哌拉西林／舒巴坦对临床分离功的体外抗菌活性研究

目的比较研究哌拉西林、舒巴坦、哌拉西林与舒巴坦不同比例联合及阿莫西林/舒巴坦(21),对临床分离309株需氧菌和30株厌氧菌的体外抗菌活性及其影响因素(研究哌拉西林/舒巴坦(21)对金葡球菌、大肠埃希氏菌和铜绿假单胞菌的的杀菌曲线).方法采用琼脂平板稀释法及肉汤稀释法测定MIC值,Nitrocefin纸片法测定细菌产生的β-内酰胺酶,时间杀菌曲线采用肉汤10倍稀释法.结果对临床分离的339株需氧菌及厌氧菌体外抗菌活性研究结果显示,哌拉西林及其与舒巴坦联合时,对革兰氏阳性球菌及厌氧菌的体外抗菌活性MIC5o为1～4μg/ml,MIC90多数低于128μg/ml,优于革兰氏阴性杆菌,其MIC50为1～128μg/ml,MIC90多数高于128μg/ml;单用舒巴坦对各种细菌的体外抗菌活性极差,多数菌的MICso及MIC90分别为64及256μg/ml.对革兰氏阴性杆菌及厌氧菌,哌拉西林与舒巴坦联合时体外抗菌活性明显优于单用哌拉西林;对于革兰氏阳性球菌,哌拉西林联合舒巴坦后体外抗菌活性改善不如革兰氏阴性杆菌及厌氧菌.哌拉西林对产酶株的MIC高于非产酶株,联合舒巴坦后,产酶株MIC降低而非产酶株MIC变化不明显.不同比例联合的体外抗菌活性比较发现,以哌拉西林/舒巴坦21联合时效果较好.哌拉西林与舒巴坦21联合时,对多数临床分离菌的体外抗菌活性与阿莫西林/舒巴坦(21)的体外抗菌活性相当.本研究中,I临床分离细菌对哌拉西林的耐药率以假单胞菌属最高,达61.5%,其次是肠杆菌属细菌及大肠埃希氏菌,分别为50.8%、50.0%.哌拉西林联合舒巴坦后,所有细菌的耐药率明显下降.体外杀菌效果研究表明,当哌拉西林联合舒巴坦21时,4×MIC浓度作用于金葡球菌、大肠埃希氏菌及铜绿假单胞菌后,细菌数均随时间延长而呈指数级减少,在作用于8h细菌均被杀灭.1×MIC及2×MIC作用于以上细菌后,杀菌效果不及4×MIC.各种细菌的体外抗菌活性主要受培养基pH值及接种菌量的影响,几乎不受小牛血清白蛋白浓度的影响.结论哌拉西林/舒巴坦对β-内酰胺酶产生菌株的体外抗菌活性优于哌拉西林,以21联合效果最好,杀菌效果以4×MIC浓度最好,体外抗菌活性受培养基pH值及接种量的影响.     

哌拉西林/舒巴坦对临床分离菌的体外抗菌活性研究

目的　比较研究哌拉西林、舒巴坦、哌拉西林与舒巴坦不同比例联合及阿莫西林 /舒巴坦 (2∶1) ,对临床分离 3 0 9株需氧菌和 3 0株厌氧菌的体外抗菌活性及其影响因素 (研究哌拉西林 /舒巴坦 (2∶1)对金葡球菌、大肠埃希氏菌和铜绿假单胞菌的的杀菌曲线 )。方法　采用琼脂平板稀释法及肉汤稀释法测定MIC值 ,Nitrocefin纸片法测定细菌产生的 β 内酰胺酶 ,时间杀菌曲线采用肉汤 10倍稀释法。结果　对临床分离的3 3 9株需氧菌及厌氧菌体外抗菌活性研究结果显示 ,哌拉西林及其与舒巴坦联合时 ,对革兰氏阳性球菌及厌氧菌的体外抗菌活性MIC50 为 1～ 4μg/ml,MIC90 多数低于 12 8μg/ml,优于革兰氏阴性杆菌 ,其MIC50 为 1～12 8μg/ml ,MIC90 多数高于 12 8μg/ml;单用舒巴坦对各种细菌的体外抗菌活性极差 ,多数菌的MIC50 及MIC90 分别为 64及 2 5 6μg/ml。对革兰氏阴性杆菌及厌氧菌 ,哌拉西林与舒巴坦联合时体外抗菌活性明显优于单用哌拉西林 ;对于革兰氏阳性球菌 ,哌拉西林联合舒巴坦后体外抗菌活性改善不如革兰氏阴性杆菌及厌氧菌。哌拉西林对产酶株的MIC高于非产酶株 ,联合舒巴坦后 ,产酶株MIC降低而非产酶株MIC变化不明显。不同比例联合的体外抗菌活性比较发现 ,以哌拉西林 /舒巴坦 2∶1联合时效果较好。     

