2010年中国CHINET肠球菌属细菌耐药性监测

目的了解2010年中国主要地区临床分离肠球菌属细菌对各类抗菌药物的耐药性。方法国内主要地区14所教学医院(12所综合性医院,2所儿童医院)按统一方案、采用统一的材料、方法(K-B法)和判断标准(CLSI 2010年版)进行肠球菌属细菌的耐药性监测。结果共分离到4 046株非重复肠球菌属细菌,最常见菌种为粪肠球菌1 829株(45.2%)、屎肠球菌1 817株(44.9%)、鹑鸡肠球菌78株(1.9%)、鸟肠球菌54株(1.3%)、铅黄肠球菌49株(1.2%)。肠球菌属对利奈唑胺、万古霉素、替考拉宁仍极敏感,耐药率<4%,万古霉素耐药粪肠球菌和屎肠球菌检出率分别为0.6%、3.6%。粪肠球菌对呋喃妥因、磷霉素和氨苄西林耐药率较低,分别为3.2%、5.7%和11.3%,对高浓度庆大霉素耐药率为44.0%;屎肠球菌耐药性明显高于粪肠球菌,对氨苄西林耐药率接近90%,对高浓度庆大霉素耐药率接近70%,对氯霉素耐药率仅为7.3%,儿童屎肠球菌分离株对磷霉素、呋喃妥因耐药率<10%。不同医院分离的肠球菌属细菌对抗菌药物的耐药率有一定差异。结论屎肠球菌的分离率有增加趋势,肠球菌属细菌对利奈唑胺、万古霉素、替考拉宁依然保持极高的敏感性。     

Susceptibility patterns of enterococci causing infections

Enterococci are among the common organisms associated with hospital-acquired infections. We examined in vitro activities of different antibiotics to 103 enterococcal isolates. Minimal inhibitory concentrations (MICs) of penicillin G, ampicillin, gentamicin, ciprofloxacin, ofloxacin, levofloxacin, grepafloxacin, trovafloxacin and gemifloxacin were determined by broth microdilution testing method. Among the isolates 71 (69%) were identified as E. faecalis and 32 (31%) as E. faecium. While over 75% of E. faecium isolates were resistant to penicillin and ampicillin, approximately 25% of E. faecalis isolates were resistant to penicillin and ampicillin. None of the E. faecalis and E. faecium isolates were resistant to vancomycin. While 17 (52%) of E. faecium isolates exhibited high-level gentamicin resistance (HLGR), high level streptomycin resistance (HLSR) was detected in 24 (74%) of the isolates. In contrast, HLGR and HLSR rates for E. faecalis were 14 (20%) and 22 (31%), respectively. Both HLGR and HLSR were detected with higher frequency in ampicillin resistant isolates. Among fluoroquinolones, gemifloxacin and trovafloxacin were the most potent antibiotics tested. There was no increase in MIC90 values of the fluoroquinolones in ampicillin resistant isolates in comparison with ampicillin susceptible isolates. Our data suggest newer fluoroquinolones would be good alternative agents to use especially for combination drug therapy where enterococci with ampicillin resistance and HLAR are prevalent.     

Comparison of high-level gentamicin-resistant Enterococcus faecium isolates from different continents.

Eight clinical isolates of Enterococcus faecium highly resistant to gentamicin (MIC, > 1,000 mg/liter) from patients in six hospitals on three continents were investigated for evidence of spread of either a clone of high-level gentamicin-resistant (HLGR) E. faecium or wide dissemination of a gentamicin resistance (Gmr) plasmid. A combination of ribotypes, plasmid profiles, and extended antimicrobial susceptibilities enabled us to distinguish all but two of the isolates and did not suggest clonal dissemination of a single strain. Two isolates from hospitals situated close together appeared identical by these methods. All of the isolates carried Gmr plasmids which appeared to be closely related following digestion with restriction endonucleases. Cross-hybridization studies confirmed extensive DNA homology between these plasmids. The fragments of these plasmids which hybridized with a probe specific for the aac6'aph2" resistance gene did not resemble those seen in the Gmr transposon Tn5281, which was characterized previously in E. faecalis HH22. This study suggests that there has been widespread dissemination of a single Gmr plasmid and its derivatives amongst isolates of HLGR E. faecium, although a Gmr plasmid from an HLGR E. faecium isolated in the United States showed little homology with the other Gmr plasmids studied.     

