铜绿假单胞菌产超广谱β-内酰胺酶与耐药性研究

目的检测铜绿假单胞菌产超广谱β-内酰胺酶(ESBLs)情况及其对常见抗菌药物的最低抑菌浓度(MIC),探索其耐药机制。方法用琼脂平板稀释法测定MIC,用PCR方法检测超广谱β-内酰胺酶基因。用SPSS统计软件分析结果。结果铜绿假单胞菌对常用药物的MIC值均较高,最高的是特治星(派拉西林/他唑巴坦)MIC90达到256μg/ml,其次为舒谱深(头孢哌酮/舒巴坦)达128μg/ml,泰能即亚胺培南达32μg/ml,最低的是美罗培南和帕珠沙星,分别达16μg/ml。PCR检测67株铜绿假单胞菌,共有21株产酶,产酶率为27·3%。产酶株与不产酶株铜绿假单胞菌对8种抗菌药物的耐药性并无显著性差异。结论我院分离的铜绿假单胞菌耐药现象非常严重,产ESBL酶并不是其主要的耐药机制。     

肺感方体外抗菌活性的实验研究

目的：观察肺感方对11种临床常见病原菌的体外抗菌作用.方法：使用肉汤微量稀释法测定肺感方对不同菌株的最低抑菌浓度（MIC）及最低杀菌浓度（MBC）.结果：肺感方对标准金黄色葡萄球菌、铜绿假单胞菌、大肠埃希菌、肺炎克雷伯菌、阴沟肠球菌、铅黄肠球菌的MIC分别为62.5,62.5,125,31.25,250,500 g/L,相应的MBC为：62.5,62.5,250,31.25,500,1 000 g/L;对临床分离菌株鲍曼不动杆菌（多重耐药）、铜绿假单胞菌（多重耐药）的MIC和MBC均分别为250,500 g/L;对粪肠球菌、白色念珠菌、肺炎克雷伯菌（超广谱β内酰胺酶阳性）、大肠埃希菌（超广谱β内酰胺酶阳性）无明显体外抗菌作用.结论：肺感方对金黄色葡萄球菌、铜绿假单胞菌、大肠埃希菌、肺炎克雷伯菌、阴沟肠杆菌、铅黄肠球菌、鲍曼不动杆菌（多重耐药）及铜绿假单胞菌（多重耐药）具有体外抗菌作用,其中对肺炎克雷伯菌的抗菌活性最强.     

1967株革兰阴性杆菌的分布及耐药性分析

目的了解近年临床分离的革兰阴性杆菌分布及耐药性特征.方法收集临床各类感染标本中分离的革兰阴性杆菌1967株,采用微量肉汤稀释法进行药敏试验,用SPSS软件完成数据分析.结果1996年～2000年共收集1967株革兰阴性杆菌,以大肠埃希菌、肺炎克雷伯菌、铜绿假单胞菌、不动杆菌最多见,头孢哌酮、头孢他啶、头孢曲松对大肠埃希菌、肺炎克雷伯菌的MIC90分别为32～256μg/ml,16～256μg/ml.环丙沙星、阿米卡星、头孢他啶对铜绿假单胞菌的MIC90分别为8,54.4,64μg/ml,有较高的耐药性.嗜麦芽窄食单胞菌对所监测的抗生索广谱耐药.结论临床细菌耐药性日趋严重.应积极开展细菌耐药性监测,强调临床合理应用抗菌药物.     

Clinical analysis of infection caused by Pseudomonas aeruginosa

目的 调查本院铜绿假单胞菌感染患者的临床资料、耐药状况及变化趋势,为临床合理应用抗菌药物提供科学的依据.方法 回顾性分析本院803株铜绿假单胞菌感染患者基础疾病、应用抗菌药物、侵入性操作及细菌药敏耐药情况.结果 247例患者中共分离出 803株铜绿假单胞菌,标本主要分离自痰液;科室分布以重症监护病房(ICU)最高,其次为老年病房、神经内科病房;患者多合并基础疾病,且患者常行吸痰、气管插管、导尿等侵人性操作;患者应用哌拉西林/他唑巴坦最多,其次为美罗培南及头孢哌酮/舒巴坦;本院铜绿假单胞菌耐药情况严重,对多粘菌素B的敏感率最高,其次为阿米卡星;多重耐药铜绿假单胞菌(MDR-PA)及泛耐药铜绿假单胞菌(PDR-PA)比率分别为88.43％和10.70％.结论 铜绿假单胞菌在痰中分离最多,老年患者多见,主要集中在ICU,与患者病情重、合并较多基础疾病、接受侵入性操作有关.临床上应限制碳青霉烯类抗菌药物的使用,以减缓铜绿假单胞菌多重耐药菌株的产生.     

