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1.
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   

2.
目的 了解我院同时产质粒介导AmpC酶和超广谱 β 内酰胺酶 (ESBLs)肺炎克雷伯菌与大肠埃希菌的耐药性及其 β 内酰胺酶的基因型特征。方法  110株临床分离无重复肺炎克雷伯菌与大肠埃希菌耐药株 ,采用酶提取物三维实验检测AmpC酶 ,美国临床实验室标准委员会 (NCCLS)表型筛选和确认实验检测ESBLs ;琼脂二倍稀释法测定抗生素对同时产AmpC酶和ESBLs菌株的最低抑菌浓度 (MICs) ;等电聚焦实验测定 β 内酰胺酶等电点 (pIs) ;质粒接合实验定位耐药基因 ;PCR通用引物扩增AmpC酶与ESBLs基因及其序列测定以确定其基因亚型。结果 同时产AmpC酶和ESBLs菌株在肺炎克雷伯菌与大肠埃希菌中的检出率分别为 7.7% (5 6 5 )、8.9% (4 4 5 )。该类产酶菌株产 2~ 3种pI5 .4~ 9.0 β 内酰胺酶 ,对第三代头孢菌素、氨曲南、头孢美唑和含酶抑制剂复合制剂的敏感性极低 ,但对亚胺培南均敏感。 9株质粒中均检出AmpC酶基因DHA 1亚型 ,其中 1株同时检出ACT 1亚型 ;ESBLs基因亚型分别为CTX M 14、CTX M 3、CTX M 9,各有 4、3、2株 ;有 3株还携带广谱酶TEM 1基因。结论 我院存在同时产质粒介导DHA 1、ACT 1型AmpC酶和CTX M型ESBLs肺炎克雷伯菌、大肠埃希菌流行株 ,药敏检测结果显示对大多数新型广谱 β 内酰胺类抗生  相似文献   

3.
目的了解产超广谱β-内酰胺酶(extended spectrum beta-lactamases,ESBLs)大肠埃希菌和肺炎克雷伯菌的遗传标记基因(整合子qacE△1、转座子tnpU)、氨基糖苷类修饰酶编码aac(6′)-Ib基因和喹诺酮类药物耐药qnrA基因分布状况,为临床使用药物治疗感染和消毒灭菌工作提供参考。方法收集本院的产ESBLs大肠埃希菌和肺炎克雷伯菌共60株,采用PCR方法检测这些菌株中qacE△1、tnpU、aac(6′)-Ib和qnrA基因,MIC法药物敏感试验分析菌株的耐药性。结果 60株产ESBLs的大肠埃希菌和肺炎克雷伯菌中qacEΔ1基因检出率61.7%,tnpU基因检出率7.6%,aac(6′)-Ib检出率为11.7%,qnrA基因检出率3.3%。60株菌中有38株含1种或以上基因,其药敏敏感度最高的是亚胺培南、厄它培南、哌拉西林/他唑巴坦,敏感率均为97.4%,而对氨苄西林和头孢唑啉完全耐药。结论产ESBLs大肠埃希菌和肺炎克雷伯菌的耐药与耐药基因传递机制整合子和转座子系统密切相关,分离株携带qacE△1、tnpU、aac(6′)-Ib和qnrA基因是细菌呈多重耐药的主要原因,提示临床应慎重用药。  相似文献   

4.
刘永瑞  张妍  李秀英 《医学信息》2019,(19):122-123126
目的 调查济宁市第一人民医院肺炎克雷伯菌质粒介导AmpC酶表型及其对常用抗生素的耐药性,为临床用药提供依据。方法 收集2017年1月~7月济宁市第一人民医院临床分离的非重复肺炎克雷伯菌97株,应用头孢西丁纸片扩散法进行肺炎克雷伯菌AmpC酶表型初筛,对初筛阳性菌用多重PCR方法检测质粒介导AmpC酶基因,分析其耐药情况。结果 97株肺炎克雷伯菌中共筛选出40株对头孢西丁不敏感菌株,经多重PCR扩增,有7株AmpC酶阳性,检出率为7.22%(7/97),均为DHA型。产质粒介导AmpC酶菌株仅对亚胺培南敏感(100.00%)。结论 济宁市第一人民医院产质粒介导AmpC酶肺炎克雷伯菌发生率相对较低,以DHA型基因为主,治疗应首选碳青霉烯类抗菌药物。  相似文献   

