肺炎克雷伯菌,采用等电聚焦电泳测定β内酰胺酶的等电点;接合试验证实酶基因有无可转移性,并用碱裂解法提取质粒;采用多重聚合酶链式反应(multiplex polymerase chain reaction,MPCR)及序列分析确定质粒AmpC酶的基因型。脉冲场凝胶电泳(pulsed field gelel ectrophoresis,PFGE)确定耐药菌株的亲缘关系。结果北京两家医院ESBL中质粒型AmCZ酶的发生率,大肠埃希菌分别为0和2%,肺炎克雷伯菌则分别为9.7%和17.1%。1株大肠埃希菌及9株肺炎克雷伯菌产生DHA-1型质粒AmpC酶,同时也产CTX-3型(6株)或CTX—M-14(1株)或SHV-12(3株)型ESBL。10株中,3株肺炎克雷伯菌可将头孢西叮耐药性传给受体菌。这10株菌均至少携带1个约33—36kb的大质粒,未发现质粒的传播。PFGE发现这10株菌来自不同的克隆株。结论北京地区发现同时产DHA-1质粒AmpC型及CTX—M型ESBL的肺炎克雷伯菌,它们来自不同的克隆。  相似文献   

4.
目的 运用变性高效液相色谱(DHPLC)技术调查广州地区产SHV型β-内酰胺酶肺炎克雷伯菌各种亚型的流行分布情况,试图建立一种方便快捷的分子诊断及其流行病学监测的新方法.方法 对73份产超广谱β-内酰胺酶(ESBL)肺炎克雷伯菌进行SHV质粒基因扩增,分别采用变性高效液相色谱(DHPLC)和测序法对扩增产物进行分析,以明确基因类型,并建立各个已知SHV基因亚型的特征性DHPLC图谱库.结果 73株产ESBL的肺炎克雷伯菌中68株确定为SHV基因型,其中62株为已知基因型,分别为SHV-1225株,SHV-1a 14株,SHV-17株,SHV-2a 8株,SHV-28 5株,SHV-2 2株,SHV-26和SHV-33各1株;6株为新的SHV基因型,其中5株获得命名;非SHV型菌株5株,分别为LEN-4型1株,OKP型4株.经过DHPLC分析,全部样本均表现为异常的洗脱峰,各种亚型的异常洗脱峰的形态迥异,其敏感性达100%(68/68),特异性为93.2%(68/73).SHV型质粒基因的突变集中在nt92、nt324~nt402及nt703~nt786这3个区段.结论 SHV-12是广州地区产SHV型β-内酰胺酶肺炎克雷伯菌主要的基因亚型,高比例基因变异的检出预示本地区即将或已经面临肺炎克雷伯菌新耐药机制的抵抗和流行,因此必须加强对产ESBL肺炎克雷伯菌的分子流行病学监测,及时调整抗菌策略;DHPLC可作为一种快速敏感的筛查方法用于产ESBL肺炎克雷伯菌的分子流行病学监测.  相似文献   

5.
目的 研究我国多中心亚胺培南耐药的鲍曼不动杆菌的耐药性、16S rRNA甲基化酶的阳性率及分子流行病学特征.方法 收集2004年11月-2005年11月国内6省市19家医院临床分离的342株亚胺培南耐药的鲍曼不动杆菌.采用琼脂稀释法和E test法对18种抗菌药物测定分离株的最低抑菌浓度(MIC)值;脉冲场凝胶电泳(PFGE)分析菌株的同源性;PCR法筛选4种16S rRNA甲基化酶基因armA、rmtA、rmtB、rmtC,克隆测序明确基因型;接合试验、质粒抽提、电转化以及Southern blot确定甲基化酶耐药基因定位.结果 所有菌株均为多重耐药株,其中对阿米卡星、庆大霉素、妥布霉素、异帕米星、奈替米星耐药率分别为92.6%、98.6%、87.4%、90.9%和92.4%.PCR扩增、测序证实221株鲍曼不动杆菌检出甲基化酶armA基因;另3种甲基化酶基因rmtA、rmtB、rmtC均阴性.在上述342株鲍曼不动杆菌临床分离株中,298株可归类为6个流行克隆,44株为散发株.3个主要克隆(A、B、C)在全国广泛播散,分别在国内6家、3家、11家医院内流行.接合试验、质粒抽提、电转化及Southern blot表明armA编码基因存在于染色体上.结论 亚胺培南耐药鲍曼不动杆菌的表型均为多重耐药.介导氨基糖苷类抗生素高度耐药的16S rRNA甲基化酶基因armA在鲍曼不动杆菌中广泛存在,其主要传播方式为克隆播散,这必将引起临床的高度关注.  相似文献   

