In vitro activity of biapenem against beta-lactamase producingEnterobacteriaceae

The activity of biapenem was compared with that of imipenem and cefotaxime against 108 strains of -lactamase producingEnterobacteriaceae. Biapenem and imipenem were very active, inhibiting 90 % of the strains at a concentration of 0.5 µg/ml. Both carbapenems were very active against plasmidic -lactamase producers, with MIC90s below 1 µg/ml. However, the MIC90 of biapenem for cephalosporinase producers was 1 µg/ml. Against strains producing extended-spectrum -lactamases, biapenem exhibited better activity against TEM-type producers (MIC90 0.25 µg/ml) than against SHV-type producers (MIC90 0.5 µg/ml). Overall, the in vitro antibacterial activity of biapenem is similar to that of imipenem.     

Comparative in vitro activity of biapenem,a new carbapenem antibiotic

Biapenem is a new carbapenem antibiotic with high stability to human renal dehydropeptidase I. Its in vitro activity was compared with that of imipenem, meropenem, ceftazidime, ceftriaxone, piperacillin and gentamicin against a total of 650 recent clinical isolates. MICs were determined by a standard agar dilution procedure and all isolates were tested at two inocula (10⁴ and 10⁶ cfu). Biapenem inhibited 90 % of isolates ofEscherichia coli, Klebsiella spp.,Proteus mirabilis, Proteus vulgaris, Morganella morganii, Providencia stuartii, Enterobacter spp.,Citrobacter freundii, Serratia marcescens, Salmonella typhi, Shigella sonnei andYersinia enterocolitica at 2 mg/l and was as active as or two- to four-fold more active than imipenem against all these species, with the exception ofSerratia marcescens, against which imipenem was two-fold more active. Biapenem was two-fold more active than imipenem againstPseudomonas aeruginosa (MIC90 4 mg/l) and had activity similar to that of imipenem against theBacteroides fragilis group (MIC90 0.5 mg/l) but was two-fold less active than imipenem against methicillin-susceptibleStaphylococcus aureus (MIC90 0.06 mg/l) and was, like imipenem, inactive against methicillin-resistantStaphylococcus aureus.     

Antimicrobial activity of doripenem (S-4661): a global surveillance report (2003)

The spectrum of activity and potency of doripenem, a broad-spectrum parenteral carbapenem currently in clinical development, was evaluated using 16 008 clinical bacterial isolates collected as part of an international surveillance project during 2003. Using reference broth microdilution methods, doripenem was found to be highly active against oxacillin-susceptible Staphylococcus aureus and coagulase-negative staphylococci (2705 and 297 isolates, respectively; MIC90s 0.06 mg/L), with a potency greater than that of other carbapenem antibiotics. Against enterococci (1474 isolates), with the exception of Enterococcus faecium, doripenem displayed modest activity (MIC50 4). Doripenem was among the most potent agents tested against Streptococcus pneumoniae, viridans group streptococci and beta-haemolytic streptococci (885, 140 and 397 isolates; MIC(90)s 0.5, 0.5 and 0.03 mg/L, respectively). For Enterobacteriaceae (> 6200 isolates), doripenem was four- to 32-fold more active than imipenem against wild-type isolates (MIC90s 0.03-0.5 mg/L). MIC90s for confirmed extended-spectrum beta-lactamase-producing Escherichia coli and Klebsiella pneumoniae (121 and 155 isolates; 0.06 and 0.12 mg/L, respectively) were two-fold higher than for wild-type isolates. Doripenem was also active against Citrobacter spp., Enterobacter spp. and Serratia spp. (MIC90s 0.06-0.25 mg/L), including ceftazidime-resistant isolates. Doripenem and meropenem were the most active agents among all beta-lactams against Pseudomonas aeruginosa (829 isolates; MIC50/90s 0.5/8 and 0.5/16 mg/L, respectively), whereas doripenem and imipenem were the most active agents against Acinetobacter spp. (155 isolates; MIC50/90s 0.5/4 and 相似文献   

Activity of meropenem against imipenem-resistant bacteria and selection in vitro of carbapenem-resistantEnterobacteriaceae

