氨曲南与阿奇霉素联用对铜绿假单胞菌的体外作用研究

目的:探讨氨曲南与阿奇霉素联用,对质控菌株铜绿假单胞菌ATCC 27853和临床分离的15株铜绿假单胞菌的体外作用效果。方法:利用肉汤稀释法、微量棋盘法、时间杀菌曲线等分别测定氨曲南、阿奇霉素单用及联用对铜绿假单胞菌的最低抑菌浓度(MIC),计算部分抑菌浓度指数(FICI),判断两药联合作用效果。结果:氨曲南与阿奇霉素联用对铜绿假单胞菌43.75%为协同作用,37.5%为相加作用,18.75%为无关作用,无拮抗作用。结论:氨曲南联用阿奇霉素对铜绿假单胞菌的体外作用主要表现为协同和相加作用。     

EDTA-2Na联合抗菌药物对铜绿假单胞菌的体外抑菌及生物膜抑制作用研究

目的 探讨乙二胺四乙酸二钠(ethylenediaminetetraacetic acid disodium,EDTA-2Na)联合抗菌药物对铜绿假单胞菌的体外抑菌及生物膜抑制作用。方法 对临床分离的10株亚胺培南耐药铜绿假单胞菌、8株黏菌素耐药铜绿假单胞菌和8株阿米卡星耐药铜绿假单胞菌,通过微量肉汤稀释棋盘法检测EDTA-2Na分别与亚胺培南、黏菌素和阿米卡星联用以及各自单用时对相应耐药菌株的最小抑菌浓度(minimal inhibititory concentration,MIC),并通过计算部分抑菌浓度指数(fractional inhibitory concentration index,FICI)评价联合抑菌效果;结晶紫生物膜试验检测EDTA-2Na分别与亚胺培南、黏菌素和阿米卡星联用及各自单用时对相应耐药菌株生物膜的抑制作用,通过测量A595值评价抑制生物膜效果。结果 EDTA-2Na与亚胺培南、黏菌素和阿米卡星联用后对相应耐药菌株的抑菌作用表现为协同或相加,对生物膜也具有明显的协同抑制作用。结论 EDTA-2Na联合抗菌药物对铜绿假单胞菌具有良好的体外抑菌作用及抑制生物膜作用。     

铜绿假单胞菌临床分离株对喹诺酮类药物的耐药性研究

目的：对铜绿假单胞菌的耐药性进行调查并研究药物联用后对铜绿假单胞菌MIC的逆转情况。方法：通过琼脂二倍稀释法检测86株铜绿假单胞菌对四种喹诺酮类药物与利舍平及维拉帕米联用前后的MIC值及86株桐绿假单胞菌对其它常用抗生素的MIC值;用微量棋盘稀释法测得氧氟沙星、环丙沙星与头孢他啶、哌拉西林联合作用后的部分抑菌浓度（FIC）指数。结果：86株铜绿假单胞菌对诺氟沙星耐药率为74.4% ;氧氟沙星的耐药率为52.2%;环丙沙星耐药率为15.1%;洛美沙星耐药率为20.9%。加入利舍平及维拉帕米后四种喹诺酮类药物对大部分菌株的MIC值均无变化,氧氟沙星和环丙沙星与头孢他啶、哌拉西林联用后FIC指数范围为0.1～1.5,66%的FIC指数≤0.5。结论：86株铜绿假单胞菌除对四种喹诺酮类药物呈现交叉耐药外,还对大多数临床常用的抗生素在耐药。利舍平及维拉帕米不能使诺氟沙星、氧氟沙星、环丙沙星、洛美少星的耐药性降低。氧氟沙星和环丙沙星与头孢他啶、哌拉西林联用有相加或协同作用,抗菌活性明显增强。     

