In vitro Gram-positive antimicrobial activity of evernimicin (SCH 27899), a novel oligosaccharide, compared with other antimicrobials: a multicentre international trial

The antimicrobial activity of evernimicin (formerly SCH 27899), a novel oligosaccharide antimicrobial of the everninomicin class, was evaluated against four groups of Gram-positive pathogens: (i) Streptococcus pneumoniae (n = 1452); (ii) methicillin- or oxacillin-resistant Staphylococcus aureus (MRSA) and coagulase-negative staphylococci (MR-CoNS; n = 1427); (iii) enterococci (n = 1517); and (iv) non-pneumococcal streptococci (n = 1388), using the Etest method at each study centre throughout Eastern and Western Europe, Scandinavia, South Africa, Turkey and North America. Comparative MICs were determined for a variety of reference compounds, including vancomycin, quinupristin/dalfopristin, chloramphenicol, penicillin, ampicillin, oxacillin, ceftriaxone and ciprofloxacin. Evernimicin was highly active against all strains tested, with MIC90 values < or = 1.0 mg/L, ranging from 0.047 mg/L against S. pneumoniae to 1.0 mg/L against MRSA/MR-CoNS and enterococci. Compared with the reference agents, the MIC90 of evernimicin were lower against all species. Against MRSA and MR-CoNS the MIC90s of evernimicin, quinupristin/dalfopristin and vancomycin (the three most active agents) were 1.0, 1.5 and 3.0 mg/L, respectively. Against all species tested, the relative activities and spectra of these agents were: evernimicin > vancomycin > quinupristin/dalfopristin. The Etest proved to be reliable and reproducible, despite occasional interpretive difficulties caused by observer inexperience. Quality control results were excellent among the 33 participant sites. The results of this in vitro, multicentre, multinational study demonstrate that evernimicin possesses high antimicrobial activity against Gram-positive organisms that compares favourably with established antibacterial treatments and newer agents such as quinupristin/dalfopristin. Further clinical investigations of everninomicin class compounds appear warranted.     

In Vitro Activities of the Everninomicin SCH 27899 and Other Newer Antimicrobial Agents against Borrelia burgdorferi

The in vitro activity of the everninomicin antibiotic SCH 27899 against 17 isolates of Borrelia spp. was investigated. MICs ranged from 0.06 to 0.5 microg/ml. Time-kill studies with the B31 strain of B. burgdorferi demonstrated >/=3-log10-unit killing after 72 h with concentrations representing four times the MIC. The in vitro activity of four other newer antimicrobial agents, meropenem, cefepime, quinupristin-dalfopristin, and linezolid, was also tested against the B31 strain. Meropenem was the most potent of the latter agents, with an MIC of 0.125 microg/ml.     

Antimicrobial activity and spectrum of SCH27899 (Ziracin) tested against gram-positive species including recommendations for routine susceptibility testing methods and quality control. Quality Control Study Group.

SCH27899 is an oligosaccharide, everninomicin antibiotic with activity primarily against Gram-positive pathogens. The activity of SCH27899 was evaluated against 360 routine clinical isolates by the broth microdilution (BMD), agar dilution (AD), disk diffusion (DD), and Etest (AB BIODISK, Solna, Sweden) methods. In addition, results from a nine center SCH27899 quality control (QC) trial were used to establish QC ranges. SCH27899 MICs for 330 Gram-Positive strains, including multiply-resistant staphylococci and enterococci, ranged from 0.015 to 1 microgram/ml with MIC90s of 0.12 to 0.5 microgram/ ml. SCH27899 had no measurable activity against the 30 selected Gram-negative strains tested (MICs, > 256 micrograms/ml), with the exception of Moraxella catarrhalis MICs, 0.12 microgram/ ml). Etest MICs for SCH27899 correlated well with AD and BMD results with > 90% of MICs within +/- one log2 dilutions of the reference test results. Three disk concentrations (2.5-, 5-, 10-microgram) of SCH27899 were evaluated, but minimal difference of zone diameters between disk drug contents was observed (+/- 2 mm). SCH27899 disk zone diameters correlated poorly with reference MICs due to small zone diameters (range, 11 to 22 mm) attributed to poor diffusion through agar mediums, a product of this compound's high molecular weight and solubility. The use of the DD method for SCH27899 was not recommended. The proposed MIC quality assurance limits for SCH27899 using Staphylococcus aureus ATCC 29213 and Enterococcus faecalis ATCC 29212 was 0.06 to 0.25 microgram/ml for both QC strains and methods. SCH27899 appears to be a eveminomicin-derivative widely active against important Gram-positive cocci, and in vitro dilution testing methods would be preferred for clinical use, validated by the recommended MIC control ranges cited in this report.     

