Ciprofloxacin对耐甲氧西林金葡菌的活性

作者采用肉汤二倍稀释法测定了 Cipr-ofloxacin 及万古霉素等六种抗生素对54株临床分离的耐甲氧西林金葡菌(MRSA)的最低抑菌浓度(MIC)和最低杀菌浓度(MBC)所有菌株对三个耐酶青霉素——甲氧西林、乙氧萘青霉素和苯唑青霉素全部耐药;许多菌株对庆大霉素也耐药;45%菌株对氯林霉素耐药;但全部菌株对 Ciprofloxacin 和万古霉素敏感。Ciprofloxacin 对这些 MRSA 的MIC_(50)为0.25μg/ml,MIC_(90)为0.5μg/ml。Ciprofloxacin 和万古霉素对所有被试菌呈现杀菌作用,MBC_(90)分别为1.0和2.0μg/ml。对15株 MRSA 杀菌动力学的研究指出,当接种菌量为5.0×10~5CFU/ml 时,Cipro-floxacin 和万古霉素的杀菌率没有显著不     

米诺环素与夫西地酸对98株耐甲氧西林金黄色葡萄球菌的联合药敏研究

目的评价米诺环素与夫西地酸对临床分离到的98株耐甲氧西林金黄色葡萄球菌(MRSA)的联合体外抗菌活性,及两药联用的抗MRSA效应。方法用棋盘法设计,用微量肉汤稀释法,测定不同浓度组合的抗菌药物对98株临床分离MRSA的最低抑菌浓度,并计算部分抑菌浓度指数(FICI),判定联用效应。结果米诺环素与夫西地酸联用后,2种抗菌药物对临床分离得到的98株MR-SA的MIC50显著降低。FICI分布:FICI≤0.5(协同作用)占57.14%;0.54(拮抗作用)为0。结论米诺环素与夫西地酸体外联用对98株临床分离的MRSA体外抗菌效应以协同作用为主;无关作用较少;无拮抗作用。     

耐甲氧西林金黄色葡萄球菌实验室诊断方法

耐甲氧西林金黄色葡萄球菌(MRSA)是携带mecA基因的金黄色葡萄球菌或苯唑西林最小抑菌浓度(MIC)≥4 mg/L的金黄色葡萄球菌。大部分MRSA菌株携带mecA基因,但少数MRSA不携带mecA基因,存在其他的耐药机制,如青     

利奈唑胺对耐甲氧西林金黄色葡萄球菌细菌生物膜的抑制与消除活性及体内外抗菌活性研究

目的：系统性评价利奈唑胺对2013~2014年耐甲氧西林金黄色葡萄球菌（MRSA）临床分离株细菌生物膜（BBF）的活性及体内外抗菌效果。方法：体外试验测定最低抑菌浓度（MIC）;最低杀菌浓度（MBC）;最小抑制BBF浓度（MBIC）和最低BBF消除浓度（MBEC）;活菌计数法绘制时间-杀菌曲线（KCs）;体内试验采用小鼠MRSA全身感染模型,尾静脉给药保护小鼠后测定半数有效剂量（ED50）;建立免疫低下小鼠MRSA大腿感染模型,记录尾静脉给药24 h后大腿组织菌量的变化。结果：利奈唑胺对2013~2014年临床分离的60株MRSA均敏感;对金黄色葡萄球菌BBF的MBIC值与万古霉素相当,敏感性显著高于阿莫西林;体内试验中,利奈唑胺对全身感染小鼠有很好的治疗效果,ED50小于万古霉素与阿莫西林;对免疫低下MRSA大腿感染模型小鼠的保护作用也要优于万古霉素和阿莫西林。结论：利奈唑胺对2013~2014年分离的MRSA临床菌株体内外活性均较高,尤其对MRSA的细菌生物膜也显示了极强的抑制作用。     

社区及院内耐甲氧西林金黄色葡萄球菌感染的临床特征比较及耐药性分析

<正>金黄色葡萄球菌(staphylococcus aureus,SAU)是院内感染常见的革兰染色阳性球菌,获得mec A基因或苯唑西林最低抑菌浓度(MIC)≥2μg/ml的菌株称为耐甲氧西林金黄色葡萄球菌(MRSA)[1]。本文对我院2014年1月至2016年3月住院期间检出MRSA的所有患者进行回顾性调查,对医疗机构相关MRSA(HA-MRSA)及社区MRSA(CA-MRSA)感染     