6.
为深入了解一组分离自浙江省杭州地区和湖州地区耐药肺炎克雷伯菌之氨基糖苷类药物耐药的遗传学背景,我们同时检测了47株耐药肺炎克雷伯菌的15种氨基糖苷类修饰酶和6种16S rRNA甲基化酶基因.现报道如下.  相似文献   

7.
肠杆菌科细菌中超广谱β-内酰胺酶(ESBL)的研究   总被引:72,自引:4,他引:68  
目的 调查我院院内肠杆菌科细菌中产超广谱β-内酰胺酶(ESBL)菌株的发生率以及ESBL的表型和基因型。方法 对1999年2月-5月临床分离的162株肠杆菌科细菌,采用美国临床实验室标准化委员会规定的ESBL表型筛选和确证试验确定ESBL的发生率;等电聚集电泳,抑制试验,接合试验确定ESBL菌株中酶的表型;质粒的提取,脉冲场凝胶电泳(PFGE)、TEM-、SHV-、CTX-M-3特异引物的PCR和测序确定ESBL的基因型。结果 11.4%(5/44)的大肠杆菌、39.5%(17/43)的肺炎克雷伯菌、6.0%(3/50)的阴沟肠杆菌和8.0%(2/25)的弗劳地枸橼酸菌产ESBL。对于这27株菌,头孢噻肟的MIC明显高于头孢他啶,除1株阴沟肠杆菌外,其它26株菌对亚胺培南敏感,大多数菌株产2-6种酶,70.3%(19/27)的菌株产生CTX-M-3型的ESBL(等电点为8.6)。这种酶能被克拉维酸抑制,其编码的耐药性能够转移至敏感株,并且对头孢噻肟的耐药高于头孢他啶,对小部分菌株用PF-GE分型发现存在多个克隆。结论 产ESBL的肠杆菌科在院内较普遍;CTX-M-3型的ESBL最为常见。  相似文献   

8.
目的探讨整合子介导的耐药机制在产AmpC酶大肠埃希菌和肺炎克雷伯菌多重耐药中的作用.方法5株产AmpC酶大肠埃希菌和肺炎克雷伯菌分离自2002年1月-2004年5月间我院呼吸科住院的患者,采用E-test试验条进行药敏试验、电转化试验,筛选、分离耐药质粒.PCR扩增Ⅰ型整合子基因盒插入序列,分子克隆和序列分析.结果所有产酶菌株通过电转化试验可将头孢西丁耐药性传递给受体菌,5个产AmpC酶耐药质粒中,有4个检出整合酶序列,其中3个携带2种抗药性基因盒,包括氨基糖苷乙酰转移酶基因aacA4;氨基糖苷腺苷转移酶基因aadA5;二氢叶酸还原酶基因dfrA17;氯霉素外排蛋白编码基因cmL44.结论整合子介导的抗药性基因盒参与了产质粒AmpC酶大肠埃希菌和肺炎克雷伯菌多重耐药的形成,应引起高度重视.  相似文献   

