大肠埃希菌和肺炎克雷伯菌耐药机制检测

目的筛查大肠埃希菌与肺炎克雷伯菌膜孔蛋白基因情况,分析其与耐药的关系。方法随机抽取2008—2010年耐3代头孢菌素(头孢他啶)的大肠埃希菌72株和肺炎克雷伯菌57株,56株头孢他啶敏感的大肠埃希菌和肺炎克雷伯菌为对照组;三维试验确定细菌头孢菌素β-内酰胺酶(AmpC酶)的产生情况;超广谱β-内酰胺酶(ESBL)确证试验检测细菌产ESBL的情况;多重聚合酶链反应(PCR)扩增AmpC基因和膜孔蛋白ompF、ompk35、ompk36基因;纸片扩散法检测抗菌药物的敏感性。结果 72株大肠埃希菌中,14株产AmpC酶,23株产ESBL,3株膜孔蛋白基因缺失;57株肺炎克雷伯菌中,13株产AmpC酶,19株产ESBL,5株膜孔蛋白缺失,膜孔蛋白缺失株4代头孢均出现耐药。结论我院大肠埃希菌和肺炎克雷伯菌对头孢类抗生素的耐药机制主要是产AmpC酶和ESBLs,同时膜孔蛋白基因的缺失会造成耐药程度增高。     

Alteration of antibacterial activity of tosufloxacin and various antibacterial agents against Streptococcus pneumoniae

The minimum inhibitory concentrations (MICs) of tosufloxacin (TFLX), levofloxacin (LVFX), ciprofloxacin (CPFX), gatifloxacin (GFLX), sparfloxacin (SPFX), azithromycin (AZM), cefteram (CFTM), cefdinir (CFDN) and cefpodoxime (CPDX) against 337 clinical isolates of Streptococcus pneumoniae isolated from Japanese hospital from 1997 to 2002 were investigated by agar plate method. The incidence of penicillin-susceptible S. pneumoniae (PSSP), penicillin-intermediate resistant S. pneumoniae (PISP), and penicillin-resistant S. pneumoniae (PRSP) in each year was studied, and the MICs of antibacterial agents against these strains were determined. As the results, the total incidence of PSSP, PISP, and PRSP was 51.0%, 40.4% and 8.6%, respectively. The incidences of PSSP from 1997 to 2002 were 46.0-55.9%, and were almost definite in each year. In quinolone antibiotics, the differences of antibacterial activity among TFLX, SPFX, and GFLX against PSSP, PISP, and PRSP, were not observed, and these 3 quinolones had potent antibacterial activity. Although CPFX and LVFX showed antibacterial activity as well as other quinolones by 2001, the CPFX-resistant or LVFX-intermediate resistant strains of PSSP were seen with 56.5% and 91.3% in 2002, respectively. Thirty percents of each PSSP, PISP, and PRSP strains were AZM-resistant strains. Such tendency of increase was recognized in PSSP. Against cephem antibiotics, the incidence of intermediate resistant and resistant strains was higher for PISP and PRSP than for PSSP. No difference in the incidence of resistant strains was noted among CFTM, CFDN, and CPDX.     

大肠埃希菌和肺炎克雷伯菌产超广谱β-内酰胺酶的探讨

目的：了解本地区分离的大肠埃希菌和肺炎克雷伯菌产超广谱β-酰胺酶的发生率、耐药性及超广谱β-酰胺酶可能的基因型。方法：用MICs试验和PCR方法研究了从武汉地区医院ICU病房收集的288株大肠埃希菌和103株肺炎克雷伯菌产超广谱β-酰胺酶的发生率、可能的基因型。结果：强产超广谱β-酰胺酶的大肠埃希菌和肺炎克雷伯菌的发生率分别为25．0％（72／288）和46．6％（48／103）。RAPD分析显示一些不同的产超广谱β-酰胺酶的菌株具有相同的RAPD型别，而不同的RAPD型别的菌株可能含有相同的产超广谱β-酰胺酶的基因型。这些菌株耐受绝大部分含β-内酰胺的药物（包括第3代头孢菌素）和不含β-酰胺的药物（例如氨基糖苷、四环素和氯霉素），几乎所有的产超广谱β-内酰胺酶菌株对亚氨培南，头孢美唑和β-酰胺／克拉维酸敏感。TEM是产超广谱β-内酰胺酶的主要基因型，CTX-M型也常见，其中以CTX-M-3为主。产超广谱β-酰胺酶一些的大肠埃希菌和大部分的肺炎克雷伯菌的菌株含不止一个超广谱β-酰胺酶的基因型。产超广谱β-酰胺酶菌株的传播绝大部分依赖质粒的水平转移。结论：这些结果证明在武汉地区分离的大肠埃希菌和肺炎克雷伯菌菌株产超广谱β-酰胺酶很常见，对这些菌株的监测和阻止其传播具有重要意义。     