The activity of meropenem against 106 imipenem-resistant (MIC 8 mg/l) clinical isolates, and the frequency of resistance to meropenem and imipenem among 24Enterobacteriaceae was determined. Both agents selected colonies on agar but 20–80 % were susceptible after one subculture and 72 % of the mutants reverted to susceptibility 1 to 6 months after selection. All isolates and stable mutants were inhibited by > 1 mg/l meropenem, although the MIC of imipenem was 4–16 mg/l. Three of sixXanthomonas maltophilia isolates were susceptible to meropenem (MICs 2–4 mg/l).Pseudomonas aeruginosa lacking outer membrane protein D2 were resistant to meropenem, although isolates with substantially reduced expression of this protein were susceptible. None of the imipenem-resistant gram-positive bacteria were susceptible to meropenem. There was no clear correlation between altered outer membrane protein expression and decreased susceptibility to carbapenems, and there was no apparent involvement of plasmid or chromosomal -lactamase.     

Antibacterial activity of the investigational oral and parenteral cephalosporin BK-218

BK-218 is a novel cephalosporin with a dual route of administration and spectrum of activity most similar to that of second-generation cephalosporins. BK-218 was active againstStreptococcus pneumoniae, Haemophilus influenzae andMoraxella catarrhalis but strains resistant to penicillins had higher MICs. BK-218 had greater activity (8-fold) than cefuroxime or cefaclor against oxacillin-susceptibleStaphylococcus spp. Moderate BK-218 activity was observed againstNeisseria gonorrhoeae and commonly isolatedEnterobacteriaceae such asEscherichia coli (MIC90, 1 mg/l),Klebsiella spp. (MIC90, 2 mg/l), andProteus mirabilis (MIC90, 2 mg/l). The following organisms were generally BK-218-resistant (MIC90, >16 mg/l):Bacteroides fragilis, Pseudomonas spp.,Acinetobacter spp.,Xanthomonas maltophilia, Citrobacter spp.,Enterobacter spp., indole-positiveProteus, Serratia spp., enterococci and oxacillin-resistant staphylococci.     

In vitro activity of imipenem — A review

A review is given of the microbiological properties of imipenem, a new carbapenem antibiotic with an exceptionally broad spectrum of antibacterial activity. An evaluation of results of numerous in vitro studies reveals that imipenem effectively inhibited growth of 53 of 55 bacterial species, the mean MIC90 being less than 8 mg/l. The MIC 90 for cocci, with the exception ofStaphylococcus epidermidis, is in the range of 0.01–3.1 mg/1. The MIC 90 for allEnterobacteriaceae is equal to or less than 8 mg/l.Pseudomonas aeruginosa and other non-fermentative gram-negative bacteria are generally susceptible to imipenem, onlyPseudomonas maltophilia andPseudomonas cepacia showing intrinsic resistance. Imipenem is currently the most active drug available against anaerobic bacteria, the MIC usually being below 1 mg/l even forBacteroides fragilis. Rare bacteria such asNocardia asteroides, Listeria monocytogenes or fast growingMycobacterium spp. which cause difficult-to-treat infections are also susceptible to imipenem. Increases in inoculum size have only a minimal effect on activity of the drug. In most species the MBC only slightly exceeded the MIC; however in the case ofStreptococcus faecalis the MBC value was many times the MIC value. Synergism has been observed in combinations of imipenem with aminoglycosides, and antagonism in combinations with other beta-lactam antibiotics againstPseudomonas aeruginosa andSerratia marcescens. Imipenem is stable in the presence of the common chromosomal and plasmid-mediated enzymes. Induction of inactivating enzymes was observed in staphylococci,Pseudomonas aeruginosa andSerratia marcescem.     

Antibacterial Activity of Meropenem against Pseudomonas aeruginosa, Including Antibiotic-Induced Morphological Changes and Endotoxin-Liberating Effects

 The in vitro effects of meropenem on Pseudomonas aeruginosa were examined by studying (i) the inhibitory and bactericidal concentrations of meropenem versus those of imipenem for clinical isolates; (ii) changes in bacterial morphology during in vitro culture; and (iii) release of endotoxin induced by meropenem compared with that induced by other antipseudomonal compounds. Meropenem MIC90 and MBC90 values for 108 clinical isolates were 2 and 4.8 mg/l compared to 4.5 and 9.6 mg/l for imipenem. Morphological studies using phase-contrast and scanning electron microscopy showed that meropenem induced the formation of indeterminate bacterial cell forms at drug concentrations of 1–2.5 mg/l (0.5- to 1.25-fold the MIC), while spheroplasts predominated at drug levels exceeding 5 mg/l (2.5-fold the MIC). Determination of free and EDTA-releasable endotoxin activity by means of the Limulus lysate test showed that both meropenem and imipenem liberated significantly less endotoxin than did ceftazidime. Therefore, although meropenem binds to penicillin-binding proteins (PBPs) 2 and 3 (in contrast to imipenem, which binds to PBP2 only), endotoxin release should not be a cause of concern when treating systemic gram-negative infections with this drug.     

