K.pneumoniae XJPD-Li甘油脱水酶基因的定点突变及其性能研究

针对菌株K.pneumoniae XJPD-Li高效转化生产1,3-丙二醇的特性,将其甘油脱水酶与已知报道的甘油脱水酶(U60992)的序列比对分析,根据差异位点设计了Nβ47I的定点突变,利用反向PCR定点突变技术构建了甘油脱水酶(dhaBCE)的突变体质粒M1821,并在E.coli BL21(DE3)中高效表达。SDS-PAGE结果显示,诱导表达后在相对分子质量66、24、16KD出现三条特征条带,与预期结果一致。突变体M1821甘油脱水酶的比酶活为38.7U/mg,催化反应最适pH为8.0,最适温度为40℃,与未突变重组甘油脱水酶比较,最适温度降低了约5℃。

budC敲除及ldhA过表达对Klebsiella pneumoniae合成D-乳酸的影响

为了提高K.pneumoniae中D-乳酸的合成效率,本文以BUD和LDH为改造目标,扩增丁二醇脱氢酶基因budC,并在其中插入四环素抗性基因tet,构建了基因敲除载体pTBT,转化K.pneumoniae,利用同源重组技术,敲除K.pneumoniae染色体上的budC基因,得到重组菌K.pneumoniae B-;在此基础上,构建了表达载体pKP-ldhA,转化K.pneumoniae B-,过量表达乳酸脱氢酶基因ldhA,得到重组菌K.pneumoniae B-L+。摇瓶发酵结果显示,重组菌K.pneumoniae B-L+的丁二醇合成浓度比原始菌降低了90%以上,D-乳酸合成浓度比K.pneumoniae B-和原始菌分别提高了77.1%和41.4%,发酵罐实验D-乳酸产量68.4 g/L,转化率0.78,生产强度1.22 g/(L.h)。结果表明,敲除budC及过表达ldhA有利于改善克雷伯肺炎杆菌中D-乳酸的合成。

Class Ⅰ integron with a novel cassette array in an ESBL-producing multidrug-resistant Klebsiella pneumoniae isolate

Objective： To analyze the molecular mechanism of integron mediated mulfi-resistanc, e in an ESBL-producing K. pneumoniae NJ 12 isolate. Methods： Susceptibility test was carried out by Kirby-Bauer method. Class Ⅰ, Ⅱ and Ⅲ integrons were detected by integrase gene PCR with primers that annealed to conserved regions of integron-encoded integrase genes intll, intl2 and intl3. The variable region of integron was amplified by integron PCR with primers that targeted the conserved flanking regions, and the product was sequenced. Six aminoglycoside modifying-enzyme genes, including ant（2＂）-Ⅰ, ant（3＂）- Ⅰ, aac（3）- Ⅰ, aac（3）-Ⅱ, aac （6＇）-Ⅰ, and aac（6＇）-Ⅱ , were detected. Results： K. pneumoniae NJ 12 was resistant to nine antibiotics, including piperacillin, ampicillin, cefuroxime, ceftazidime, cefotaxime, aztreonam, streptomycin, gentamicin and amikacin. This isolate was shown that there was positive with class Ⅰ integron, ant（2＂）- Ⅰ , ant（3＂）- Ⅰ , aac（3）-Ⅱ and aac（6＇）- Ⅰ modifying-enzyme genes. Neither class Ⅱ nor Ⅲ integron was detected; DNA sequencing of the fragment amplified by integron PCR revealed a novel cassette array aadR-cat-blaoxa-10/ aadA1. Conclusion： Class I integron with a novel cassette array in an ESBL-producing multidrug-resistant K. pneumon/ae NJ 12 isolate was reported from Nanjing area of China, with the GenBank accession number DQ141319.