肺炎克雷伯菌、大肠埃希菌耐药性变迁分析

目的了解临床分离肺炎克雷伯菌、大肠埃希菌对抗生素耐药性变迁。方法采用VITEK-32微生物全自动分析系统进行细菌鉴定和药敏检测。结果4年中肺炎克雷伯菌、大肠埃希菌超广谱β-内酰胺酶（ESBLs）的发生率呈逐年上升的趋势。2005年至2008年肺炎克雷伯菌、大肠埃希菌ESBLs菌发生率分别为36．6％、40．6％、41．5％、41．0％;产ESBLs菌对三代头孢、氨基糖苷类、喹诺酮类和磺胺类交叉耐药,且呈逐年上升趋势。结论肺炎克雷伯菌、大肠埃希菌的发生率呈逐年上升趋势,耐药率升高,临床应及时了解它们的耐药特点和变化,合理使用抗生素,有效控制ESBLs的传播。     

产超广谱β-内酰胺酶的大肠埃希菌和肺炎克雷伯菌所致医院感染的危险因素分析

目的:分析产超广谱β-内酰胺酶的大肠埃希菌和肺炎克雷伯菌(ESBLs-EK)所致医院感染的危险因素。方法:以2008-2010年产ESBLs-EK所致医院感染的84例患者为病例组,同期168例非产ESBLs-EK所致医院感染的患者为对照组,采用单因素和多因素Logistic回归分析其危险因素。结果:单因素分析表明,气管插管或切开,体内留置导管,含酶抑制剂、喹诺酮类、第3代头孢菌素类的应用是产ESBLs-EK所致医院感染的危险因素;多因素Logistic回归分析表明,气管插管或切开,含酶抑制剂、喹诺酮类及第3代头孢菌素类的应用是独立的危险因素。结论:ESBLs-EK所致医院感染的危险因素为多种,主要与抗菌药物如含酶抑制剂、喹诺酮类、第3代头孢菌素类的使用及侵袭性操作有关。     

Therapeutic challenges associated with extended-spectrum, beta-lactamase-producing Escherichia coli and Klebsiella pneumoniae

The emergence of extended-spectrum beta-lactamase (ESBL)-producing Enterobacteriaceae, particularly Escherichia coli and Klebsiella pneumoniae, presents significant diagnostic and therapeutic challenges to the management of infections due to these organisms. Detection of resistant isolates is difficult based on routine susceptibility testing performed by a clinical microbiology laboratory. In addition, the utility of penicillins, cephalosporins, and aztreonam in treating serious infections due to these organisms is uncertain due to reports of treatment failure despite apparent in vitro susceptibility. A critical evaluation of the English literature was performed on treatment outcomes associated with ESBL-producing Enterobacteriaceae. Imipenem and extended-spectrum cephalosporins were commonly administered. Discordant outcomes in relation to in vitro susceptibility of the agent did not occur exclusively with cephalosporins but with all drugs including imipenem. Until more outcome data are available, drug selection must take into consideration whether or not an outbreak is occurring and whether therapy is empirical or definitive.     

Distribution and antibiotic sensitivity of Escherichia coli and Klebsiella pneumoniae in bloodstream infections

目的 回顾性分析大肠埃希菌和肺炎克雷伯杆菌血流感染临床分布及药敏特征.方法 收集71例次大肠埃希菌及21例次肺炎克雷伯杆菌血流感染患者的年龄、性别、入住科室、基础疾病及其药敏结果资料.药敏试验采用Kirby-Bauer法.结果 急性白血病是高发基础疾病.大肠埃希菌及肺炎克雷伯杆菌产超广谱β-内酰胺酶(ESBLs)阳性率分别为67.6％和42.8％.近3年中,肺炎克雷伯杆菌产ESBLs的比例有上升趋势,产ESBLs菌对除亚胺培南、丁胺卡那霉素外的其它常用抗菌药物敏感率均明显低于非产ESBLs菌(P＜0.05).结论 血流感染中,大肠埃希菌、肺炎克雷伯杆菌产ESBLs率高,产酶菌对多种常用抗菌药物高度耐药,亚胺培南仍是经验治疗的首选药物.     