蛇葡萄素与8种抗生素联用的体外抗铜绿假单胞菌作用研究

目的:研究蛇葡萄素与8种抗生素联用的体外抗铜绿假单胞菌作用。方法:采用棋盘式微量稀释法测定蛇葡萄素分别与头孢曲松、头孢哌酮/舒巴坦、哌拉西林/他唑巴坦、头孢哌酮、环丙沙星、阿米卡星、哌拉西林、头孢吡肟8种抗生素联用对铜绿假单胞菌(PA)标准菌株ATCC27853和7株临床分离菌株PA135、PA216、PA276、PA281、PA291、PA314、PA319的最小抑菌浓度(MIC),以分级抑菌浓度指数(FICI)评价其联用效果;并以临床分离菌株PA319为目的菌株,设置正常对照组、蛇葡萄素单用组、抗生素单用组以及二者联用组,以联用时蛇葡萄素与抗生素的MIC为作用浓度,计数作用0、4、8、12、24 h的菌落数,绘制时间-杀菌曲线。结果:针对上述8株菌株,蛇葡萄素单用的MIC为128～256 mg/L,分别与头孢曲松、头孢哌酮/舒巴坦、哌拉西林/他唑巴坦、头孢哌酮、环丙沙星、阿米卡星、哌拉西林、头孢吡肟联用时FICI≤1的分别有8、8、7、6、4、4、6、6株。在时间-杀菌曲线中,与抗生素单用比较,蛇葡萄素分别与头孢曲松、头孢哌酮/舒巴坦、哌拉西林/他唑巴坦、头孢哌酮、环丙沙星、阿米卡星、哌拉西林、头孢吡肟联用后菌落数的下降幅度分别为2.65、2.30、0.42、0.47、0.53、1.19、1.74、1.04 lgCFU/mL。结论:蛇葡萄素与头孢曲松、头孢哌酮/舒巴坦联用时对铜绿假单胞菌的抗菌效果更好。     

牡丹皮中丹皮酚、总苷、多糖单用及合用后的协同抑菌作用考查

目的:考查牡丹皮中抑菌药效成分丹皮酚、总苷、多糖单用及合用后的协同抑菌作用.方法:分别提取牡丹皮中的丹皮酚、总苷、多糖,定量后再以大肠埃希菌、肺炎克雷白菌、铜绿假单胞菌、粪肠球菌为实验菌株,用琼脂二倍稀释法测定最小抑菌浓度(MIC,minimal inhibitory concentrations),并分析比较抑菌活性.结果:牡丹皮总苷对大肠埃希菌、肺炎克雷白菌、铜绿假单胞菌、粪肠球菌标准株和临床株均有抑菌作用,其中对铜绿假单胞菌作用最强,对肺炎克雷白菌作用相对较弱;丹皮酚与总苷相比也具有抑菌作用,MIC明显高于总苷;多糖仅对粪肠球菌及铜绿假单胞菌有抑菌效果;丹皮酚与总苷合用后有协同抑菌作用,对粪肠球菌尤为显著.结论:牡丹皮总苷及丹皮酚具有一定的抑菌活性,且二者合用效果更强,提示该作用可进一步开发利用.     

亚抑菌浓度莫匹罗星对烧伤创面分离铜绿假单胞菌生物膜的影响

目的:研究烧伤患者伤口分离铜绿假单胞菌的耐药性,并探讨亚抑菌浓度莫匹罗星对铜绿假单胞菌生物膜的作用。方法:采用琼脂平板倍比稀释法检测30株临床分离铜绿假单胞菌的最低抑菌浓度(MIC),菌落计数法分析亚抑菌浓度(1/4 MIC)莫匹罗星对铜绿假单胞菌黏附性的影响,96孔板结晶紫染色法检测亚抑菌浓度莫匹罗星对铜绿假单胞菌生物膜形成的影响。结果:我院临床烧伤患者分离的铜绿假单胞菌对莫匹罗星、哌拉西林、亚胺培南、美罗培南、左氧氟沙星、庆大霉素、奈替米星具有较高的耐药性,而对头孢他啶和氨曲南的敏感性较高。亚抑菌浓度莫匹罗星对临床分离铜绿假单胞菌的黏附性和生物膜形成均有抑制作用。结论:莫匹罗星可抑制铜绿假单胞菌生物膜形成,但其抑制程度具有菌株差异性。     