耐甲氧西林金黄色葡萄球菌耐药表型分型与耐药基因检测分析研究

目的分析研究耐甲氧西林金黄色葡萄球菌(methicillin-resistant staphylococcus aureus,MRSA)的耐药表型及耐药基因,探索治疗MRSA感染的有效手段。方法对临床分离的耐甲氧西林金黄色葡萄球菌株,依据美国临床实验室标准化研究所(CLSI)标准操作规程进行万古霉素、利奈唑胺和苯唑西林等药物的药物敏感性试验和耐药基因检测,分别采用微量肉汤稀释法和多重聚合酶链反应(PCR)扩增法。结果 MRSA耐药表型分为Ⅰ~Ⅶ型,MRSA对抗生素产生多重耐药,万古霉素、利奈唑胺、氯霉素、复方新诺明、利福平耐药率分别为0、7.0%、40.8%、47.9%、60.6%,β-内酰胺类药物耐药率高达100%;实验菌株mecA、ermA、ermC、tetK、tetM、ratA基因检出率分别为98.6%、60.6%、18.3%、100%、7.0%和0。结论 MRSA对万古霉素、利奈唑胺敏感,其他药物呈多重耐药,需加强MRSA对万古霉素、利奈唑胺、氯霉素、复方磺胺、利福平等常用药物最小抑菌浓度(MIC)监测和临床报告,关注万古霉素对MRSA治疗不佳患者。     

大蒜素联合头孢唑林或苯唑西林对葡萄球菌的抗菌作用

目的：评价大蒜素分别与头孢唑林或苯唑西林联合用药,对于临床分离的革兰阳性球菌,包括金黄色葡萄球菌（staphylococcus aureus）和表皮葡萄球菌（staphylococcus epidermidis）的体外联合抗菌效应.方法：采用棋盘法设计,微量肉汤稀释法测定.测定不同浓度组合的二组抗菌药物对40株临床分离的革兰阳性球菌的最低抑菌浓度,并计算FIC指数,也称部分抑菌浓度（Fractiona inhibitory concentration index）判定联合效应.FIC≤0.5 为协同作用,0.5＜FIC≤1为相加作用,1＜FIC≤2为无关作用,FIC＞2为拮抗作用.结果：大蒜素与头孢唑林或苯唑西林联合应用后,其MIC50显著降低.FIC指数分布：FIC≤0.5占55%～75%;0.5＜FIC≤1占20%～40%;1＜FIC≤2占0～5.88%;FIC＞2为0.结论：头孢唑林或苯唑西林这2种抗菌药物与大蒜素联合用药后,对革兰阳性球菌基本表现为协同作用和相加作用.     

儿茶素类化合物增强β-内酰胺类抗生素抗MRSA的作用

目的确定儿茶素类化合物——儿茶素(C)、表儿茶素没食子酸酯(ECG)、表没食子酸儿茶素(EGC)联合增强β-内酰胺类抗生素对耐甲氧西林的金黄色葡萄球菌(MRSA)产生抗菌增敏作用的最佳配伍比并对其可能的抗菌增敏作用的机制进行初步探讨。方法以微量稀释法测定C、ECG、EGC和几种β-内酰胺类抗生素单独对MRSA WHO-2菌株的最小抑菌浓度(MIC),以棋盘法测定C、ECG和EGC联合β-内酰胺类抗生素后对MRSA WHO-2菌株和25株MRSA临床分离株的最小抑菌浓度(MIC);以荧光分光光度计法和激光共聚焦扫描显微镜法观察C、ECG、EGC单独、两两联合、三者联合后对柔红霉素在MRSA WHO-2菌株菌体聚集的影响。结果 C、ECG、EGC三者联用时可以增强苯唑西林抗MRSA WHO-2菌株的能力,其中C、ECG、EGC按照1:1:1的比例配伍后可以取得最佳的抗菌增敏效果,后续实验选用此药物配伍。药物总浓度为16μg/mL的C2E(C+ECG+EGC)与苯唑西林、头孢唑林、氨苄西林联合时对于MRSA WHO-2菌株可产生抗菌增敏作用,对应的FIC指数均为0.38,同样浓度的C2E联合苯唑西林、氨苄西林、头孢唑林、头孢吡肟、泰能后对25株MRSA临床分离株中可产生抗菌增敏作用的菌株数所占比例分别为80%、76%、88%、80%、92%,说明C2E在MRSA临床分离株中同样存在广泛的抗菌增敏作用。经过均为16μg/mL的C、ECG、EGC三者联合处理后,MRSA WHO-2菌株菌体内的柔红霉素在荧光分光光度计下测得的A值为9.26±0.16,大于单独或两两联合处理时的A值(P<0.05),提示三者联合处理后增强了柔红霉素在MRSA WHO-2菌体内的聚集;激光共聚焦扫描显微镜法也显示出相同的结果。结论 C、ECG、EGC三者联合后可显著增强β-内酰胺类抗生素抗MRSA的作用,其最佳配伍比为1:1:1。抗菌增敏作用机制可能与其增加药物在菌体内的聚集有关。     