In vitro activity of tigecycline and comparators against Gram-negative pathogens isolated from blood in Europe (2004-2009)

Here we report on the antimicrobial resistance amongst Gram-negative isolates (excluding Acinetobacter spp.) collected from blood culture sources at European study sites as part of the global Tigecycline Evaluation and Surveillance Trial (T.E.S.T.) from the study start in 2004 until August 2009. All isolates were collected and tested for minimum inhibitory concentrations using Clinical and Laboratory Standards Institute methodology. Over the collection period, extended-spectrum β-lactamase (ESBL) production was recorded in 21.1% of Klebsiella pneumoniae, 2.6% of Klebsiella oxytoca and 11.3% of Escherichia coli, primarily in Croatia, Greece, Hungary, Italy, Poland, Romania and the Slovak Republic. ESBL rates stabilised amongst K. pneumoniae over 2006-2009, but doubled amongst E. coli in 2008-2009. The patterns of antimicrobial resistance changed accordingly for both organisms. Generally, Greece had the highest antimicrobial resistance for K. pneumoniae, Italy for E. coli, Serratia marcescens and Enterobacter spp., and Croatia for Pseudomonas aeruginosa. High resistance rates amongst K. pneumoniae were also seen in Croatia and Italy. Imipenem resistance amongst K. pneumoniae was reported exclusively in Greece (13.8%); amongst other Enterobacteriaceae, imipenem resistance was absent or low. Similarly, meropenem resistance was low amongst the Enterobacteriaceae except K. pneumoniae from Greece (42.6%). Across Europe, the most active antimicrobial agents against the Enterobacteriaceae were tigecycline, amikacin and the carbapenems, each with <10% resistance each year. Against the other antimicrobials, significant increases in non-susceptibility were reported for K. pneumoniae and E. coli, both important causative pathogens of bacteraemia.     

Antibacterial activities of cefotiam against various pathogens isolated from clinical materials (author's transl)

Bacteriological evaluation was made on cefotiam (CTM), a new broad-spectrum cephalosporin antibiotic, and the following results wer obtained. 1) CTM has shown very potent antibacterial activities against Staphylococcus aureus, Escherichia coli, Edwardsiella tarda, Citrobacter intermedius, Salmonella, Klebsiella, Proteus mirabilis, Proteus rettgeri, Proteus inconstans, Yersinia enterocolitica, Aeromonas hydrophila, Plesiomonas shigelloides and Pseudomonas putrefaciens. 2) Streptococcus faecalis, Enterobacter and Proteus morganii isolated from urine, Serratia and glucose non fermentative Gram-negative bacilli except Pseudomonas putrefaciens, were almost insusceptible to cefotiam.     

In vitro activities of beta-lactam antibiotics alone and in combination with sulbactam against Gram-negative bacteria

The resistance rates of ampicillin/sulbactam 2:1 against imipenem-susceptible and -resistant Acinetobacter baumannii were 23.5 and 30%, respectively. Ceftazidime/sulbactam combination showed significant reduction of resistant rates against Enterobacter cloacae, A. baumannii, ESBL Klebsiella pneumoniae. MIC₉₀ of cefoperazone against E. cloacae, Serratia marcescens, A. baumannii and ESBL K. pneumoniae were >128 mg/l. Addition of sulbactam enhanced the antimicrobial activities significantly. When imipenem was combined with sulbactam, the resistant rates against imipenem-resistant A. baumanni were significantly reduced. Cefepime/sulbactam combination was active against imipenem-resistant A. baumanni. The resistance rates of aztreonam/sulbactam combination against E. cloacae, imipenem-sensitive and resistant A. baumannii, ESBL K. pneumoniae were lowered significantly. The cefotaxime/sulbactam combination showed a significant improvement of activities against E. cloacae, S. marcescens, A. baumannii and ESBL K. pneumoniae.     

