2008—2016年临床分离阴沟肠杆菌的 分布及耐药性变迁

摘要：目的 了解贵州医科大学附属医院2008—2016年阴沟肠杆菌的临床感染分布及耐药性变迁。方法 采用WHONET 5.6软件回顾性分析各年阴沟肠杆菌的检出率、标本类型分布及耐药情况。结果 2008—2016年共分离出2 009株阴沟肠杆菌,主要来源于痰液标本,占52.41％。药敏结果显示,阴沟肠杆菌对氨苄西林/舒巴坦的耐药率最高,对亚胺培南的耐药率最低。与2009年相比,2016年阴沟肠杆菌对氨苄西林/舒巴坦和亚胺培南之外的10种抗生素的耐药率均显著下降（P＜0.05）。结论 阴沟肠杆菌对临床常用抗生素的耐药率基本呈下降趋势,对碳青霉烯类抗生素耐药的阴沟肠杆菌应引起重视。     

产AmpC酶阴沟肠杆菌的基因分析及其耐药性

探讨昆明地区阴沟肠杆菌的耐药性及与结构基因ampC和调节基因ampD的相关性。通过K-B法检测阴沟肠杆菌的药敏情况,头孢西丁三维试验检测AmpC酶,PCR法扩增ampC和ampD基因。结果显示74株阴沟肠杆菌经头孢西丁三维试验检测,产AmpC酶的有17株,检出率为22.3%,而且产酶菌株抗生素敏感率低于非产酶菌株。ampC基因扩增阳性率为89.2%(66/74);64株ampD基因阳性率为86.5%(64/74)。实验证实昆明地区产酶阴沟肠杆菌耐药状况严重,与结构基因ampC和调节基因ampD密切相关。     

院内感染阴沟肠杆菌的分布及耐药性分析

随着抗生素的广泛使用,带来了严重的细菌耐药性问题。阴沟肠杆菌作为一种条件致病菌可致人体多部位感染,由于其感染率高和耐药率高,越来越引起人们的重视。我们从１９９４年６月～１９９７年６月院内感染的患者的各种标本中分离出３１０株阴沟肠杆菌,测定了对１７种抗...     

第3代头孢耐药的阴沟肠杆菌AmpC酶及ESBLs的表型测定

目的检测3代头孢耐药的阴沟肠杆菌,了解阴沟肠杆菌对3代头孢耐药的机制,以利于耐药性的控制与指导临床用药。方法收集2002年1月-2004年6月浙江省人民医院,来自各种标本对3代头孢耐药的阴沟肠杆菌165株,用三维试验检测ESBLs与AmpC酶。结果165株阴沟肠杆菌中,产ESBLs120株,占72．7％,产AmpC酶有40株,占24．2％,同时产2种酶的有1株,占0．6％,2种酶均不产的有4株,占2．5％。体外抗生素敏感试验显示,亚胺培南、头孢替坦、头孢吡肟、环丙沙星的耐药率分别为1．2％、66．0％、92．1％和92．1％,氨苄西林、头孢唑啉的耐药率达到100％。结论该院对3代头孢耐药的阴沟肠杆菌主要产ESBLs,药物敏感试验表明亚胺培南敏感率最高（97．6％）,头孢替坦次之（27．3％）,而对其它抗菌药物敏感率较低。     

阴沟肠杆菌产AmpC酶菌和非产酶菌的耐药性研究

目的：探讨阴沟肠杆菌分布特征及产AmpC酶菌和非AmpC酶菌的耐药性。方法：对临床分离的158株阴沟肠杆菌分布科室、感染部位及对16种抗生素耐药性进行分析,并通过酶粗提物头孢西丁三维试验结合PCR法检测AmpC酶。结果：标本来源主要为患者的痰液、尿液、创口分泌物等,科室以重症监护室为多,感染部位以呼吸道为主,耐药性较高的抗生素为头孢西丁、头孢噻肟、头孢曲松等,158株阴沟肠杆菌中产AmpC酶菌株共33株,产AmpC酶阳性率占总菌株数20．9％,产AmpC酶菌株对各种抗生素的耐药率比不产AmpC酶的明显增高。结论：阴沟肠杆菌的耐药与产AmpC酶有关,治疗首选亚胺培南。     