Comparative in vitro activity of BAY 12-8039 and five other antimicrobial agents against anaerobic bacteria

The in vitro activity of BAY 12-8039 against 360 anaerobic clinical isolates was determined by the agar dilution method and compared to that of five other antimicrobial agents. BAY 12-8039 and imipenem were the most active agents tested. The following MIC90 values were determined for BAY 12-8039Peptostreptococcus spp. (50 isolates), 1 mg/l;Propionibacterium acnes (30 isolates), 0.25 mg/l;Clostridium perfringens (30 isolates), 0.5 mg/l;Clostridium difficile (50 isolates), 2 mg/l;Bacteroides fragilis (50 isolates), 1 mg/l;non- fragilis Bacteroides, Porphyromonas, andPrevotella spp. (100 isolates), 2 mg/l; andFusobacterium spp. (50 isolates), 0.25 mg/l. The results of the present study show that BAY 12-8039 may be useful in the treatment and prophylaxis of anaerobic infections.     

Comparative activity of meropenem (SM-7338) against major respiratory pathogens and amikacin-resistant nosocomial isolates

Meropenem, a new broad-spectrum carbapenem antibiotic, demonstrated excellent in vitro activity against major respiratory pathogens includingMoraxella catarrhalis, Haemophilus influenzae andStreptococcus pneumoniae. Minimal inhibitory concentrations of meropenem forMoraxella catarrhalis andHaemophilus influenzae isolates were frequently less than those of imipenem. For nosocomial amikacin-resistant gram-negative bacilli, meropenem had eightfold lower MIC90 values compared to imipenem against strains ofSerratia marcescens, Enterobacter cloacae andEscherichia coli; it was 32-fold more active than imipenem againstProteus mirabilis isolates. Activity was similar to that of imipenem againstPseudomonas aeruginosa isolates. Overall, meropenem showed excellent activity against common community-acquired pathogens as well as amikacin-resistant nosocomial pathogens.     

Comparative in vitro antibacterial activity of the new carbapenem meropenem (SM-7338)

The in vitro antimicrobial activity of the new carbapenem meropenem (SM-7338) was determined by an agar dilution method in comparison with imipenem, ticarcillin/calvulanic acid, ceftazidime and the fourth-generation cephalosporin cefepime (BMY 28142). Meropenem showed superior activity againstEnterobacteriaceae (MIC900.06 mg/l) and against non-fermentative gram-negative rods, with the exception ofXanthomonas maltophilia. Meropenem had excellent activity against beta-lactamase-producingHaemophilus influenzae andNeisseria gonorrhoeae, and against theBacteroides fragilis group. Imipenem was slightly more active then meropenem against gram-positive cocci especiallyEnterococcus faecalis.     

Comparative in vitro activity of cefpiramide,a new parenteral cephalosporin

The in vitro activity of cefpiramide was compared with that of nine other cephalosporins by determining the MIC values by means of an agar dilution method for 300 representative clinical isolates of non-fastidious bacteria. Cefpiramide had a broad-spectrum of activity, similar to that of the third-generation cephalosporins. As judged by the MIC50 and the MIC90 values, cefpiramide was one of the most active cephalosporins againstPseudomonas aeruginosa (MIC50 2.9 µg/ml, MIC90 64 µg/ml), staphylococci (MIC50 1.2 µg/ml, MIC90 10 µg/ml) andEnterococcus faecalis (MIC50 13 µg/ml, MIC90 43 µg/ml). Cefpiramide had moderate activity againstEnterobacteriaceae (MIC50 4 µg/ml, MIC90 108 µg/ml), comparable to that of the older second-generation cephalosporins. Ticarcillin-resistant strains of gram-negative rods were inhibited by higher concentrations of cefpiramide than ticarcillin-susceptible strains.     