The in vitro activity of BMS-284756, a new des-fluorinated quinolone.

The in vitro activity of BMS-284756 (previously T-3811ME), a des-fluoro(6) quinolone, was investigated and compared with those of six other antimicrobial agents. Susceptibility tests were performed on 919 Gram-positive, Gram-negative (including nine quinolone-resistant Escherichia coli) and anaerobic bacteria, three Chlamydia isolates and four Mycobacteria spp. BMS-284756 was marginally less active against the Enterobacteriaceae, but was the most active quinolone against staphylococci, enterococci and peptostreptococci. Against Streptococcus pneumoniae, BMS-284756 and gemifloxacin were more active than other quinolones. The MIC(90) of BMS-284756 was > or = 2 mg/L for the following bacteria: E. coli (MIC(90) 16 mg/L), Acinetobacter spp. (8 mg/L), Pseudomonas aeruginosa (64 mg/L) and Enterococcus faecium (4 mg/L). The MIC of BMS-284756 for Mycobacterium spp. was within one dilution of the MIC of ciprofloxacin. BMS-284756 was markedly more active than ciprofloxacin against the Chlamydia isolates tested.     

Comparison of in-vitro activities of SCH27899 and other antibiotics against Mycoplasma pneumoniae

We examined the in-vitro activities of various antibiotics against 25 strains of Mycoplasma pneumoniae (22 clinical isolates and 3 standard strains). In the 22 clinical isolates, the 90% minimum inhibitory concentrations (MIC 90) of SCH27899, ofloxacin, levofloxacin, ciprofloxacin, erythromycin, clarithromycin, roxithromycin, clindamycin, and minocycline were 16, 2, 2, 4, 0.0039, 0.0039, 0.016, 2, and 4 μg/ml, respectively. The minimum bactericidal concentrations (MBC 90) of SCH27899, ofloxacin, levofloxacin, ciprofloxacin, erythromycin, clarithromycin, roxithromycin, clindamycin, and minocycline were 64, 4, 2, 8, 0.0625, 0.0625, 0.125, 8, and 64 μg/ml, respectively. The low sensitivity of M. pneumoniae to SCH27899 may be a result of the impermeability of the bacteria to this molecule. The results of this study suggest that SCH27899 would not be a suitable antimicrobial agent to use in the alternative chemotherapy of M. pneumoniae infection. Received: August 17, 2000 / Accepted: January 22, 2001     

Faropenem,a new oral penem: antibacterial activity against selected anaerobic and fastidious periodontal isolates

The in vitro activity of faropenem, an oral penem, was compared with those of penicillin, co-amoxiclav, cefoxitin, clindamycin, erythromycin and metronidazole against 106 isolates of anaerobic pathogens involved in systemic infections. The organisms tested comprised Porphyromonas gingivalis (29), Prevotella spp. (eight), Prevotella melaninogenica (seven), Prevotella intermedia (five), Actinomyces spp. (25), Fusobacterium nucleatum (14), Peptostreptococcus spp. (11), Bacteroides ureolyticus (five) and Bacteroides forsythus (two). The antimicrobial properties of faropenem were investigated by studying MICs, MBCs, time-kill kinetics and post-antibiotic effect (PAE). Faropenem was highly active against all the anaerobes tested (MIC(90) < or = 0.5 mg/L) and was bactericidal against both beta-lactamase-positive and -negative anaerobes, with a maximum bactericidal effect at 10 x MIC at between 12 and 24 h. In addition, faropenem had an in vitro PAE on all the tested isolates and this was not influenced by beta-lactamase production. Faropenem may be useful for treating infections caused by periodontal bacteria or oral flora.     