229株阴沟肠杆菌的标本分布及耐药性分析

目的 了解阴沟肠杆菌在医院感染的标本分布和耐药情况,为临床合理选择和应用抗生素提供依据.方法 采用VITEK 60全自动微生物分析仪和配套的GNI、GNS-143、GNI-448,对229株阴沟肠杆菌进行分离鉴定和药敏试验,药敏结果使用WHONET 5.5软件进行分析.结果 从2007年1月至2011年9月共分离到阴沟肠杆菌229株,59.0％来自于呼吸道标本,其次是尿液占13.5％,再次为创面分泌物/脓液占12.7％.阴沟肠杆菌对美洛培南、亚胺培南和头孢哌酮/舒巴坦的耐药率分别为0.0％、0.4％和2.5％,对氨苄西林、头孢唑啉、头孢西丁的耐药率分别为98.7％、96.9％、97.5％.结论 阴沟肠杆菌耐药机制复杂,对抗生素具有多重耐药性,临床应合理使用抗菌药物,以减少阴沟肠杆菌耐药性的产生和在院内扩散.     

老年患者阴沟肠杆菌感染的临床特点及耐药性分析

目的 了解我院老年患者阴沟肠杆菌感染的临床分布及耐药性变迁,为临床合理用药提供参考依据。方法 采用回顾性分析方法,统计临床数据并分析我院2011年9月至2016年4月期间老年患者感染标本中分离出的阴沟肠杆菌的感染现状及耐药性。结果 共检出149株阴沟肠杆菌,主要分离于痰液、全血和尿液中,分别占31.54%、24.16%和18.12%。在科室分布中,阴沟肠杆菌感染主要来源于普通外科、重症监护病房和呼吸内科,分别占26.84%、14.10%和14.10%。药敏结果显示阴沟肠杆菌对美罗培南、亚胺培南和阿米卡星具有较好的抗菌活性,敏感率分别为100.00%、96.64%和95.97%,而对阿莫西林/克拉维酸、氨苄西林、头孢替坦、头孢西丁和头孢唑啉的耐药率分别为96.36%、96.36%、97.67%、100.00%和100.00%。结论 阴沟肠杆菌易引起呼吸道、泌尿道以及伤口的感染,且其耐药现象较为严重,应加强耐药性的监测,根据药敏结果合理选用抗菌药物,以控制医院感染。     

医院感染阴沟肠杆菌的耐药性及基因型分析

了解中南大学湘雅三医院重症监护病房(ICU)医院感染阴沟肠杆菌的耐药谱及分子流行病学特征,指导临床合理用药。基因分型采用优化反应体系的随机扩增多态性DNA(RAPD)法,耐药分析选用K-B法。RAPD分型将28株阴沟肠杆菌分为11种株型,耐药谱则将其分为12种不同的耐药型。基因分型和耐药分析显示ICU有多重耐药的阴沟肠杆菌株爆发流行现象,它为控制阴沟肠杆菌的医院内感染、追踪传染原、切断传播途径提供遗传学信息,指导临床医生选用敏感有效的抗生素。     

NDM-1对阴沟肠杆菌的致病性及适应性的影响

产生新德里金属β-内酰胺酶-1 (New delhi metallol-β-lactamase 1,NDM-1)的肠杆菌科细菌对大部分β-内酰胺抗生素耐药,其导致的感染难以治疗。细菌中编码NDM-1基因的获得可能会影响它的致病性和适应性,这可能使产NDM-1的细菌的感染治疗和传播更加复杂。产NDM-1阴沟肠杆菌流行率高,现对阴沟肠杆菌的致病过程以及NDM-1对其致病性和适应性的影响作一概述,为产NDM-1阴沟肠杆菌的感染治疗和传播控制提供应对策略。     