铜绿假单胞菌所致感染的临床分析

目的调查本院铜绿假单胞菌感染患者的临床资料、耐药状况及变化趋势,为临床合理应用抗菌药物提供科学的依据。方法回顾性分析本院803株铜绿假单胞菌感染患者基础疾病、应用抗菌药物、侵入性操作及细菌药敏耐药情况。结果 247例患者中共分离出803株铜绿假单胞菌,标本主要分离自痰液;科室分布以重症监护病房(ICU)最高,其次为老年病房、神经内科病房;患者多合并基础疾病,且患者常行吸痰、气管插管、导尿等侵入性操作;患者应用哌拉西林/他唑巴坦最多,其次为美罗培南及头孢哌酮/舒巴坦;本院铜绿假单胞菌耐药情况严重,对多粘菌素B的敏感率最高,其次为阿米卡星;多重耐药铜绿假单胞菌(MDR-PA)及泛耐药铜绿假单胞菌(PDR-PA)比率分别为88.43%和10.70%。结论铜绿假单胞菌在痰中分离最多,老年患者多见,主要集中在ICU,与患者病情重、合并较多基础疾病、接受侵入性操作有关。临床上应限制碳青霉烯类抗菌药物的使用,以减缓铜绿假单胞菌多重耐药菌株的产生。     

多粘菌素B联合美罗培南用于泛耐药铜绿假单胞菌体外抗菌活性的有效性分析

目的:对多粘菌素B联合美罗培南用于泛耐药铜绿假单胞菌体外抗菌活性的有效性进行分析。方法:用微量肉汤稀释法、棋盘法等对多粘菌素B与美罗培南单独用药及两者联合用药后进行测定,临床分离出的60株泛耐药铜绿假单胞菌的最小抑菌浓度(MIC),并计算出部分抑菌浓度指数(FIC),同时依据FIC指数来判定出联合效应的类型,判定其有效性。结果:多粘菌素B和美罗培南在联用后,药物对泛耐药铜绿假单胞菌的MIC值都明显降低,FIC指数处于0~0.5的占全部菌株数量的60%;FIC指数处于0.5~1.0的占全部菌株数量的30%;FIC指数处于1.0~2.0的占全部菌株数量的10%;无FIC指数大于2的菌株。结论:多粘菌素B和美罗培南两药联用后,主要以协同作用及相加作用为主,测定分离的60株泛耐药铜绿假单胞菌具备抗菌作用,但是并不具备拮抗作用。多粘菌素B联合美罗培南用于疾病临床治疗,可有效提高临床治疗效果,且安全性较高,值得临床推广。     

青橄榄叶提取物体外抑菌活性研究

[目的]测定青橄榄叶提取物及大孔树脂AB-8不同极性洗脱产物对供试菌株的体外抑菌活性.[方法]采用96孔板微量稀释法测定青橄榄叶总提取物及不同极性洗脱产物对白色念珠菌、铜绿假单胞杆菌、耐甲氧西林金黄色葡萄球菌、耐药白色念珠菌、酿酒酵母和金黄色葡萄球菌的最低抑菌浓度(MIC).[结果]大孔树脂水洗极性部位对白色念珠菌的MIC为20.62 g/ml,50％乙醇洗脱部分对铜绿假单胞杆菌的MIC为82.5 μg/ml,90％乙醇洗脱部分对白色念珠菌、铜绿假单胞菌、耐甲氧西林金黄色葡萄球菌、耐药白色念珠菌、酿酒酵母和金黄色葡萄球菌的MIC分别为41.25,20.62,20.62,10.32,165.0和2.58μg/ml.[结论]青橄榄叶洗脱产物的水、50％乙醇及90％乙醇洗脱部分对白色念珠菌、铜绿假单胞杆菌、耐甲氧西林金黄色葡萄球菌、耐药白色念珠菌、酿酒酵母和金黄色葡萄球菌有较好的抑菌活性,尤其是90％乙醇洗脱部位的抑菌范围广,活性强且呈现量效依赖关系.     