大肠埃希菌及肺炎克雷伯杆菌血流感染分布及药敏分析

目的回顾性分析大肠埃希菌和肺炎克雷伯杆菌血流感染临床分布及药敏特征。方法收集71例次大肠埃希菌及21例次肺炎克雷伯杆菌血流感染患者的年龄、性别、入住科室、基础疾病及其药敏结果资料。药敏试验采用Kirby-Bauer法。结果急性白血病是高发基础疾病。大肠埃希菌及肺炎克雷伯杆菌产超广谱β-内酰胺酶(ESBLs)阳性率分别为67.6%和42.8%。近3年中,肺炎克雷伯杆菌产ESBLs的比例有上升趋势,产ESBLs菌对除亚胺培南、丁胺卡那霉素外的其它常用抗菌药物敏感率均明显低于非产ESBLs菌(P<0.05)。结论血流感染中,大肠埃希菌、肺炎克雷伯杆菌产ESBLs率高,产酶菌对多种常用抗菌药物高度耐药,亚胺培南仍是经验治疗的首选药物。     

福州地区肺炎克雷伯氏菌和大肠埃希氏菌的药敏监测

目的监测福州地区肺炎克雷伯氏菌和大肠埃希氏菌对14种常用抗生素的药敏情况，为临床合理选用抗生素提供依据。方法收集2001年3月-10月福州地区4家医院分离的肺炎克雷伯氏菌和大肠埃希氏菌426株，用K-B琼脂扩散法作药敏试验；用表型确认试验检测超广谱β-内酰胺酶(ESBLs)。结果在14种抗生素中，敏感性最高的是亚胺培南(100％)、头孢哌酮／舒巴坦(100％)、哌拉西林／三唑巴坦(99．53％)、头孢吡肟(94．37％)和头孢美唑(91．08％)，敏感性最低的是阿莫西林(12．68％)、哌拉西林(48．83％)和环丙沙星(50．70％)；除头孢他啶外，第三代头孢菌素对肺炎克雷伯氏菌和大肠埃希氏菌的耐药率均在30％以上；产ESBLs菌检出率为33．33％(142／426)；除亚胺培南、头孢哌酮／舒巴坦、哌拉西林／三唑巴坦和头孢美唑外，产ESBLs菌对其它10种抗生素的耐药率均显著高于非产ESBLs菌。结论亚胺培南、头孢哌酮／舒巴坦、哌拉西林／三唑巴坦、头孢吡肟和头孢美唑的敏感性最高，产ESBLs是肺炎克雷伯氏菌和大肠埃希氏菌产生耐药的主要机制之一，临床实验室有必要常规检测肺炎克雷伯氏菌和大肠埃希氏菌是否产ESBLs。     