In vitro activity of voriconazole against Candida species isolated in Taiwan

The activity of voriconazole was determined against 285 Candida species consisting of 53 resistant isolates, 43 susceptible-dose dependent and 189 isolates susceptible to fluconazole. The MIC(50) and MIC(90) to fluconazole were 8 and 64 mg/l, respectively. The range of minimum inhibitory concentrations (MICs) to voriconazole was from 0.0325 to 2 mg/l and the MIC(50) and MIC(90) were 0.125 and 0.5 mg/l, respectively. Only 3 of 285 tested isolates had MICs to voriconazole equal to 2 mg/l. A total of 38 isolates, consisted of 3 Candida albicans, 5 Candida krusei, 7 Candida tropicalis and 21 Candida glabrata, had >/= 0.5 mg/l to voriconazole. There was correlation between the susceptibility to fluconazole and voriconazole.     

In vitro inhibitory activities of essential oils from two KoreanThymus species against antibiotic-resistant pathogens

The in vitro inhibitory activities of essential oils from Thymus magnus and T. quinquecostatus as well as their main constituents were evaluated against susceptible and resistant species of Streptococcus pneumoniae, Staphylococcus aureus, Salmonella enteritidis, and Salmonella typhimurium. Notably, the essential oil fraction of T. magnus and its main components displayed significant inhibitory action against both antibiotic-susceptible and resistant strains of S. pneumoniae, S. aureus, and S. typhimurium with minimum inhibitory concentrations (MICs) ranging from 0.125 to 8 mg/mL. The differential MIC values imply that the oil fraction and its main components exhibit distinct patterns of activity against the tested bacterial species. Moreover, the disk diffusion test revealed that the inhibitory activities of oil fraction and components were dose-dependent. Data from the checkerboard titer test confirmed synergism between the antibiotic, norfloxacin, and T. magnus oil or thymol, particularly against the resistant strains of S. aureus.     

舒巴坦单剂及舒巴坦与第三代头孢菌素联合对鲍曼不动杆菌的体外抗菌作用比较

目的比较舒巴坦（SB）单剂和舒巴坦联合第三代头孢菌素对鲍曼不动杆菌的体外抗菌活性，探讨舒巴坦在联合制剂中的实际作用。方法从临床分离的表型为对头孢哌酮（CPZ）、头孢他啶（CAZ）和头孢噻肟（CTX）3种第三代头孢菌素中1种以上耐药或中介的56株鲍曼不动杆菌分为3组。A组（27株）对上述2种以上药物耐药；B组（11株）仅对CPZ耐药；C组（18株）仅对CPZ或CTX中介。采用微量肉汤稀释法检测sB单剂以及SB分别联合上述3种第三代头孢菌素敏感和耐药折点浓度的最低抑菌浓度（MICs）。采用CPZ三维酶提取和抑制试验检测β-内酰胺酶，并选择对CPZ中介（A株）和耐药（B株）进行杀菌曲线试验。结果SB对B组和C组菌的MICs≤1μg／ml；SB对A组菌的MICs范围在4～64μg／ml之间，并且与CPZ、CAZ或CTX任一药物的敏感和耐药折点浓度联合，均不能使联合后SB的MICs低于单剂SB的MICs。在三维β-内酰胺酶抑制试验中，酶活性不能被SB抑制的菌株，其SB的MICs值高于酶活性能被SB抑制的菌株。杀菌曲线显示在SB和CPZ之间无协同作用。结论SB单剂对多重耐药的鲍曼不动杆菌有抗菌活性，这些菌株对联合制剂的敏感可能主要是SB在发挥杀菌作用。     