4种中药对30株广泛耐药铜绿假单胞菌的抑菌作用

目的:探讨黄芩等4种中药对广泛耐药铜绿假单胞菌的抑菌作用。方法:采用中药抗菌试验试管法测定药物的最低抑菌浓度(MIC)。结果:黄芩、连翘、黄连、金银花对30株广泛耐药铜绿假单胞菌有不同程度的体外抑菌作用,MIC均值分别为475.00,345.83,60.94,379.17 mg/m L,与标准菌株ATCC27853的MIC相近。其中黄连的抑菌作用最强。结论:4种中草药对30株广泛耐药铜绿假单胞菌均有不同程度的抑菌作用,本地与外地收集的菌株,抑菌作用无显著性差异(P>0.05)。     

桂皮醛联合伏立康唑对临床分离烟曲霉菌的体外作用研究

摘要： 目的 评价桂皮醛与伏立康唑（VRC）联合应用对临床分离烟曲霉菌的体外抗菌活性。 方法 参照美国临床和实验室标准协会（CLSI）推荐的微量液基稀释法及棋盘法, 分别测定桂皮醛、VRC 单独使用及联合使用对 42 株临床分离烟曲霉菌的最小抑菌浓度（MIC）, 比较 2 药单用与联用的 MIC50、MIC90MIC 几何均数（MICG）及 MIC 分布; 绘制浓度-累积抑菌百分率曲线并计算分级抑菌指数（FICI）, 判断药物联合作用的类型。 结果 桂皮醛与 VRC联用后, 2 药的 MIC50、MIC90及 MICG 均较各自单用时明显降低（P＜ 0.01）, MIC 峰值分布及浓度-累积抑菌百分率曲线较单用时左移; 2 药联用的 FICI 值为 0.187 5~1.5, 其中 16 株（38.10%）体现为协同作用, 19 株（45.23%）为相加作用, 7 株（16.67%）为无关作用, 未出现拮抗作用。 受试菌株对 VRC 的敏感性越低, 2 药联用的 FICI 均数越小。 结论 桂皮醛与 VRC 联用对临床分离烟曲霉菌的体外联合抗菌效应主要表现为协同和相加作用,且该药物组合对VRC 敏感性较低的烟曲霉菌表现出较强的协同抗菌作用。     

双黄连口服液联合庆大霉素的体外抗菌作用研究

目的研究双黄连口服液和庆大霉素联用对金黄色葡萄球菌、铜绿假单胞菌的体外抗菌作用。方法采用微量溶液稀释法,测定双黄连口服液和庆大霉素分别对金黄色葡萄球菌、铜绿假单胞菌的最低抑菌浓度(MIC);采用棋盘联合药敏试验法,测定双黄连口服液和庆大霉素联用分别对金黄色葡萄球菌、铜绿假单胞菌的部分抑菌浓度(FIC)指数。结果双黄连口服液对金黄色葡萄球菌和铜绿假单胞菌的MIC分别是46.88 mg.mL-1(稀释度1∶32)和375 mg.mL-1(稀释度为1∶4);庆大霉素对金黄色葡萄球菌和铜绿假单胞菌的MIC分别是0.25和1 U.mL-1;双黄连口服液和庆大霉素联用对金黄色葡萄球菌和铜绿假单胞菌的FIC指数均是0.56。结论双黄连口服液联用庆大霉素对金黄色葡萄球菌和铜绿假单胞菌药敏结果均呈相加作用。     

