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1.  LY164846 in vitro antimicrobial activity testing, including disk diffusion susceptibility tests using 30-microgram disks. 
A new oral cephalosporin, LY164846 (Eli Lilly & Co., Indianapolis, Ind.), was found to have a unique antimicrobial spectrum confined to methicillin-susceptible Staphylococcus spp., streptococci (except Enterococcus spp.), Haemophilus influenzae, Branhamella catarrhalis, and some anaerobes. Cephalothin in vitro tests (30-microgram disks or dilution) can represent LY164846 for laboratory testing if comparable interpretive breakpoints are applied to strains within the spectrum of LY164846. Organisms not inhibited by LY164846 (MICs greater than or equal to 32 micrograms/ml) were members of the family Enterobacteriaceae, Pseudomonas spp., Acinetobacter spp., enterococci, and some strains of Staphylococcus haemolyticus and of the Bacteroides fragilis group.
PMCID: PMC180430  PMID: 3755018
3.  Antimicrobial activity of Ro 23-9424, a novel ester-linked codrug of fleroxacin and desacetylcefotaxime. 
Ro 23-9424 is a novel ester-linked codrug of fleroxacin (Ro 23-6240; AM-833) and the cefotaxime metabolite desacetylcefotaxime. Its potency was determined against over 1,000 organisms and found to be intermediate between those of the two components. More than 99% of members of the family Enterobacteriaceae were inhibited by greater than or equal micrograms of Ro 23-9424 per ml; its MIC for 50% of strains tested ranged from greater than or equal to 0.06 to 1 micrograms/ml. Staphylococci, streptococci, Branhamella catarrhalis, Corynebacterium jeikeium, Bacillus spp., Haemophilus influenzae, Listeria monocytogenes, and the pathogenic Neisseria spp., including oxacillin-resistant Staphylococcus aureus, beta-lactamase-producing strains, and penicillin-resistant pneumococci, were also inhibited by Ro 23-9424. Pseudomonas aeruginosa, Enterococcus spp., and Bacteroides fragilis group isolates were more refractory to Ro 23-9424 (the MIC for 90% of strains tested was less than or equal to 32 micrograms/ml). Overall, Ro 23-9424 inhibited 97% of the aerobic strains, compared with 90% for ceftazidime and 92% for cefoperazone. Ro 23-9424 was bactericidal, was relatively stable to inoculum effects on MICs at 10(7) CFU/ml, and was determined to be highly active against organisms resistant to fluoroquinolones or ceftazidime. Preliminary quality control guidelines were determined, and a 30-micrograms disk concentration appears to be the most usable form.
PMCID: PMC284260  PMID: 2504106
4.  Cefoperazone (T-1551), a new semisynthetic cephalosporin: comparison with cephalothin and gentamicin. 
The in vitro activity of cefoperazone (T-1551) against almost 9,000 recent clinical isolates at six institutions was tested and compared with that of cephalothin and gentamicin. The modal minimum inhibitory concentrations of cefoperazone were 16- and 4-fold less than those of cephalothin and gentamicin, respectively, against 5,503 strains of Enterobacteriaceae. Species normally resistant to cephalothin, such as indole-positive protease and enterobacters, were almost universally susceptible to cefoperazone. Cefoperazone demonstrated activity comparable to gentamicin against Pseudomonas aeruginosa and other pseudomonads.
PMCID: PMC283865  PMID: 6446879
5.  Antibacterial activity of trospectomycin (U-63366F) and initial evaluations of disk diffusion susceptibility tests. 
The in vitro activities of trospectomycin sulfate were compared with those spectinomycin against 632 aerobic microorganisms, including 66 Neisseria gonorrhoeae isolates. Against species other than gram-negative bacilli, trospectomycin was about 4- to 16-fold more active than spectinomycin. For disk diffusion tests, a 30-micrograms disk is recommended, with tentative zone size breakpoints of less than or equal to 13 mm for resistance (MIC, greater than or equal to 64 micrograms/ml) and greater than or equal to 17 mm for susceptibility (MIC, less than or equal to 16 micrograms/ml).
