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Query: UMLS:C0519030 (Klebsiella)
 21,988 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The authors studied the activity of fosfomycin (FOS) and/or gentamicin (GEN) against a Klebsiella pneumoniae strain resistant to all beta-lactams--except cephamycins and imipenem--by production of a plasmid mediated extended broad-spectrum beta-lactamase-TEM-3, to all aminoglycosides--except gentamicin--by production of a plasmid mediated 6' aminoglycoside acetyltransferase IV, to sulfonamides and to tetracyclines. In vitro, the combination FOS (MIC = MBC = 32 mg/l) + GEN (MIC = MBC = 2) appeared indifferent (FIC = 0.75; FBC = 1). In vivo, on experimental endocarditis in rabbits, FOS alone was ineffective, GEN alone was active but only at high dose regimen, FOS - GEN combination was active as compared with controls. Fosfomycin - gentamicin combination may be an alternative in the therapy of severe infections due to multiresistant Enterobacteriacae.
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PMID:[A fosfomycin-gentamicin combination in the treatment of experimental endocarditis caused by Klebsiella pneumoniae producing type TEM-3 beta-lactamase]. 269 65

Ciprofloxacin's in vitro activity was tested against 385 hospital isolates originating from three geographically distinct regions. Of all strains tested, only three (1 Acinetobacter sp. and 2 Pseudomonas aeruginosa) were ciprofloxacin resistant. Ciprofloxacin was more active against Escherichia coli, Enterobacter cloacae, Enterobacter aerogenes, Acinetobacter sp., Proteus sp., Shigella sp. than gentamicin, mezlocillin and cefotaxime. It was more active than azlocillin and cefsulodin against P. aeruginosa. It was more active than cloxacillin and cefamandole against staphylococci. It was as active as cefotaxime against Klebsiella pneumoniae, Citrobacter freundii and Serratia marcescens. Ciprofloxacin demonstrated similar activity in broth and solid agar. The minimal inhibitory concentrations (MIC's) of all strains were similar to the minimal bactericidal concentrations (MBC's). Ciprofloxacin's MIC was not influenced by increase of the inoculum or addition of human serum and only slightly influenced by anaerobic conditions. Decrease of the medium pH increased the MIC substantially. Ciprofloxacin exhibited a rapid bactericidal effect and had only a minimal post-antibiotic effect. These favorable in vitro characteristics of ciprofloxacin warrant further studies.
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PMID:In vitro activity of ciprofloxacin compared with other agents against recent hospital isolates. 293 66

Nalidixic and five newer 4-quinolones, ciprofloxacin, enoxacin, norfloxacin, ofloxacin and pefloxacin were tested against 576 recent clinical aerobic bacterial isolates. The 4-quinolones were regularly active (MIC90 less than 4 mg/l) against the following bacteria: Staphylococcus aureus, S. epidermidis, S. saprophyticus, different Enterobacteriaceae, Haemophilus influenzae, Campylobacter jejuni, Pseudomonas aeruginosa, Agrobacter spp., Aeromonas spp., Plesiomonas spp., Neisseria meningitidis. Other bacteria were usually intermediately susceptible or resistant: different streptococci, Listeria monocytogenes, Nocardia asteroides, P. maltophilia, Achromobacter xylosoxydans and Alcaligenes denitrificans. Ciprofloxacin was the most potent compound, followed by ofloxacin and pefloxacin, norfloxacin and enoxacin being less active. All the 4-quinolones were much more active than nalidixic acid. The MBC/MIC ratios of the 4-quinolones were between 1 and 2 with a majority of strains, and between 2 and 3 with Streptococcus agalactiae, Str. faecalis and L. monocytogenes. A two- to eight-fold increase of MIC was observed by increasing the inoculum 10,000-fold with most of the strains tested. Susceptible bacterial population of Klebsiella pneumoniae, Enterobacter cloacae, Serratia marcescens and P. aeruginosa contained more clones resistant to nalidixic acid (10(4) to 10(8) at four times the MIC) than to 4-quinolones (10(5) to 10(9) at four times the MIC). Supplementing the media with MgSO4 produced smaller inhibition zone diameters with a disc diffusion method than those obtained with non-supplemented agar, with all quinolone or strains. Less regular effect, or no effect was obtained after supplementation with ZnSO4 or Ca(NO3)2.
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PMID:In-vitro activity of newer quinolones against aerobic bacteria. 294 Feb 14

The antibacterial activities of ciprofloxacin versus ceftazidime against Klebsiella pneumoniae in vitro and in vivo were compared. Although there was only a minor difference in MBC values between both drugs ciprofloxacin demonstrated a high and dose-dependent bacterial killing rate in vitro and in lungs of leukopenic rats in contrast to the more time-dependent bactericidal activity of ceftazidime. After treatment of a K.pneumoniae pneumonia and septicemia the efficacy of ciprofloxacin was only slightly influenced by the mode of administration, either at 6-h intervals or continuously, whereas ceftazidime was far more effective after continuous administration. This resulted in a superior efficacy of ciprofloxacin after intermittent treatment as compared to ceftazidime, whereas ceftazidime was more effective after continuous administration as compared to ciprofloxacin. Also ciprofloxacin proved to be bactericidal against bacteria that were not actively growing, both in vitro and in vivo, whereas ceftazidime was not.
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PMID:Influence of dose frequency on the therapeutic efficacies of ciprofloxacin and ceftazidime in experimental Klebsiella pneumoniae pneumonia and septicemia in relation to their bactericidal activities in vitro. 332 28