三唑巴坦/哌拉西林的体内外抗菌活性研究

目的：评价三唑巴坦/哌拉西林的体内外抗菌活性。方法：采用平皿二倍稀释法测定三唑巴坦/哌拉西林对临床分离菌的体外抗菌作用；采用小鼠腹腔感染模型，观察三唑巴坦/哌拉西林对金葡球菌、大肠埃希菌、肺炎克雷伯杆菌感染小鼠的体内抗菌作用。结果：国产和进口三唑巴坦/哌拉西林对甲氧西林敏感的金葡球菌、甲氧西林耐药的金葡球菌、产β-内酰胺酶的金葡球菌、表皮葡萄球菌、大肠埃希菌、奇异变形杆菌、肺炎克雷伯杆菌、醋酸钙不动杆菌、阴沟肠杆菌、产气肠杆菌、聚团肠杆菌、异型构檬酸杆菌、弗劳地构檬酸杆菌和黏质沙雷菌的抗菌活性比哌拉西林强2～4倍。三唑巴坦/哌拉西林对金葡球菌和大肠埃希菌显示杀菌作用，不同β-H值、接种量和血清浓度对三唑巴坦/哌拉西林抗金葡球菌和大肠埃希菌的活性无明显影响。国产和进口三唑巴坦/哌拉西林对金葡球菌、大肠埃希菌和肺炎克雷伯杆菌感染小鼠具有较好保护作用，两者疗效相近，对产酶的金葡球菌15，金葡球菌44，大肠埃希菌12，肺炎克雷伯杆菌7和肺炎克雷伯杆菌13感染小鼠的疗效明显均优于哌拉西林，对不产酶大肠埃希菌1515感染小鼠的疗效与哌拉西林无显著性差异。结论：国产和进口三唑巴坦/哌拉西林具有较强和相同的体内外抗菌活性，三唑巴坦增强了哌拉西林抗产β-内酰胺酶细菌的活性。     

In vitro antimicrobial activity of various antibiotics against Haemophilus influenzae isolated from clinical specimens in 1983

In vitro susceptibilities of 73 strains of Haemophilus influenzae isolated from clinical specimens in 1983 to various antibiotics were studied. The following antibiotics were evaluated; ampicillin (ABPC), piperacillin (PIPC), cefotaxime (CTX), cefoperazone (CPZ), ceftizoxime (CZX), cefmenoxime (CMX), latamoxef (LMOX), tetracycline (TC), doxycycline (DOXY), minocycline (MINO), chloramphenicol (CP) and erythromycin (EM). Susceptible strains to ABPC and PIPC with MICs less than 3 micrograms/ml were 80.3 and 84.1%, respectively. With this break point of MIC, all strains showed susceptibility to CPZ, CZX, and CMX, but resistant strains were observed in 1.5% against CTX and LMOX. Susceptible strains to TC, DOXY and MINO at MICs less than 2 micrograms/ml were 86.3, 80, and 87.7%, respectively. Those to CP at MICs less than or equal to 4 micrograms/ml and to EM at MICs less than or equal to 1 microgram/ml were 86.2 and 71.9%.     

In vitro synergistic activity of NCL195 in combination with colistin against Gram-negative bacterial pathogens

In this study, the potential of using the novel antibiotic NCL195 combined with subinhibitory concentrations of colistin against infections caused by Gram-negative bacteria (GNB) was investigated. We showed synergistic activity of the combination NCL195 + colistin against clinical multidrug-resistant GNB pathogens with minimum inhibitory concentrations (MICs) for NCL195 ranging from 0.5–4 μg/mL for Acinetobacter baumannii, Escherichia coli, Klebsiella pneumoniae and Pseudomonas aeruginosa, whereas NCL195 alone had no activity. Transmission electron microscopy of the membrane morphology of E. coli and P. aeruginosa after single colistin or combination drug treatment showed marked ultrastructural changes most frequently in the cell envelope. Exposure to NCL195 alone did not show any change compared with untreated control cells, whereas treatment with the NCL195 + colistin combination caused more damage than colistin alone. Direct evidence for this interaction was demonstrated by fluorescence-based membrane potential measurements. We conclude that the synergistic antimicrobial activity of the combination NCL195 + colistin against GNB pathogens warrants further exploration for specific treatment of acute GNB infections.     

In vitro activity of piperacillin/tazobactam against isolates from patients enrolled in clinical trials

The in vitro activity of piperacillin alone or titrated with a constant concentration of 4 mug/ml tazobactam was evaluated against 3962 baseline pathogens isolated from 1899 patients enrolled in 9 clinical trial studies in North America. Tazobactam increased susceptibility rates of piperacillin for Enterobacteriaceae from 81% to 96%, Staphylococcus (methicillin susceptible) spp. from 6% to 100%, Bacteroides fragilis group from 79% to >99% and Haemophilus from 85% to 98%. The excellent activity of piperacillin against Pseudomonas, Streptococcus and Enterococcus was maintained in the presence of tazobactam. Overall piperacillin/tazobactam had better activity than ticarcillin/clavulanic acid, ceftazidime, and in general equaled the activity of imipenem. The excellent in vitro, extended-spectrum activity of piperacillin/tazobactam suggests its utility for various infections.     