南特桉体外抗菌实验研究

目的:研究南特桉（NTA）的体外抗菌能力。方法:测定67株临床分离耐药菌株的MIC值和3株标准菌株（大肠埃希氏菌ATCC 25922,金黄色葡萄球菌ATCC 25923,铜绿假单胞菌 ATCC 27853）的时间-杀菌曲线。结果:南特桉的抑菌能力随菌种不同而有差异,对金黄色葡萄球菌、铜绿假单胞菌、肠杆菌科细菌、其它菌的MIC50分别为1.708,3.217,8.123,87.222 mg/ml,MIC90分别为5.946,4.578,69.631,141.685mg/ml。总的MIC范围为0.625-80mg/ml。时间-杀菌曲线的结果表明NTA能分别在30,5,5min内完全杀灭金黄色葡萄球菌、铜绿假单胞菌和大肠埃希氏菌。结论:南特桉具有广谱抗菌作用,不仅能抑制多种耐药菌株的生长,还有杀菌能力,在烧伤治疗中具有较大的开发和应用前景。     

鱼腥草素钠增强妥布霉素抗铜绿假单胞菌生物被膜作用及抗菌协同作用

目的：研究鱼腥草素钠增强妥布霉素抗铜绿假单胞菌生物被膜的作用。方法：微量倍比稀释法测定鱼腥草素钠、妥布霉素对铜绿假单胞菌的最小抑菌浓度（MIC）,棋盘稀释法测定两者联合抗菌作用,结晶紫染色法测定单药及联合用药对铜绿假单胞菌生物被膜的最小抑膜浓度（SMIC）,扫描电镜下观察药物对铜绿假单胞菌生物被膜形态的影响,采用倾注平板法进行菌落数计数。结果：鱼腥草素钠对铜绿假单胞菌的MIC为512μg/mL,妥布霉素对铜绿假单胞菌的MIC为4μg/mL,两药联合后MIC分别为64μg/mL和1μg/mL,分级抑菌浓度指数（FIC）为0.375,提示两药协同作用明显。妥布霉素对铜绿假单胞菌生物被膜SMIC50黏附期为8μg/mL,早期生物被膜阶段为16μg/mL,成熟期生物被膜阶段为32μg/mL,两药联合后铜绿假单胞菌生物被膜SMIC50黏附期为8μg/mL,早期为0.5μg/mL,成熟期为8μg/mL,鱼腥草素钠对妥布霉素抗铜绿假单胞菌生物被膜有增强作用。结论：鱼腥草素钠与妥布霉素抗菌协同作用明显,鱼腥草素钠对妥布霉素抗铜绿假单胞菌生物被膜有增强作用。     

681株铜绿假单胞菌感染的临床分布及耐药性分析

目的：分析铜绿假单胞菌的标本来源、病区分布特点及其对常用抗菌药物的耐药性,为临床预防铜绿假单胞菌感染及合理用药提供依据。方法：分析分离出681株铜绿假单胞菌在不同标本、不同科室中的分布特点及其对常用抗菌药物的耐药性。菌株鉴定采用生物梅里埃A TB鉴定仪,药敏试验采用K‐B法进行,结果采用WHONET5.5软件进行数据分析。结果：分离到的681株铜绿假单胞菌分别来自痰标本（347株,占50.95％）、脓和分泌物、尿液、血液等,科室分布以IC U 最多,其次为神经外科、呼吸内科、骨科和烧伤科等。681株铜绿假单胞菌对多粘菌素B、美罗培南、亚胺培南、阿米卡星、氨曲南、哌拉西林、哌拉西林／他唑巴坦、庆大霉素、头孢吡肟、头孢哌酮／舒巴坦、头孢他啶和左氧氟沙星耐药率较低,均小于35％;对米诺环素和替卡西林／克拉维酸的耐药率较高,其中多重耐药与泛耐药铜绿假单胞菌2010年出现3株,2011年1株,2012年8株,2013年21株,2014年1株。结论：铜绿假单胞菌耐药情况复杂,且易产生多重耐药,应加强对其耐药性的监测,临床应合理使用抗生素,预防及减少医院感染的发生。     