利奈唑胺与万古霉素对耐甲氧西林金黄色葡萄球菌体外抗菌活性

目的 评价利奈唑胺(嗯唑烷酮类抗菌药)、万古霉素(胺基糖苷类抗生素)2种抗菌药物对耐甲氧西林金黄色葡萄球菌(MRSA)的体外抗菌活性.方法 用琼脂二倍稀释法,测定抗菌药物的最低抑菌浓度(MIC);用肉汤稀释法,测定抗菌药物的最低杀菌浓度(MBC),绘制杀菌曲线(KCs).结果 利奈唑胺对临床分离的98株MRSA的MIC50为1 μg·mL-1,MIC90为2 μg·mL-1,MBC50为8 μg·mL-1,MBC90为32 μg·mL-1,敏感率为100%;万古霉素对临床分离的98株MRSA的MIC50为1 μg·mL-1,MIC90为1 μg·mL-1,MBC50为8 μg·mL-1,MBC90为32 μg·mL-1,敏感率为100%.随着抗菌药物浓度的升高,其杀菌时间缩短不甚明显,呈现非浓度依赖性的特点.结论 利奈唑胺对MRSA的体外抗菌活性与万古霉素相当,均显示非浓度依赖性的杀菌曲线.     

β 内酰胺类抗生素相互配伍的合理性

在感染性疾病治疗中 ,β 内酰胺类抗生素以其抗菌效力强、毒性低被经常选用。我院在住院处方抽查中发现 ,β 内酰胺类抗生素不只单用 ,还两种或多种联合使用 ,有时还加用环丙沙星、氧氟沙星、甲硝唑等。下面是两种 β 内酰胺类抗生素配伍使用的 9组例子 :①青霉素Ｇ +氨苄西林钠 ;②青霉素Ｇ +头孢噻肟钠 ;③青霉素Ｇ +头孢曲松 ;④头孢拉啶 +氨苄西林钠 ;⑤青霉素Ｇ +苯唑西林钠 ;⑥头孢拉啶 +苯唑西林钠 ;⑦头孢噻肟钠 +苯唑西林钠 ;⑧氨苄西林钠 +苯唑西林钠 ;⑨哌拉西林钠+苯唑西林钠。各药用量均为单用时的常用量 ,静脉滴注 ,ｑｄ ,用…     

Synergistic effects of berberines with antibiotics on clinical multi-drug resistant isolates of methicillin-resistant Staphylococcus aureus (MRSA)

N-Methyl-dihydroberberine (M-Ber) was synthesized, and antibacterial activities of Berberine (Ber) and M-Ber alone and combined with antibiotics were studied against ten clinical MRSA isolates. MICs/MBCs (μg/ml, alone) ranges were 32–128/64–256 (Ber) and 64–128/256–1,024 (M-Ber) by a broth microdilution method. Significant synergies of Ber (M-Ber)/Azithromycin and Ber (M-Ber)/Levofloxacin combinations were observed by the chequerboard test. The Ber (M-Ber)/Ampicillin and Ber (M-Ber)/Cefazolin combinations showed indifference. These results demonstrated that Ber and M-Ber enhanced the in vitro inhibitory efficacy of Azithromycin and Levofloxacin, which had potential for combinatory therapy of patients infected with MRSA.     