哌拉西林／他唑巴坦对656株临床分离致病菌的体外抗菌作用研究

研究比较了国产哌拉西林／他佐巴坦及哌拉西林和其它联合制剂对６５６株临床分离菌的体外抗菌作用，结果表明，对大多数革兰氏阴性杆菌哌拉西林／他唑巴坦联合制剂与哌拉西林相比显示出了较强的抗菌活性，对大肠埃希氏菌、耐药粘质沙雷氏菌和铜绿假单胞菌，哌拉西林／他唑巴坦ＭＩＣ９０是哌拉西林的ＭＩＣ９０１／１６～１／３２。哌拉西林／他唑巴坦与其他酶抑制剂联合制剂抗菌活性比较表明，哌拉西林／他唑巴坦对大肠埃希氏菌、粘质沙雷氏菌、铜绿假单胞菌、变形杆菌和福氏痢疾杆菌抗菌活性比氨苄西林／舒巴坦、阿莫西林／克拉维酸和替卡西林／克拉维酸联合制剂强４～１６倍。对革兰氏阳性及革兰氏阴性球菌，哌拉西林／他唑巴坦联合制剂对肺炎链球菌、甲氧西林敏感的金葡球菌以及淋病奈瑟氏球菌的ＭＩＣ９０与哌拉西林ＭＩＣ９０相似，但对表葡球菌、其他金葡球菌和化脓性链球菌，哌拉西林／他唑巴坦联合制剂的ＭＩＣ９０是哌拉西林的１／８，而且，哌拉西林／他唑巴坦联合制剂的抗菌活性较其他酶抑制剂联合制剂强４～１６倍。对脆弱拟杆菌，哌拉西林／他唑巴坦ＭＩＣ９０是哌拉西林的１／８。     

In vitro activity against clinically important gram-positive and gram-negative bacteria of sulbactam, alone and in combination with ampicillin, cefotaxime, mezlocillin, and piperacillin

The in vitro effects of the single agents, and the synergistic/antagonistic action of three different combinations of ampicillin (AMP, CAS 69-53-4), cefotaxime (CTX, CAS 63527-52-6), mezlocillin (MEZ, CAS 51481-65-3), and piperacillin (PIP, CAS 61477-96-1) with the beta-lactamase inhibitor sulbactam (SUL, CAS 68373-14-8) were determined against 675 gram-positive and gram-negative, both aerobic and anaerobic bacteria. All the combinations of sulbactam and the antibiotics (1: 1, 1:2 and 1:4) exhibited very similar synergistic action. The percentage of the total strains tested for which synergistic activity was found was 51% with SUL + AMP (1:1), 24% with SUL + CTX (1:1), 31% with SUL + MEZ (1:1), and 28% with SUL + PIP (1:1). A fourfold or greater reduction of MIC's in the comparison with the antibiotics alone was found with 23% of the total strains tested for the SUL + AMP, with 9% of the strains tested with SUL + CTX, with 11% of the strains tested with SUL + MEZ, and with 15% of the strains tested with the SUL + PIP-combination. In the presence of sulbactam, 18% of the strains tested showed a significant reduction in the number of resistant strains with ampicillin, 7% with cefotaxime, 16% with mezlocillin, 14% with piperacillin, and in parallel there was an increase in the number of fully susceptible strains (shift from resistant or moderately sensitive to sensitive) by about 14%. In comparison with the antibiotic alone, the most marked reductions in the number of resistant strains on combination with sulbactam were as follows (the percentage of reduction is shown in brackets): for SUL + AMP and Acine-tobacter spp. (39% fewer resistant strains). Citrobacter spp. (-60%), Enterobacter aerogenes (-48%), Klebsiella oxytoca (-49%), Klebsiella pneumoniae (-63%), Morganella morganii (-74%), and Proteus vulgaris (-55%); for SUL + CTX and Acinetobacter spp. (-38%), Enterobacter cloacae (-6%), Klebsiella pneumoniae (-16%), Serratia marcescens (-9%), and Bacteroides fragilis (-31%); for SUL + MEZ and Acinetobacter spp. (-68%), Citrobacter spp. (-27%), Enterobacter spp. (-23%), Klebsiella pneumoniae (-32%), and Serratia marcescens (-19%); for SUL + PIP and Acinetobacter spp. (-41%), Citrobacter spp. (-30%), Klebsiella spp. (-30%), and Serratia marcescens (-33%).     