Characteristics of β-Lactamase Synthesis in E. coli and K. pneumanie Strains in Nosocomial Infections

Background: Recently micro-organisms that synthesize extended-spectrum β-lactamase (ESBLs) were increased. The peculiarities of ESBL synthesis of Escherichia coli and Klebsiella pneumoniae strains that cause nosocomial urinary tract infections, surgical site infections and pneumonia in surgical clinic were studied. ESBL synthesis were observed 38.9% of E. coli strains obtained from urine, 92.3% of strains obtained from surgical site infections, and 50% of strains obtained from sputum. ESBL synthesis were observed 37.5% of K. pneumoniae strains obtained from urine, 85.7% of strains obtained from surgical site infections, and 60% of strains obtained from sputum. Different levels of ESBL synthesize of E. coli and K. pneumoniae strains isolated from different pattern is discussed. Conclusion. ESBL synthesis is common in E. coli and K. pneumoniae strains, which cause nosocomial infections. The frequency of occurrence of ESBL s synthesis among of these strains depends on clinical forms of nosocomial infections.

Study of OmpK35 and OmpK36 Expression in Carbapenem Resistant ESBL Producing Clinical Isolates of Klebsiella pneumoniae

Background: Carbapenem resistant extended spectrum β-lactamase (ESBL) producing Klebsiella pneumoniae (K. pneumoniae) is increasing worldwide. Carbapenem resistance (CR) has been attributed not only to production of carbapenemases but also to permeability barriers due to outer membrane proteins (OmpK35 and OmpK36) disruption. Objective: Phenotypic detection of CR among ESBL producing K. pneumoniae isolates, followed by the evaluation of the role of ompK35 and ompK36 gene expression among carbapenem resistant K. pneumoniae (CR-KP) isolates. Methods: 100 ESBL producing K. pneumoniae isolates were included in this study. Minimum inhibitory concentration (MIC) of imipenem was performed for all isolates by broth microdilution method. For CR-KP isolates, phenotypic detection of K. pneumoniae carbapenemase (KPC), metallo-β-lactamase (MBL) and AmpC enzymes was performed followed by Realtime qRT-PCR to detect and quantify ompK35 and ompK36 gene expression. Results: 42% of our isolates were carbapenem resistant, and all of them were KPC producers either singly or in combination with MBL and/or AmpC production. Reduced expression of both ompK35 and ompK36 was detected in (52.38%) of CR-KP isolates, while reduced expression of ompK36 or ompK35 alone was found in (2.38%) and (33.33%) respectively. Twenty of 42 CR-KP isolates (47.62%), showing reduced ompK35 and ompK36 expression, exhibited high level resistance (HLR) (>32 μg/ml) to imipenem. There was a significant correlation between reduced expression of ompK36 and increase MIC values (p < 0.05). The combined production of MBL or AmpC together with reduced expression of ompK35 and/or ompK36 resulted in significant increase in imipenem MIC (p < 0.05). Conclusion: The combined OmpK35/OmpK36 loss resulted in HLR. However OmpK36 seems to play a major role in those strains. Imipenem MIC was markedly increased among K. pneumoniae showing carbapenemase and/or AmpC production together with loss of OmpK35 and/or OmpK36.

Incidence of Extended-Spectrum Be-ta-Lactamase-Producing Klebsiella pneumoniae among Patients and in the Environment of Hassan II Hospital, Settat, Morocco

Aim: The aim of the current study is to determine: (1) the prevalence of extended-spectrum β-lactamase-producing K. pneumoniae (ESBL-Kp) isolated from clinical samples and a hospital environment in Hassan II Hospital (Settat, Morocco);(2) the associated risk factors of ESBL-Kp infections;(3) the link between clinical and environmental isolates. Methods: During the study period (April 2010 to March 2011), all patients infected and hospital environment sites contaminated by K. pneumoniae were considered as the potential study population and environmental site. The clinical data were collected to identify risk factors for ESBL carriage of K. pneumoniae infection. Screening of ESBL-and carbapenemase-producing isolates was performed by using a double-disk synergy test and the modified Hodge test, respectively. ESBL-Kp isolates were tested for the presence of genes encoding β-lactamases and were investigated by PCR. The clonal relationship between ESBL-producing isolates was analysed by ERIC- and REP-PCR method. Results: The overall prevalence of ESBL-Kp among clinical and environmental K. pneumoniae isolates was 35.13% (13/37) and 4.04% (4/99), respectively. The main risk factors for carrying ESBL-Kp were renal disease (46.15%), recent surgery (53.84%), previous hospitalisation (76.92%), and the presence of many invasive devices (53.84%). All ESBL isolates were multidrug resistant. The blaCTX-M group1and blaSHV (70.58% for each) were the most prevalent followed by blaTEM (52.94%). Thirteen strains expressed at least two bla genes. One isolate was positive in the modified Hodge test and was a blaOXA-48 producer. ERIC and Rep-PCR methods revealed an epidemic clonal dissemination of these isolates. Conclusion: The emergence of OXA-48 carbapenemase, endemic clonal dissemination and multi-drug resistance of ESBL-Kp isolates in our institution is highly alarming.