肠杆菌科细菌肺部感染病原菌分布与耐药性监测

目的了解浙江龙游县人民医院肠杆菌科细菌肺部感染病原菌分布及耐药性,为临床合理使用抗菌药物提供依据。方法采用纸片扩散法对病原菌进行药敏试验,并进行ESBLs检测,按CLSI 2012年标准判定药敏结果,用WHONET 5.6软件分析结果。结果痰培养共分离出371株肠杆科细菌,主要为肺炎克雷伯菌、大肠埃希菌和阴沟肠杆菌,产ESBLs菌阳性率高,对碳青霉烯类抗菌药物耐药率低,均在10.00%以下,其他药物均有不同程度耐药,测试抗菌药物的耐药率差异有统计学意义（P〈0.05）。结论临床常见肠杆菌科细菌耐药率高,开展病原菌耐药性监测,对指导临床抗感染治疗合理选择抗菌药物具有重要意义。     

Expression of AmpC beta-lactamase in Enterobacter cloacae isolated from retail ground beef, cattle farm and processing facilities

AIMS: To better understand antibiotic resistance of Enterobacter cloacae isolates originated from food animals, the phenotypic and genotypic resistance of Ent. cloacae isolates from retail ground beef, cattle farm, processing facilities and clinical settings were investigated. METHODS AND RESULTS: The ampC, ampD and ampR genes in the isolates were sequenced and analysed. beta-Lactamase activities and beta-lactamase profiles of the isolates were analysed by the enzymatic hydrolysis of nitrocefin and isoelectric focussing, respectively. The ampC gene of the Ent. cloacae isolate was cloned and transformed into Escherichia coli strains. The genomic DNA profiles of Ent. cloacae isolates were analysed by using pulse field gel electrophoresis (PFGE). Mutation at one residue (Val-54-->Ile) in the AmpR amino acid sequence was consistently found in Ent. cloacae isolates that were resistant to a broadspectrum of beta-lactam agents. The enzyme activity in the isolates was induced by cefoxitin. The pI (isoelectric point) of the enzymes produced by the test strains ranged from 8.4 to 8.9. Cloning of ampC gene of the Ent. cloacae isolate conferred the resistance to ampicillin, cephalothin and amoxicillin in recipient E. coli strains. One recipient of E. coli O157:H7 strain additionally acquired resistance to ceftiofur. The genomic analysis of Ent. cloacae isolates by PFGE showed that the isolates from various sources were genetically unrelated. CONCLUSIONS: The spread of diverse clones of AmpC-producing Ent. cloacae occurred in the ecosystem and retail products. SIGNIFICANCE AND IMPACT OF THE STUDY: Our findings suggested that AmpC-producing Ent. cloacae could be a contributor in spreading beta-lactamase genes in farm environments and food processing environments.     

164株阴沟肠杆菌的药物敏感性分析

目的了解阴沟肠杆菌的药物敏感性情况以指导临床合理用药。方法对中山大学附属第一医院近3年分离出的阴沟肠杆菌的标本分布及耐药情况进行回顾性分析。结果共分离出164株阴沟肠杆菌,其对亚胺培南、头孢吡肟、阿米卡星和氧氟沙星的敏感性较高。结论阴沟肠杆菌对3代头孢菌素耐药严重,呈多重耐药性,亚胺培南仍为治疗阴沟肠杆菌严重感染的首选用药。     

Diversity of chromosomal AmpC beta-lactamases from Enterobacter cloacae isolates in a Portuguese hospital

A new regulator gene named pltZ, which is located downstream of the plt gene cluster in the genome of Pseudomonas sp. M18, was identified, sequenced and characterized in this report. The deduced amino acid sequence of PltZ shares significant homology with other bacterial regulators in the TetR family. The chromosomal pltZ disruption mutant gave rise to 4.4-fold enhancement of pyoluteorin biosynthesis but did not exert significant influence on the accumulation of phenazine-1-carboxylic acid compared with the wild-type M18. The negative regulation of pltZ on pyoluteorin biosynthesis was further confirmed by multiplied pltZ gene dosage experiments and pltA'-'lacZ translational fusion analyses.     