Surveillance of susceptibility patterns in 1297 European and US anaerobic and capnophilic isolates to co-amoxiclav and five other antimicrobial agents

In vitro susceptibility data were collected for co-amoxiclav and other antimicrobial agents against 1297 recent anaerobe isolates collected in Europe and the USA. The co-amoxiclav (amoxicillin/clavulanic acid) MIC(50/90)s (amoxicillin/clavulanic acid concentration in a ratio of 2:1, expressed in terms of amoxicillin concentration in mg/L) were 0.5/4 for Bacteroides fragilis, 96% susceptible) except E. corrodens (MIC(50/90) of >32/>64 mg/L), which is a capnophilic organism. Imipenem was also highly active against all species (>98% susceptible). Levofloxacin and clindamycin were the least potent agents tested, particularly against Bacteroides, Prevotella and Peptostreptococcus (levofloxacin susceptibility rates: Bacteroides 72.7%, Prevotella 71.5%, F. magna 72.4%; clindamycin susceptibility rates: Bacteroides 79.5%, Prevotella 92.1%, F. magna 84.7%).     

In vitro activity of gatifloxacin, compared with ciprofloxacin, clarithromycin, erythromycin, and rifampin, against Legionella species

Gatifloxacin, a new advanced-generation, 8-methoxy fluoroquinolone, has shown efficacy against a broad spectrum of microorganisms. In this study, the in vitro activity of gatifloxacin was compared with that of ciprofloxacin, clarithromycin, erythromycin, and rifampin against 214 Legionella spp. Species tested in order of frequency were: L. pneumophila serogroups 1 to 9 (181 strains); L. dumoffii (10 strains); L. micdadei (9 strains); L. longbeachae (7 strains); and other Legionella spp. (7 strains). MICs were determined by a standard dilution procedure using buffered yeast extract agar. Gatifloxacin and rifampin were the most active agents against all strains of Legionella tested. Moreover, against L. pneumophila strains tested, gatifloxacin was found to be more active (highest MIC90 = 0.03 mg/L) than ciprofloxacin (highest MIC90 = 0.06 mg/L) and clarithromycin (highest MIC90 = 0.12 mg/L). L. pneumophila serogroups 1 to 4 and 6 to 9 (MIC90 = 0.016 mg/L) were more susceptible to gatifloxacinthan L. pneumophila serogroup 5 (MIC90 = 0.03 mg/L). The activity of gatifloxacin against L. micdadei was equal to that of ciprofloxacin (MIC90 = 0.016 mg/L) and greater than that of erythromycin (MIC90 = 1.0 mg/L). The activity of gatifloxacin against L. dumoffii and L. longbeachae was equal to that of ciprofloxacin (MIC90 = 0.03 mg/L). The activity of gatifloxacin was similar against isolates obtained from both patients and environmental sources.     

Comparative in vitro activities of ABT-773 against 362 clinical isolates of anaerobic bacteria

The activity of ABT-773, a novel ketolide antibiotic, against clinical isolates of anaerobic bacteria was determined and compared to the activities of other antimicrobial agents. MICs at which 90% of isolates were inhibited (MIC(90)s) were 32 microg/ml, respectively, for Eubacterium spp., Lactobacillus spp., Clostridium difficile, and Clostridium ramosum. The MIC(90) for Bilophila wadsworthia, Bacteroides ureolyticus, and Campylobacter gracilis was 1 microg/ml, and that for Prevotella bivia and other Prevotella spp. was 0.5 microg/ml. The MIC(90) for Fusobacterium nucleatum was 8 microg/ml, and that for Fusobacterium mortiferum and Fusobacterium varium was >32 microg/ml. The MIC(90)s for the Bacteroides fragilis group were as follows: for B. fragilis, 8 microg/ml; for Bacteroides thetaiotaomicron, Bacteroides ovatus, Bacteroides distasonis, and Bacteroides uniformis, >32 microg/ml; and for Bacteroides vulgatus, 4 microg/ml. Telithromycin MICs for the B. fragilis group were usually 1 to 2 dilutions higher than ABT-773 MICs. For all strains, ABT-773 was more active than erythromycin by 4 or more dilutions, and for some strains this drug was more active than clindamycin.     