Evolution of Resistance among Clinical Isolates of Acinetobacter over a 6-Year Period

 The aim of this report was to study the evolution of susceptibilities of 1532 clinical isolates of Acinetobacter recovered over a period of 6 years. The minimal inhibitory concentrations (MICs) of 15 antimicrobial agents were determined for all the isolates. The respective percentages of resistant strains in the years 1991 and 1996 were as follows: ciprofloxacin, 54.4% and 90.4%; tobramycin, 33% and 71.8%; amikacin, 21% and 83.7%; ampicillin plus sulbactam, 65.7% and 84.1%; ceftazidime, 57.4% and 86.8%; ticarcillin, 70% and 89.4%; trimethoprim plus sulfamethoxazole, 41.1% and 88.9%; and imipenem, 1.3% and 80%. The MIC90s of ciprofloxacin, sparfloxacin, biapenem, meropenem, imipenem, cefepime, cefpirome, and rifampicin against 250 imipenem-resistant Acinetobacter strains were >32, >32, 128, >256, 256, >256, 256, and 16 mg/l, respectively. With serious infections, it was necessary to resort to the use of colistin, the only antibiotic active in vitro.     

Antimicrobial activity of doripenem and other carbapenems against gram-negative pathogens from Korea

A total of 950 gram-negative bacterial isolates from patients with bacteremia and urinary tract infections were collected from tertiary-care hospitals in Korea. In vitro antimicrobial susceptibility testing was performed using broth microdilution test according to Clinical and Laboratory Standards Institute protocol. In general, carbapenems such as doripenem, imipenem, and meropenem were very active against Enterobacteriaceae, Moraxella catarrhalis, Pseudomonas aeruginosa, and Acinetobacter sp. isolates. Doripenem was more potent than imipenem against most Enterobacteriaceae species except Proteus spp. based on minimum inhibitory concentration (MIC)(50) and MIC(90). In addition, doripenem displayed similar activity to meropenem but was superior to imipenem against ceftazidime-resistant Enterobacteriaceae isolates. For P. aeruginosa and Acinetobacter spp. isolates, MIC(50)s of doripenem were 1 and 0.5 mg/L, respectively, which were the same with those of meropenem but two- to fourfold lower than those of imipenem (both 2 mg/L). On the basis of the in vitro data, we conclude that doripenem has equivalent or more activity than other carbapenems such as imipenem and meropenem against most gram-negative pathogens from Korea. Thus, doripenem may be a promising new antimicrobial agent for the treatment of infections caused by gram-negative pathogens in Korea.     

Multicentre comparative study on the antibacterial activity of FK-037, a new parenteral cephalosporin

The in vitro antibacterial activity of FK-037, a new parenteral cephalosporin structurally related to cefpirome and cefepime, was compared with that of cefotaxime, ceftazidime, aztreonam, cefpirome, cefepime, imipenem and meropenem against 1,837 clinical isolates obtained from three Spanish hospitals. FK-037 inhibited 90 % ofEnterobacteriaceae isolates at 0.25 µg/ml, with the exception ofEnterobacter aerogenes (MIC90 1 µg/ml),Enterobacter cloacae andCitrobacter freundii (MIC90 8 µg/ml). In cefotaxime-and ceftazidime-resistantKlebsiella pneumoniae strains producing SHV-2 and SHV-6 -lactamases, the activity of FK-037, cefpirome and cefepime was similar (MIC range 0.25–32 µg/ml). InEnterobacteriaceae strains hyperproducing chromosomally inducible -lactamases, FK-037 (MIC90 range, 0.25–8 µg/ml) was 8- to 16-fold more active than cefotaxime and ceftazidime but two- to eightfold less active than cefpirome and cefepime. FK-037 and cefpirome were twofold more active than ceftazidime and cefepime againstPseudomonas aeruginosa isolates, with MIC90 values of 16 µg/ml. The activity of FK-037, cefpirome and cefepime was two- to eightfold lower in ceftazidime-resistant derepressedPseudomonas aeruginosa mutants. FK-037 (MIC range, 0.12–2 µg/ml) and the other -lactam agents tested were active against methicillin-susceptible staphylococci; however, only cefpirome and, particularly, FK-037 (MIC90 of 32 µg/ml) displayed some activity against methicillin-resistant strains. In penicillin-susceptible,-intermediate and -resistantStreptococcus pneumoniae isolates, the MIC90s of FK-037 were 0.03, 0.5 and 1 µg/ml, respectively. The corresponding values forStreptococcus viridans isolates were 0.12, 1 and 8 µg/ml, respectively. In bothStreptococcus pneumoniae andStreptococcus viridans isolates, FK-037 displayed activity similar to that of cefotaxime and cefpirome and slightly higher than that of cefepime.     