5.
大肠埃希菌是临床常见致病菌,也是院内获得性感染的重要病原菌。其耐药性的变迁和多重耐药的出现,主要与耐药基因编码酶有关,其中以质粒介导的超广谱β-内酰胺酶(ESBL)和AmpC酶最为重要。我们在最近一项关于大肠埃希菌抗生素耐药相关基因的研究中,发现1株大肠埃希菌(ZY163)同时携带2种新型ESBL和AmpC酶,现报告如下。  相似文献   

6.
目的对产超广谱β-内酰胺酶(ESBLs)的大肠埃希菌和肺炎克雷伯菌携带的ESBLs耐药基因进行分型,为临床合理应用抗生素提供理论依据。方法收集住院患者标本中分离出的51株大肠埃希菌和32株肺炎克雷伯菌,经PCR对上述菌株所携带的ESBLs耐药基因进行分型。结果产ESBLs大肠埃希菌中耐药质粒编码TEM型、SHV型和非TEM非SHV型超广谱β-内酰胺酶基因的百分率依次为80.4%,7.8%和11.8%;而在肺炎克雷伯菌中的百分率依次为78.1%,71.9%和25.0%。多数产ESBLs肺炎克雷伯菌同时产生一种以上的β-内酰胺酶。结论获得了吉林地区大肠埃希菌和肺炎克雷伯菌ESBLs的不同基因型,ESBLs基因型具有地区性差异。  相似文献   

7.
目的 研究氨基糖苷乙酰胺转移酶基因的突变形式aac(6’) -Ib -cr在肺炎克雷伯菌和大肠埃希菌临床株中的分布状况;分析携带该基因菌株对环丙沙星、氨基糖苷类和头孢菌素类的耐药特征.方法 利用多聚酶链式反应检测肺炎克雷伯菌和大肠埃希菌临床分离株中aac(6’)-Ib基因携带情况,采用BtsC I酶切消化,经DNA测序确认aac(6 ’)-Ib-cr基因;统计分析aac(6’) -Ib-cr基因与环丙沙星、头孢菌素类和氨基糖苷类耐药性关系.结果 aac(6’)-Ib-cr基因在肺炎克雷伯菌和大肠埃希菌的检出率分别为12.6% (30/238)和18.8% (13/69);aac(6 ’)-Ib-cr阳性株与阴性株对环丙沙星的耐药率分别为72.1% (31/43)和48.1%(127/264),差异有统计学意义(X2=8.52,P<0.05).肺炎克雷伯菌aac(6’)-Ib-cr基因阳性株对阿米卡星的耐药率高于aac(6’) -Ib-cr基因阴性株(X2=4.25,P<0.05).aac(6’)- Ib-cr基因阳性株和阴性株对庆大霉素的耐药率、常用的头孢菌素类的耐药率和多重耐药率均较高,无统计学差异.结论 本地区肺炎克雷伯菌和大肠埃希菌临床分离株中,aac(6’) -Ib-cr基因均有检出;aac(6’)-Ib-cr基因阳性株对环丙沙星耐药率明显高于阴性株,肺炎克雷伯菌中aac(6’)-Ib-cr基因阳性株对阿米卡星的耐药率明显高于阴性株,具有统计学意义.aac(6’) - Ib-cr基因阳性株和阴性株对常用头孢菌素类的耐药率和多重耐药率均较高,无统计学意义.  相似文献   