Klebsilla pneumonia XJ-Li甘油脱水酶产酶条件研究

甘油脱水酶是生物法合成1,3-丙二醇的关键限速酶,对1,3-丙二醇的合成速度和发酵终浓度具有重要的影响。本文通过实验研究了Klebsilla pneumoniae XJ-Li的基础产酶条件,结果表明:该菌株甘油脱水酶的合成与菌体的生长具有较好的偶联性,发酵8 h即可达到最大产酶高峰,同时菌体生长也达到稳定期;其最适产酶条件为:温度40℃,pH值8.0,甘油浓度20g/L,氮源为6.0g/L的硫酸铵。

Epidemiology and genetic characterization of tet(X4)-positive Klebsiella pneumoniae and Klebsiella quasipneumoniae isolated from raw meat in Chengdu City, China

The rapid spread of mobile tigecycline resistance presents a significant public health threat,particularly with the increasing prevalence of tet(X4)-positive Enterobacterales across various species.This study aimed to inves-tigate the epidemic features and transmission dynamics of tet(X4)-positive Klebsiella pneumoniae(K.pneumo-niae)through the analysis of 206 raw meats,including pork(n=182),beef(n=16),duck(n=5),and chicken(n=3).These samples were collected from schools,markets,and restaurants in Chengdu City,China.A total of 25 isolates were obtained from 13 administrative regions.All isolates exhibited resistance to tetracycline,tigecycline,ampicillin,chloramphenicol,and florfenicol.Over half of the isolates also demon-strated resistance to streptomycin(80%),sulfamethoxazole/trimethoprim(72%),ciprofloxacin(64%),and ampicillin/sulbactam(56%).Among these strains,14 distinct sequence types(STs)were identified,revealing evidence of inter-regional clonal spread,notably among 9 K.pneumoniae ST3393.Phylogenetic analysis revealed the presence of two K.pneumoniae ST5 closely resembling hypervirulent K.pneumoniae from Jiangsu.Importantly,12 isolates were capable of transferring tigecycline resistance to Escherichia coli J53.Further plasmid analysis showed that the tet(X4)-harboring plasmids in K.pneumoniae could be classified into four types,primarily belonging to the IncFIA(HI1)/HI1A/HI1B hybrid plasmid(n=16)and IncFII plasmid(n=7),which significantly contributed to the cross-species dissemination of tet(X4).In summary,this study highlights the prevalence of MDR tet(X4)-positive K.pneumoniae in Chengdu,driven predominantly by clonal expansion and plasmid-mediated horizontal gene transfer.These findings emphasize the importance of contin-uous surveillance of tet(X4)-positive K.pneumoniae in raw meat and the implementation of effective measures to control their spread.