Activity of ceftolozane-tazobactam against Gram-negative pathogens isolated from lower respiratory tract infections in the Asia-Pacific region: SMART 2015-2016

The aim of this study was to investigate the susceptibility of respiratory Gram-negative bacteria to ceftolozane/tazobactam and other antibiotics in the Asia-Pacific region during 2015-2016. MICs were determined using the CLSI standard broth microdilution method and interpreted accordingly. Pseudomonas aeruginosa (1574 isolates), Klebsiella pneumoniae (1226), Acinetobacter baumannii (627) and Escherichia coli (476) accounted for 73.1% of 5342 Gram-negative respiratory pathogens. Susceptibility to ceftolozane/tazobactam of individual Enterobacteriaceae was >80%, except for Enterobacter cloacae (76.6%). Ceftolozane/tazobactam inhibited 81.9% of K. pneumoniae and 91.9% of E. coli, with respective MIC₅₀/MIC₉₀ values of 0.5/>32 and 0.25/2 mg/L. For carbapenem-susceptible, ESBL-producing K. pneumoniae and E. coli, susceptibility was 65.5% and 93.3%, respectively, and respective MIC₅₀/MIC₉₀ values were 2/>32 and 0.5/2 mg/L. Bla_{CTX-M-1 group} was most prevalent in selected ESBL-producing K. pneumoniae (40 of 54 isolates) and E. coli (15 of 22 isolates), with ceftolozane/tazobactam susceptibility rates of 50% and 80%, respectively. Bla_SHV-ESBL was the second most prevalent, and ceftolozane/tazobactam inhibited 20% of 20 K. pneumoniae isolates with bla_SHV-ESBL. The only effective antibiotics for carbapenem-non-susceptible K. pneumoniae (111 isolates) and E. coli (24 isolates) were amikacin and colistin. Ceftolozane/tazobactam was effective against almost all tested P. aeruginosa and carbapenem-non-susceptible strains, with susceptibility of 92.3% and 72.8%, respectively; the respective MIC₅₀/MIC₉₀ values were 1/4 and 2/>32 mg/L. The high susceptibility of ceftolozane/tazobactam remained in different age groups, patient locations, recovery times and countries, except Vietnam. In conclusion, ceftolozane/tazobactam was effective against most respiratory Gram-negative pathogens in the Asia-Pacific region; however, the emergence of carbapenem resistance mandates ongoing surveillance.     

In vitro activity of moxifloxacin against recent community-acquired respiratory tract pathogens isolated in France: a national survey

Between February and June 2000, 2345 consecutive strains of Streptococcus pneumoniae, Haemophilus influenzae, Moraxella catarrhalis, Staphylococcus aureus and Klebsiella pneumoniae were isolated from 2088 adult patients suffering from community-acquired respiratory tract infections, in 97 hospital laboratories. Of the 1037 S. pneumoniae isolates, 48.3% were intermediately or highly penicillin resistant. For invasive isolates, the MIC90s of penicillin G, amoxycillin, cefuroxime, ceftriaxone, erythromycin, ofloxacin, ciprofloxacin and moxifloxacin were 2, 2, 4, 0.5, 1024, 2, 2 and 0.25 mg/l, respectively. All but one invasive strain were susceptible to moxifloxacin whereas 97.5% were susceptible to levofloxacin. The MIC90s of clinical isolates with intermediate susceptibility or high resistance to penicillin G, were 2, 2, 4, 1, 1024, 2, 2 and 0.25 mg/l. About 98.1, 97.0, and 83.1% of strains were inhibited by concentrations < or = 1 mg/l of moxifloxacin, levofloxacin and ciprofloxacin, respectively (E-test). Eight of the 1037 S. pneumoniae strains were not susceptible to moxifloxacin and had mutations in gyrA (eight strains), parC (four strains) or parE (three strains). Against H. influenzae (32.7% were beta-lactamase producers) and M. catarrhalis (96.3% were beta-lactamase producers), the MIC90s of moxifloxacin, amoxycillin and co-amoxiclav were 0.094 and 0.125 mg/l, 64 and 8 mg/l, and 1.5 and 0.25 mg/l, respectively. Against oxacillin-susceptible S. aureus and K. pneumoniae, the MIC90s of moxifloxacin were 0.125 and 0.84 mg/l respectively. Moxifloxacin had the highest in vitro activity of all antibiotics tested.     