左氧氟沙星联合头孢哌酮舒巴坦对铜绿假单胞菌突变选择窗的影响

目的 在体外研究左氧氟沙星(LVX)联合头孢哌酮舒巴坦(SCF)对铜绿假单胞菌突变选择窗(MSW)的影响,为防止细菌耐药的产生提供依据.方法 采用琼脂二倍稀释法,测定LVX与SCF单用及联用时,对临床分离10株铜绿假单胞菌的最低抑菌浓度(MIC)和防耐药突变浓度(MPC),计算选择指数(SI=MPC/MIC).结果 LVX单用时,LVX对铜绿假单胞菌的SI值为16~64,LVX和SCF联用时,LVX对铜绿假单胞菌的SI值为8~32.两药联合使用后LVX对铜绿假单胞菌的SI值显著低于LVX单用(χ2=11.88,P<0.05).结论 LVX与SCF联合使用可降LVX单用对铜绿假单胞菌MPC,缩小MSW,减少耐药菌产生.     

某院1998—2010年两种非发酵菌耐药率情况及与抗生素使用相关性分析

目的研究1998—2010年铜绿假单胞菌、鲍曼不动杆菌两种非发酵菌耐药性水平变化情况,以及耐药率与抗生素使用之间的相关关系。方法回顾性调查1998—2010年本院铜绿假单胞菌、鲍曼不动杆菌两种非发酵菌分离及耐药情况,同时调查同期抗生素的使用消耗情况,采用世界卫生组织(WHO)推荐的限定日剂量(DDD)法分析抗生素的用药频度(DDDs),用SPSS13.0统计软件统计抗生素使用与细菌耐药之间的相关分析。结果铜绿假单胞菌对丁胺卡那、头孢他啶较敏感,耐药率在20%左右,对其他抗生素的耐药率都超过了30%。鲍曼不动杆菌对亚胺培南、美洛培南耐药率上升较快,到2010年接近40%,耐药率较低的为头孢哌酮舒巴坦,但也超过了30%。统计结果显示亚胺培南、氨曲南的使用DDDs与铜绿假单胞菌的耐药率呈正相关;亚胺培南、美洛培南、头孢哌酮/舒巴坦、哌拉西林/他唑巴坦的使用DDDs与鲍曼不动杆菌的耐药率呈正相关。铜绿假单胞菌与不同类抗生素累计DDDs之间相关性统计显示头孢类抗生素的使用与头孢哌酮、氨曲南及亚胺培南的耐药率之间,复方制剂的使用与环丙沙星、左氧氟沙星的耐药率之间,碳青霉素类抗生素的使用与头孢哌酮、氨曲南及亚胺培南的耐药率之间呈正相关关系。鲍曼不动杆菌耐药率与不同类抗生素累计DDDs之间相关性统计显示,头孢类抗生素的使用与亚胺培南、头孢噻肟及哌拉西林钠他唑巴坦的耐药率之间,复方制剂的使用对头孢他啶、环丙沙星及头孢哌酮/舒巴坦耐药率之间,碳青霉烯类抗生素的使用对亚胺培南、美洛培南、头孢噻肟及哌拉西林/他唑巴坦耐药率之间呈正相关。结论抗菌药物的使用对两种非发酵菌造成了很大压力,耐药现象严重。     

In vitro activity of beta-lactams in combination with other antimicrobial agents against resistant strains of Pseudomonas aeruginosa

Using the chequerboard titration method, the activity in combination of beta-lactams, fluoroquinolones and aminoglycosides was investigated against 24 Pseudomonas aeruginosa isolates resistant to these antibiotics. Synergy was detected with one or more antimicrobial combinations against 15 of 24 (63%) isolates and partial synergy was detected with one or more combinations against all 24 isolates. No antagonism was seen with any combination. Ceftazidime and cefepime with aztreonam, amikacin and isepamicin showed synergy or partial synergy against 12-20 (50-80%) isolates. Imipenem and meropenem with amikacin and isepamicin showed synergy or partial synergy against eight to 12 (33-50%) isolates. The results of this study indicate that against P. aeruginosa, synergy may occur between beta-lactams, fluoroquinolones and aminoglycosides although the strains are resistant to the individual antibiotics.     