产KPC型碳青霉烯酶肠杆菌科细菌感染的临床和微生物学特点

目的研究分析产KPC型碳青霉烯酶肠杆菌科细菌感染的临床和微生物学特点。方法收集2011年1—12月武警总医院18株产KPC酶的肠杆菌科细菌,使用PCR和测序的方法对菌株进行鉴定,用微量肉汤稀释法检测其对常用抗菌药物的耐药性,并对产碳青霉烯酶肺炎克雷伯菌感染的病例临床资料进行调查分析。结果 2011年从临床送检的标本中,通过表型鉴定和PCR检测,共分离出产KPC型碳青霉烯酶细菌18株,其中肺炎克雷伯菌13株,大肠埃希菌4株,产气肠杆菌1株。90%患者在产KPC型碳青霉烯酶肠杆菌科细菌分离之前,使用过头孢菌素类(包括第二、三、四代头孢菌素)、头霉素、氨曲南和β内酰胺酶抑制剂复方制剂,70%患者使用过碳青霉烯类抗生素。所有菌株对头孢菌素类和碳青霉烯类抗生素耐药,对阿米卡星的敏感率为60.0%,对替加环素的敏感率为100%。经过治疗后,7例患者死亡,病死率43.8%。结论产KPC型碳青霉烯酶肠杆菌科细菌的出现,提示临床上应严格控制抗生素的使用,加强医院感染控制措施,防止和减少此类耐药菌在医院内的传播。

肺炎克雷伯菌中 K1、K2血清型菌株的分布及其耐药性分析

目的了解K1、K2血清型肺炎克雷伯菌、毒性因子rmpA在临床感染中的分布及耐药性。方法拉丝试验确定144株肺炎克雷伯菌黏液表型,用多重聚合酶链反应(PCR)检测K1、K2和rmpA基因。结果 144株不同感染来源的肺炎克雷伯菌中,黏液型菌株占62.5%(90/144);K1、K2血清型阳性率为52.1%(75/144),rmpA阳性率为65.3%(94/144),其中K1、K2血清型与rmpA共同阳性菌株占K1、K2血清型总数的90.7%(68/75)。K1、K2血清型、rmpA基因黏液型和非黏液型菌株分别为63.3%(57/90)、85.6%(77/90)和33.3%(18/54)、31.5%(17/54)。K1、K2血清型肺炎克雷伯菌在有无rmpA基因肺炎克雷伯菌中分别为72.3%(68/94)和14.0%(7/50)。黏液型菌株在42例肝脓肿、16例其他部位脓肿、37例血流感染、14例社区获得性肺炎(CAP)、21例尿路感染(UTI)和14例胆道感染中分别占85.7%(36/42)、81.3%(13/16)、40.5%(15/37)、85.7%(12/14)、52.4%(11/21)和21.4%(3/14)。K1、K2血清型分别为88.1%(37/42)、56.3%(9/16)、29.7%(11/37)、64.3%、(9/14)、38.1%(8/21)和7.1%(1/14)。K1血清型在肝脓肿占61.9%(26/42);K1、K2血清型在其他部位脓肿、CAP、UTI和血流感染中比例相近;非-K1、K2血清型则多见于胆道感染。黏液型和非黏液型菌株产超广谱β内酰胺酶(ESBL)率分别为5.6%和33.3%。前者对多数抗菌药物耐药率低于后者。结论 rmpA基因与肺炎克雷伯菌黏液表型密切相关,并多与K1、K2血清型肺炎克雷伯菌共存,K1、K2血清型肺炎克雷伯菌是肝脓肿和CAP的重要病原菌,在其他部位脓肿、UTI、血流感染也较常见,K1血清型肺炎克雷伯菌在肝脓肿多见,K1、K2血清型肺炎克雷伯菌在其他感染中比例相近。黏液型菌株产ESBL率和对多数抗菌药耐药率低于非黏液型菌株。

Oxidative stress-initiated one-carbon metabolism drives the generation of interleukin-10-producing B cells to resolve pneumonia

The metabolic reprogramming underlying the generation of regulatory B cells during infectious diseases remains unknown.Using a Pseudomonas aeruginosa-induced pneumonia model,we reported that IL-10-producing B cells(IL-10+B cells)play a key role in spontaneously resolving infection-mediated inflammation.Accumulated cytosolic reactive oxygen species(ROS)during inflammation were shown to drive IL-10+B-cell generation by remodeling one-carbon metabolism.Depletion of the enzyme serine hydroxymethyltransferase 1(Shmt1)led to inadequate one-carbon metabolism and decreased IL-10+B-cell production.Furthermore,increased one-carbon flux elevated the levels of the methyl donor S-adenosylmethionine(SAM),altering histone H3 lysine 4 methylation(H3K4me)at the Il10 gene to promote chromatin accessibility and upregulate Il10 expression in B cells.Therefore,the one-carbon metabolism-associated compound ethacrynic acid(EA)was screened and found to potentially treat infectious pneumonia by boosting IL-10+B-cell generation.Overall,these findings reveal that ROS serve as modulators to resolve inflammation by reprogramming one-carbon metabolism pathways in B cells.