In vitro activity of PD 117596-2, a broad-spectrum difluoroquinolone

The activity of PD 117596-2, a novel quinolone, was compared to that of other quinolones, ceftazidime, imipenem and gentamicin. PD 117596-2 inhibited mostEnterobacteriaceae at concentrations <0.25 µg/ml, being equal or superior in activity to ciprofloxacin and 2- to 4-fold more active than ofloxacin. It inhibited ceftazidime-resistantEnterobacter spp.,Citrobacter spp. andSerratia marcescens. The MIC90 forPseudomonas aeruginosa, including strains with imipenem MICs of 8 µg/ml and gentamicin MICs > 16 µg/ml, was 0.25 µg/ml. PD 117596-2 was more active than ciprofloxacin againstPseudomonas cepacia andPseudomonas maltophilia, and it inhibitedNeisseria gonorrhoeae andHaemophilus influenzae at < 0.03 µg/ml. PD 117596-2 inhibited staphylococci at 0.5 µg/ml, being 2-fold superior to other quinolones, and with an MIC of 0.25 µg/ml was more active against group A, B, C and G streptococci andStreptococcus pneumoniae. MICs forBacteroides spp. were 2 µg/ml compared to 8–32 µg/ml for other agents. The frequency of spontaneous resistance was low (< 10^–10). Differences in MICs and MBCs were within one dilution, and there was a minimal effect of inoculum size. Although PD 117596-2 was less active at pH 5.5, MICs were < 0.5 µg/ml.     

Reevaluation of interpretive criteria for Haemophilus influenzae by using meropenem (10-microgram), imipenem (10-microgram), and ampicillin (2- and 10-microgram) disks.

A collection of 300 Haemophilus influenzae clinical strains was used to assess in vitro susceptibility to carbapenems (meropenem, imipenem) by MIC and disk diffusion methods and to compare disk diffusion test results with two potencies of ampicillin disks (2 and 10 micrograms). The isolates included ampicillin-susceptible or- intermediate (167 strains), beta-lactamase-positive (117 strains), and beta-lactamase-negative ampicillin-resistant (BLNAR; 16 strains) organisms. Disk diffusion testing was performed with 10-micrograms meropenem disks from two manufacturers. Meropenem was highly active against H. influenzae strains (MIC50, 0.06 microgram/ml; MIC90, 0.25 microgram/ml; MIC50 and MIC90, MICs at which 50 and 90%, respectively, of strains are inhibited) and was 8- to 16-fold more potent than imipenem (MIC50, 1 microgram/ml; MIC90, 2 micrograms/ml). Five non-imipenem-susceptible strains were identified (MIC, 8 micrograms/ml), but the disk diffusion test indicated susceptibility (zone diameters, 18 to 21 mm). MIC values of meropenem, doxycycline, ceftazidime, and ceftriaxone for BLNAR strains were two- to fourfold greater than those for other strains. The performance of both meropenem disks was comparable and considered acceptable. A single susceptible interpretive zone diameter of > or = 17 mm (MIC, < = or 4 micrograms/ml) was proposed for meropenem. Testing with the 2-micrograms ampicillin disk was preferred because of an excellent correlation between MIC values and zone diameters (r = 0.94) and superior interpretive accuracy with the susceptible criteria at > or = 17 mm (MIC, < or = 1 microgram/ml) and the resistant criteria at < or = 13 mm (MIC, > or = 4 micrograms/ml). Among the BLNAR strains tested, 81.3% were miscategorized as susceptible or intermediate when the 10-micrograms ampicillin disk was used, while the 2-micrograms disk produced only minor interpretive errors (12.5%). Use of these criteria for testing H. influenzae against meropenem and ampicillin should maximize reference test and standardized disk diffusion test performance with the Haemophilus Test Medium. The imipenem disk diffusion test appears compromised and should be used with caution for detecting strains for which imipenem MICs are elevated.     