PMCID: PMC172481  PMID: 2524997
6.  Antimicrobial activity and spectrum of LY146032, a lipopeptide antibiotic, including susceptibility testing recommendations. 
LY146032, a new lipopeptide, was found to have a spectrum of gram-positive antimicrobial activity that includes activity against staphylococci (methicillin susceptible and resistant), beta-hemolytic Streptococcus spp., pneumococci, viridans group Streptococcus spp., anaerobic gram-positive cocci, Clostridium spp., and enterococci. The new lipopeptide was generally bactericidal and showed more rapid killing of Listeria spp. (MIC, 1 to 2 micrograms/ml) and staphylococci than either vancomycin or teicoplanin. The 30-micrograms disk was preferred to the 15-micrograms disk on the basis of the preliminary interpretive criteria for susceptibility which indicated zone diameters of greater than or equal to 16 mm for susceptible strains (MIC, less than or equal to 2.0 micrograms/ml) and greater than or equal to 12 mm for resistant strains (MIC, greater than or equal to 8.0 micrograms/ml). These criteria are valid pending the testing of additional gram-positive strains which have LY146032 MICs of greater than or equal to 8 micrograms/ml.
PMCID: PMC174792  PMID: 3038001
7.  Evaluation of the in vitro activity of BMY-28142, a new broad-spectrum cephalosporin. 
The in vitro activity of BMY-28142, a new cephalosporin, was tested by a broth microdilution system and compared with those of cefotaxime, ceftazidime, cefoperazone, moxalactam, and HR 810 against 747 bacterial isolates, one-third of which were resistant to one or more third-generation cephalosporins. BMY-28142 was the most active drug tested against 326 Enterobacteriaceae with an MIC for 90% of the organisms tested (MIC90) of 1.0 micrograms/ml. Against these Enterobacteriaceae the relative activities were: BMY-28142 greater than HR 810 greater than moxalactam and ceftazidime greater than cefotaxime greater than cefoperazone. For cefotaxime- and cefoperazone-resistant strains, the MIC90 of BMY-28142 was 4.0 micrograms/ml (compared with 0.13 micrograms/ml for susceptible strains). BMY-28142, with an MIC90 of 8.0 micrograms/ml for Pseudomonas aeruginosa, was about half as active as ceftazidime. The relative activities against P. aeruginosa were: ceftazidime greater than BMY-28142 greater than HR 810 greater than cefoperazone greater than moxalactam and cefotaxime. The MIC90 of BMY-28142 against staphylococci was 2.0 micrograms/ml, which was fourfold less active than HR 810, slightly less active than cefotaxime and cefoperazone, and fourfold more active than ceftazidime and moxalactam. BMY-28142 was very active against beta-lactamase-positive and -negative Haemophilus influenzae (MIC90, 0.06 micrograms/ml), Neisseria gonorrhoeae (MIC90, 0.015 micrograms/ml),aand nonenterococcal streptococci. Its activity against Streptococcus faecalis was poor (MIC90, 64 micrograms/ml). BMY-28142 was stable against the several beta-lactamases tested but exhibited little beta-lactamase inhibitory effect.