产KPC酶肺炎克雷伯菌9株的药敏试验结果分析

目的分析产KPC酶肺炎克雷伯菌的耐药性和基因型及对替加环素的敏感性,为临床治疗该类菌感染提供依据。方法收集2012年2月—2013年5月自临床科室分离的碳青霉烯类耐药肺炎克雷伯菌9株,采用VITEK2 Compact全自动微生物鉴定系统进行细菌鉴定及药敏试验,改良Hodge试验检测碳青霉烯酶,聚合酶链反应(PCR)法检测菌株的KPC酶基因型,E试验法检测替加环素对菌株的体外抗菌活性。结果所分离的9株肺炎克雷伯菌对所测试的19种抗菌药物均显耐药,7株改良Hodge试验阳性。9株肺炎克雷伯菌均扩增出KPC目的基因条带,均为KPC-2型基因。9株耐药菌对替加环素均敏感。结论产KPC酶肺炎克雷伯菌耐药形势严峻,替加环素作为新一代抗生素对其有良好的体外抗菌活性。

产KPC铜绿假单胞菌的耐药性研究

目的探讨产肺炎克雷伯菌碳青霉烯酶(KPC)铜绿假单胞菌的耐药性。方法铜绿假单胞菌菌株来自2例痰液标本。采用VITEK 2COMPACT全自动微生物鉴定/药敏分析仪进行细菌菌株的鉴定,应用聚合酶链反应(PCR)及基因测序法鉴定KPC酶基因型,采用肉汤稀释法进行抗菌药的最低抑菌浓度(MIC)测定。结果 2例菌株均对β-内酰胺类抗菌药、左氧氟沙星耐药,对环丙沙星中介,对庆大霉素、奈替米星、妥布霉素、黏菌素及多黏菌素B敏感;其中1株还对替加环素敏感。2例菌株所产碳青霉烯酶不是金属β-内酰胺酶,其亚型为KPC-2。接合实验未能证明bla KPC基因能接合转移到大肠埃希菌J53中。结论产KPC铜绿假单胞菌的出现给临床抗感染治疗带来严峻挑战。

基于K-means的脑卒中相关肺炎的预测模型研究

目的:通过机器学习对天坛医院大数据平台的脑卒中并发肺炎相关数据进行分析,并评估智能统计预测手段在临床的应用价值。方法:从大数据平台抽取278例卒中并发肺炎患者的完整病例资料,采用K-means聚类算法进行预测分析。结果:基于K-means建立的预测模型准确度为0.713,F1值为0.681,AUC曲线下面积为0.734。结论:K-means除了用于聚类分析以外,在脑卒中患者是否并发相关肺炎应用中具有良好的预测性能。

Increasing Incidence of Extended-Spectrum Beta-Lactamase-Producing Enterobacteriaceae (ESBL) and the Relation to Consumption of Broad-Spectrum Antimicrobial Agents 2003-2011 in a Large Area of Copenhagen, Denmark