Antibacterial activity of aztreonam: a synthetic monobactam. A comparative study with thirteen other antibiotics

The in vitro activity of aztreoman (SQ 26, 776), a new monocyclic beta-lactam antimicrobial agent, was determined against 1720 bacteria, all clinical isolates, and compared with that of thirteen beta-lactam and aminoglycoside antibiotics. Aztreonam inhibited 90% of Citrobacter diversus, Citrobacter freundii, Enterobacter agglomerans, E. coli, Klebsiella pneumoniae, Proteus mirabilis, Proteus morganii, Proteus rettgeri, Proteus vulgaris and Salmonella sp. by less than or equal to 0.4 micrograms ml-1. This activity was superior to moxalactam, piperacillin, cefamandole, cefoperazone, cefoxitin, cefsulodin, ceftazidime and aminoglycoside antibiotics. Aztreonam was as active as moxalactam against Enterobacter aerogenes, Enterobacter cloacae and Shigella species. Pseudomonas aeruginosa strains resistant to moxalactam, piperacillin, cefamandole, cefoperazone, cefotaxime, cefoxitin, cefsulodin and ceftazidime were inhibited by aztreonam 50% by 6.3 micrograms ml-1 and 90% by 16 micrograms ml-1. Aztreonam was as active as ceftazidime against Serratia marcescens, all strains were inhibited by 3.1 micrograms ml-1 and 90% by 1.6 micrograms ml-1. There was no major difference between MBC and MIC values of aztreonam and the effect of inoculum size upon MIC values was observed at 10(7) CFU.     

不同剂量左氧氟沙星使用频度与细菌耐药率相关性研究

目的：了解不同荆量左氧氟沙星使用频度与8种细菌耐药率的相关性,为临床合理用药提供依据。方法：分别统计2002～2009年0．3g,0．4g、0．5g3种剂量左氧氟沙星、总左氧氟沙星及喹诺酮类抗菌药的用药频度与8种细菌对左氧氟沙星的耐药率,采用SPSS13．0统计软件进行相关性分析。结果：8种细菌中肺炎克雷伯菌对左氧氟沙星的耐药率最低（17．3％-35．4％）,耐甲氧西林金黄色葡萄球菌和产ESBL大肠埃希菌对左氧氟沙星耐药率较高,分别为75．4％～95．6％和81．1％～92．6％。左氧氟沙星（0．5g）的用药频度与大肠埃希菌、铜绿假单胞菌耐药率呈负相关（r=-0．9974,P〈0．01;r=-1．0000,P〈0．01）;左氧氟沙星（0．3g）、总左氧氟沙星、喹诺酮类抗菌药的用药频度与产ESBL肺炎克雷伯菌耐药率呈负相关（r=-0．8678,P〈0．05;r=-0．8465,P〈0．05;r=-0．7857,P〈0．05）;左氧氟沙星（0．3g）和总左氧氟沙星的用药频度分别与金黄色葡萄球菌和鲍曼不动杆菌的耐药率呈正相关（r=0．7256,P〈0．05,r=0．8214,P〈0．05）。结论：不同剂量左氧氟沙星、总左氧氟沙星、喹诺酮类抗菌药用药频度与细菌耐药率存在相关性,临床应注意合理使用不同剂量的左氧氟沙星。     