PMCID: PMC180130  PMID: 3893316
8.  In vitro evaluation of HR810, a new wide-spectrum aminothiazolyl alpha-methoxyimino cephalosporin. 
HR810 (Hoechst-Roussel Pharmaceuticals Inc., Somerville, N.J.) is a new, cyclical-pyridinium cephalosporin that appeared superior to numerous comparison drugs against 658 strains of aerobic and facultative anaerobic bacteria. Seventeen Enterobacteriaceae spp. were tested by broth microdilution methods, and the 50% MICs (MIC50S) and 90% MICs (MIC90s) were 0.03 to 0.12 and 0.03 to 2.0 micrograms/ml, respectively. Only one strain had an MIC greater than 8.0 micrograms/ml (99.6% is considered susceptible). HR810 inhibited 98% of Pseudomonas aeruginosa isolates at less than or equal to 16 micrograms/ml, and the MIC90 for Acinetobacter spp. was 4.0 micrograms/ml. It was also very active against Pseudomonas spp. and Staphylococcus aureus (MIC90, 0.5 micrograms/ml) but marginally active against methicillin-resistant staphylococcal strains (MIC90, 16 micrograms/ml) and enterococcus (MIC90, 32 micrograms/ml). Non-enterococcal streptococci had MIC50s ranging from 0.008 micrograms/ml for Streptococcus pyogenes to 0.12 micrograms/ml for pneumococci. All MICs of HR810 against Haemophilus and Neisseria spp. were less than or equal to 0.03 micrograms/ml (MIC50, 0.002 to 0.008 micrograms/ml). HR810 poorly inhibited beta-lactamases and was very stable against 11 tested beta-lactamases of plasmid (TEM, OXA, SHV-1, and PSE) and chromosomal (K1, K14, P99) types.
PMCID: PMC185628  PMID: 6611135
9.  Compound A49759, the 3-O-demethyl derivative of fortimicin A: in vitro comparison with six other aminoglycoside antibiotics. 
O-Demethylfortimicin A (compound A49759) was tested against 445 bacteria, and the results were compared with those obtained with fortimicin A, amikacin, gentamicin, netilmicin, sisomicin, and tobramycin. A49759 was found to be active and bactericidal against the Enterobacteriaceae, nonfermentative gram-negative bacilli, and Staphylococcus aureus. A49759 was two- to fourfold more active than fortimicin A against most species tested, but generally fourfold less active than amikacin against this population of Pseudomonas aeruginosa (85% inhibited at less than or equal to 16 microgram of amikacin per ml and 85% inhibited at less than or equal to 64 microgram of A49759 per ml). Only amikacin and A49759 were resistant to most aminoglucoside-inactivating enzymes and also had significant antipseudomonal activity. Amikacin was inactivated by aminoglycoside 6'-acetyltransferase, and A49759 was inactivated by aminoglycoside 3-acetyltransferase. The minimal inhibitory concentrations of all tested aminoglycosides were increased by augmenting the inoculum size.
PMCID: PMC284090  PMID: 7447431
10.  Antifungal pharmacodynamic characteristics of fluconazole and amphotericin B tested against Candida albicans. 
Time-kill curves were determined for three isolates of Candida albicans tested against fluconazole and amphotericin B at multiples of the MIC. Fluconazole produced fungistatic activity, with concentration-related growth effects observed over a narrow range of concentrations. Amphotericin B exhibited fungicidal activity, with enhancement of activity over a broader range of concentrations.
PMCID: PMC163923  PMID: 9174207
11.  In vitro evaluation of a novel ketolide antimicrobial agent, RU-64004. 
Ketolides, a novel macrolide subclass, possess a mode of action that is similar to that of structurally related macrolide-lincosamide-streptogramin (MLS) compounds. By using reference in vitro tests, the in vitro activity of RU-64004 was compared to those of six other MLS compounds against more than 800 clinical pathogens, including 356 gram-positive organisms. The spectrum of activity of the ketolide was most similar to that of clindamycin versus staphylococci and streptococci and superior to those of all macrolides tested against oxacillin-resistant staphylococci and vancomycin-resistant (vanA, vanB, and vanC) enterococcal isolates. The activity of the ketolide was greater than those of the macrolides, azalides, or clindamycin tested against vancomycin-susceptible enterococci (MICs at which 90% of isolates are inhibited [MIC90S], 0.25 to 4 micrograms/ml), penicillin-resistant pneumococci (MIC90, 0.25 micrograms/ml), and most beta-hemolytic streptococci. All Streptococcus pneumoniae and beta-hemolytic streptococcus strain were inhibited by ketolide concentrations of < or = 0.25 micrograms/ml. Against 165 erythromycin-resistant strains, RU-64004 inhibited (MICs, < or = 0.5 micrograms/ml) approximately one-third of staphylococci, all streptococci, and slightly more than one-half of the enterococci. Quinupristin-dalfopristin (a streptogramin combination) was active against all tested isolates with the exception of non-Enterococcus faecium enterococci, against which the ketolide exhibited greater potency (MIC50S, 0.03 to 2 micrograms/ml). The ketolide was also active against Haemophilus influenzae (MIC90, 2 micrograms/ml), Moraxella catarrhalis (MIC90, 0.12 micrograms/ml), pathogenic Neisseria spp. (MIC90, 0.5 micrograms/ml), and many gram-positive anaerobes (MIC90, 0.5 micrograms/ml). RU-64004 may enhance the role of macrolide drugs in the treatment of some serious infections caused by MLS-resistant gram-positive organisms.