绿茶及其提取物抗耐甲氧西林金黄色葡萄球菌作用研究

目的 研究绿茶及提取物对耐甲氧西林金黄色葡萄球菌(MRSA)的抗菌作用并分析其主要抗菌成分.方法 采用琼脂稀释法测定各种茶叶的水浸出物及茶叶的主要成分对MRSA的MIC.纸片扩散法观察绿茶浸出物和茶叶主要成份与抗生素合用对MRSA的协同抗菌情况.结果 ①绿茶浸出物对MRSA的MIC范围为0.125-0.5%,青茶浸出物为0.125-0.5%,白茶浸出物为0.0625-0.25%,红茶浸出物为0.5%,黑茶浸出物为0.25-0.5%.②茶多酚对MRSA的MIC范围为128-256μg/mL,茶色素为256-512μg/mL,茶多糖为512-1024μg/mL,茶皂素和咖啡因则均大于1024μg/mL.③青霉素、苯唑西林、氨苄西林、头孢他啶、头孢替唑、米诺环素、四环素与绿茶浸出物合用的抑菌圈明显大于单用抗生素的抑菌圈,红霉素和氯霉素单用/合用的抑菌圈相同,环丙沙星加入绿茶浸出物后抑菌圈反而减小.④茶多糖、茶皂素、茶色素、咖啡因与苯唑西林单用/合用的抑菌圈均相同,茶多酚与苯唑西林合用的抑菌圈明显大于单用苯唑西林的抑菌圈,表儿茶素没食子酸酯(ECg)/表没食子儿茶素没食子酸酯(EGCg)与苯唑西林合用的抑菌圈明显大于各自单用的抑菌圈.结论 各种茶叶对MRSA均有一定的抗菌作用,其中绿茶和白茶的抗菌作用最强.绿茶抗MRSA的主要成分为茶多酚,并且茶多酚对β-内酰胺类抗生素和四环素抗MRSA有增效作用,但对其它类抗生素呈无关或拮抗作用.茶多酚中的2个单体ECg和EGCg能增强苯唑西林的抗MRSA作用.     

Synergistic effect of emodin in combination with ampicillin or oxacillin against methicillin-resistant Staphylococcus aureus

Methicillin-resistant Staphylococcus aureus (MRSA) is a substantial contributor to morbidity and mortality. In search of a natural products capable of inhibiting this multidrug resistant bacteria, we have investigated the antimicrobial activity of emodin (EM) isolated from Rheum palmatum L. (Polygonaceae) against 17 different strains of the bacterium. New antimicrobial activity was found using the paper disc diffusion method, agar dilution as well as checkerboard method. Against the 17 strains, the disc diffusion test was in the range of 18-30?mm, and the minimum inhibitory concentrations (MICs) of EM were in the range of 1.5-25 μg/mL. From those results we performed the checkerboard test to determine the synergism of EM in combination with ampicillin (AM) or oxacillin (OX) against all strains. The combined activity of EM and two antimicrobial agents (AM, OX) against all strains resulted in a fractional inhibitory concentrations index (FICI) ranging from 0.37-0.5 and from 0.37-0.75, respectively. The effect of EM with AM and OX was found to be synergistic or partially synergistic. We found that EM reduced the MICs of AM and OX. EM and in combination with AM or OX could lead to the development of new combination antibiotics against MRSA infection.     

两种方法测定替加环素对鲍曼不动杆菌药敏结果的比较

目的：比较采用两种方法测定替加环素对鲍曼不动杆菌药敏结果的差异。方法：分别采用琼脂平板稀释法和微量肉汤稀释法测定替加环素对70株鲍曼不动杆菌的MIC值,比较其结果差异性。结果：应用琼脂平板稀释法测定的MIC50和MIC90为1μg·mL-1和2μg·mL-1,敏感率、中介率、耐药率分别为47.1%、48.6%、4.3%;应用微量肉汤稀释法测定的替加环素对鲍曼不动杆菌的MIC50和MIC90分别为0.25μg·mL-1和0.5μg·mL-1,敏感率为100%。两种方法测定结果的一致性和相关性均较差;以微量肉汤稀释法为基准时,应用琼脂平板稀释法测定的总误差率为52.9%。结论：应用琼脂平板稀释法和微量肉汤稀释法进行替加环素对鲍曼不动杆菌药敏测定时,其敏感率有明显的差别。     

Synergistic effect of emodin in combination with ampicillin or oxacillin against methicillin-resistant Staphylococcus aureus

Methicillin-resistant Staphylococcus aureus (MRSA) is a substantial contributor to morbidity and mortality. In search of a natural products capable of inhibiting this multidrug resistant bacteria, we have investigated the antimicrobial activity of emodin (EM) isolated from Rheum palmatum L. (Polygonaceae) against 17 different strains of the bacterium. New antimicrobial activity was found using the paper disc diffusion method, agar dilution as well as checkerboard method. Against the 17 strains, the disc diffusion test was in the range of 18–30?mm, and the minimum inhibitory concentrations (MICs) of EM were in the range of 1.5–25 μg/mL. From those results we performed the checkerboard test to determine the synergism of EM in combination with ampicillin (AM) or oxacillin (OX) against all strains. The combined activity of EM and two antimicrobial agents (AM, OX) against all strains resulted in a fractional inhibitory concentrations index (FICI) ranging from 0.37–0.5 and from 0.37–0.75, respectively. The effect of EM with AM and OX was found to be synergistic or partially synergistic. We found that EM reduced the MICs of AM and OX. EM and in combination with AM or OX could lead to the development of new combination antibiotics against MRSA infection.     