271株肠球菌属细菌的分布和耐药性分析

目的了解内蒙古鄂尔多斯市中心医院临床分离的肠球菌属细菌的分布情况及对各类抗菌药物的耐药性。方法使用VITEK 2 compact全自动细菌检测分析系统对2010年1月至2013年6月从临床标本中分离的271株肠球菌属细菌进行菌种鉴定和药敏试验,并用WHONET5．6软件对结果进行统计分析。结果271株肠球菌属细菌中,屎肠球菌137株（50．6％）,粪肠球菌80株（29．5％）,其他肠球菌54株（19．9％）。肠球菌属细菌主要分离自尿液69株（25．5％）、脓液40株（14．8o,4）、伤口等分泌物34株（12．5％）。粪肠球菌对万古霉素和利奈唑胺的耐药率分别为1．3％和1．5％;未检出呋喃妥因耐药株;对青霉素和氨苄西林的耐药率较低,分别为11．8％和2．6％;对高浓度庆大霉素和高浓度链霉素的耐药率分别为31．0％和22．9％。屎肠球菌的耐药率明显高于粪肠球菌,对万古霉素的耐药率为4．4％,未检出利奈唑胺耐药株,对呋喃妥因的耐药率为19．1％;对高浓度庆大霉素和高浓度链霉素的耐药率分别为44．8％和26．4％;但对四环素和奎奴普丁一达福普汀的耐药率低于粪肠球菌,分别为58．3％和0。结论屎肠球菌对抗菌药物的耐药率较粪肠球菌高;并已出现对万古霉素耐药株;其耐药性存在地区和菌种间差异,临床治疗应根据细菌药敏结果合理选用抗菌药物。     

肠球菌属细菌高水平庆大霉素耐药及其转座子的检测

目的研究2006—2009年北京地区临床分离高水平庆大霉素耐药(HLGR)肠球菌属细菌的双功能修饰酶基因转座子结构。方法采用脑心肉汤微稀释法测定北京地区169株临床分离粪肠球菌和21株屎肠球菌的高水平庆大霉素耐药性,应用菌落PCR扩增方法检测HLGR菌株中双功能修饰酶基因及两端插入序列(IS256),分析转座子结构。结果 169株粪肠球菌中,111株(65.7%)为HLGR株,HLGR菌中97.3%含有双功能修饰酶基因,其中10.2%含有完整结构的转座子(双功能修饰酶基因两端均含有IS256插入序列),89.8%含有截断结构的转座子(缺失一端或两端的插入序列)。21株屎肠球菌中,15株(71.4%)为HLGR株,所有HLGR菌株均含有双功能修饰酶基因,其中13.3%含有完整结构的转座子,86.7%含有截断结构的转座子。结论 2006—2009年北京地区临床分离肠球菌HLGR率高,并且绝大多数HLGR株含双功能修饰酶基因,通常形成截断结构的转座子。     

肠球菌耐药现状调查及抗感染用药探讨

目的了解肠球菌尤其是对万古霉素耐药肠球菌（ＶＲＥ）和庆大霉素高水平耐药（ＨＬＧＲ）肠球菌的耐药状况,指导临床合理用药。方法对北京５家教学医院感染标本中分离出的１６１４株肠球菌,分别进行纸片扩散法药敏试验和β内酰胺酶测试,并以“ＷＨＯＮＥＴ４”软件对试验数据进行分析处理。结果ＶＲＥ和ＨＬＧＲ肠球菌分别占肠球菌感染标本总数的３．４％和５２．６％,产β内酰胺酶的肠球菌占５．８％;对常用抗生素的耐药率,屎肠球菌明显高于粪肠球菌,ＨＬＧＲ株明显高于低耐株;万古霉素和高浓度庆大霉素多重耐药株检出率为０．９％。结论肠球菌对临床常用的８种抗生素以万古霉素最敏感。对不同特征肠球菌感染应采取不同的治疗方案。     

Absence of synergistic activity between ampicillin and vancomycin against highly vancomycin-resistant enterococci.