PMCID: PMC163729  PMID: 9021207
12.  Activity of a new triazole, Sch 56592, compared with those of four other antifungal agents tested against clinical isolates of Candida spp. and Saccharomyces cerevisiae. 
Sch 56592 is a new triazole agent with potent, broad-spectrum antifungal activity. The in vitro activities of Sch 56592, itraconazole, fluconazole, amphotericin B, and flucytosine (5-FC) against 404 clinical isolates of Candida spp. (382 isolates) and Saccharomyces cerevisiae (22 isolates) were investigated. In vitro susceptibility testing was performed by a broth microdilution method performed according to National Committee for Clinical Laboratory Standards guidelines. Overall, Sch 56592 was very active (MIC at which 90% of isolates are inhibited [MIC90], 0.5 microgram/ml) against these yeast isolates. Sch 56592 was most active against Candida tropicalis, Candida parapsilosis, candida lusitaniae, and Candida stellatoidea (MIC90, < or = 0.12 microgram/ml) and was least active against Candida glabrata (MIC90, 2.0 micrograms/ml). Sch 56592 was 2- to 32-fold more active than amphotericin B and 5-FC against all species except C. glabrata. By comparison with the other triazoles, Sch 56592 was equivalent to itraconazole and greater than or equal to eightfold more active than fluconazole. On the basis of these results, Sch 56592 has promising antifungal activity, and further in vitro and in vivo investigations are warranted.
PMCID: PMC163694  PMID: 9021172
13.  In vitro activity and spectrum of LY333328, a novel glycopeptide derivative. 
Reference methods were used to determine the potency of LY333328, a semisynthetic glycopeptide derivative with a key N-alkylation substitution, against 833 strains (393 gram-positive strains and representative gram-negative bacilli) with various defined resistance mechanisms. The MICs at which 90% of the isolates are inhibited (MIC90S) (in micrograms per milliliter) of LY333328 and the percentages of strains at < or = 8 micrograms/ml were as follows: for oxacillin-susceptible Staphylococcus aureus, 2 and 100%, and for oxacillin-resistant Staphylococcus aureus, 4 and 100%; for oxacillin-susceptible Staphylococcus epidermis, 4 and 100%, and for oxacillin-resistant Staphylococcus aureus, 8 and 96%; for Streptococcus serogroups A, B, C, and G, 0.25 to 1 and 100%; for Streptococcus pneumoniae < or = 0.015 to 0.06 and 100%; for Enterococcus faecalis, 2 and 100%; and for vancomycin-susceptible Enterococcus faecium, 0.25 and 100%, and for vancomycin-resistant Enterococcus faecium, 4 and 100%. LY333328 was not active (MIC50, > or = 16 micrograms/ml) against more than 400 representative strains of Enterobacteriaceae, pseudomonads, Acinetobacter spp., Stenotrophomonas maltophilia, Haemophilus influenzae, Moraxella catarrhalis, pathogenic Neisseria spp., and anaerobic gram-negative bacilli. Gram-positive anaerobes were LY333328 susceptible (MICs, < or = 2 micrograms/ml). Test methods and conditions may have affected MICs of LY333328, with most (species variation) agar dilution MICs being greater than the broth microdilution MICs.