8.
目的 调查2004年北京地区临床收集的耐庆大霉素大肠埃希菌对氨基糖苷类抗生素的敏感性和氨基糖苷类钝化酶基因的流行状况.方法 采用微量肉汤稀释法检测64株大肠埃希菌对16种氨基糖苷类抗生素的最低抑菌浓度(MIC)值;利用巢式PCR方法对其可能含有的7种氨基糖苷类钝化酶基因进行检测和确证.结果 临床大肠埃希菌的耐药表型较为复杂,与钝化酶基因表达有关.测试菌株中存在aac(3)-Ⅱc、aac(6')-Ⅰ b、ant(2")-Ⅰ a和ant(3")-Ⅰ a 4种耐药基因,aac(3)-Ⅱc和aac(6′)-Ⅰ b是主要的产酶基因.约40%的耐药菌中存在2种或2种以上的钝化酶基因.结论 产生氨基糖苷类钝化酶是临床分离的大肠埃希菌对氨基糖苷类抗生素主要的耐药机制.采用巢式PCR方法检测耐药基因,特别是在缺少阳性对照菌株的情况下,可以保障检测结果的特异性和准确性.临床菌的耐药表型和钝化酶基因关系较为复杂,这可能与耐药菌中尚存在其他耐药基因有关.  相似文献   

9.
目的了解我院肺炎克雷伯菌AmpC酶的基因分型及耐药情况,指导临床合理使用抗生素。方法采用K-B法初筛出可疑产AmpC酶的菌株,再用三维试验检测产AmpC酶的情况,用多重PCR进行基因分型、随机扩增DNA多态性技术进行同源性的分析。结果从临床260株肺炎克雷伯菌中初筛出57株可疑产AmpC酶的菌株,三维试验检测57株菌中AmpC酶阳性有51株,产AmpC酶的肺炎克雷伯菌大多数是DHA型占90%,只有很少一部分产MIX型占6%、FOX型占2%和ACC型占2%。通过15种药物对产AmpC酶肺炎克雷伯菌耐药性的分析,51株对亚胺培南的敏感性为98.0%,对头孢西丁耐药性为100%,对其他第三代头孢菌素的耐药性均超过70%。结论我院临床分离产AmpC酶的肺炎克雷伯菌主要基因型是DHA型,且呈多重耐药。  相似文献   

10.
目的研究氨基糖苷乙酰胺转移酶基因的突变形式aac(6′)-Ib-cr在肺炎克雷伯菌和大肠埃希菌临床株中的分布状况;分析携带该基因菌株对环丙沙星、氨基糖苷类和头孢菌素类的耐药特征。方法利用多聚酶链式反应检测肺炎克雷伯菌和大肠埃希菌临床分离株中aac(6′)-Ib-cr基因携带情况,采用BtsCI酶切消化,经DNA测序确认aac(6′)-Ib-cr基因;统计分析aac(6′)-Ib-cr基因与环丙沙星、头孢菌素类和氨基糖苷类耐药性关系。结果aac(6′)-Ib-cr基因在肺炎克雷伯菌和大肠埃希菌的检出率分别为12.6%(30/238)和18.8%(13/69);aac(6′)-Ib-cr阳性株与阴性株对环丙沙星的耐药率分别为72.1%(31/43)和48.1%(127/264),差异有统计学意义(x2=8.52,P〈0.05)。肺炎克雷伯菌aac(6′)-Ib-cr基因阳性株对阿米卡星的耐药率高于aac(6′)-Ib-cr基因阴性株(x2=4.25,P〈0.05)。aac(6′)-Ib-cr基因阳性株和阴性株对庆大霉素的耐药率、常用的头孢菌素类的耐药率和多重耐药率均较高,无统计学差异。结论本地区肺炎克雷伯菌和大肠埃希菌临床分离株中,aac(6′)-Ib-cr基因均有检出;aac(6′)-Ib-cr基因阳性株对环丙沙星耐药率明显高于阴性株,肺炎克雷伯菌中aac(6′)-Ib-cr基因阳性株对阿米卡星的耐药率明显高于阴性株,具有统计学意义。aac(6′)-Ib-cr基因阳性株和阴性株对常用头孢菌素类的耐药率和多重耐药率均较高,无统计学意义。  相似文献   

