社区医疗机构多重耐药铜绿假单胞菌产金属β内酰胺酶检测

目的 了解多重耐药铜绿假单胞菌(M RPA)的社区感染情况及产金属β内酰胺酶(MBL)情况.方法 2011年1月至12月在广州市多个社区医院收集分离出MRPA 54株.采用MicroScan Walk Away 40S1全自动细菌鉴定与药敏检测系统检测其对亚胺培南等11种抗菌药物的耐药性,比较亚胺培南耐药铜绿假单胞菌与亚胺培南敏感铜绿假单胞菌对常用9种抗菌药物的耐药率.改良三维实验分析亚胺培南耐药铜绿假单胞菌产MBL情况.结果 54株MRPA中有29株对亚胺培南耐药,占53.7％( 29/54).三维试验显示有9株亚胺培南耐药铜绿假单胞菌产MBL,占31.0％( 9/29).亚胺培南耐药铜绿假单胞菌对常用7种抗菌药物的耐药率显著高于亚胺培南敏感铜绿假单胞菌(头孢他啶:65.5％比36.0％;头孢噻肟:89.7％比44.0％;头孢曲松:100.0％比52.0％:氨曲南:72.4％比36.0％,氧氟沙星:70.0％比32.0％;哌拉西林-他唑巴坦:58.6％比16.0％;阿米卡星:62.1％比32.0％,均P＜0.05).结论 社区医疗机构临床分离MRPA 产MBL的比率较高.     

我院200株铜绿假单胞菌感染分布及耐药性分析

目的：了解我院2007年1月--2008年6月200株铜绿假单胞菌感染分布及耐药情况，为临床提供预防措施和合理使用抗菌药物的依据。方法：采用回顾性的方法统计分析我院分离的铜绿假单胞菌的标本来源、感染科室分布及对20种抗菌药物的耐药状况。结果：200株铜绿假单胞菌主要来自痰液（85％），其次来自分泌物（9．0％），在临床各病区分布情况：重症监护室（ICU）23．0％（46／200）、脑外科22．0％（44／200）、呼吸科，19．5％（39／200）、急诊科6％（12／200）、神内科5．0％（10／200）、肿瘤科4．5％（9／200）、烧伤科4．0％（8／200）、西骨科3．5％（7／200）、其他科与肾内科等12．5％（25／200）。药敏结果显示，该细菌对抗菌药物活性较好的仅有阿米卡星和亚胺培南，耐药率分别为14．5％、24．I％。耐药率较高的是哌拉西林、头孢他啶、左氧氟沙星、哌拉西林／他唑巴坦、环丙沙星、氨曲南、妥布霉素、头孢吡肟，耐药率分别为70．1％、68．5％、61．0％、60．2％、57．8％、56．2％、55．3％、54．7％。结论：铜绿假单胞菌对多种抗菌药物耐药率较高，临床应加强对铜绿假单胞菌耐药性监控和药敏试验分析，合理使用抗菌药物，防治耐药菌株的传播流行。     

深圳地区铜绿假单胞菌医院感染及耐药性

目的了解铜绿假单胞菌(队)引起医院感染的特点以及对抗生素的耐药性的变化趋势．方法对2001-2003年分离出的317株铜绿假单胞菌选用12种抗生素进行药敏实验，按NCCLS标准判断．结果该菌主要来源于痰液和咽拭子(65％)，主要分布在呼吸科(12％)、脑外科(12％)、ICU(10％)、新生儿科(9％)、呼吸科ICU(7％)、老年病科(7％)．2001年．2003年铜绿假单胞菌对环丙沙星耐药率呈上升趋势，2001年-2002年对头孢噻肟耐药呈直线上升，2003年稍有下降．2001年．2003年对哌拉西林(PIP)、哌拉西林／他唑巴坦(TZP)、庆大霉素(GEN)、阿米卡星(AMK)、头孢吡肟(FEP)、氨曲南(ATM)、头孢他啶(CAZ)耐药率呈下降趋势．2001年-2002年对亚胺培南(IPM)、美罗培南(MEM)耐药率呈显著下降趋势，2002年-2003年稍有上升．对头孢曲松(CRO)耐药率相对稳定．结论了解铜绿假单胞菌的耐药现状，有利于为临床合理用药提供依据．     