替加环素与临床常用抗菌药物对碳青霉烯类耐药肠杆菌科细菌的协同作用研究

目的评价替加环素与临床常用抗菌药物对碳青霉烯类耐药肠杆菌科细菌(CRE)的协同作用。方法收集2014—2016年临床分离的非重复CRE共235株。琼脂稀释法进行药物敏感性试验并分析替加环素和9种常用抗菌药物的耐药率。选取替加环素非敏感的35株作为研究对象,并采用棋盘稀释法检测替加环素联合其他9种抗菌药物(亚胺培南、美罗培南、头孢他啶、头孢噻肟、氨曲南、左氧氟沙星、阿米卡星、哌拉西林/三唑巴坦和头孢哌酮/舒巴坦)对CRE的协同作用。结果肺炎克雷伯菌、沙雷菌属、产气肠杆菌、阴沟肠杆菌对替加环素的耐药率较高,分别是5.1%(7/137)、5.6%(1/18)、7.7%(1/13)和8.3%(1/12)。替加环素与头孢他啶、哌拉西林/三唑巴坦联合效果最明显,协同百分比都是28.6%(10/35)。替加环素与头孢噻肟(9/35,25.7%)、左氧氟沙星(8/35,22.9%)和头孢哌酮/舒巴坦(7/35,20.0%)也显示出较好的协同作用。研究中未出现药物拮抗的作用。结论替加环素与头孢他啶、哌拉西林/三唑巴坦联合对CRE的协同作用比较明显。替加环素的联合治疗可能比单用更为有效。     

Comprehensive in vitro evaluation of cefepime combined with aztreonam or ampicillin/sulbactam against multi-drug resistant Pseudomonas aeruginosa and Acinetobacter spp

Pseudomonas aeruginosa and Acinetobacter spp. are becoming increasingly resistant to antimicrobial agents, and serious infections caused by these organisms often require combination therapy. Interactions of cefepime with either aztreonam (P. aeruginosa; n=46) or ampicillin/sulbactam (Acinetobacter spp.; n=34) were investigated by the chequerboard synergy method against isolates with various resistance phenotypes, including resistance to imipenem (36 P. aeruginosa and 19 Acinetobacter spp.). Synergy or partial synergy interactions occurred with 56.5% of P. aeruginosa and 88.2% of Acinetobacter spp. strains examined. Among the imipenem-resistant strains, synergy or partial synergy interactions were observed in 47.2% of P. aeruginosa and 84.2% of Acinetobacter spp. strains. In addition, the vast majority of impenem-resistant strains showed MIC values within achievable concentrations in plasma for at least one of the antimicrobials evaluated in the combination. The role of combination antimicrobial therapy in the treatment of severe infections caused by multidrug-resistant P. aeruginosa and Acinetobacter spp. should be further evaluated to maximize favourable clinical outcomes.     

没食子酸联合氟康唑抗耐药非白念珠菌作用的体外试验

目的：研究没食子酸与氟康唑联用对耐药光滑念珠菌和克柔念珠菌的体外抗真菌活性。方法：采用棋盘微量稀释法测定没食子酸与氟康唑单用及联用对耐药光滑念珠菌和克柔念珠菌的抗真菌作用,以部分抑菌浓度指数（FICI）评价其联用效果;并以CG2、CK8为目标菌株,采用时间-杀菌曲线进行验证;通过测定没食子酸对耐药株生物膜形成早期黏附性的影响,初步探讨药物联合抗真菌耐药的作用。结果：联用时8~16 μg·mL^-1没食子酸能将氟康唑的MIC值降为单用时的1/4~1/8,FICI值为0.375,呈现较好的协同作用,且量效关系呈正相关。时间-杀菌曲线表明,与氟康唑单用相比,没食子酸与氟康唑联用24 h时,CG2、CK8菌株CFU的lg值分别下降了2.1个单位和2.25个单位,均表现为协同作用。另外,研究发现没食子酸对生物膜形成的早期黏附有明显的抑制作用。结论：没食子酸与氟康唑联用对耐药光滑念珠菌和克柔念珠菌的浮游菌表现出体外协同抗真菌作用,且没食子酸能够明显抑制非白色念珠菌生物膜形成的早期黏附。     