11.
Multiresistant Escherichia coli isolates of the normal intestinal flora of healthy fattening pigs were examined for the presence of integron class 1 by XL (extra long) PCR. The class 1 integron was detected in 17 isolates originating from 14 healthy animals on seven different farms. One isolate contained two class 1 integrons. The inserted gene cassettes were characterized by DNA sequencing and PCR. The ant(3")-Ia gene responsible for resistance to streptomycin/spectinomycin was inserted in all integrons detected. Fifteen isolates contained this gene cassette as the only inserted cassette. Three isolates contained integrons with two gene cassettes. Two isolates contained integrons with the trimethoprim resistance gene dfr1 and one isolate contained the oxa1 beta-lactamase gene upstream to the ant(3")-Ia gene. Detection of these three different resistance gene cassettes in bacteria from swine shows that cassettes occurring in integrons in human clinical isolates also appear in bacteria of the normal intestinal flora of healthy swine. Two integron-harboring strains were obtained from each of three different animals. These strains were probably not clonal derivatives of each other, suggesting the existence of different multiresistance clones within the intestinal normal flora of one specific animal. The oxa1 nucleotide sequence found in E. coli from swine differ by seven nucleotides from the oxa1 nucleotide sequence of the gene from the R-plasmid RGN238. The fact that these two sequences are not identical might indicate that the two genes have evolved separately in different surroundings from the common ancestor. Transmissible plasmids of approximately 200 kb containing integron class I were detected in eight of the isolates when conjugation experiments were performed with E. coli DH5 as recipient strain. The transfer frequency ranged from 4x10(-4) to 6x10(-2) transconjugants per recipient cell. This study shows that the enteric commensals of domestic animals may be considered as a reservoir of integron-containing transmissible plasmids and gene cassettes that might be transferable to the pathogens of swine and to important zoonotic bacteria associated with the enteric flora of swine such as Salmonella typhimurium DT104.  相似文献   

12.
分析下呼吸道感染患者气道分泌物或痰液标本分离的产AmpC酶和超广谱β-内酰胺酶(ESBL)肺炎克雷伯菌耐药基因的特点及亲缘性。方法 2009年1月至2010年8月由本院呼吸病区住院的下呼吸道感染患者气道分泌物或痰液标本分离得到53株肺炎克雷伯菌,采用K-B纸片扩散法测定其对常用抗菌药物的敏感性;三维实验检测AmpC酶;PCR检测ESBL、质粒介导的AmpC酶、喹诺酮类耐药基因、耐消毒剂-磺胺基因qacE△1-sul1、Ⅰ类整合酶基因Int Ⅰ 1的携带情况,并进行聚类分析。结果 53株肺炎克雷伯菌未发现对亚胺培南、美罗培南、厄他培南耐药;对环丙沙星、左旋氧氟沙星耐药率均>80%;对其他抗菌药物也有不同程度的耐药。53株肺炎克雷伯菌中Int Ⅰ 1基因阳性率60.4%(32/53),qnrA基因阳性率54.7% (29/53),qnrS基因阳性率13.2% (7/53),qnrB基因阳性率5.7%(3/53),qacE△1-sul1基因阳性率71.7%(38/53),TEM基因阳性率92.5% (49/53),CTX-M基因阳性率100%(53/53),SHV基因阳性率9.4%(5/53),AmpC基因阳性率92.5%(49/53);其中4株同时携带qnrA、qnrS、intⅠ 1、qacE△1-sul1、AmpC、CTX-M基因。聚类分析显示40、41、10与18号,25与42号,8与35号菌株有亲缘关系。结论 产ESBL肺炎克雷伯菌的多重耐药与整合子相关,且携带多种耐药基因,聚类分析显示存在克隆传播和医院内感染。  相似文献   