重症监护病房下呼吸道感染的病原菌分布及耐药性分析

目的探讨重症监护病房（ICU）患者下呼吸道感染病原菌的分布及耐药性,为临床防治提供科学依据。方法整理分析我院ICU2003年1月至2007年12月下呼吸道感染患者痰培养的1146株病原菌．采用CLSI推荐的K．B法进行药敏试验。并对其耐药性进行分析。结果分离出的1146株病原菌中。革兰阴性杆菌占64．1％,革兰阳性球菌占28．4％。前5位病原菌依次为金黄色葡萄球菌、铜绿假单胞菌、鲍曼不动杆菌、洋葱伯克霍尔德菌、肺炎克雷伯菌。铜绿假单胞菌、鲍曼不动杆菌对亚胺培南耐药率分别为37．8％、10．6％,肺炎克雷伯菌、大肠埃希菌产超广谱β内酰胺酶（ESBLs）的检出率分别是68．5％、83．7％,肠杆菌科菌对亚胺培南全部敏感。未检出耐万古霉素的革兰阳性球菌。结论ICU下呼吸道感染以革兰阴性杆菌为主,病原菌耐药性严重。临床治疗应根据药敏试验结果。合理应用抗生素。     

2012年深圳市光明新区人民医院细菌耐药监测

目的了解2012年深圳市光明新区人民医院临床分离菌对常用抗菌药物的耐药性。方法采用Microscanauto4鉴定及药敏系统对临床常规细菌进行监测．按CLSl2009年版标准判断药敏结果．并用WHONET5．4软件统计分析。结果全年共分离细菌1818株,其中革兰阳性菌占35．6％,革兰阴性菌占58．O％。葡萄球菌中耐甲氧西林金黄色葡萄球菌（MRSA）占18．3％,凝固酶阴性葡萄球菌（MRCNS）占71．9％。肺炎链球菌中青霉素非敏感的肺炎链球菌（PNSSP）占20．7％。大肠埃希菌和肺炎克雷伯杆菌产ESBLs菌株分别占43．2％和22．4％。检出5株亚胺培南耐药的肠杆科细菌。铜绿假单胞菌和鲍曼不动杆菌对头孢他啶、哌拉西林、妥布霉素、阿米卡星、环丙沙星、亚胺培南的耐药率均低于10％。结论本院常见致病菌耐药性不是十分严重,尤其是院内感染的铜绿假单胞菌和鲍曼不动杆菌对常用抗菌药物耐药率较低。     

铜绿假单胞菌对β-内酰胺类抗生素的耐药性分析

目的:分析铜绿假单胞菌对β-内酰胺类抗生素的耐药性,为今后临床用药工作提供参考。方法:选取2017年1月至2017年12月期间我院微生物室分离出的131株头孢他啶耐药(MIC≥16μg·ml~(-1))铜绿假单胞菌作为研究对象,采用梅里埃VITEK-2全自动微生物鉴定药敏系统(法国)分析铜绿假单胞菌对头孢哌酮、头孢曲松、哌拉西林/他唑巴坦、阿米卡星、头孢哌酮/舒巴坦、头孢他啶、哌拉西林、头孢吡肟、亚胺培南的耐药性特点和多重耐药情况,并通过表型确证试验对产超广谱β-内酰胺酶(Extended-spectrum-β-lactamases,ESBLs)的菌株进行筛选,并行相关耐药基因的多重PCR检测。结果:(1)研究发现,本组131株铜绿假单胞菌株中阳性率为21.37%,铜绿假单胞菌对头孢曲松、庆大霉素、氨曲南、头孢哌酮的耐药率分别为71.76%、42.75%、44.28%与49.62%,铜绿假单胞菌对哌拉西林/他唑巴坦、阿米卡星、头孢哌酮/舒巴坦、头孢他啶、左氧氟沙星、哌拉西林、头孢吡肟以及亚胺培南的耐药率均40%。(2)金属β-内酰胺酶阳性菌株对11种抗生素的耐药率均明显高于金属β-内酰胺酶阴性菌株,具有统计学意义(P0.05)。结论:产金属β-内酰胺酶是铜绿假单胞菌对β-内酰胺类抗生素明显耐药的主要原因,在临床治疗中要及时开展细菌培养和药敏试验,以促进合理用药,避免耐药性的发生。     