9.
目的了解革兰阴性菌质粒介导qmA耐药基因的发生率、分子遗传学背景及其阳性株的耐药谱。方法收集2004年4月-2006年4月对萘啶酸耐药的临床分离无重复株共629株,采用特异引物PCR结合测序进行qnrA阳性株的识别,表型确认试验结合PCR检测识别产ESBL或AmpC酶的qnrA阳性株,Kirby-Bauer法和Etest法进行qnrA阳性株的药敏检测,质粒接合转移及Southem杂交检测进行qmA基因的质粒定位,PCR策略克隆携带qnrA基因整合子基因结构并进行引物步移测序。结果qnrA阳性株的总检出率为1.9%(12/629)。菌种分布为肺炎克雷伯菌2.2%(3/138),阴沟肠杆菌17.1%(6/35),产气肠杆菌9.1%(1/11),枸橼酸杆菌属12.5%(1/8),沙门菌属14.3%(1/7)。qnrA基因定位在80~180kb大小质粒上的su/1型Ⅰ类整合子基因结构中。其中4株菌qnrA基因定位在整合子In37上,另外8株菌qnrA基因定位在一种新型的整合子InX上。所有qnrA阳性株均产ESBL,并具有可转移多重耐药的特征。结论广东地区喹诺酮抗菌药耐药株中存在着质粒介导的耐药机制,但发生率较低;其耐药基因qnrA的水平传播能力有可能导致细菌耐药性的播散。  相似文献   

10.
目的分析一株同时产KPC-2和NDM-5碳青霉烯酶的肺炎克雷伯菌耐药基因特征。方法肺炎克雷伯菌KPN-hnqyy分离自我院血液科一位患者的粪便标本, 使用仪器BD Phenix-M50鉴定菌株并测定最小抑菌浓度;酶联免疫层析试验和PCR方法检测碳青霉烯酶基因型;接合试验检测相关质粒的转移性;PacBio和Illumina平台对菌株全基因组测序, 并在BacWGSTdb数据库中检索菌株MLST分型、耐药基因和质粒类型, 使用软件Easyfig2.2.3比对基因组和开放读码框序列, BRIG v0.95生成可视化质粒圈图。结果肺炎克雷伯菌KPN-hnqyy对碳青霉烯类抗生素耐药, MLST分型为ST11型, blaKPC-2和blaNDM-5碳青霉烯酶基因阳性;接合子blaKPC-2基因阳性, blaNDM-5阴性;全基因组测序显示菌株含有1个染色体和3个质粒;肺炎克雷伯菌KP69和KP19-2029等与本研究菌株染色体基因组相似性大于99.9%, 且其各自携带的不同种类的质粒上含有相似的IncR和IncFⅠ耐药基因融合区, blaKPC-2基因位于此融合区中一个由T...  相似文献   

11.
Over 200 schizophrenic patients belonging to three major and interrelated pedigree complexes have been investigated over the past 30 years in a North Swedish geographically isolated population, presently numbering about 6,000. An intensive investigation of a number of biochemical correlates and genetic markers in a few selected families belonging to one of the major pedigrees has indicated new strategies for the current research program.
Schizophrenia, as defined operationally, is significantly associated with decreased activities of two enzymes (1) blood platelet monoamine oxidase, (2) plasma dopamine-β-hydroxylase, and (3) with the genetic marker Gc2 (group specific antigen). Both enzymes are subject to genetic variation. A positive score for linkage between schizophrenia and low plasma DBH activity has been calculated, but, so far, available data are insufficient for discrimination between linkage and partial contribution of genetically controlled low plasma DBH to the pathogenesis of the disease. Alternatively, both mechanisms could be involved.
As a model for continued research, schizophrenia is explained as based on a double dominant-recessive genotype (Aabb), representing a vulnerability which in about 50 % of cases develops into clinical schizophrenia. It is suggested that the dominant mutation (A) operates on or affects MAO activity, and that the recessive genotype (bb) is instrumental in low variates of DBH activity and very likely such variates within the normal range of physiological variation. Moreover, it is suggested that the combined effects of MAO- and DBH-reduced efficiency on the metabolism of e.g. dopamine could be an essential pathogenic mechanism for the schizophrenic illness which is segregating in this population.  相似文献   