Comparative Activity of Moxifloxacin in Vitro Against Obligately Anaerobic Bacteria

 The antimicrobial activity of moxifloxacin and seven other antibiotics (four of them quinolones) against 292 strains of obligately anaerobic bacteria was assessed employing a broth microdilution technique performed in Wilkens-Chalgren broth. MIC50/MIC90 values (mg/l) for moxifloxacin were as follows: Bacteroides fragilis (n=62) 0.25/2, Bacteroides ovatus (n=70) 1/4, Bacteroides vulgatus (n=29) 0.25/1, Bacteroides thetaiotaomicron (n=17) 2/2, Bacteroides caccae (n=11) 1/2, Prevotella spp. (n=11) 0.25/2, Fusobacterium spp. (n=17) 1/4, Bilophila wadsworthia (n=29) 0.5/1, and Clostridium spp. (n=29) 0.125/0.5, respectively. MIC50 values (mg/l) for Bacteroides distasonis (n=8) and Peptostreptococcus spp. (n=9) were 0.25. The results indicated that moxifloxacin was almost as active as trovafloxacin, as active as gatifloxacin, and more active than levofloxacin and ciprofloxacin against the anaerobes tested.     

In vitro activity of quinupristin/dalfopristin against erythromycin-susceptible and erythromycin-resistantStreptococcus pneumoniae

Minimal inhibitory concentrations (MICs) of quinupristin/dalfopristin, penicillin, erythromycin, and clindamycin were determined by a standard agar dilution method for 93Streptococcus pneumoniae strains isolated from patients with invasive disease in Germany. Quinupristin/dalfopristin showed good activity against 32 penicillin-susceptible/erythromycin-susceptible strains (MIC90 0.5 mg/l; range 0.25–0.5 mg/l) and 31 penicillin-intermediate/erythromycin-susceptible strains (MIC90 0.5 mg/l; range 0.25–1 mg/l). Erythromycin-resistant strains (n=30) were slightly less susceptible (MIC90 1 mg/l; range 0.125–2 mg/l). Quinupristin/dalfopristin was bactericidal (99.9% killing) for all six strains investigated after 2 h at a concentration of 4 mg/l.     

In vitro activity of the novel cephalosporin GR69153

The in vitro activity of GR69153 was compared to that of ceftazidime, ceftriaxone, imipenem and gentamicin against a total of 702 recent clinical isolates. MICs were determined by a standard agar dilution procedure and two inocula (10⁴ and 10⁸ cfu) were used throughout. GR69153 inhibited 90 % of isolates ofEscherichia coli, Klebsiella pneumonia andProteus mirabilis at 0.25 mg/l and 90 % of isolates ofPseudomonas aeruginosa at 1 mg/l.Citrobacter freundii (MIC90 16 mg/l),Morganella morganii (MIC90 128 mg/l) andEnterobacter spp. (MIC90>128 mg/l) were considerably more resistant to GR69153. GR69153 was four-fold more active than ceftazidime against methicillin-sensitiveStaphylococcus aureus but was inactive against methicillin-resistantStaphylococcus aureus, Enterococcus faecalis andBacteroides fragilis group.     

In vitro activities of tigecycline, ertapenem, isepamicin, and other antimicrobial agents against clinically isolated organisms in Taiwan

This study evaluated the in vitro activities of tigecycline, ertapenem, isepamicin, and other comparators against 861 bacterial isolates recovered from patients treated in three major teaching hospitals in 2003. MICs to antimicrobial agents were determined by the agar dilution method. High rates of oxacillin resistance (58%) in Staphylococcus aureus (60 isolates), and vancomycin resistance (21%) and quinupristin-dalfopristin non-susceptibility (39%) in Enterococcus faecium (34 isolates) were found. Carbapenems had excellent in vitro activities (>or=98% susceptibility) against the 419 isolates of Enterobacteriaceae, with the MIC(50) and MIC(90) of imipenem, meropenem, and ertapenem being 0.25 and 4 mg/L, 0.03 and 0.12 mg/L, and 0.03 and 0.5 mg/L, respectively. For, Pseudomonas aeruginosa (74 isolates) and Burkholderia cepacia (21 isolates), meropenem (MIC(90), 0.25, 2, and 4 mg/L, respectively) had better in vitro activities than imipenem (MIC(90), 8, 4, and 32 mg/L, respectively) and ertapenem (MIC(90), 0.5, >32, and 32 mg/L, respectively). Isepamicin had a similar activity with amikacin against all Enterobacteriaceae, Pseudomonas aeruginosa, B. cepacia, and Acinetobacter baumannii, except for C. freundii isolates in which isepamicin had an eight-fold activity better than amikacin. Tigecycline had excellent in vitro activities against all isolates tested (MIC(90), 相似文献