The emergence of clinical enterococcal isolates resistant to both ampicillin and vancomycin is a cause of great concern, as there are few therapeutic alternatives for treatment of infections caused by such organisms. We evaluated the effects of the combination of ampicillin with vancomycin against vancomycin-resistant clinical enterococcal isolates. Using both the checkerboard technique and time-kill curves, we examined 28 strains of enterococci (17 Enterococcus faecalis and 11 Enterococcus faecium strains) with different levels of resistance to vancomycin. Of these, 15 strains were also highly gentamicin resistant, and 9 demonstrated resistance to ampicillin. Only seven strains of E. faecalis were inhibited synergistically by the combination of vancomycin with ampicillin, and even then, the concentrations of vancomycin at which synergism was demonstrated were above levels achievable in serum. None of the ampicillin-resistant isolates (all E. faecium) were inhibited synergistically at any concentration of the drugs. In no instance was bactericidal synergism observed, and in most cases the combination resulted in less killing than with ampicillin alone. Antagonism was not observed at clinically relevant concentrations. The results of this study suggest that the combination of vancomycin with ampicillin has little to offer against these emerging pathogens.     

氨苄西林预报粪肠球菌和屎肠球菌亚胺培南敏感性的可行性研究

目的 评价氨苄西林预报粪肠球菌和屎肠球菌亚胺培南敏感性的可行性。方法 收集23家医院的127株粪肠球菌和124株屎肠球菌非重复临床分离株。采用微量肉汤稀释法和纸片扩散法测定粪肠球菌和屎肠球菌对青霉素、氨苄西林、亚胺培南的敏感性。结果 纸片扩散法青霉素和氨苄西林均敏感或均耐药的粪肠球菌,微量肉汤稀释法氨苄西林-亚胺培南的分类一致率（CA）均为100.0%,未出现非常重大误差（VME）和重大误差（ME）;纸片扩散法青霉素和氨苄西林均耐药的粪肠球菌,微量肉汤稀释法氨苄西林-亚胺培南的CA为77.8%,ME占22.2%;青霉素耐药、氨苄西林敏感的粪肠球菌,微量肉汤稀释法氨苄西林-亚胺培南的CA为57.1%,纸片扩散法的CA为81.8%。结论 氨苄西林预报粪肠球菌和屎肠球菌亚胺培南敏感性的可靠性优于青霉素,但氨苄西林的敏感性不能用于预报青霉素耐药、氨苄西林敏感表型粪肠球菌和屎肠球菌的亚胺培南敏感性;青霉素敏感可预报粪肠球菌和屎肠球菌对氨苄西林敏感。     

Comparison of antimicrobial resistance phenotypes and resistance genes in Enterococcus faecalis and Enterococcus faecium from humans in the community, broilers, and pigs in Denmark

Enterococcus faecalis and E. faecium isolated from humans in the community (98 and 65 isolates), broilers (126 and 122), and pigs (102 and 88) during 1998 were tested for susceptibility to 12 different antimicrobial agents and for the presence of selected genes encoding resistance using PCR. Furthermore, the presence of vancomycin resistant enterococci was examined in 38 human stool samples using selective enrichment. Widespread resistance to chloramphenicol, macrolides, kanamycin, streptomycin, and tetracycline was found among isolates from all three sources. All E. faecium isolates from humans and pigs were susceptible to avilamycin, whereas 35% of isolates from broilers were resistant. All E. faecium isolates from humans were susceptible to vancomycin, whereas 10% and 17% of isolates from broilers and pigs, respectively, were resistant. A vancomycin resistant E. faecium isolate was found in one of the 38 human fecal samples examined using selective enrichment. All vancomycin resistant isolates contained the vanA gene, all chloramphenicol resistant isolates the cat(pIP501) gene, and all five gentamicin resistant isolates the aac6-aph2 gene. Sixty-one (85%) of 72 erythromycin resistant E. faecalis examined and 57 (90%) of 63 erythromycin resistant E. faecium isolates examined contained ermB. Forty (91%) of the kanamycin resistant E. faecalis and 18 (72%) of the kanamycin resistant E. faecium isolates contained aphA3. The tet(M) gene was found in 95% of the tetracycline resistant E. faecalis and E. faecium isolates of human and animal origin, examined. tet(K) was not observed, whereas tet(L) was detected in 17% of tetracycline resistant E. faecalis isolates and in 16% of the E. faecium isolates. tet(O) was not detected in any of the isolates from pigs, but was observed in 38% of E. faecalis isolates from broilers, in two E. faecalis isolates from humans and in three E. faecium isolates from broilers. tet(S) was not detected among isolates from animals, but was observed in 31% of E. faecalis and one E. faecium isolate from humans. This study showed a frequent occurrence of antimicrobial resistance and the presence of selected resistance genes in E. faecalis and E. faecium isolated from humans, broilers and pigs. Differences in the occurrence of resistance and tetracycline resistance genes were observed among isolates from the different sources. However, similar resistance patterns and resistance genes were detected frequently indicating that transmission of resistant enterococci or resistance genes takes place between humans, broilers, and pigs.     