对碳青霉烯类耐药的铜绿假单胞菌的金属β-内酰胺酶研究

目的：研究耐碳青霉烯类的铜绿假单胞菌产金属β-内酰胺酶的情况及铜绿假单胞菌的耐药机制。方法：微量二倍稀释法测定亚安培南及美洛培南对铜绿假单胞菌的MIC值；DETA纸片法检测产金属β-内酰胺酶的铜绿假单胞菌。结果：从62株临床分离的铜绿假单胞菌中共检测到28株对亚胺培南耐药，耐药率为45％，18株对美洛培南耐药，耐药率为29．03％。从18株同时对亚胺培南及美洛培南耐药株中共检测到16株产金属β-内酰胺酶，占同期分离铜绿假单胞菌的25．8％。结论：产生金属β-内酰胺酶是铜绿假单胞菌对碳青霉烯类药物耐药的机制之一。     

河源地区铜绿假单胞菌碳青霉烯耐药机制分析

目的研究本院铜绿假单胞菌耐碳青霉烯类抗生素的耐药现况及主要耐药机制。方法用E-test方法检测铜绿假单胞菌对哌拉西林、头孢他啶、亚胺培南、美洛培南、庆大霉素、妥布霉素、环丙沙星7种抗生素的最小抑菌浓度,用EDTA双纸片扩散法及三维实验分别对金属酶及AmpC、KPC酶表型进行确证。结果从1 068例致病菌中共分离出108例铜绿假单胞菌,18例是对亚胺培南和/或美罗培南不敏感的菌株,耐药率为16.7%,其中有9例金属酶确证实验阳性,3例为AmpC酶持续高产型菌株,KPC酶确证实验尚没有检测出阳性菌株。结论耐碳青霉烯类铜绿假单胞菌多表现为多重耐药,这是多因素共同作用的结果 。     

耐环丙沙星铜绿假单胞菌的耐药性分析

目的 了解本地区铜绿假单胞菌的耐药情况及超广谱β-内酰酶（ESBLS）的检出率，以指导临床合理用药。方法对90株临床分离菌用纸片扩散法（K-B法）进行药物敏感性试验；纸片扩散表型确证法进行ESBLS检侧。结果本地区铜绿假单胞菌对氨苄西林、萘啶酸、哌拉西林、头胞噻肟、头胞吡肟、阿米卡星、环丙沙星、左氧氟沙星、司帕沙星、加替沙星、氨曲南、头胞他啶、亚胺培南、头胞呋辛的耐药率分别是90．0％、83．3％、77．2％、29．4％、5％、8．9％、65．0％、60．0％、62．2％、50．0％、7．2％、18．3％、0、47．2％；ESBLS的检出率为24．4％。结论本地区铜绿假单胞菌耐药情况不容乐观且多重耐药菌株较多；氟喹诺酮药物之间交叉耐药明显；产ESBLS率较高。     