Comparative in vitro activity of CGP 31608, a new penem antibiotic.

The in vitro activity of a new penem antimicrobial agent, CGP 31608, was compared with those of imipenem, SCH 34343, and several other antimicrobial agents against approximately 600 bacterial isolates. CGP 31608 was active against gram-positive organisms, including methicillin-susceptible Staphylococcus aureus (MIC for 90% of the isolates [MIC90], 0.25 microgram/ml) and penicillin-susceptible streptococci (MIC90s, less than or equal to 2 micrograms/ml). Penicillin-resistant streptococci (including enterococci) and methicillin-resistant S. aureus were more resistant to the penem. Activities of CGP 31608 against members of the family Enterobacteriaceae were remarkably uniform, with MIC90s of 8 to 16 micrograms/ml. CGP 31608 was at least as active as imipenem and ceftazidime and more active than piperacillin against Pseudomonas aeruginosa. Drug activity was not influenced by the presence of any of 10 plasmid-mediated beta-lactamases. Against strains of Serratia marcescens, Enterobacter cloacae, and P. aeruginosa with derepressible chromosomally mediated beta-lactamases, the presence of cefoxitin did not induce increased resistance to CGP 31608. The new drug was also active against anaerobes (MIC90s, 0.25 to 8 micrograms/ml), Haemophilus influenzae (MIC90s, 0.5 to 1.0 micrograms/ml), and Legionella spp. (MIC90, 2 micrograms/ml). CGP 31608 showed an antibacterial spectrum similar to those of imipenem and SCH 34343 (except that the latter is not active against P. aeruginosa) but was generally less potent than these drugs. However, CGP 31608 demonstrated more activity (MIC90) than imipenem against P. aeruginosa, Pseudomonas cepacia, and methicillin-resistant Staphylococcus epidermidis and S. aureus.     

In-vitro activity of PD 117 596, a new quinolone, against bacterial isolates from cancer patients

The in-vitro activity of PD117 596, a new 4-quinolone antimicrobial agent was compared with that of ciprofloxacin against 798 Gram-positive and Gram-negative distinct isolates from cancer patients. PD117 596 was found to have a broad antimicrobial spectrum with excellent activity against the Enterobacteriaceae (MIC90 0.03 mg/l) Acinetobacter spp. (MIC90 0.25 mg/l), Aeromonas spp. (MIC100 0.06 mg/l) and Pseudomonas spp. including Ps. aeruginosa (MIC90 0.5 mg/l). It was also extremely active against Gram-positive micro-organisms particularly Staphylococcus spp. (including methicillin-resistant and coagulase-negative isolates) Bacillus spp. and streptococci. PD117 596 had lower minimal inhibitory concentrations against most isolates tested than ciprofloxacin, the most active currently available 4-quinolone.     

Comparative activity of garenoxacin and other agents by susceptibility and time-kill testing against Staphylococcus aureus, Streptococcus pyogenes and respiratory pathogens