Purpose: To investigate 1) the development in the incidence of ESBL-producing bacteria in hospitals and primary health care, 2) the contribution of primary health care to the incidence of ESBL-producing bacteria, and 3) the development in resistance patterns for all Escherichia coli and Klebsiella pneumoniae isolates in relation to antimicrobial consumption in hospitals and primary health care. Methods: ESBL-data were retrospectively collected from bacterial isolates from all specimens received at the Department of Clinical Microbiology from 2003 to 2011 together with the corresponding patient data. ESBL-production was detected in isolates from 1067 of 59,373 patients (1.8%) with an E. coli infection and in 263 of 8660 patients (3.0%) with a K. pneumoniae infection. Results: From 2003 to 2009, an increase in patients with an ESBL-producing isolate occurred in both hospitals and primary health care at the same time as an increased consumption of broad-spectrum antimicrobial agents was seen. Interventions to reduce prescription of cephalosporins and ciprofloxacin at the hospitals from 2010 resulted in a remarkable decrease in patients with ESBL-producing K. pneumoniae whereas a continuing increase was seen in patients with ESBL-producing E. coli both at hospitals and in primary health care. The proportion of patients with community-acquired ESBL-producing E. coli was stable with an increase of only 1.4% from 2007 to 2011. Conclusions: Reduction in prescription of broad-spectrum antimicrobial agents at the hospital level had an important impact on the incidence of ESBL-producing K. pneumoniae, but not on ESBL-producing E. coli.

Isolation and Identification of Alkali-Resistant 1,3-Propanediol Producing Strain

1,3-Propanediol is a promising renewable resource produced by microbial production. It is mainly used in many synthetic reactions, particularly applied to the polymer synthesis and cosmetics industry. We described here the isolation of strain ZH-1, which has the ability of high production with 1,3-propanediol, from Fenhe River in China. It was classified as a member of K. pneumoniae after the study of phenotypic, physio-logical, biochemical and phylogenetic (16S rDNA). The initial glycerol concentration, fermentation time and pH value of strain ZH-1 were determined to be 50 g·L-1, 36 h and 8.0. Under these conditions, the practical yield of 1,3-PD was 18.53 g·L-1 and a molar yield (mol1,3-PD molGlycerol-1 of 1,3-propanediol to glycerol of 0.497. In addition, we found that for the strain ZH-1, the optimum grown pH was 9.0, so we can deter-mine that it is a new member of alkali-resistant strains.

云南某医院多耐药E.coli和K.pneumoniae分子流行病学分析

目的分析云南某医院E.coli和K.pneumonia菌耐药基因分子流行病学特征。方法全自动微生物分析仪分类鉴定菌株及抗生素敏感试验。扩增并序列分析耐药基因。MLST及PFGE分析菌株遗传变异关系。结果共收集23株E.coli菌和9株K.pneumonia菌,除了1株XDR K.pneumoniae,其余均为MDR菌。全部菌株对一代、二代头孢霉素,甚至三代头孢霉素CRO耐药。绝大多数菌株对氟化奎林酮类、氨基苷类及磺胺类抗生素耐药。39.1%和69.6%E.coli携带blaTEM和blaCTX基因,而44.4%和100.0%K.pneumoniae检测到blaTEM和blaCTX基因。bla TEM均为TEM-1基因型。CTX-M-55及CTX-M-15为该地区优势基因型。所有K.pneumonia菌株携带blaSHV基因,SHV-11为优势型。87.5%E.coli和77.8%K.pneumoniae菌株携带ISEcp1。91.3%E.coli和77.8%K.pneumoniae携带int1。44.4%K.pneumoniae携带ISCR1基因。PFGE及MLST研究显示菌株存在明显的遗传多态性。结论云南该医院多重耐药E.coli和K.pneumonia菌呈高度流行,耐药基因在不同菌株及菌种间快速传播。

甘油和半纤维素水解液共发酵生产1,3-丙二醇

建立了以K.pneumoniae为菌种,甘油和半纤维素水解液(HH)共发酵生产1,3-丙二醇(1,3-PDO)的体系。通过添加HH,1,3-PDO的质量浓度、甘油的转化率和生产力比甘油单独发酵分别提高了18.2%,24.4%,18.0%。HH中的木糖和甘露糖能显著提高1,3-PDO的产量和生物量,葡萄糖对1,3-PDO的合成产生抑制,半乳糖和阿拉伯糖对1,3-PDO的合成没有影响。与不添加抑制物相比,添加0.28 g/L糠醛时,生物量提高了12%,1,3-PDO的产量有微量提高;添加0.61 g/L甲酸盐时,对细胞生长和1,3-PDO的合成产生轻微抑制,分别降低了9.8%和1.1%;添加1.46 g/L乙酸盐时,细胞生长略有提高,1,3-PDO的质量浓度从8.77 g/L增至11.73 g/L。在补料分批发酵中添加HH,1,3-PDO的质量浓度、甘油的转化率和生产力分别提高到71.58 g/L,65%,1.93 g/(L.h),比甘油单独发酵分别提高了17.8%,25.0%,17.7%。