PMCID: PMC163738  PMID: 9021216
14.  Antimicrobial activity and spectrum of LB20304, a novel fluoronaphthyridone. 
Compound LB20304 is a fluoronaphthyridone carboxylic acid with a novel pyrrolidine substituent. This drug was compared with ciprofloxacin, levofloxacin, ofloxacin, and trovafloxacin against over 800 pathogens, most from blood stream infections, by National Committee for Clinical Laboratory Standards reference methods. LB20304 was the most active agent against gram-positive species including strains observed to be resistant to other fluoroquinolones and glycopeptides. The potency of LB20304 (MIC50, 0.03 micrograms/ml) against the Enterobacteriaceae was exceeded only by that of ciprofloxacin (0.015 micrograms/ml). It has limited activity against gram-negative anaerobes.
PMCID: PMC163688  PMID: 8980783
15.  In vitro antimicrobial activities and spectra of U-100592 and U-100766, two novel fluorinated oxazolidinones. 
Two new fluorinated oxazolidinones, U-100592 and U-100766, were evaluated against more than 659 gram-positive and -negative organisms and compared with glycopeptides, erythromycin, clindamycin, clinafloxacin, and chloramphenicol. U-100592 and U-100766 were usually equally potent, but the MICs at which 90% of the isolates are inhibited (MIC90s) of U-100592 for some staphylococci and enterococci were slightly lower than those of U-100766 (1 versus 2 micrograms/ml). The MIC90 of U-100592 and U-100766 for oxacillin-resistant Staphylococcus aureus was 2 micrograms/ml, the same as observed for oxacillin-susceptible strains. The oxazolidinone MICs for other Staphylococcus spp. were < or = 2 micrograms/ml (MIC50, 0.5 to 1 microgram/ml). All enterococci were inhibited by < or = 4 and < or = 2 micrograms of U-100592 and U-100766 per ml, respectively. Against 152 vancomycin-resistant enterococci (five species), both compounds had a narrow range of MICs (0.25 to 2 micrograms/ml) and a MIC90 of 1 microgram/ml. Corynebacterium jeikeium, Bacillus spp., and all tested streptococci were inhibited (< or = 4 micrograms/ml). Members of the family Enterobacteriaceae and other gram-negative bacilli were not susceptible (MIC50, > 64 micrograms/ml) to either oxazolidinone. Three potencies of U-100592 and U-100766 disks were tested (5, 15, and 30 micrograms), and acceptable correlations (r = 0.81 to 0.90) with the measured MICs were observed. Best discrimination of the tentatively susceptible organisms (MICs, < or = 4 micrograms/ml) was demonstrated with the 30-micrograms disk concentration. The oxazolidinones demonstrated a dominant bacteristatic action. These oxazolidinones (U-100592 and U-100766) appear promising for treatment of gram-positive organisms that demonstrate resistance to contemporary therapeutic agents.
PMCID: PMC163187  PMID: 8851600
16.  Antimicrobial activity of CS-940, a new trifluorinated quinolone. 
Antimicrobial Agents and Chemotherapy  1995;39(10):2325-2330.
The antimicrobial activity of CS-940, a new trifluorinated quinolone drug, was tested against 761 clinical isolates. CS-940 activity against members of the family Enterobacteriaceae was most similar to that of ciprofloxacin and ofloxacin, with a large range of MICs inhibiting 90% of isolates tested (MIC90S) of 0.015 to 16 micrograms/ml (median MIC90, 0.06 micrograms/ml). CS-940 had greater activity than ciprofloxacin or ofloxacin when they were tested against Acinetobacter spp. (MIC90S, 0.03 micrograms/ml) and Stenotrophomonas (Xanthomonas) maltophilia (MIC90S, 2 micrograms/ml). CS-940 demonstrated a high degree of potency against Haemophilus influenzae, Moraxella catarrhalis, and Neisseria spp. (MIC90S, < or = 0.06 micrograms/ml). CS-940 was two- to eightfold more active than ciprofloxacin or ofloxacin against oxacillin-susceptible Staphylococcus aureus, Staphylococcus epidermidis, Staphylococcus haemolyticus, and coagulase-negative Staphylococcus spp. CS-940 was also very active against Streptococcus spp. and enterococci, for which MIC90S were < or = 2 micrograms/ml; for Enterococcus faecium, however, the MIC90 was 4 micrograms/ml. CS-940 was generally less active than a comparison investigational fluoroquinolone, clinafloxacin. This compound appears promising by in vitro test analysis and warrants further in vivo trials.