OBJECTIVES: Garenoxacin is a novel des-F(6)quinolone that has shown excellent antimicrobial activity against a wide range of clinically important microorganisms. In this study, its activity was examined, in comparison with that of other antimicrobial agents, by susceptibility and time-kill testing against Staphylococcus aureus, Streptococcus pyogenes and respiratory pathogens. METHODS: Overall, 200 bacterial strains were tested. The antimicrobial activity of garenoxacin was compared with that of ciprofloxacin, levofloxacin, moxifloxacin, amoxicillin, co-amoxiclav, cefuroxime, cefotaxime, ceftriaxone, imipenem, erythromycin and clarithromycin. In addition, the bactericidal activity of garenoxacin, moxifloxacin, levofloxacin and ciprofloxacin was evaluated by time-kill analysis against four strains each of staphylococci [two methicillin-susceptible (MSSA) and two methicillin-resistant (MRSA)], pneumococci (two penicillin-susceptible and two penicillin-resistant) and Streptococcus pyogenes (two erythromycin-susceptible and two erythromycin-resistant). Antibiotics were tested at concentrations 1-8 x MIC. RESULTS: MIC90 values of garenoxacin for the MSSA and MRSA strains were 0.03 and 2 mg/L, respectively. Among all the quinolones tested, garenoxacin yielded the lowest MIC values against all pneumococci (MIC90 0.12 mg/L) irrespective of macrolide resistance; the rank order of activity was garenoxacin> moxifloxacin>levofloxacin>ciprofloxacin. Excellent activity was shown also against Haemophilus influenzae (MIC90 or= 3 log10 decrease in viable counts (cfu/mL) within 3 h at 4 x MIC, whereas a moderate, slower killing rate was observed versus streptococci. CONCLUSIONS: This investigational des-F(6)quinolone represents a promising alternative for the treatment of respiratory tract infections.     

Comparative in vitro activity of ertapenem and 11 other antimicrobial agents against aerobic and anaerobic pathogens isolated from skin and soft tissue animal and human bite wound infections.

We studied the comparative in vitro activity of ertapenem, a new carbapenem, against 240 aerobic and 180 anaerobic recent clinical bite isolates using an agar dilution method and an inoculum of 10(4) cfu/spot for aerobes and 10(5) cfu/spot for anaerobes. Ertapenem inhibited 410/420 (98%) of the isolates tested at < or = 4 mg/L with only 4/5 Campylobacter gracilis and 1/3 Campylobacter rectus strains requiring . or = 16 mg/L for inhibition. Ertapenem was only moderately active (MIC 8 mg/L) against 4/6 Enterococcus faecalis and 1/11 Staphylococcus epidermidis strains. All Pasteurella multocida, Pasteurella septica, Pasteurella canis, Pasteurella dagmatis, Moraxella spp. and EF-4 isolates were inhibited at < or = 0.015 mg/L. MIC(90)s for other aerobic genera and species were as follows: Corynebacterium spp., 4 mg/L; Staphylococcus aureus, 0.25 mg/L; Staphylococcus epidermidis, 4 mg/L; other coagulasenegative staphylococci, 0.25 mg/L; Streptococcus milleri group, 0.5 mg/L; Eikenella corrodens, 0.03 mg/L; and Bergeyella zoohelcum, 0.5 mg/L. For anaerobes the range of MICs and MIC(90)s were: Prevotella ssp., < or = 0.015-0.5, 0.125 mg/L; Porphyromonas spp., < or = 0.015-0.03, 0.015 mg/L; Fusobacterium spp., 0.015-0.125, 0.03 mg/L; Bacteroides tectum, 0.03-0.125, 0.125 mg/L; and Peptostreptococcus spp., 0.01-2, 1 mg/L. Ertapenem showed excellent potency against the full range of animal and human bite wound pathogens.     

In vitro activities of SCH27899 alone and in combination with 17 other antimicrobial agents

SCH27899, an everninomicin antibiotic, was tested for its in vitro activity against 718 bacterial isolates representing 27 species. The Enterobacteriaceae and nonenteric gram-negative bacilli were resistant to > or = 8.0 microg/ml, but all others were inhibited by < or = 1.0 microg/ml. When tested in combination with 17 other antimicrobial agents against 110 strains, SCH27899 demonstrated no significant antagonism or synergy. Consequently, combination therapy is not contraindicated.     

In-vitro activity and beta-lactamase stability of SR 44337, a new long acting cephalosporin.