12.
Renal dysplasia and asplenia in two sibs   总被引:2,自引:0,他引:2  
A family is reported in which two sibs, one male and the other female, both died within 24 hours of birth with enlarged polycystic kidneys. Postmortem histology in the second child showed gross renal dysplasia. In both children the pancreas was enlarged, nodular and cystic but the liver appeared macroscopically normal. In the second child, histological examination confirmed pancreatic fibrosis with cystic dilation of ducts, but showed portal fibrosis with bile duct proliferation in the liver.
This combination of findings is very reminiscent of those in a girl and her brother reported by Ivemark et al. (1959). The children reported here also showed absence or hypoplasia of the spleen, cardiac anomalies and other features of the Ivemark syndrome (Ivemark 1955), a quite different, usually sporadic, congenital disorder. It is suggested that the children described here have a distinct lethal congenital disorder, probably inherited in an autosomal recessive manner.  相似文献   

13.
About 1900, modern food selection and processing caused widespread epidemics of the B vitamin deficiency diseases of beriberi and pellagra which, for genetic reasons, often expressed as different diseases ranging from bowel and heart disease to dermatoses and psychoses. But the B vitamins merely help convert essential fatty acids (EFA) into the prostaglandin (PG) tissue regulators and it now turns out that, through hydrogenation, milling and selection of w3-poor southern foods, we have also been systematically depleting, by as much as 90%, a newly discovered trace Nordic EFA (w3) of special importance to primates and sole precursor of the PG3(4) series, even as a concurrent fiber deficiency increases body demand for EFA. Since substrate EFA is processed by many B vitamin catalysts, an EFA deficiency will mimic a panhypovitaminosis B, i.e., a mixture of substrate beriberi and substrate pellagra resembling vitamin beriberi and pellagra but exhibiting as even more diverse endemic disease. This would consitute a second stage of the Modern Malnutrition and explain why some workers now hold the dominant diseases of modermized societies to be new, nutritionally based, pellagraform yet lipid-related and to range, once again, from heart disease to psychosis. It is an assumption that our dominant diseases are unrelated to each other or are merely revealed by our diagnostic acumen and therapeutic success; and that hydrogenating millions of tons of food oils annually, to destroy the rancidity producing w3-EFA, is safe for primates. Extensive beriberiform disease is reported here in 32 typical cases taken from medical practice which responds strikingly to linseed oil supplements (60% w3-EFA) in confirmation of identical results in Capuchins.  相似文献   

14.
15.
Newton H 《Medical history》2011,55(2):153-182
Sick children were ubiquitous in early modern England, and yet they have received very little attention from historians. Taking the elusive perspective of the child, this article explores the physical, emotional, and spiritual experience of illness in England between approximately 1580 and 1720. What was it like being ill and suffering pain? How did the young respond emotionally to the anticipation of death? It is argued that children’s experiences were characterised by profound ambivalence: illness could be terrifying and distressing, but also a source of emotional and spiritual fulfilment and joy. This interpretation challenges the common assumption amongst medical historians that the experiences of early modern patients were utterly miserable. It also sheds light on children’s emotional feelings for their parents, a subject often overlooked in the historiography of childhood. The primary sources used in this article include diaries, autobiographies, letters, the biographies of pious children, printed possession cases, doctors’ casebooks, and theological treatises concerning the afterlife.  相似文献   

16.
Recent advancements in agricultural biotechnology have created a need for analytical techniques to determine introduced proteins in crops enhanced through modern biotechnology techniques. These proteins are expressed in plant tissues and may be present in food ingredients. Immunoassays are ideally suited for protein detection and may be used as both quantitative and threshold methods. Microplate ELISA and lateral flow devices are two of the most commonly used immunoassay formats for agricultural biotechnology applications. This paper provides general background information and a discussion of criteria for the validation and application of immunochemical methods to the analysis of proteins introduced into plants and food ingredients using biotechnology methods. It is the result of a collaborative effort of members of the Analytical Environmental Immunochemical Consortium. This collaborative effort represents the combined expertise of several organizations to reach consensus on establishing guidelines for the validation and use of immunoassays. Further, the paper offers developers and users a consistent approach to adopting the technology as well as aid in producing accurate and meaningful results.  相似文献   