PMCID: PMC162937  PMID: 8619590
17.  In vitro evaluation of DV-7751a, a new fluoroquinolone with an enhanced spectrum of activity against gram-positive aerobic organisms and anaerobes. 
DV-7751a is an investigational fluoroquinolone with improved spectrum and potency against gram-positive bacteria. We studied the in vitro activity of this compound against 771 recent clinical isolates by the reference agar and broth microdilution methods. Its activity was compared with those of ciprofloxacin, levofloxacin, and ofloxacin and with those of ceftazidime, oxacillin, and gentamicin where relevant. DV-7751a was four- to eightfold more active than the comparison fluoroquinolones against Enterococcus spp. (including vancomycin-resistant strains), Staphylococcus spp. (including oxacillin-resistant Staphylococcus aureus), Streptococcus spp., other gram-positive pathogens, and some anaerobes. The DV-7751a activity against most gram-negative species was similar to that of ofloxacin and ciprofloxacin. DV-7751a appears to be a candidate for the therapy of some mixed-flora infections and the treatment of bacteria resistant to the current fluoroquinolones.
PMCID: PMC162799  PMID: 7492122
18.  In vitro activity of DU-6859a, a new fluorocyclopropyl quinolone. 
Antimicrobial Agents and Chemotherapy  1993;37(12):2747-2753.
DU-6859a was tested against 844 recent clinical isolates (most from bacteremias) by using reference MIC determination procedures. The activity of DU-6859a against members of the family Enterobacteriaceae was comparable to that of ciprofloxacin (range of MICs for 90% of isolates [MIC90], < or = 0.015 to 1 microgram/ml), and the highest MICs were observed among Serratia marcescens and Providencia rettgeri isolates. The DU-6859a MIC90 for Pseudomonas aeruginosa and Xanthomonas maltophilia was 0.5 microgram/ml. Pneumococci (MIC90, 0.06 microgram/ml), Haemophilus influenzae (MIC90, < or = 0.004 microgram/ml), Moraxella catarrhalis (MIC90, < or = 0.015 microgram/ml), and pathogenic neisseriae (MIC90, 0.015 to 0.03 microgram/ml) were very susceptible to DU-6859a. All staphylococci had DU-6859a MICs of < or = 1 microgram/ml, including oxacillin- and ciprofloxacin-resistant strains. DU-6859a was very active against isolates resistant to ceftazidime (MIC90, < or = 0.12 microgram/ml), ciprofloxacin (MIC90, < or = 8 micrograms/ml), and gentamicin (MIC90, < or = 1 microgram/ml).
PMCID: PMC192801  PMID: 8109948
19.  In vitro antimicrobial activity of CP-99,219, a novel azabicyclo-naphthyridone. 
CP-99,219 is a trifluoronaphthyridone with significant antibacterial activity that includes the family Enterobacteriaceae (MICs for 90% of the strains tested [MIC90s], < or = 0.015 to 0.5 micrograms/ml), Moraxella catarrhalis, Haemophilus influenzae, and gonococci (MICs, < or = 0.015 micrograms/ml). Legionella spp. were also CP-99,219 susceptible, with MICs of 0.008 to 0.12 micrograms/ml. CP-99,219 demonstrated activity greater than that of ciprofloxacin, ofloxacin, or enoxacin against Pseudomonas aeruginosa (MIC90, 1 microgram/ml), Xanthomonas maltophilia (MIC90, 2 micrograms/ml), Staphylococcus haemolyticus (MIC90, 0.5 micrograms/ml), Enterococcus faecalis (MIC90, 1 microgram/ml), and pneumococci (MIC90, 0.12 micrograms/ml). Numerous ciprofloxacin-resistant isolates were susceptible to CP-99,219, a new compound showing potential value for further in vivo trials.