肺炎克雷伯菌和大肠埃希菌耐药性与对多种抗菌药物使用量间的相关性分析

目的 了解严格执行抗菌药使用分级管理,控制抗菌药使用的情况下,肺炎克雷伯菌(Kp)和大肠埃希菌(E.coli)耐药的变化,探讨抗菌药使用与耐药之间的关系,为合理使用抗菌药物提供依据.方法 按季度对药敏试验结果和抗菌药使用频度(DDDS)进行统计,以Spearman相关分析法进行分析.结果 只有头孢哌酮/舒巴坦(CSL)对Kp始终保持高度敏感性,哌拉西林舒巴坦(TZP),美罗培南(IMP)和亚胺培南(MEM)耐药增长较大.对于大肠埃希菌,只有头孢他啶(CAZ),头孢吡肟(FEP)耐药呈上升趋势.头孢美唑(CMZ),头霉素类(Cephamycin),MEM以及氨基糖苷类都可影响两种细菌对其他抗菌药物的耐药率.对于Kp,CMZ DDDS与MEM,IMP,头孢噻肟(CTX),TZP高度相关(r=0.816、0.847、0.806和0.782).头霉素类DDDS与CTX、MEM和IMP中度到高度相关(r=0.585、0.673和0.815).MEM DDDS与CMZ和IMP中度相关(r＝-0.599和0.595),氨基糖苷类DDDS与MEM和CMZ的耐药率中度相关(r=0.617和0.711).对于大肠埃希菌,头霉素类、CMZ、MEM和氨基糖苷类DDDS与哌拉西林(PIP)耐药相关(r=0.722、0.721、0.634和0.606),CMZ和氨基糖苷类DDDS与CTX耐药相关(r=0.77,0.594).Kp抗菌药耐药率间相关分析发现只有环丙沙星(CIP)、SXT、CSL和FEP耐药不与其它抗菌药耐药相关,对于大肠埃希菌,只有PIP、CTX、CAZ、FEP、头孢克洛(CEC)和头孢呋辛(CXM)耐药率相互问存在相关.结论 头霉素类对其它抗菌药耐药的影响,抗菌药耐药率间相关分析可能有助于多重耐药的Kp和大肠埃希菌经验用药的选择.要控制耐药率增长,除了合理使用抗菌药,还必须控制医院感染,实行严格的隔离消毒制度.     

Sequential loss of outer membrane lipopolysaccharide and sensitivity of Escherichia coli to antibacterial agents

The effects of 3 phenolics and of a homologous series of esters of para-hydroxybenzoic acid (the parabens) on Escherichia coli with known deletions in outer membrane lipopolysaccharide (LPS) are described. Of the phenolics, chlorocresol was the most active and phenol the least, with butyl p-hydroxybenzoate the most effective paraben. The most sensitive strain to the various inhibitors was usually a deep rough mutant (heptoseless LPS). Studies were also made with a chelating agent, ethylenediamine tetraacetate (EDTA) in combination with some parabens. EDTA potentiated, to some extent, the activity of the methyl and butyl esters, its activity depending upon the concentration at which it was employed.     

Extended-spectrum beta-lactamase types in Klebsiella pneumoniae and Escherichia coli in two Greek hospitals

Seventy-nine Klebsiella pneumoniae and 124 Escherichia coli clinical strains, isolated consecutively during August-October 2001 in two Greek hospitals, were examined for production of extended-spectrum beta-lactamases (ESBLs). Seventy-one (35%) isolates (46 K. pneumoniae and 25 E. coli) were ESBL-positive by phenotypic methods. Isoelectric focusing of beta-lactamases and PCR assays for bla genes showed that SHV-5-type ESBLs were the most frequent (45 isolates, 22%) followed by CTX-M (24 isolates, 12%) and IBC (three isolates, 1.5%). The latter two ESBL types may have been established recently in this setting.     

大肠埃希菌和肺炎克雷伯菌门诊与住院患者分离菌株耐药性比较及临床意义

目的比较大肠埃希菌和肺炎克雷伯菌门诊与住院患者分离菌株耐药性的差异及临床意义。方法用MicroScan Walk-AWay-40全自动微生物分析仪鉴定细菌,用微量液体稀释法测定18种抗菌药物的耐药性,用NCCLS2004推荐的确证试验检测ES-BLs。结果住院患者分离大肠埃希菌对头孢唑啉、头孢噻吩、头孢呋肟、氨苄西林/舒巴坦、庆大霉素、头孢他啶、妥布霉素、头孢西丁、阿米卡星等抗菌药物耐药率显著高于门诊患者（P〈0.05）;住院患者分离肺炎克雷伯菌对氨苄西林/舒巴坦、哌拉西林、头孢唑啉、头孢噻吩、头孢呋肟、环丙沙星、复方新诺明、庆大霉素、头孢他啶、妥布霉素、氨曲南、头孢西丁、头孢曲松、头孢噻肟、阿米卡星、哌拉西林/他唑巴坦等抗菌药物的耐药率显著高于门诊患者（P〈0.05）;两种细菌住院患者分离菌株ESBLs菌株检出率均显著高于门诊患者（P〈0.05）。结论社区感染菌株的药物敏感性较高,可用抗菌药物的范围较广,对门诊患者的治疗要选用不同与住院患者的抗菌治疗方案,尽量使用青霉素类或第一代、第二代头孢菌素,减少第三代头孢菌素和亚胺培南的使用。     

Another look at differences in the susceptibility of Escherichia coli and Klebsiella pneumoniae to cephalothin and cefazolin