24株洋葱伯克霍尔德菌耐药性分析及β-内酰胺酶耐药基因检测

目的 了解洋葱伯克霍尔德菌耐药情况及耐药基因,为临床用药提供指导.方法 琼脂稀释法检测洋葱伯克霍尔德菌对10种抗生素的最低抑菌浓度(MIC); PCR法测定β-内酰胺酶耐药基因.结果 洋葱伯克霍尔德菌对头孢呋辛耐药率最高,达71.5%,其次氨曲南69.9%,左旋氧氟沙星66.7%,美罗培南66.6%,氯霉素62%;耐药...     

头孢他啶使用量与铜绿假单胞菌耐药性的相关性研究

目的:了解某院抗菌药物尤其是头孢他啶使用量的变化,探讨其对铜绿假单胞菌(PA)耐药情况的影响。方法:统计某院2005~2006年用药人/次排序列前10位的抗菌药物使用量与PA耐药率,并进行相关性分析。结果:头孢他啶使用量与下季度PA对头孢他啶和其它7种抗菌药物的耐药率呈线性关系(P<0·05),其它结果无统计学意义。结论:头孢他啶的使用量与PA对多种抗菌药物耐药性的发展有关。     

Influence of human albumin on bactericidal or antibacterial activities of cephems and monobactams

Influence of human albumin on bactericidal or antibacterial activities of 11 beta-lactams were examined. The 11 beta-lactams included second generation cephems (cefsulodin, cefotiam and cefmetazole), third generation cephems (ceftazidime, latamoxef, cefmenoxime, cefoperazone, cefotetan and cefpiramide) and monobactams (carumonam and aztreonam). The micro-broth-dilution method was used to determine antibacterial activities. Bactericidal activities were determined using the time-kill method. Used in the broth-dilution method were 2 media, MUELLER-HINTON broth (MHB) and the same medium supplemented with 5 g human albumin/d1 (MHB-A). The first experiment was to compare minimum inhibitory concentrations (MICs) determined in MHB were compared with those in MHB-A of 6 antibiotics against Staphylococcus aureus FDA 209P JC-1, of 7 antibiotics against Escherichia coli ATCC 25922 and of 5 antibiotics against Pseudomonas aeruginosa NCTC 10490. MICs using MHB-A were higher than MIC using MHB for 2 of the 6 antibiotics against S. aureus, and for all the 7 antibiotics against E. coli, and for 3 of the 5 antibiotics against P. aeruginosa. The second experiment was done to compare MICs of 5 antibiotics determined in MHB-A with those determined in MHB against 10 clinical isolates of S. aureus, of 6 antibiotics against 10 clinical isolates of Klebsiella pneumoniae and of 6 antibiotics against 10 clinical isolates of P. aeruginosa. The results obtained in the second experiment were varied for different antibiotics and different strains of organisms, and same antibiotics produced different results for different strains. MICs determined in MHB-A were lower than those in MHB for antibiotics with relatively low protein binding rates against 22 of 170 isolates tested (12.9%), whereas the former was higher than the latter against 103 out of 170 isolates tested (60.6%). MICs of antibiotics with relatively high protein binding rates showed an opposite trend. In the third experiment, time-kill curves were determined in the 2 media for 5 antibiotics against S. aureus FDA 209P JC-1, for 6 drugs against E. coli ATCC 25922 and for 5 drugs against P. aeruginosa NCTC 10490. The concentrations of these antibiotics used were 1/2 x MIC, 1 x MIC and 2 x MIC. MICs determined in the first experiment were used here. Time-kill curves determined in MHB-A didn't reflect MICs determined in MHB. Using MHB-A, antibiotics with lower MICs determined in MHB-A showed bactericidal activities in lower concentrations. Human albumin influenced antibacterial or bactericidal activities of beta-lactams.(ABSTRACT TRUNCATED AT 400 WORDS)