PMCID: PMC187667  PMID: 8043036
20.  Antimicrobial activities of two investigational fluoroquinolones (CI-960 and E4695) against over 100 Legionella sp. isolates. 
The antimicrobial activities of two investigational fluoroquinolones (CI-960 and E4695) were compared with those of five similar compounds and four comparison drugs against 103 strains of Legionella pneumophila and five other Legionella species type strains. When concentrations inhibiting 90% of strains tested (MIC90s) for L. pneumophila were determined, CI-960 and temafloxacin emerged as the most active (0.015 microgram/ml) and were followed in potency by E4695 (0.03 microgram/ml). This activity was two- to fourfold greater than that of the reference drug, ciprofloxacin, and approached that of rifampin (MIC90, 0.008 microgram/ml). All fluoroquinolones studied were more active than erythromycin (MIC90, 0.5 microgram/ml). These two investigational fluoroquinolones appear well suited for further in vivo study of legionellosis therapy.
PMCID: PMC192436  PMID: 1329642
21.  In vitro activity of decaplanin (M86-1410), a new glycopeptide antibiotic. 
The in vitro activity of decaplanin (formerly M86-1410), a novel glycopeptide antimicrobial agent, was tested against 169 gram-positive bloodstream isolates from patients at the University of Iowa Hospitals and Clinics and 12 selected vancomycin-resistant strains. Enterococcus faecalis, E. faecium, Staphylococcus aureus, streptococci, bacilli, corynebacteria, and listeria were inhibited by decaplanin (MICs for 90% of the strains tested [MIC90s], 0.12 to 4 micrograms/ml). However, some rarely isolated and selected Enterococcus sp. populations had a MIC90 of 16 micrograms/ml, and S. haemolyticus strains had a MIC90 of 8 micrograms/ml. These in vitro results suggest that decaplanin may be useful against most gram-positive strains, even though some Enterococcus species and coagulase-negative staphylococci were potentially resistant (MICs, greater than or equal to 8 micrograms/ml).
PMCID: PMC189476  PMID: 1386973
22.  In vitro evaluation of Ro 09-1227, a novel catechol-substituted cephalosporin. 
Ro 09-1227 is a novel 7-position catechol-substituted parenteral cephalosporin that also has a 3-position radical similar to previously described cephems. The Ro 09-1227 spectrum was slightly wider than that of ceftazidime against members of the family Enterobacteriaceae tested, principally because of greater activity against species producing Richmond-Sykes type I beta-lactamases. Ro 09-1227 was also more active than ceftazidime against some strains producing extended-spectrum plasmid-encoded beta-lactamases, such as TEM-3, -4, -5, -6, -7, and -9, SHV-2 and -3, and CAZ-2. Most strains of Pseudomonas aeruginosa, Xanthomonas maltophilia, and Acinetobacter spp. were also more susceptible to Ro 09-1227 than cefotaxime, ceftriaxone, cefoperazone, and ceftazidime. Haemophilus influenzae (MIC for 90% of strains tested [MIC90], 0.5 micrograms/ml), Neisseria gonorrhoeae (MIC90, 0.015 micrograms/ml), and Moraxella (Branhamella) catarrhalis (MIC90, 0.5 micrograms/ml) were also Ro 09-1227 susceptible. Ro 09-1227 activity against important gram-positive cocci was most comparable to that of ceftazidime. Bacteroides fragilis (MIC90, greater than 32 micrograms/ml) and the enterococci (MIC90, greater than 32 micrograms/ml) were resistant to Ro 09-1227. These in vitro results indicate that this catechol-substituted cephalosporin may be useful as an empiric agent, especially for some isolates resistant to currently available broad-spectrum cephalosporins.