产超广谱酶大肠埃希菌和肺炎克雷伯菌对头孢替坦等抗菌药物的耐药性研究

目的初步探讨头孢替坦等8种临床常用抗菌药物对产超广谱酶（ESBLs）的大肠埃希菌及肺炎克雷伯菌的体外抗菌活性,为临床合理用药提供依据。方法四川大学华西医院抗感染药物研究室分离自临床感染患者的120株经双纸片法确证为产ESBLs大肠埃希菌及肺炎克雷伯菌,采用琼脂二倍稀释法进行8种临床常用抗菌药物体外抗菌活性试验。结果亚胺培南等碳青霉烯类抗生素对产ESBLs抗菌作用有较强的抗菌活性,大肠埃希菌的MIC50为〈0．03μg／ml,MIC90为0．06μg／ml,肺炎克雷伯菌的MIC50为〈0．03μg/ml,MIC9。为O．06μg/ml;头孢替坦对大肠埃希菌及肺炎克雷伯菌也有很好的抗菌活性,MIC50分别为0．06和0．06μg/ml,MIC90分别为1和2μg／ml。结论头抱替坦对临床常见产ESBLs的大肠埃希菌和肺炎克雷伯菌具有良好的抗菌活性。     

STUDY OF IN VITRO ANTIBACTERIAL ACTIVITY OF 19 ANTIMICROBIAL AGENTS AGAINST PSEUDOMONAS AERUGINOSA

The in vitro antibacterial activity of 19 antimicrobial agents against 40 strains of P aeruginosa was studied. The 19 antimicrobial agents included 7 semisynthetic penicillins, 6 third generation cephalosporins, 5 aminoglycosides and l quinolone agent. The minimal inhibition concentrations (MIGs) were measured by the serial dilution on solid agar. Ceftazidime was the most active in 19 antimicrobial agents again P aeruginosa (MIC50: I pg / ml, MIC90: 2 /ig / ml) Amikacin and ofloxaxin followed it in activity. Acylureido-penicillins, such as azlocillin, fur- benicillin and piperacillin were highly active against P aeruginosa, which could inhibit, 92.5%, 90% and 85% of these strains at a concentration of 8 µg/ml. Cefsulodine and cefoperazone were also active against the same strains, inhibiting 92.5% and 99% of the strains at a concentration of 8 µg / ml. The potency of the agents mentioned above against P.aeruginosa was similar to that of aminoglycosides. The drug susceptibility of 10 strains isolated in our hospital was compared with that of 29 strains of other hospitals in Beijing. The MICS of 5 penicillins and 3 cephalosporins against the isolates of our hospi- tal was higher than that of other hospitals, suggesting that the susceptibility of β-lactam antibiotics against isolates of our hospital was lower. The effects of combined use of azlocillin with oxacillin and piperacillin with ofloxacin against 4 strains of carbenicillin-resistant P aeruginosa was studied using check-board testing. The synergy and partial synergy were observed in both combinations.     

大观霉素与其他4种抗生素体外抗淋球菌活性比较

目的：比较大观霉素与其他4种抗生素对临床分离淋球菌的体外抗菌活性。方法采用琼脂稀释法测定淋球菌株抗生素的最小抑茵浓度（ MIC）,按WH0西太区淋球菌耐药性监测统一标准判断敏感性。用纸片酸度定量法检测产B一内酰胺酶淋球菌菌株。结果本研究共测定493株淋球菌,大观霉素对淋球菌的敏感性为100%,其MIC50和MIC90均为16μg/ml,对产B一内酰胺酶淋球菌,大观霉素的MIC50和MIC90也为16μg/ml,均比耐药标准低8倍;其次为头孢曲松,虽未检出耐药株但中敏检出l64株（33.3%）;抗淋球菌活性最差的是青霉素,耐药率为89.0%;环丙沙星和四环素的耐药率也较高,分别为88.2%和85.6%。青霉素、四环素和环丙沙星的MIC。及MIC。均已超过耐药标准,尤其是青霉素最严重,其MIC50和MIC90均超过耐药标准的4倍和l28倍。结论大观霉素对淋球菌具有强大的抗菌活性,头孢曲松对淋球菌的抗菌活性也较高,两者可作为治疗淋病的首选药物,大观霉素对青霉素、四环素和环丙沙星耐药率较高,提示这3种抗生素对淋病的治疗作用差。     