19家医院大肠埃希菌和肺炎克雷伯菌中TEM型β-内酰胺酶的研究

目的检测全国19家医院大肠埃希菌和肺炎克雷伯菌中的TEM型ESBLs。方法收集2004～2005年全国19家医院对头孢他啶耐药的大肠埃希菌98株和肺炎克雷伯菌109株，琼脂稀释法测定菌株MICs，PCR扩增blaTEM基因。扩增阳性菌株进行接合实验，测定接合子MICs并PCR扩增blaTEM基因。扩增阳性的菌株和接合子以等电聚焦电泳（IEF）检测其β-内酰胺酶等电点。对具有典型TEM型ESBLs表型的菌株进行测序和变性高效液相色谱（DHPLC）分析。进一步收集检出突变菌株的宿主患者及其所在病房分离的对头孢他啶不敏感的菌株，进行测序、DHPLC分析，以及ERIC—PCR和RAPD分型。结果实验菌株中大肠埃希菌和肺炎克雷伯菌ESBL阳性率分别为84．7％和68．8％，blaTEM基因阳性率分别为67．3％和69．7％。仅1株大肠埃希茵P34表达TEM-12型ESBL，其他均为TEM-1（广谱β-内酰胺酶）。P34宿主患者分离的21株大肠埃希菌中有18株表达TEM-12，且所有菌株均为同一克隆。该患者住院期间所在病房分离的11株对头孢他啶不敏感大肠埃希菌均表达TEM-1，与P34均不是同一克隆，但不同患者间存在菌株的水平传播。结论TEM型ESBLs已在中国出现，但仍罕见，不是导致菌株对头孢他啶耐药的主要原因。本研究在国内首次报道了TEM-12型ESBL，该菌株虽未引起流行，但仍应引起重视。必须加强感染控制，防止TEM型ESBLs在中国的传播。

安徽省809株肺炎克雷伯菌感染的临床分布、耐药性与基因型分析

目的了解安徽省2013年与2014年肺炎克雷伯菌感染的临床分布及耐药情况,为临床合理使用抗菌药物药供参考依据。方法收集安徽省内35所医院送检的临床标本,从中分离出肺炎克雷伯菌株,采用琼脂倍比稀释法进行抗菌药物敏感性测定,用WHONET 5.6和SPSS l7.0软件对肺炎克雷伯菌的来源、耐药率及其变化情况进行统计分析。结果 2013—2014年共分离出肺炎克雷伯菌809株,其中来源于ICU的标本中的检出率最高,平均检出率为30.7%。绝大部分菌株分离于痰液标本,占总菌株的57.8%。两年的菌株产ESBLs菌株的检出率分别为32.5%和38.9%,多重耐药检出率分别为37.2%和40.9%。药物敏感试验结果显示:在所有进行检测的抗菌药物里,碳青霉烯类药物的耐药率最低;耐药率最高的药物为氨苄西林,分别为55.4%和63.4%。产ESBLs的肺炎克雷伯菌菌株对多种类抗菌药物的耐药率均高于非产ESBLs菌株。282株产ESBLs肺炎克雷伯菌中,97株细菌携带blaCTX-M-14基因。结论临床标本分离出肺炎克雷伯菌株较多,CTX-M-14型超广谱β-内酰胺酶为主要的耐药机制,因此该菌株对临床常用的各类抗菌药物呈现出不同程度的耐药;治疗上可优先选用含酶抑制剂的复合制剂或碳青霉烯类药物。加强细菌的耐药性监测与防控,有利于临床合理使用抗菌药物。