Chromate-resistance in a chromate-reducing strain of Enterobacter cloacae

Resistance to toxic hexavalent chromium (chromate: CrO4(2)) in Enterobacter cloacae strain HO1, isolated from an activated sludge sample, was investigated under aerobic and anaerobic conditions. Decreased uptake of 51CrO4(2-) in E. cloacae strain HO1 was observed under aerobic conditions, when compared with a standard laboratory E. cloacae strain (IAM 1624). Under anaerobic conditions E. cloacae strain HO1 was able to reduce hexavalent chromium to the less toxic trivalent form. When E. clocacae strain HO1 was grown with nitrate anaerobically, the cells were observed to lose simultaneously their chromate-reducing ability and chromate-resistance under anaerobic conditions.     

多重耐药阴沟肠杆菌质粒型AmpC酶DHA-1基因的检出

目的测定56株同时耐头孢噻肟、庆大霉素和环丙沙星的阴沟肠杆菌质粒型AmpC酶基因型。方法先后用头孢西丁纸片法、三维试验、等电聚焦及酶抑制试验和微量稀释法进行表型检测。接合试验证实酶基因的转移性。多重聚合酶链反应以及基因测序等方法鉴定质粒型AmpC酶基因型。结果受试的56株细菌中有5株三维试验阳性,其中1株能转移接合,接合子多重聚合酶链反应扩增结果呈阳性,等电点为7．8,基因测序表明和DHA-1型AmpC酶一致。结论我国的多重耐药阴沟肠杆菌已获得质粒型DHA基因,DHA基因可通过转化、接合等方式转移给其他细菌且易于传播,因此应加强监控以防DHA基因在革兰阴性菌中流行。     

Extension of resistance to cefepime and cefpirome associated to a six amino acid deletion in the H-10 helix of the cephalosporinase of an Enterobacter cloacae clinical isolate

Enterobacter cloacae CHE, a clinical strain with overproduced cephalosporinase was found to be highly resistant to the new cephalosporins, cefepime and cefpirome (MICs> or =128 microg ml(-1)). The strain was isolated from a child previously treated with cefepime. The catalytic efficiency of the purified enzyme with the third-generation cephalosporins, cefepime and cefpirome, was 10 times higher than that with the E. cloacae P99 enzyme. This was mostly due to a decrease in K(m) for these beta-lactams. The clinical isolate produced large amounts of the cephalosporinase because introduction of the ampD gene decreased ampC expression and partially restored the wild-type phenotype. Indeed, MICs of cefepime and cefpirome remained 10 times higher than those for a stable derepressed clinical isolate (OUDhyp) transformed with an ampD gene. Sequencing of the ampC gene showed that 18 nucleotides had been deleted, corresponding to the six amino acids SKVALA (residues 289--294). According to the crystal structure of P99 beta-lactamase, this deletion was located in the H-10 helix. The ampR-ampC genes from the clinical isolates CHE and OUDhyp were cloned and expressed in Escherichia coli JM101. The MICs of cefpirome and cefepime of E. coli harboring ampC and ampR genes from CHE were 100--200 times higher than those of E. coli harboring ampC and ampR genes from OUDhyp. This suggests that the deletion, confirmed by sequencing of the ampC gene, is involved in resistance to cefepime and cefpirome. However, the high level of resistance to cefepime and cefpirome observed in the E. cloacae clinical isolate was due to a combination of hyperproduction of the AmpC beta-lactamase and structural modification of the enzyme. This is the first example of an AmpC variant conferring resistance to cefepime and cefpirome, isolated as a clinical strain.     

亚胺培南不敏感的阴沟肠杆菌碳青霉烯酶基因检测

为了解亚胺培南不敏感的阴沟肠杆菌碳青霉烯酶的主要基因型及其流行情况,收集哈尔滨医科大学附属第一医院临床分离出的亚胺培南不敏感的阴沟肠杆菌24株,采用Vitek-2 Compact进行细菌鉴定、药敏试验,聚合酶链反应（PCR）扩增,DNA测序确定菌株产碳青霉烯酶基因型情况。结果显示,24株阴沟肠杆菌均表现为多重耐药,20株菌扩增出KPC-2条带,经测序证实为KPC-2型碳青霉烯酶基因。该院亚胺培南不敏感的阴沟肠杆菌产碳青霉烯酶的主要基因型别为KPC-2型,临床与实验室应加强监测和控制。