The significance of in vitro susceptibility tests on Enterobacteriaceae to cephalothin and cefazolin has not been exactly defined in the guidelines of the National Committee for Clinical Laboratory Standards. In the hope of clarifying this confusion, we provide additional information from an ancillary study of the Taiwan Surveillance of Antimicrobial Resistance 1998 (TSAR I). There were 505 Escherichia coli and 227 Klebsiella pneumoniae isolates susceptible to cephalothin, reported by 42 participating hospitals. The susceptibility of these isolates were re-tested at the Microbial Infections Reference Laboratory using cefazolin, with the result that 72% of the 252 cephalothin-resistant E. coli isolates and 24% of the 41 cephalothin-resistant K. pneumoniae isolates were found to be susceptible to cefazolin. We further surveyed the availability of cephalothin and cefazolin in Pharmacy Departments; all of the TSAR I hospitals had cefazolin available in their pharmacies. The resistance rate of E. coli was significantly lower for 12 hospitals that had cefazolin in both pharmacy and laboratory compared with 11 hospitals that had cefazolin available in pharmacy but cephalothin in laboratory. In addition, for all the hospitals that had cephalothin available for clinical use, the resistance rate was twice as low in two hospitals reporting cefazolin susceptibility as in the seven hospitals reporting cephalothin susceptibility. Our findings suggest that inappropriate selection of cephalothin and cefazolin for susceptibility testing contribute to inaccurate indications of in vivo activity for first generation cephalosporins in the treatment of E. coli infections.     

头孢吡肟对肺炎克雷伯氏菌和大肠埃希氏菌的体外敏感性

目的　评价第四代头孢菌素头孢吡肟对 4 2 6株肺炎克雷伯氏菌和大肠埃希氏菌的体外敏感性。方法　收集 2 0 0 1年 3～ 10月福州地区 4家医院分离的肺炎克雷伯氏菌和大肠埃希氏菌 4 2 6株 ,用 Kirby-Bauer琼脂扩散法作药敏试验 :用表型确认试验检测 ESBL s。结果　 4 2 6株肺炎克雷伯氏菌和大肠埃希氏菌中 ,头孢吡肟的敏感性为 94 .37% ,仅次于亚胺培南 (10 0 % )、头孢哌酮 /舒巴坦 (10 0 % )和哌拉西林 /三唑巴坦(99.5 3% ) ,明显高于青霉素类抗生素哌拉西林 (48.83% )和第二代头孢菌素头孢呋辛 (6 0 .0 9% ) ,也高于第三代头孢菌素头孢曲松 (6 2 .91% )、头孢噻肟 (6 4 .79% )、头孢哌酮 (6 5 .73% )和头孢他啶 (88.2 6 % )。经表型确认试验证实 14 2株 (33.33% )为产超广谱 β-内酰胺酶 (ESBL s)菌 ;头孢吡肟对产 ESBL s菌和非产 ESBL s菌体外敏感性分别为 84 .5 1%、99.30 %。结论　头孢吡肟对肺炎克雷伯氏菌和大肠埃希氏菌的体外抗菌活性高于第三代头孢菌素 ,低于亚胺培南、头孢哌酮 /舒巴坦和哌拉西林 /三唑巴坦 ,头孢吡肟可考虑作为医院内感染的经验性一线用药。     

对临床分离的大肠埃希杆菌和肺炎克雷伯菌耐药状况分析

目的：调查和分析上海市杨浦区市东医院临床分离的大肠埃希杆菌和肺炎克雷伯菌分布特征与药敏结果。方法：收集本院2010年临床送检标本所分离的大肠埃希杆菌和肺炎克雷伯菌药敏资料,用WHONET 5.5软件进行数据分析。结果：共获得大肠埃希杆菌696株和肺炎克雷伯菌409株,在菌株总数中排名第一和第三。大肠埃希杆菌检出率较高的科室为普外科（20.3%）、急诊科（14.1%）、风湿肾病科（12.6%）,主要分离自尿（46.3%）、脓液（11.6%）和痰（10.8%）等标本。肺炎克雷伯菌检出率较高的科室为急诊科（17.6%）、呼吸科（14.2%）、肿瘤内科（11.7%）,主要分离自痰（40.8%）、咽拭子（26.4%）和尿（9.5%）等标本。大肠埃希杆菌和肺炎克雷伯菌中产超广谱β-内酰胺酶（ESBLs）菌株检出率分别为56.0%和17.1%,两者的检出率之间具有显著性差异（P〈0.01）,产ESBLs菌株的耐药率明显高于非产ESBLs菌株。结论：本院大肠埃希杆菌和肺炎克雷伯菌在泌尿系统、呼吸系统疾病高发的科室分离率高,其耐药率水平主要受产ESBLs菌株的影响。     