2014~2018年临床患者送检样本肠球菌的菌种分布及耐药性分析

目的　探讨肠球菌属菌种分布及其耐药性,为临床治疗提供依据。方法　采用回溯性方法,收集2014 年1 月 ~2018 年12 月医院临床患者送检样本检出的肠球菌223 株,进行细菌鉴定及药物敏感性监测,并对数据进行统计分 析。结果　5 年来,223 株肠球菌多分布于泌尿外科、ICU,胃肠烧伤科、肾脏科等;标本主要来源于尿液、体液、血 液;其中分离出粪肠球菌123 株、屎肠球菌90 株、鸡肠球菌4 株、鸟肠球菌 3 株、坚韧球菌2 株和恶臭肠球菌1 株, 分离株主要为粪肠球菌占55.16%、屎肠球菌占40.36%;223 株肠球菌对大多数抗生素耐药率屎肠球菌均高于粪肠球菌 （χ2=9.184~93.217,P <0.05）, 而对四环素耐药率屎肠球菌低于粪肠球菌（χ2=23.207,P <0.05）;粪肠球菌、屎肠球菌 对高浓度的庆大霉素、利奈唑胺、万古霉素和替考拉宁的耐药率无统计学意义（P >0.05）,而对氨苄西林尿肠球菌耐药 率（81.1%）与粪肠球菌耐药率（1.6%）相比差异有统计学意义（χ2=93.217,P <0.05）,两者耐药性呈多重耐药,耐药 率逐年上升。结论　院内感染的肠球菌属主要以粪肠球菌、屎肠球菌为主;其耐药率逐年上升且呈多重耐药,但对利奈 唑胺、万古霉素、替考拉宁仍保持较好的敏感性,临床应建立完善的医院感染监测系统,根据药敏结果进行合理用药。     

屎肠球菌高水平庆大霉素耐药基因研究

目的研究我国临床分离高水平庆大霉素耐药屎肠球菌中庆大霉素耐药基因分类及其水平传递情况。方法采用PCR法检测庆大霉素耐药基因aac（6’）-Ie-aph（2″）-Ia、aph（2″）-Ib、aph（2″）-Ic、aph（2″）-Id和aph（3″）-Ⅲa，采用质粒酶切图谱分析耐药菌同源性，采用液体传递和固体传递法研究庆大霉素耐药基因水平传递情况。结果105株临床分离屎肠球菌中，76．2％（80／105）为高水平庆大霉素耐药，其中aac（6′）-Ie-aph（2″）-Ia基因阳性率为95．0％（76／80），aph（3″）-Ⅲa基因阳性率为78．8％（63／80），aph（2″）-Ib、aph（2″）-Ic、aph（2″）-Id基因皆阴性。这些高水平庆大霉素耐药屎肠球菌间大多无明显同源性。21．1％（16／76）菌株携带的aac（6’）-Ie-aph（2″）-Ia基因在屎肠球菌间固体传递，13．2％（10／76）菌株携带的aac（6’）-Ie-aph（2″）-Ia基因在屎肠球菌间液体环境中水平传递。结论本次研究中屎肠球菌中高水平庆大霉素耐药主要由aac（6’）-Ie—aph（2″）-Ia和aph（3″）-Ⅲa基因介导，这些菌株间没有明显同源性，且该基因可在屎肠球菌间水平传递。     

高水平氨基糖苷耐药肠球菌的监测

目的了解高水平氨基糖苷耐药(HLAR)肠球菌的分离率,探讨青霉素类或糖肽类与氨基糖苷类药物合用对院内感染肠球菌的协同杀菌作用,为临床治疗肠球菌感染提供参考与指导。方法采用VITEK-AMS仪器对分离自临床标本的101株肠球菌进行氨苄西林、青霉素、万古霉素耐药性和高水平庆大霉素耐药(HLGR)及高水平链霉素耐药(HLSR)测定。结果101株肠球菌中,粪肠球菌、屎肠球菌、鸟肠球菌、母鸡肠球菌和耐久肠球菌菌株分别为71、13、8、7和2株。药敏测试结果显示肠球菌对氨苄西林、青霉素、万古霉素耐药分别为21、34和0株;HLGR和HLSR分别为79株和46株。结论院内感染肠球菌对抗菌药物存在严重耐药性,合理的抗菌药物治疗对高水平氨基糖苷耐药肠球菌感染患者的康复尤为重要。     