烧伤创面细菌学检测及耐药性分析

目的本研究通过对烧伤创面细菌学调查及耐药性分析，为临床治疗提供参考。方法从2004年1月至2007年4月本院收治的69例烧伤患者创面细菌培养分离出细菌170株，用纸片琼脂扩散法进行药物敏感试验，就其中前5种细菌进行回顾性分析。结果在本组检出的细菌中，革兰阴性杆（G^-）菌122株（71．76％），革兰阳性（G^＋）菌48株（28．24％）。其中，数量较多的前5种细菌为鲍曼不动杆菌（17．00％），阴沟肠杆菌（11．18％），铜绿假单胞菌（10．00％），金黄色葡萄球菌（10．59％），肺炎克雷伯菌（8、82％）。鲍曼不动杆菌占G^-杆菌的23．77％，该菌对几乎所有抗菌药物耐药，对亚胺培南的耐药率高达75．86％。阴沟肠杆菌占G^-杆菌的15．57％，对抗菌药物的耐药率超过90％，对亚胺培南敏感。铜绿假单胞菌和肺炎克雷伯菌对抗菌药物的耐药率超过50％。金黄色葡萄球菌占G^＋菌的37．5％，对万古霉素的耐药率为17．65％。以上5种细菌对大多数常用抗菌药物表现出高耐药性。结论本组烧伤患者感染细菌以G^-杆菌为主，G^＋菌次之，这些细菌对常用抗菌药物有多重耐药性，亚胺培南对大多数G^-杆菌仍有较高的抗菌活性。G^＋菌对万古霉素敏感。     

Risk factors for antimicrobial resistance and influence of resistance on mortality in patients with bloodstream infection caused by Pseudomonas aeruginosa

This study was conducted to evaluate risk factors for antimicrobial resistance and influence of resistance on mortality in Pseudomonas aeruginosa bacteremia. Data on 190 patients with P. aeruginosa bacteremia were analyzed retrospectively. Antimicrobial resistance to antipseudomonal antibiotics was evaluated. The main outcome measure was 30-day mortality. In P. aeruginosa bacteremia, resistance rates to piperacillin (PIP), ceftazidime (CAZ), ciprofloxacin (CIP), and imipenem (IPM) were 29 (56/190), 19 (36/190), 17 (32/190) and 15% (28/190), respectively. Prior uses of fluoroquinolones or carbapenems were independent risk factors for resistance to CIP and IPM, and prior use of extended-spectrum cephalosporins was a risk factor for PIP-R. An indwelling urinary catheter was a risk factor for PIP-R, CAZ-R, and CIP-R. An invasive procedure was a risk factor for CIP-R and IPM-R. The 30-day mortality rate was 44% (33/75) in patients infected by strains resistant to any of the antipseudomonal antibiotics, but 33.9% (39/115) in those by strains susceptible to all antipseudomonal antibiotics (p = 0.161). Among patients with bloodstream infection due to antimicrobial-resistant P. aeruginosa, those infected by IPM-R strains had the highest mortality (IPM-R, 53.6% vs. CAZ-R, 47.2% vs. CIP-R 46.9%, PIP-R, 39.3%). In this study regarding P. aeruginosa bacteremia, prior uses of fluoroquinolones, carbapenems, or extended-spectrum cephalosporins, a prior invasive procedure, and an indwelling urinary catheter were found to be associated with antimicrobial resistance. The patients with bloodstream infection caused by antimicrobial-resistant P. aeruginosa, especially to imipenem, had a tendency toward higher mortality than those infected by susceptible strains.     

Evaluation of Double-Disk Potentiation and Disk Potentiation Tests Using Dipicolinic Acid for Detection of Metallo-β-Lactamase-Producing Pseudomonas spp. and Acinetobacter spp