基因芯片技术检测大肠埃希菌、肺炎克雷伯菌和产酸克雷伯菌中ESBLs和AmpC酶基因

目的检测大肠埃希菌、肺炎克雷伯菌和产酸克雷伯菌产生的ESBLs和AmpC酶的基因。方法在对ESBLs和AmpC酶表型检测的基础上,利用基因芯片和PCR技术研究大肠埃希菌、肺炎克雷伯菌和产酸克雷伯菌产生ESBLs和AmpC酶的基因,并对部分ESBLs和AmpC酶的基因扩增产物进行序列分析。结果大肠埃希菌和产酸克雷伯菌以单产ESBLs为主,肺炎克雷伯菌则以同时产生ESBLs和AmpC酶为主。大肠埃希菌产生的ESBLs(除TEM型外)主要是CTX-M-9组型,占63.5%。肺炎克雷伯菌和产酸克雷伯菌产生的ESBLs分别以SHV型和CTX-M-3组型为主,分别占70.4%和89.8%。肺炎克雷伯菌和产酸克雷伯菌的AmpC酶均为DHA-1型酶的基因,大肠埃希菌的AmpC酶主要编码CMY-2型AmpC酶。结论基因芯片技术可同时检测多种耐药基因,是ESBLs和AmpC酶基因检测的新途径。     

SLO4, a new interferon inducer isolated from Klebsiella pneumoniae and Escherichia coli

A product isolated from Klebsiella pneumoniae and Escherichia coli, coded SLO4, has been shown to be effective in endogenous interferon induction in vivo in mouse when administered IP or IV, and in vitro with human leukocyte cultures. In these two systems induced interferon was defined. The inducer has not yet been characterized but seems not to belong to any components known to be interferon inducers such as viral particles, nucleic acids or endotoxins. An analytical study will be carried out to specify the constitution of this interferon inducer.     

Faropenem resistance causes in vitro cross-resistance to carbapenems in ESBL-producing Escherichia coli

ObjectiveFaropenem is an oral penem drug with activity against Gram-positive and Gram-negative bacteria, including CTX-M-15-type extended spectrum beta-lactamase (ESBL)-producing Enterobacteriales and anaerobic bacteria. As there are structural similarities, there is concern for the development of carbapenem cross-resistance; however, there are no studies confirming this. This study examined whether in vitro development of faropenem resistance in Escherichia coli isolates would result in cross-resistance to carbapenems.MethodsFour well-characterized E. coli isolates from the US Centers for Disease Control and Prevention antibiotic resistance isolate bank were utilized. Three isolates (NSF1, NSF2 and NSF3) are ESBL producers (CTX-M-15) and one (NSF4) is pan-susceptible. Faropenem minimum inhibitory concentrations (MICs) were determined and resistance was induced by serial passaging in increasing concentrations of faropenem. Susceptibility to carbapenems was determined and whole-genome sequencing (WGS) was performed to identify the underlying genetic mechanism leading to carbapenem resistance.ResultsFaropenem MIC increased from 1 mg/L to 64 mg/L within 10 days for NSF2 and NSF4 isolates, and from 2 mg/L to 64 mg/L within 7 days for NSF1 and NSF3 isolates. Reduced carbapenem susceptibility (ertapenem MIC ≥8 mg/L, doripenem/meropenem ≥2 mg/L and imipenem ≥1 mg/L) developed among three CTX-M-15-producing isolates that were faropenem-resistant, but not in NSF4 isolate that lacked ESBL enzyme. WGS analysis revealed non-synonymous changes in the ompC gene among three CTX-M-15-producing isolates, and a single nucleotide polymorphism (SNP) in the envZ gene in NSF4 isolate.ConclusionInduced resistance to faropenem causes cross-resistance to carbapenems among E. coli isolates containing CTX-M-15-type ESBL enzymes.