Measurement of ampicillin, vancomycin, linezolid and gentamicin activity against enterococcal biofilms

BACKGROUND: Enterococci frequently cause biofilm infections but susceptibility of clinical isolates growing in biofilms has not been investigated. The minimum biofilm eradicating concentration (MBEC) has been suggested as a guide to treatment of biofilm infections. We measured an alternative endpoint, the minimum biofilm inhibitory concentration (MBIC) and compared the results with MIC and MBC. OBJECTIVES: To compare the MIC, MBC and MBIC of ampicillin, vancomycin and linezolid against enterococcal biofilms, to assess the impact of additional gentamicin and correlate findings with clinical outcome. METHODS: MIC and MBC were measured using standard techniques. MBICs were measured using a modification of the Calgary biofilm device method. Fifty-eight enterococcal isolates from episodes of intravascular catheter-related bloodstream infection were tested. RESULTS: Tolerance to ampicillin, vancomycin and linezolid was seen in 93%, 100% and 93% of isolates, respectively. MIC(90)s of ampicillin, vancomycin and linezolid were all 4 mg/L for Enterococcus faecalis isolates. MBC(90)s of ampicillin, vancomycin and linezolid for E. faecalis isolates were 1024, >128 and 2048 mg/L, respectively. MBIC(90)s of ampicillin, vancomycin and linezolid for E. faecalis isolates were 8192, 4096 and 4096 mg/L, respectively. Results for Enterococcus faecium were similar for vancomycin and linezolid but this species was generally more resistant to ampicillin. Adding 10 mg/L gentamicin had a variable effect on MIC, MBC or MBIC, which was not predictable by gentamicin susceptibility on disc testing. CONCLUSIONS: Very high concentrations of ampicillin, vancomycin and linezolid are required to inhibit enterococcal biofilms in vitro. Combining these agents with gentamicin significantly reduced MIC, MBC and MBIC against only a proportion of enterococcal isolates. No correlation between MBIC and outcome was found.     

Differences in antibiotic resistance patterns of Enterococcus faecalis and Enterococcus faecium strains isolated from farm and pet animals

The prevalence of acquired resistance in 146 Enterococcus faecium and 166 Enterococcus faecalis strains from farm and pet animals, isolated in 1998 and 1999 in Belgium, against antibiotics used for growth promotion and for therapy was determined. Acquired resistance against flavomycin and monensin, two antibiotics used solely for growth promotion, was not detected. Avoparcin (glycopeptide) resistance was found sporadically in E. faecium only. Avilamycin resistance was almost exclusively seen in strains from farm animals. Resistance rates were higher in E. faecium strains from broiler chickens than in strains from other animal groups with tylosin and virginiamycin and in E. faecalis as well as in E. faecium strains with narasin and bacitracin. Resistance against ampicillin was mainly found among E. faecium strains from pets and was absent in E. faecalis. Tetracycline resistance occurred most often in strains from farm animals, while enrofloxacin resistance, only found in E. faecalis, occurred equally among strains from all origins. Resistance against gentamicin was very rare in broiler strains, whereas resistance rates were high in strains from other origins. It can be concluded that resistance against antibiotics used solely for growth promotion was more prevalent in E. faecium strains than in E. faecalis strains. With few exceptions, resistance against the different categories of antibiotics was more prevalent in strains from farm animals than in those from pets.     

Antimicrobial susceptibility patterns of enterococci in intensive care units in Sweden evaluated by different MIC breakpoint systems.