加替沙星与头孢他啶对临床分离革兰阴性致病菌的体外抗菌活性比较

目的观察比较加替沙星对革兰阴性致病菌株的体外抗菌活性。方法用琼脂二倍稀释法测定药物在体外的最低抑菌浓度(MIC)。结果临床分离革兰阴性致病菌对加替沙星和头孢他啶的敏感率分别为72. 3%、75%,耐药率分别为16. 9%、14.2%。经统计学处理两组差异无显著性。结论加替沙星对革兰阴性致病菌的体外抗菌活性较强,和头孢他啶相似,是一种高效的新型抗菌药物。     

两面针叶抗菌活性部位研究

目的研究两面针叶不同溶剂萃取部位对6种菌株的抗菌活性,为评价两面针叶抗菌活性部位提供实验依据。方法应用液体试管两倍稀释法测定两面针叶不同提取部位对大肠埃希菌、乙型副伤寒沙门菌、枯草芽孢杆菌、金黄色葡萄球菌、白色念珠菌、副溶血性弧菌等菌株进行最低抑菌浓度和最低杀菌浓度测定。结果乙酸乙酯部位对其中的4个菌株有抑菌活性,它们的抑菌活性依次为：副溶血性弧菌、白色念珠菌、金黄色葡萄球菌、枯草芽孢杆菌;正丁醇部位对白色念珠菌的抑菌活性最好,其最低杀菌浓度（MBC）和最低抑菌浓度（MIC）分别为750μg/mL和375μg/mL;水层对副溶血性弧菌抗菌活性最强;其MBC和MIC分别为750μg/mL和375μg/mL。结论乙酸乙酯部位、正丁醇部位及水层对白色念珠菌、副溶血性弧菌均有较好的抗菌活性,可考虑综合应用两面针叶在抗菌活性方面的应用与研究。     

三种国产氟喹诺酮药物体外抗菌作用

测试了国产氟哌酸、氟啶酸和甲氟哌酸等三种氟喹诺酮类药物(FQs)对8种共80株细菌的体外抗菌活性(MIC)及其对大肠杆菌2280杀菌作用的量效关系,结果表明,主种药物对大肠杆菌,阴沟扦菌、志贺氏菌属、沙门菌属、克雷白氏肺炎杆菌和金萄菌具有强大的抗菌活性(MIC90多≤1ug/ml)。对绿脓杆菌的作用较弱(MIC90为2—4ug/ml4株变形杆菌对三种FQS药物也较敏感(MIC为0、25—2ug/ml),但1株耐利福平杆菌的MIC为9ug/ml,提示利福平与FQS药物之间可能存在交叉耐药性。三种药物对大肠杆菌2280的杀菌量效关系呈双相变化,最强杀菌浓度为1—2ug/ml。本文对其临床意义进行了讨论。     

Synergy of drug combinations in treating multidrug-resistant Pseudomonas aeruginosa

Background

With the emergence of metallo-betalactamases (MBL) in Pseudomonas aeruginosa (P. aeruginosa), the value of carbapenem, the drug of last resort, is being severely compromised. Curtailing the use of carbapenems becomes paramount if resistance is to be reined in.

Aims

To study the role of synergy between combinations of drugs as an alternative treatment choice for P. aeruginosa. Synergy was studied between combinations of levofloxacin with piperacillin-tazobactam and levofloxacin with cefoperazone-sulbactam by time-kill and chequerboard techniques.