13.
Over a 21/2-month period in 1999, 37 ceftazidime-resistant nonrepetitive enterobacterial isolates were collected from 37 patients in a Bangkok hospital, Thailand. Eighty-one percent of these strains expressed a clavulanic acid-inhibited extended-cephalosporin resistance profile. An identical extended-spectrum beta-lactamase (ESBL), VEB-1, was found in 16 unrelated enterobacterial isolates (Escherichia coli, n = 10; Enterobacter cloacae, n = 2; Enterobacter sakazakii, n = 1; and Klebsiella pneumoniae, n = 3) and in two clonally related E. cloacae isolates. The bla(VEB-1) gene was located on mostly self-conjugative plasmids (ca. 24 to 200 kb) that conferred additional non-beta-lactam antibiotic resistance patterns. Additionally, the bla(VEB-1) gene cassette was part of class 1 integrons varying in size and structure. The bla(VEB-1)-containing integrons were mostly associated with bla(OXA-10)-like and arr-2-like gene cassettes, the latter conferring resistance to rifampin. These data indicated the spread of bla(VEB-1) in Bangkok due to frequent transfer of different plasmids and class 1 integrons and rarely to clonally related strains. Plasmid- and integron-mediated resistance to rifampin was also found in enterobacterial isolates.  相似文献   

14.
Antibiotic disks with and without clavulanic acid, 3-aminophenylboronic acid, or EDTA were tested with a set of 55 Klebsiella pneumoniae and Escherichia coli strains producing well-characterized extended-spectrum, AmpC, or carbapenem-hydrolyzing beta-lactamases. A relatively simple scheme was devised for distinguishing beta-lactamase types in clinical isolates with or without intact outer membrane porins.  相似文献   

15.
Plasmid-mediated quinolone resistance in Australia   总被引:5,自引:0,他引:5  
The aim of this study was to search for plasmid-encoded quinolone resistance determinants QnrA and QnrS in fluoroquinolone-resistant and extended-spectrum beta-lactamase (ESBL)-producing enterobacterial isolates recovered in Sydney, Australia, in 2002. Twenty-three fluoroquinolone-resistant, of which 16 were also ESBL-positive, enterobacterial and nonrelated isolates were studied. PCR with primers specific for qnrA and qnrS genes and primers specific for a series of ESBL genes were used. A qnrA gene was identified in two ESBL-positive isolates, whereas no qnrS-positive strain was found. The QnrA1 determinant was identified in an Enterobacter cloacae isolate and in a carbapenem-resistant Klebsiella pneumoniae isolate, both of which expressed the same ESBL SHV- 12. Whereas no plasmid was identified in the E. cloacae isolate, K. pneumoniae K149 possessed two conjugative plasmids, one that harbored the qnrA and bla (SHV)-12 genes whereas the other expressed the carbapenemase gene bla (IMP-4). The qnrA gene, was located in both cases downstream of the orf513 recombinase gene and upstream of the qnrA1 gene, a structure identical to that found in sul1-type integron In36 and qnrA-positive strains from Shanghai, China. However, the gene cassettes of the sul1-type integrons were different. This study identified the first plasmid-mediated quinolone resistance determinant in Enterobacteriaceae in Australia.  相似文献   

16.
Preliminary results suggested that the diffusion in France of the SHV-4 extended-spectrum beta-lactamase was probably due to the spread of one single epidemic strain of Klebsiella pneumoniae. In this study, we tested various phenotypic and genotypic markers to compare K. pneumoniae strains producing this enzyme isolated in 14 French hospitals between 1987 and 1989. All of the strains were of the same capsule serotype, K25. Twelve of them were of the same biotype: weak urease activity and no sucrose fermentation. Among the six plasmid profiles observed, one accounted for eight strains. Large plasmids of 170 kb encoding SHV-4 beta-lactamase were present in all strains of K. pneumoniae and could be transferred by conjugation with high frequency to Escherichia coli J53-2 or HB101 from all except one strain. Plasmid EcoRI restriction patterns suggested that these plasmids were closely related and similar to pUD18 encoding SHV-3 beta-lactamase, originally described in France and differing from SHV-4 by one amino acid substitution. Ribotyping with EcoRI and HindIII and genomic fingerprinting with XbaI by pulsed-field gel electrophoresis were concordant and suggested that 12 of the isolates recovered from the 14 hospitals were probably the same strain. Dissemination in France of the SHV-4 extended-spectrum beta-lactamase was thus essentially due to the diffusion of a single K. pneumoniae clone.  相似文献   