17.
The preparation steps usually necessary for obtaining ultrathin frozen sections of biological material (chemical prefixation, enclosing, cryoprotective treatment, freezing, sectioning, and post-staining the sections for transmission electron microscopy) are submitted to a critical analysis. The application of cryo-ultramicrotomy, in particularly for cytochemical purposes, is reviewed. Fundamental considerations of chemical prefixation and poststaining are supported by examples from yeast cytology. Furthermore, the efficiency of the cryo-ultramicrotomy (electron optical resolution of ultrastructural details) is demonstrated on yeast cells and protoplasts.  相似文献   

18.
HLA-A,-B,-C,-DRB1 and -DQB1 alleles have been studied in Chimila Amerindians from Sabana de San Angel (North Colombian Coast) by using high resolution molecular typing. A frequent extended haplotype was found:HLA-A*24:02-B*51:10-C*15:02-BRB1*04:07-DQB1*03:02 (28.7%) which has also been described in Amerinndian Mayos Mexican population (Mexico, California Gulf, Pacific Ocean). Other haplotypes had already been found in Amerindians from Mexico (Pacific and Atlantic Coast), Peru (highlands and Amazon Basin), Bolivia and North USA. A geographic pattern according to HLA allele or haplotype frequencies is lacking in Amerindians, as already known. Also, five new extended haplotypes were found in Chimila Amerindians. Their HLA-A*24:02 high frequencies characteristic is shared with aboriginal populations of Taiwan; also, HLA-C*01:02 high frequencies are found in New Zealand Maoris, New Caledonians and Kimberly Aborigines from Australia. Finally, this study may show a model of evolutionary factors acting and rising one HLA allele frequency (-A*24:02), but not in others that belong to the same or different HLA loci.  相似文献   

19.
Starting with the integument, we see many organs are contractile sacs or multiples thereof, which tubes or bags constitute the major part of the entire body. Recognition of this basic unit and its characteristics sheds new light, individually and collectively, on many disorders previously considered unrelated. Muscular tears and perforations develop in the walls of these chambers, being no way peculiar to those organs, wherein, hydrochloric acid occurs. So, it is not necessary to explain the absence of excessive acid from patients who exhibit holes in the gastric, uterine, aortic, duodenal, rectal, pulmonary, retina, and other walls. Muscle, not acid is the great common factor relating idiopathic disorders in the gastrointestinal tract to each other and to similar diseases in other systems. When the units are linked together, the lesions tend to appear as arthropathies, i.e. at the joints. Rephrasing common-place observations, frees us from conventional, conceptual cul-de-sacs. An observation is only as good as its interpretation, so all possibilities must be considered, otherwise, we will remain blinded by our misconceptions.  相似文献   

20.
Zusammenfassung Der Einfluß von verschiedenen Nahrungsmitteln auf Methoden zur Bestimmung von Adrenalin (AD), Noradrenalin (NA), Vanillinmandelsäure (VMS), Metanephrinen (MN), Homovanillinsäure (HVS) und 5-Hydroxyindolessigsäure (5-HIE) im 24 h-Harn zur Diagnose des Phäochromozytoms bzw. Karzinoid-Syndroms wurde untersucht. Die in die Untersuchung einbezogenen Nahrungsmittel waren: Tee, Kaffee, Mandeln, Ananas, Käse, Walnüsse, Vanillepudding, Bananen, Tomaten und Milchschokolade. Außerdem wurde der Einfluß des Zigarettenrauchens auf die Bestimmung von AD, NA, VMS und MN untersucht.Walnüsse führten zu einer starken Erhöhung der 5-HIE-Ausscheidung. Bananen erhöhten die Ausscheidung von AD, NA, VMS, MN und 5-HIE. Kaffee und Ananas bewirkten eine geringe Zunahme der MN-Werte. Rauchen von 20–30 Zigaretten/Tag beeinflußte keine der vier Variablen.Wenn die beschriebenen Methoden benutzt werden, sollte lediglich auf den Verzehr von Bananen und Walnüssen vor und während der Harnsammelperioden verzichtet werden, da die oberen Normgrenzen im Harn überschritten werden könnten. Ein Verzicht auf Kaffee und Ananas in normalen Mengen ist nicht erforderlich. Es besteht kein Anlaß, weiterhin die bisherigen umfangreichen Restriktionen der übrigen Nahrungsmittel beizubehalten.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号