Accurate detection of metallo-β-lactamase (MBL)-producing Pseudomonas spp. and Acinetobacter spp. became very important with the increasing prevalence of carbapenem-nonsusceptible clinical isolates. The performance of phenotypic MBL detection methods may depend on the types of MBL and the characteristics of the isolates. A high false-positive rate is a problem with EDTA-based MBL detection methods. We evaluated the performance of double-disk potentiation tests (DDPTs) and disk potentiation tests (DPTs) with dipicolinic acid (DPA) using 44 isolates of Pseudomonas spp. and Acinetobacter spp. producing IMP-1-like, VIM-2-like, and SIM-1 type MBLs. Also, we characterized P. aeruginosa isolates with positive imipenem (IPM)-DPA DDPT, but negative meropenem (MEM)-DPA DDPT, and determined possibility of improving a DDPT by using MacConkey agar. Among five different DDPT methods, the IPM-DPA 250-μg method showed the highest sensitivity (97.7%) and specificity (100%). Among four DPT tests, the highest sensitivity (100%) was shown by the IPM-EDTA 1,900-μg disk method, but the specificity was very low (11.4%). Five of six P. aeruginosa isolates with false-negative DDPTs with MEM-DPA 250-μg disks carried bla(IMP-6,) and the high level resistance to MEM (MIC ≥ 512 μg/ml) was reduced by the presence of phenylalanine arginine β-naphtylamide. Improvement of DDPTs was observed when MacConkey agar was used instead of Mueller-Hinton agar. In conclusion, DPA is a better MBL inhibitor than EDTA for detection of Pseudomonas spp. and Acinetobacter spp. with IMP-1-like, VIM-2-like, and SIM-1-type MBLs. In DPA DDPTs, IPM disks perform better than MEM disks when the isolates are highly resistant to MEM due to the overexpression of efflux pumps.     

我院重症监护室铜绿假单胞菌感染趋势及其耐药性分析

目的铜绿假单胞菌（Pseudomonas aeruginosa,PA）为院内感染的重要代表菌及临床分离率较高的菌株,在我院PA占所有菌株检出率的24.5%、占革兰阴性杆菌检出率的35.4%。通过对我院2006年1月-2009年6月期间4个重症监护室铜绿假单胞菌的感染情况及其耐药性进行分析,并与同期非重症监护室的病区进行比较,分析PA产碳青霉烯酶水解碳青霉烯类抗生素后同时携带多种耐药基因对其他药物敏感性的影响。方法采用Micro Scan全自动细菌鉴定和药敏分析仪,数据的分析采用WHONET软件。结果 4年间我院重症监护室铜绿假单胞菌检出数为559株,依次为：内科ICU272株、外科ICU149株、急诊ICU126株、儿科ICU12株。药敏结果显示：铜绿假单胞菌对大部分抗生素的敏感性呈逐年下降的趋势,尤其是重症监护室感染菌株。PA对碳青霉烯类抗菌素耐药的菌株产生多重甚至广泛耐药的几率较高。结论 4年间我院重症监护室铜绿假单胞菌对抗生素的耐药状况严重,尤其对头孢菌素,氨基糖苷类抗生素耐药率明显增加。对亚胺培南的耐药株同时携带多种耐药机制,产生多重耐药甚至泛耐药。多重耐药株和泛耐药株的检出亦呈逐年上升的趋势。     

铜绿假单胞菌oprD2基因突变及表达量改变与碳青霉烯类耐药的关系

目的 研究铜绿假单胞菌外膜通道蛋白OprD2的表达减弱或缺失,以及OprD2蛋白自身突变是否会影响铜绿假单胞菌对碳青霉烯类药物的耐药性.方法 收集分离自临床对亚胺培南(IPM)的最低抑菌浓度(MIC)值≥8μg/m1的铜绿假单胞菌共101株,采用肉汤稀释法检测菌株对比阿培南(BPM)、美罗培南(MEM)、帕尼培南(PEM)的MIC值;荧光定量RT-PCR检测铜绿假单胞菌膜通道蛋白oprD2基因的表达量情况;针对oprD2相对表达量正常并对亚胺培南耐药的铜绿假单胞菌,采用普通PCR的方法扩增oprD2全长基因并测序.结果 根据铜绿假单胞菌的OprD2蛋白相对表达量结果,将101株铜绿假单胞菌分成两组,组1为OprD2相对表达量降低组;组2为OprD2相对表达量正常组;组1与组2相比,对IPM、BPM、MEM、PEM的MIC值≥16μg/ml的菌株比例差异均有统计学意义(P＜0.01).组1中,28株同时对4种药物的MIC均≥16 μg/ml,其中有25株的OprD2的相对表达量明显减低(＜0.4);外膜孔蛋白OprD2转录水平与4种碳青霉烯类药物MICs之间呈负相关趋势.组2中,有16株9prD2基因发生突变,按照突变的类型主要分成4组;与PAO1相比,这些菌株对IPM、BPM、MEM、PEM的MIC值有不同程度的增加.结论 OprD2外膜蛋白的表达量减少或缺失是铜绿假单胞菌对亚胺培南耐药的主要机制,可能也与其他3种碳青霉烯类药物耐药有密切关系;铜绿假单胞菌的oprD2基因发生突变,可能会降低铜绿假单胞菌对这儿种碳青霉烯类药物的敏感性.     