Methods

P. aeruginosa were tested for antibiotic susceptibility by the disc diffusion assay (260 isolates) and E-test (60 isolates). Synergy testing by chequerboard and time-kill assays was performed with combinations of piperacillin-tazobactam with levofloxacin (11 isolates) and cefoperazone-sulbactam with levofloxacin (10 isolates).

Results

Nearly all isolates were susceptible to piperacillin-tazobactam (96.1 per cent), followed by piperacillin (78.5 per cent). Seventy-one isolates (27.3 per cent) were found to be multidrug resistant and 19.6 per cent were ESBL producers. MIC₅₀ of amikacin was 32μg/ml and MIC₉₀ was 64μg/ml. MIC₅₀ and MIC₉₀ of cefoperazone-sulbactam was 32μg/ml and 64μg/ml, and for levofloxacin it was 10μg/ml and 240μg/ml, respectively. Piperacillin-tazobactam had MIC₅₀ and MIC₉₀ of 5μg/ml and 10μg/ml, respectively. Synergy was noted in 72.7 per cent isolates for levofloxacin and piperacillin-tazobactam combination, the remaining 27.3 per cent isolates showed addition by both chequerboard and time-kill assay. For levofloxacin and cefoperazone-sulbactam, only 30 per cent isolates had synergy, 40 per cent showed addition, 20 per cent indifference, and 10 per cent were antagonistic by the chequerboard method.

Conclusion

The combination of levofloxacin and piperacillin-tazobactam is a good choice for treatment of such strains.     

Characterization of multidrug-resistant and metallo-beta- lactamase-producing Pseudomonas aeruginosa isolates from a paediatric clinic in China

Background In the present study, we characterized multidrug-resistant Pseudomonas aeruginosa （MDRP） clinical isolates from a paediatric facility and investigated the types and features of the metallo-β-lactamases （MBLs） produced by carbapenem-resistant strains. Methods Four hundred and ninety-eight strains of Pseudomonas aeruginosa were isolated from patients at Beijing Children＇s Hospital between January 2005 and December 2006. The minimal inhibition concentrations （MICs） of the strains for 13 antibiotics were measured. A combination of the E test and PCR amplification/DNA sequencing was used to define the carbapenem-resistant strains. Results We found that 24.1% （120/498） of the isolates were MDRP. The frequencies of resistance to imipenem and meropenem were 34.2% and 35.8%, respectively, and the MIC50 and MIC90values for the two antibiotics were identical at 4 pg/ml and 32 pg/ml, respectively. The detection rate for carbapenem resistance was 49.2% （59/120）. Among the 59 carbapenem-resistant Pseudomonas aeruginosa strains, 39 （66.1%） were positive for the MBL genotype; 35 （89.7%） strains carried the blaiMp gene and 4 （10.3%） strains carried the blavm gene. Neither blasPM nor blaGiM was amplified from any of the 59 isolates. DNA sequencing revealed that IMP-1 was present in 35 IMP-producing isolates and VIM-2 was detected in four VIM-producing isolates. Conclusions These MDRP isolates exhibited high frequencies of resistance to carbapenems among clinical isolates from a paediatric facility in Beijing, China. The production of MBL appears to be an important mechanism for carbapenem resistance in Pseudomonas aeruginosa.     

抗菌药物对解脲支原体作用的实验室研究

目的 :探讨解脲支原体 (Uu)对抗生素的敏感性。方法 :采用肉汤稀释法对 6 5株Uu进行了体外敏感性测定。结果 :大环内酯类药物 ,尤其是罗红霉素对Uu的体外抑制作用最强 ,MIC50 和MIC90 分别是 1mg/L和 2mg/L ,而红霉素分别为 2mg/L和 8mg/L ;喹诺酮类、左旋氟嗪酸MIC50 和MIC90 分别为 2mg/L和 4mg/L ,而氟嗪酸分别为4mg/L和 8mg/L ;四环素类、强力霉素对Uu抑制效果较好 ,MIC50 和MIC90 分别为 2mg/L和 4mg/L ,8株Uu对四环素高度耐药 ,其MIC50 与MIC90 是 6 4mg/L和 12 8mg/L。结论 :大环内酯类药物是目前治疗Uu感染的首选药物 ,其次为左旋氟嗪酸和强力霉素。