PMCID: PMC189283  PMID: 1590695
23.  In vitro evaluation of GR69153, a novel catechol-substituted cephalosporin. 
GR69153 is a C-7 catechol cephalosporin with a broad spectrum of activity against members of the family Enterobacteriaceae (MICs for 50% of strains tested [MIC50s], 0.008 to 0.5 micrograms/ml), Staphylococcus aureus (MIC50, 4 micrograms/ml), Pseudomonas aeruginosa (MIC50, 0.25 micrograms/ml), Haemophilus influenzae (MIC50, 0.03 micrograms/ml), Neisseria gonorrhoeae (MIC50, 0.03 micrograms/ml), and Acinetobacter spp. (MIC50, 2 micrograms/ml). Potent GR69153 activity was also demonstrated against Moraxella catarrhalis, pneumococci, beta-hemolytic streptococci, gram-positive anaerobes, and most species of coagulase-negative staphylococci. The activity of GR69153 was generally two- to fourfold greater than that of ceftazidime. Resistance level GR69153 MICs for 90% of strains tested (greater than or equal to 32 micrograms/ml) were found most often among Citrobacter freundii, Enterobacter spp. and Morganella morganii strains. GR69153 did not significantly inhibit enterococci, Xanthomonas maltophilia, the Bacteroides fragilis group, Corynebacterium jeikeium, or Listeria monocytogenes. GR69153 was bactericidal and was generally beta-lactamase stable, and MICs were only slightly increased by high inoculum concentrations. Activity was enhanced in an iron-deficient medium, and a modest MIC difference attributed to iron availability was noted between standard agar and broth test results. GR69153 was confirmed to be a potent, catechol-substituted cephalosporin with a spectrum slightly wider than that of ceftazidime, but it was less active than cefpirome or imipenem against some gram-positive pathogens and anaerobes.
PMCID: PMC245131  PMID: 1854174
24.  In vitro antibacterial spectrum of E1040 compared with those of cefpirome and ceftazidime and disk diffusion interpretive criteria for E1040. 
E1040 is a new parenteral cephalosporin which was tested against 690 clinical isolates and compared with cefpirome and ceftazidime. E1040 had the best activity of the three drugs against Pseudomonas aeruginosa, inhibiting 89% of strains at 8.0 micrograms/ml. E1040 demonstrated good activity against members of the family Enterobacteriaceae, including cefpirome-resistant and ceftazidime-resistant strains. E1040 also had good activity against streptococci but much poorer activity against enterococci and staphylococci. When E1040 broth microdilution and disk diffusion susceptibility test results were compared, the 30-micrograms disk was recommended, with the following tentative interpretive criteria: susceptible, greater than or equal to 18 mm (MIC, less than or equal to 8.0 micrograms/ml); intermediate, 15 to 17 mm (MIC, 16 micrograms/ml); and resistant, less than or equal to 14 mm (MIC, greater than or equal to 32 micrograms/ml).
PMCID: PMC171720  PMID: 2193626
25.  Multicenter in vitro evaluation of SM-7338, a new carbapenem. 
A new carbapenem, SM-7338, was compared with imipenem, cefotaxime, and ceftazidime at five medical centers. Nearly 6,000 strains were tested by reference methods of the National Committee for Clinical Laboratory Standards, and SM-7338 inhibited the largest percentage of gram-negative bacilli. Its spectrum included all members of the family Enterobacteriaceae (99.7% were susceptible to less than or equal to 4 micrograms/ml), Pseudomonas spp. (but not Xanthomonas maltophilia), and Acinetobacter spp. The potency and spectrum of SM-7338 against the gram-positive organisms were less than those of imipenem and superior to those of ceftazidime. Only the enterococci and some oxacillin-resistant staphylococci were less susceptible to SM-7338 (MICs for 90% of isolates, greater than or equal to 8 micrograms/ml). Organisms resistant to ceftazidime were generally susceptible to SM-7338 and imipenem (76%). However, for one-third of the imipenem-resistant gram-negative bacilli (MICs, greater than 8 micrograms/ml), SM-7338 MICs were less than or equal to 4 micrograms/ml. Some endemic differences in patterns of SM-7338 activity against selected gram-negative species were found among some medical centers.
PMCID: PMC172479  PMID: 2658796

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