Antibiotic sensitivity patterns of Pseudomonas aeruginosa strains isolated from various clinical specimens

1567 clinical samples were obtained for the study; 494 strains of Pseudomonas aeruginosa were isolated (isolation rate of 31.52) and their antibiotic sensitivity patterns tested using Kirby Bauer disk diffusion method. The antibiotic sensitivity testing revealed that Pseudomonas aeruginosa strains were highly resistant to most anti-pseudomonal antibiotics; Amikacin was found to be most suitable for routine use with a sensitivity of 68.01% and the most resistant antibiotic was Netilmicin showing 70.04% resistance. Surprisingly, Gentamycin showed a relatively higher sensitivity of 55.87%. Sensitivity to Imipenem and Meropenem was 100%.     

Comparison of disc and MIC reduction methods with polymerase chain reaction for the detection of metallo-β-lactamase in Pseudomonas aeruginosa

Purpose: The present study was undertaken to evaluate the screening antibiotic, confirmatory phenotypic test and agent against PCR as gold standard and to detect the prevalent MBL gene. Materials and Methods: Three hundred and twenty-six Pseudomonas aeruginosa isolates were screened for resistance to Imipenem (IPM), Meropemem (MEM) and Ceftazidime (CAZ) by disc diffusion. Isolates resistant to any of these were considered screen test-positive for MBL and were subjected to Double disc synergy test (DDST) and Disc potentiation test (DPT: Using IPM, MEM and CAZ alone and with EDTA), Minimum inhibitory concentration (MIC) reduction [four-fold or more reduction in MIC of IPM and MEM in presence of chelators: EDTA and 1,10-phenanthroline (EPI/EPM: EDTA-phenanthroline- Imipenem/Meropenem Broth Microdilution method)] and polymerase chain reaction (PCR) for bla_IMP and bla_VIM. Results: Screen test-positives by MEM and CAZ were 19.3% as against 17.8% by IPM. MEMDDST, DPT and EPM confirmed 100% screen-test positives as against 93.7% by CAZ DDST and DPT-2, 76.2% by CAZ DPT-1, 88.9% by IPM DDST, 85.7% by IPM DPT-1 and 92.1% by EPI. IPMand CAZ DDST together confirmed 100% while IPM and CAZ DPT-2 confirmed 96.8%. All 63 screen-test positives showed the presence of bla_VIM. Conclusions: MEM was found to be the best screening and confirmatory agent for MBL detection and bla_VIM was found to be the prevalent MBL gene in this part of the country.     

The resistance of Pseudomonas aeruginosa strains to fluoroquinolone group of antibiotics

Fluoroquinolones are antibiotics that are very effective against many gram negative microorganisms, including P. aeruginosa. However, resistance to these antibiotics has been reported in recent years as well. In this study, the sensitivity of 136 P. aeruginosa strains, isolated from various clinical materials, to fluoroquinolones has been investigated. The lowest resistance rate was in ciprofloxacin with 12.5%. The resistance rates of the others were as follows: norfloxacin 14.7%, levofloxacin 16.9%, ofloxacin 19.9% and pefloxacin 28.7%. The 88.2% of the resistant strains to all fluoroquinolones were originated from intensive care unit.