Three hundred and twenty-two (322) clinical isolates were collected from patients admitted to intensive care units (ICUs) at eight Swedish hospitals between December 1996 and December 1998. Of the isolates, 244 (76%) were Enterococcus faecalis, 74 (23%) were Enterococcus faecium and four (1%) were other Enterococcus spp. MICs of ampicillin, imipenem, meropenem, piperacillin/tazobactam, ciprofloxacin, trovafloxacin, clinafloxacin, gentamicin, streptomycin, vancomycin, teicoplanin, quinupristin/dalfopristin, linezolid and evernimicin were determined by Etest. Susceptible and resistant isolates were defined according to the species-related MIC breakpoints of the British Society for Antimicrobial Chemotherapy (BSAC), the National Committee for Clinical Laboratory Standards (NCCLS) and the Swedish Reference Group for Antibiotics (SRGA). Tentative breakpoints were applied for new/experimental antibiotics. Multidrug resistance among enterococci in ICUs is not uncommon in Sweden, particularly among E. faecium, and includes ampicillin resistance and concomitant resistance to fluoroquinolones. Almost 20% of E. faecalis isolates showed high-level resistance to gentamicin and concomitant resistance to fluoroquinolones. Vancomycin-resistant enterococci were only found sporadically. Among the new antimicrobial agents, linezolid and evernimicin showed the best activity against all enterococcal isolates. There was good concordance between the BSAC, NCCLS and SRGA breakpoints in detecting resistance. When applying the SRGA breakpoints for susceptibility, isolates were more frequently interpreted as intermediate. This might indicate earlier detection of emerging resistance using the SRGA breakpoint when the native population is considered susceptible, but with the risk that isolates belonging to the native susceptible population will be incorrectly interpreted as intermediate.     

2015年重庆市粪肠球菌和屎肠球菌耐药性监测结果分析

目的 统计分析2015年重庆市细菌耐药监测网成员单位提交的粪肠球菌和屎肠球菌耐药性监测数据,为该市有效应用抗菌药物提供依据和参考.方法 各成员单位根据全国细菌耐药监测网技术方案要求,对目标细菌进行鉴定和药敏试验,并依据美国临床和实验室标准化协会(CLSI)2015版标准进行结果判读,使用WHONET5.6软件对药敏数据进行统计分析,耐药性差异采用SPSS21.0软件进行分析.结果 共分离到非重复粪肠球菌和屎肠球菌分别为1 811株和1 601株,共占所有阳性菌株的13.1%,两者对万古霉素的耐药性分别为0.5%和1.8%,对利奈唑胺的耐药率分别为2.5%和0.5%,均未发现对替加环素耐药的菌株.粪肠球菌对奎奴普丁/达福普汀的耐药性最高,为90.1%,对四环素的耐药率也高达78.8%,对高浓度庆大霉素的耐药率为43.0%,对青霉素、氨苄西林、呋喃妥因的耐药率均低于7.0%.除奎奴普丁/达福普汀和四环素外,屎肠球菌对其他药物的耐药率高于粪肠球菌(P<0.05).儿童和成人患者,以及重症监护病房(ICU)和非ICU患者分离株对部分药物的耐药率比较差异有统计学意义(P<0.05).结论 该市肠球菌感染主要病原菌是屎肠球菌和粪肠球菌,两者耐药性不同.做好耐药性监测有助于指导临床医生规范、有效使用抗菌药物.     

Genetic relatedness among Enterococcus faecalis with transposon-mediated high-level gentamicin resistance in Swedish intensive care units

We studied 45 isolates of Enterococcus faecalis with high-level gentamicin resistance (HLGR), all but one concomitantly resistant to ciprofloxacin, and 25 ciprofloxacin-resistant isolates without HLGR for genetic relatedness using pulsed-field gel electrophoresis (PFGE). E. faecalis were isolated from patients admitted to intensive care units at eight hospitals in southern Sweden from December 1996 through December 1998. Genomic analysis by PFGE resulted in three clusters of genetically related isolates (designated clusters I, II and III) and 23 unique clones. Cluster I was found predominantly in the eastern and central parts of southern Sweden and clusters II and III in south-western Sweden. Among the 45 isolates with HLGR, 69% belonged to cluster I, 20% to cluster II, and 11% had unique PFGE patterns, which suggests that the majority of isolates with HLGR are closely related. Among the 25 ciprofloxacin-resistant isolates without HLGR, 68% had unique PFGE patterns, 12% belonged to cluster I and 20% to cluster III, which suggests the ciprofloxacin-resistant isolates are not related. All isolates with HLGR contained the aac(6')Ie-aph(2")Ia gene, which was carried on a Tn5281-like transposon in all isolates except one. We conclude that HLGR in E. faecalis was mainly due to dissemination of genetically related clones during the time studied, and that HLGR in these isolates was due to the presence of the aac(6')Ie-aph(2")Ia gene.     