17.
Klebsiella pneumoniae is an opportunistic gram-negative pathogen involved in outbreaks of nosocomial infections in intensive care units. Strains are resistant to multiple antibiotics, and 15 to 30% of them are also resistant to the broad-spectrum cephalosporins by the production of R plasmid-encoded extended-spectrum beta-lactamases. Because the gastrointestinal tracts of patients have been shown to be the reservoir for nosocomial strains of K. pneumoniae, we looked for a correlation between antibiotic resistance and adhesion of K. pneumoniae strains to intestinal cells. We investigated adhesion to the human intestinal epithelial Caco-2 cell line of 61 clinical K. pneumoniae strains isolated in hospitals in Clermont-Ferrand, France. None of the strains tested expressed the previously described adhesive factors CF29K and KPF-28. Adhesive properties were found for 42.6% of the strains tested (26 strains). Just 7.7% (2 strains) of the 26 strains producing only the chromosomally encoded SHV-1 beta-lactamase adhered to the Caco-2 cell line, whereas 68.5% (24 strains) of the 35 strains producing a plasmid-encoded beta-lactamase were adherent. All the adherent strains, and even the two strains producing only the SHV-1 enzyme, harbored at least one self-transmissible R plasmid. At variance for CAZ-1/TEM-5 or CAZ-5/SHV-4 beta-lactamase-producing K. pneumoniae strains, curing and mating experiments demonstrated that the self-transmissible R plasmids encoding the TEM-1, CTX-1/TEM-3, CAZ-2/TEM-8, CAZ-6/TEM-24, or CAZ-7/TEM-16 beta-lactamase were not involved in the adhesion of K. pneumoniae strains to intestinal epithelial cells. Nevertheless, there was an association of multiple antibiotic resistance, including resistance to extended-spectrum cephalosporins, and adhesive properties in K. pneumoniae clinical isolates.  相似文献   

18.
The emergence of Escherichia coli resistant to extended-spectrum cephalosporins (ESCs) is of concern as ESC is often used to treat infections by Gram-negative bacteria. One-hundred and ten E. coli strains isolated in 2009-2010 from children warded in a Malaysian tertiary hospital were analyzed for their antibiograms, carriage of extended-spectrum beta-lactamase (ESBL) and AmpC genes, possible inclusion of the beta-lactamase genes on an integron platform, and their genetic relatedness. All E. coli strains were sensitive to carbapenems. About 46% of strains were multidrug resistant (MDR; i.e., resistant to ≥3 antibiotic classes) and almost half (45%) were nonsusceptible to ESCs. Among the MDR strains, high resistance rates were observed for ampicillin (98%), tetracycline (75%), and trimethoprim/sulfamethoxazole (73%). Out of 110 strains, bla(TEM-1) (49.1%), bla(CTX-M) (11.8%), and bla(CMY-2) (6.4%) were detected. Twenty-one strains were ESBL producers. CTX-M-15 was the predominant CTX-M variant found and this is the first report of a CTX-M-27-producing E. coli strain from Malaysia. Majority (3.1%) of the strains harbored class 1 integron-encoded integrases with a predominance of aadA and dfr genes within the integron variable region. No gene cassette encoding ESBL genes was found and integrons were not significantly associated with ESBL or non-ESBL producers. Possible clonal expansion was observed for few CTX-M-15-positive strains but the O25-ST131 E. coli clone known to harbor CTX-M-15 was not detected while CMY-2-positive strains were genetically diverse.  相似文献   

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