The in-vitro activity of SR 44337 was compared with that of other broad-spectrum parenteral cephalosporins, plus imipenem and co-amoxiclav. SR 44337 showed good activity against the Enterobacteriaceae, with MIC90s of less than 0.5 mg/L against all species tested, with the exception of Citrobacter spp. (MIC90 2 mg/L) and Serratia spp. (MIC90 4 mg/L). Of the agents tested, only ceftriaxone showed consistently greater activity against this family of organisms. SR 44337 had higher activity than ceftriaxone against Acinetobacter spp. and Pseudomonas aeruginosa, and was the most active agent tested against Neisseria meningitidis (MIC90 0.004 mg/L). All strains of N. gonorrhoeae, Haemophilus influenzae and the streptococci (excluding the enterococci) were susceptible to less than or equal to 0.25 mg/L of SR 44337, which was also the most active cephalosporin tested against Staphylococcus aureus. SR 44337 was stable to hydrolysis by the TEM-1, SHV-1 and P99 beta-lactamases, and was more stable than ceftriaxone to the K-1 beta-lactamase.     

Review of the in vitro activity of gemifloxacin against gram-positive and gram-negative anaerobic pathogens

Published reports on the in vitro activity of gemifloxacin mesylate (SB 265805), a new fluoronaphthyridone, against anaerobic pathogens are reviewed here. The studies used a variety of media, inocula and antimicrobial agents. Using a proposed breakpoint of 0.5 mg/L, these studies showed that gemifloxacin had generally higher potency against Gram-positive anaerobes (Clostridium perfringens, all Peptostreptococcus spp.) and fusobacteria (Fusobacterium nucleatum, Fusobacterium necrophorum) and moderate but variable potency against Gram-negative anaerobes. Bacteroides stercoris, Bacteroides tectum and many Bacteroides fragilis isolates were inhibited by concentrations of < or =0.5 mg/L, while the other species of the B. fragilis group required higher concentrations for inhibition. Species variability was evident: Porphyromonas asaccharolytica, Porphyromonas canoris, Porphyromonas gingivalis, Porphyromonas macaccae, Prevotella heparinolytica and Prevotella intermedia were susceptible to 0.5 mg/L of gemifloxacin while most other Porphyromonas and Prevotella spp. were not. These data suggest that gemifloxacin may have a clinical role in the treatment of certain dental, head and neck and pleuropulmonary infections in which Gram-positive anaerobes, fusobacteria and some Prevotella and Porphyromonas spp. may predominate.     

Preliminary interpretive criteria for disk diffusion susceptibility testing of SCH 27899, a compound in the everninomicin class of antimicrobial agents

As antimicrobial resistance among Gram-positive species becomes more common, alternative agents need to be developed for the therapy of serious infections. SCH 27899 is a compound from the everninomicin class of antimicrobial agents that possesses a potent Gram-positive spectrum. We evaluated three disk concentrations (0.25,1, and 5 μg) of three SCH 27899 formulations including SCH 27899 base (SCHB), N-methylglucamine SCH 27899 (NMG-SCH), and NMG-SCH complexed with hydroxypropyl β-cyclodextrin. Disk zone diameters were correlated with minimum inhibitory concentration for 209 aerobic, nonfastidious Gram-positive strains and selected Gram-negative bacilli to develop disk diffusion interpretive criteria. No significant differences in activity were noted among the three SCH 27899 preparations. Of the three disk concentrations, the correlation coefficient was greatest (r = 0.88) for the 5-μg SCHB disk test. For a tentative break point of ≤2 μg SCHB/ml, preliminary disk interpretive criteria were: susceptible at ≥12 mm, intermediate at 10–11 mm, and resistant at ≤9 mm (absolute categorical agreement, 99.5%). Zones were small secondary to drug solubility and diffusion limitations. Using these criteria for the SCHB 5-μg disks, nearly all of the tested Gram-positive organisms were susceptible including methicillin-resistant staphylococci and vancomycin-resistant enterococci.     