儿童患者中肠球菌属临床分离株耐药特征分析

目的了解儿童患者临床分离肠球菌属的耐药特征，指导临床合理用药。方法测定11种抗菌药物对158株肠球菌的MIC，Nithocefin纸片法检测B内酰胺酶，数据用WHONET5．3软件分析处理。结果158株儿童临床分离肠球菌中，粪肠球菌、屎肠球菌、坚韧肠球菌、鸟肠球菌和海氏肠球菌分别占56．3％、39．9％、1．3％、1．3％和1．3％；屎肠球菌对氨苄西林、阿莫西林-克拉维酸和环丙沙星的耐药率分别为96．8％，95，2％和84．1％，粪肠球菌对上述3种抗菌药的耐药率分别为23．6％，18％和49，4％，屎肠球菌的耐药率明显高于粪肠球菌（P〈20，001）；粪肠球菌出现2株万古霉素MIC为8mg／L的耐药菌，粪肠球菌和屎肠球菌对替考拉宁全部敏感。儿童患者中多重耐药肠球菌属菌株占88．6％。结论儿童患者肠球菌属的耐药状况十分严重，尤其屎肠球菌对B内酰胺类、氨基糖苷类和氟喹诺酮类抗菌药耐药率很高。     

Diversity among high-level aminoglycoside-resistant enterococci

A total of 55 Enterococcus faecalis and 21 Enterococcus faecium non-replicate isolates were obtained from routine clinical specimens, during a 1 year period, in a tertiary care hospital in Athens, Greece. The most common isolation site was the urinary tract (44% of E. faecalis and 33% of E. faecium isolates). No vancomycin resistance was detected. Ampicillin-resistant isolates did not produce beta-lactamase. High-level gentamicin resistance was detected in 22% and 0% of E. faecalis and E. faecium isolates, respectively. The corresponding figures for high-level streptomycin resistance were 40% and 33%. The aminoglycoside-modifying enzyme gene aac(6')+aph(2") was detected by PCR in 10 of 12 high-level gentamicin-resistant E. faecalis isolates, and the ant(6)-I gene in all high-level streptomycin-resistant isolates of both species. DNA fingerprinting by PFGE grouped 31 of 55 E. faecalis isolates into 10 clusters, and 10 of 21 E. faecium isolates into two clusters, containing two to seven isolates each. Two E. faecalis PFGE types, comprising isolates expressing high-level aminoglycoside resistance, and not observed among non-high-level aminoglycoside-resistant strains, were disseminated in building A of the hospital. In contrast, high-level aminoglycoside resistance seemed to have been acquired nosocomially by a number of genotypically different E. faecium types. Molecular typing was therefore instrumental in understanding the differences in the mode of spread and acquisition of high-level aminoglycoside resistance among these two different enterococcal species.     

424株临床分离肠球菌属细菌的耐药性变异

目的探讨肠球菌属临床分离情况与耐药变迁,为指导临床合理用药,控制感染提供依据。方法对广东省东莞中山大学附属东华医院2007--2009年临床送检标本进行常规微生物培养、鉴定和药敏试验,并用WHONET5．4软件统计分析这3年间肠球菌临床分离株在各标本、科室中的分布与耐药性的变迁情况。结果2007--2009年临床分离出肠球菌属细菌424株,其中粪肠球菌338株,占79．7％,屎肠球菌75株,占17．7%,鸟肠球菌11株,占2．6％;肠球菌属在各标本中的分布以尿液为主,占50．2％,其次为伤口分泌物（14．4％）、血液（12．5％）。3年来肠球菌属的菌种和耐药均发生了较大变化,粪肠球菌所占比率每年保持在80％左右,屎肠球菌呈逐年上升趋势,从2007年的13．9%上升至2009年的20．9％,而鸟肠球菌则逐年下降,从4．7％降至0．6％。粪肠球菌对红霉素和四环素的耐药率最高,分别为79．4％～85．7％和84．1％～87．4%,屎肠球菌对氨苄西林、青霉素以及呋喃妥因的耐药率明显高于粪肠球菌,对红霉素、左氧氟沙星、青霉素的耐药率高达80％以上,对呋喃妥因、高浓度的庆大霉素、环丙沙星、四环素、氨苄西林等抗菌药物的耐药率也接近或超过50％。2007年发现1株屎肠球菌对万古霉素耐药。结论肠球菌属耐药性较为严重,不同菌种耐药性有所差异。临床抗感染治疗应以分离菌株的体外抗菌药物敏感性为依据,合理选用抗菌药物,以提高疗效。