In vitro activities of 23 antimicrobial agents against 4,993 gram-positive and gram-negative bacterial strains isolated from multicenter of Japan during 1994--in vitro susceptibility surveillance.Levofloxacin-Surveillance Group

In a surveillance study conducted during 1994 at 24 medical institutes from different geographical areas of Japan, the susceptibility of clinical isolates to twenty three comparative agents, such as ofloxacin, levofloxacin, ciprofloxacin, tosufloxacin, ampicillin, clavulanic acid/amoxicillin, oxacillin, piperacillin, cefaclor, cefotiam, cefdinir, cefclidin, ceftazidime, cefpirome, imipenem, aztreonam, vancomycin, minocycline, chloramphenicol, clarithromycin, sulfamethoxazole/trimethoprim, amikacin, and gentamicin, were tested by the standard broth micro-dilution method. A total of 4,993 isolates tested in this study included Streptococcus pneumoniae, methicillin susceptible Staphylococcus aureus (MSSA), methicillin resistant Staphylococcus aureus (MRSA), coagllase negative streptococci (CNS), Enterococcus faecalis, Enterococcus faecium, Enterobactericeae, Pseudomonas aeruginosa from patients with urinary tract infections or respiratory tract infections, and Haemophilus influenzae. For MSSA, S. pneumoniae, Enterobacteriaceae, and H. influenzae, more than 70% of the isolates was susceptible to fluoloquinolones. However, resistance occurred in more than 50% of MRSA and P. aeruginosa isolated from UTI. Fluoroquinolones were found to be effective against high level penicillin-resistant S. pneumoniae, the third generation cephem-resistant Enterobacteriaceae and ampicillin-resistant H. influenzae.     

Comparison of in vitro activity of first, second and third generation cephem antibiotics against various pathogens isolated from clinical materials in 1983

In vitro susceptibilities of 3,286 strains of various pathogens isolated from clinical materials in 1983 to various cephem antibiotics were studied using the Showa disk diffusion test. The following antibiotics were evaluated: cephalexin (CEX), cephalothin (CET), cefazolin (CEZ), cefotiam (CTM), cefoxitin (CFX), cefmetazole (CMZ), cefotaxime (CTX), cefoperazone (CPZ), ceftizoxime (CZX), cefmenoxime (CMX) and latamoxef (LMOX). S. aureus: Susceptible strains to CET, CEZ, CTM, CFX and CMZ with MIC less than 15 micrograms/ml accounted for 93, 75, 93, 70 and 96% of the strains tested, while those to CTX, CPZ, CZX, CMX and LMOX for 89, 65, 61, 86 and 62%, respectively. Susceptible strains to CEX at MICs less than or equal to 20 micrograms/ml were 60%. Prevalence of bacterial resistance to CEX and CEZ, which have been used extensively, was greater than that to CET, CTM or CMZ, showing a bimodal distribution of MICs. The third generation cephems studied, in general, also showed bimodal distributions of MICs. S. pyogenes: All strains studied were susceptible to CET, CTX, CPZ, CZX, CMX and LMOX at MICs less than or equal to 15 micrograms/ml. However, susceptible strains to CEZ, CTM, CFX and CMZ accounted for 95, 95, 80 and 90%, respectively, while those to CEX at MICs less than or equal to 20 micrograms/ml for 79%. S. pneumoniae: At MICs less than 3 micrograms/ml, all strains were susceptible to all cephem antibiotics tested. S. faecalis: Only a very few strains were susceptible to these antibiotics. E. coli, K. pneumoniae and Proteus spp.: Susceptible strains of E. coli and K. pneumoniae to CEX at MICs less than or equal to 20 micrograms/ml accounted for 80 and 81% of the strains tested, while those of indole negative and positive Proteus for 69 and 4%, respectively. Strains of E. coli susceptible to CET, CEZ, CTM, CFX and CMZ at MICs less than or equal to 15 micrograms/ml were 78 to 96%, while those to CTX, CPZ, CZX, CMX and LMOX were 94 to 100%. Those of K. pneumoniae to these 2 groups of antibiotics were 81 to 95% and 94 to 100%, respectively. Susceptible strains of indole negative Proteus to the former group were 81 to 93% and those to the latter were 100%.(ABSTRACT TRUNCATED AT 400 WORDS)