Doripenem (S-4661), a novel carbapenem: comparative activity against contemporary pathogens including bactericidal action and preliminary in vitro methods evaluations

OBJECTIVES: To investigate the potency of doripenem, a broad-spectrum carbapenem characterized by a wider spectrum of activity combining antimicrobial and bactericidal features of imipenem and meropenem. METHODS: This parenteral compound was studied against recent clinical isolates (2001-2002) from a worldwide organism collection. A total of 902 strains were susceptibility tested by reference methods against doripenem and six to 28 comparators including ertapenem, imipenem and meropenem. The organisms tested included: Enterobacteriaceae (281 strains), Acinetobacter spp. (33), Pseudomonas aeruginosa (35), Stenotrophomonas maltophilia (36), other non-fermenters (22), Haemophilus influenzae (61), Moraxella catarrhalis (33), oxacillin-susceptible staphylococci (39), enterococci (84), streptococci (163), various anaerobes (98), and other Gram-positive species such as Corynebacterium and Bacillus spp. (17). RESULTS: Against Enterobacteriaceae, the average doripenem MIC90 was 0.03 mg/L (range, < or =0.015-0.25 mg/L). Doripenem was two- to 16-fold more potent than imipenem and comparable to ertapenem and meropenem; all doripenem MIC values with enteric bacilli were < or =4 mg/L. Doripenem was active against Aeromonas (MIC50, 0.03 mg/L), Bacillus spp. (MIC50, 0.03 mg/L) and all tested anaerobic species (MIC range, < or =0.015-4 mg/L), but was less active against S. maltophilia (MIC90, >32 mg/L) and Enterococcus faecium (MIC90, >32 mg/L) among the enterococcal species. Time-dependent bactericidal action was observed for doripenem and broth MIC results were slightly greater when compared to agar MIC results. In pilot testing, the optimal doripenem disc concentration was 10 microg, identical to standardized reagents for other clinically available carbapenems. CONCLUSIONS: Doripenem appears to be a potent carbapenem with a spectrum resembling currently marketed antipseudomonal carbapenems, but with greater activity when tested against some non-fermentative bacillary strains. Continued evaluation of doripenem against isolates resistant to other beta-lactams appears to be warranted.     

In vitro antianaerobic activity of DX-619, a new des-fluoro(6) quinolone

The in vitro activity of DX-619, a new des-F(6) quinolone, against anaerobic bacteria was evaluated. DX-619 showed potent activity against Bacteroides, Prevotella, Fusobacterium, Micromonas, Actinomyces, and Clostridium spp., with MIC(50)s/MIC(90)s of 相似文献   

Daptomycin activity and spectrum: a worldwide sample of 6737 clinical Gram-positive organisms

BACKGROUND: Increasing antimicrobial resistance among bacterial pathogens has prompted attempts to develop new antimicrobial agents active against multidrug-resistant Gram-positive pathogens. OBJECTIVES: To evaluate the in vitro activity of daptomycin against a worldwide collection of clinical bacterial isolates. METHODS: Daptomycin is a novel cyclic lipopeptide recently approved by the United States Food and Drug Administration. Daptomycin and selected comparators were tested against 6737 clinical Gram-positive strains from more than 70 centres located in Europe, North America and South America. RESULTS: The overall distribution of daptomycin MIC values were in the range < or = 0.12-8 mg/L and 99.4% of all strains were inhibited at < or = 2 mg/L. Despite resistances to other antimicrobial agents, >99.9% of staphylococcal isolates were inhibited at < or = 1 mg/L of daptomycin (MIC90 0.5 mg/L for staphylococci). Streptococcal isolates were very susceptible to daptomycin independent of their susceptibility to penicillin. MIC50/90 values were < or = 0.12 and 0.25 mg/L, respectively. Enterococci showed the highest daptomycin MIC values, but all isolates tested were inhibited at < or = 4 mg/L (except for one Enterococcus faecium isolate which showed a daptomycin MIC of 8 mg/L). CONCLUSIONS: Daptomycin exhibited excellent in vitro activity against a wide spectrum of Gram-positive organisms and may represent a therapeutic option for infections caused by multidrug-resistant pathogens worldwide.