Methicillin-resistant Staphylococcus aureus in the hospitals of central Greece.

A total of 250 consecutive Staphylococcus aureus clinical isolates were collected during the period 1999-2000 from the five major hospitals of the district of Thessaly (Central Greece). Thirty seven (14.8%) of the isolates were mecA-positive (MRSA) in a PCR-based assay; all exhibited resistance to oxacillin (agar dilution MICs > or =4 mg/L) and were also resistant to multiple antibiotics. Most of the MRSA isolates had been collected in the intensive care units and the surgical wards of the participating hospitals in a sporadic fashion. The MRSA incidence found here was significantly lower than reported in previous studies from Greece. Molecular typing by PFGE showed that the MRSA isolates were distributed between three pulsotypes. Evaluation of various conventional methods for assessing methicillin resistance showed that oxacillin agar dilution and immunological detection of PBP2a with the Slidex MRSA Detection kit were the most reliable in this setting. Misclassifications of isolates exhibiting low-level resistance (oxacillin MIC 2-4 mg/L) occurred with the salt agar screen, the oxacillin disk diffusion and the ATB Staph System methods.     

Potentiation of antimicrobial activity of aminoglycosides by carnosol from Salvia officinalis

We found that a crude extract from Salvia officinalis (sage) reduced the minimum inhibitory concentrations (MICs) of aminoglycosides in vancomycin-resistant enterococci (VRE). We isolated the effective compound from the extract and identified it as carnosol, one of diterpenoids. Carnosol showed a weak antimicrobial activity, and greatly reduced the MICs of various aminoglycosides (potentiated the antimicrobial activity of aminoglycosides) and some other types of antimicrobial agents in VRE. Carnosic acid, a related compound, showed the similar activity. The effect of carnosol and carnosic acid with gentamicin was synergistic.     

耐甲氧西林金黄色葡萄球菌耐药性分析

目的了解耐甲氧西林金黄色葡萄球菌(MRSA)对各种抗菌药物的耐药性。方法 对30株MRSA进行药敏实验,药敏实验采用VITEK32全自动微生物分析仪GPS药敏板。结果 在测试的14种抗菌药物中,万古霉素未出现耐药菌株,对呋喃妥因、利福平、复方磺胺甲口恶唑耐药率低(分别为6.7%、10.0%、20.0%)。对氯霉素耐药率为53.3%,对克林霉素、红霉素、庆大霉素、四环素、左氧氟沙星耐药率均在90.0%以上。对氨苄西林、头孢唑啉、苯唑西林、青霉素则是全耐药。结论 应加强抗菌药物的合理应用,减少MRSA耐药事件的发生。     

Synergistic effects of mupirocin and an isoflavanone isolated from Erythrina variegata on growth and recovery of methicillin-resistant Staphylococcus aureus

The phytochemical 2',4'-dihydroxy-8-gamma,gamma-dimethylallyl-2",2"-dimethylpyrano[5",6":6,7]isoflavanone (bidwillon B) was isolated from Erythrina variegata and its antibacterial properties against methicillin-resistant Staphylococcus aureus (MRSA) were investigated. Bidwillon B inhibited the growth of 12 MRSA strains at minimum inhibitory concentrations (MICs) of 3.13-6.25mg/l, while MICs of mupirocin were 0.20-3.13 mg/l. The minimum bactericidal concentration (MBC) for bidwillon B and mupirocin against MRSA were 6.25-25mg/l (MBC(90): 12.5mg/l) and 3.13-25mg/l (MBC(90): 25mg/l), respectively. When bidwillon B and mupirocin were combined, synergistic effects were observed for 11 strains of MRSA (fractional inhibitory concentration indices, 0.5-0.75). The MBCs of mupirocin in the presence of bidwillon B (3.13 mg/l) were reduced to 0.05-1.56 mg/l. Bidwillon B at MIC values strongly inhibited incorporation of radio-labelled thymidine, uridine, glucose and isoleucine into MRSA cells. Mupirocin showed lower inhibitory effects than bidwillon B on thymidine, uridine and glucose incorporation, but incorporation of isoleucine was completely blocked with this antibiotic. These results indicate that bidwillon B possesses sufficient anti-MRSA activity for inhibiting growth and recovery, and that the compound acts synergistically with mupirocin. The results also suggest that both compounds act on MRSA via different mechanisms. Bidwillon B may prove to be a potent phytotherapeutic and/or combination agent with mupirocin in the elimination of nasal and skin carriage of MRSA.