Thirteen adult patients (47-81 yr) with gram-negative bacteremia and normal (less than or equal to 1.5 mg/dl) serum creatinines were treated with 1 or 2 gm of cefotaxime every 8 or 12 hr. The infecting organisms were Escherichia coli (9 strains), Klebsiella pneumoniae (2 strains), and one isolate of Salmonella enteritidis and Serratia marcescens. All patients recovered without any serious sequelae. The range of MICs for cefotaxime and desacetyl-cefotaxime were 0.015-0.25 micrograms/ml and 0.015-4.0 micrograms/ml, respectively. The MBC values for cefotaxime and desacetyl-cefotaxime were identical to the MIC values except for two strains. The trough levels of cefotaxime varied from 65.9 to 1.1 micrograms/ml. The serum concentration of desacetyl-cefotaxime varied from 84 to less than 1.0 microgram/ml. All corresponding trough serum inhibitory activities (SIA) were greater than or equal to 1:32. Comparisons of calculated and directly measured serum bactericidal activity (SBA) and SIA results suggest an additive and occasional synergistic benefit of the cefotaxime desacetyl metabolite. This study supports the clinical efficacy and cost-effectiveness of 8- and 12-hr dosing intervals for cefotaxime against bacteremic gram-negative strains having the usual high susceptibility (MICs, less than or equal to 0.25 micrograms/ml) to the newer cephalosporins.
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PMID:Optimal cefotaxime dosing for gram-negative bacteremia: effective trough serum bactericidal titers and drug concentrations 8 and 12 hr after 1- or 2-gm infusions. 338 50

The in-vitro MICs and MBCs of ciprofloxacin, cefoperazone, ceftazidime, ceftriaxone, gentamicin and imipenem were measured for five strains each of Escherichia coli, Klebsiella pneumoniae and Pseudomonas aeruginosa with standard and high inocula. The MBC was raised more than the MIC at the higher inoculum for all the drugs except ciprofloxacin. However, the MBC of imipenem against P. aeruginosa was increased relatively little at the higher inoculum in contrast to the findings with other beta-lactam drugs. In a rabbit model of endophthalmitis both cefoperazone and imipenem were markedly more bactericidal against a high inoculum of K. pneumoniae than would have been predicted from the results of in-vitro time kill curve studies. We conclude that the therapeutic relevance of the inoculum effect remains to be proved.
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PMID:The inoculum effect with gram-negative bacteria in vitro and in vivo. 342 69

S-25930 and S-25932, two new 4-quinolones, were compared to ciprofloxacin, enoxacin, ofloxacin, norfloxacin, cefotaxime, gentamicin, trimethoprim, and ampicillin. S-25930 and S-25932 inhibited 90% of Enterobacteriaceae at less than or equal to 1 mg/l, usually differing only two-fold. The MIC90 for Pseudomonas aeruginosa was 8 mg/l for S-25930 and 16 mg/l for S-25932, compared to MICs of 1 to 8 for the other four quinolones. Both drugs inhibited Enterobacter cloacae, Serratia marcescens and Citrobacter freundii resistant to cefotaxime and Klebsiella species resistant to gentamicin and trimethoprim. The MICs90 were 0.125 and 0.25 mg/l against staphylococci, including methicillin-resistant Staphylococcus aureus and were superior to the MICs of other quinolones; activity against haemolytic streptococci at 1-2 mg/l was also superior. S-25930 and S-25932 showed rapid bactericidal activity at the MBC concentration and both agents showed post-antibiotic suppression of growth of bacteria. The agents were active in acid medium, but activity was reduced by magnesium at 9 mM. A stepwise increase in resistance was produced by serial passage in increasing concentrations of drug.
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PMID:In-vitro activity of two new quinolone antimicrobial agents, S-25930 and S-25932 compared with that of other agents. 357 Oct 42

Ten healthy volunteers received 1 g of BRL-36650, a new formamido-penicillin derivative, given by intravenous infusion over 15 min. Levels in serum were measured microbiologically 30, 60, and 120 min after the start of the 15-min infusion and were (mean +/- standard deviation) 102.7 +/- 28.4, 59.7 +/- 11.5, and 9.6 +/- 1.9 mg/liter, respectively. A total of 10 strains each of Escherichia coli, Klebsiella pneumoniae, Serratia spp., and Enterobacter spp. and 14 strains of Pseudomonas aeruginosa were selected according to their susceptibility or resistance to piperacillin for the study of serum bactericidal activity (SBA). The MICs and MBCs of these strains were influenced by the choice of medium. Median SBA against E. coli and K. pneumoniae were greater than or equal to 1:2,048 and 1:512, respectively. The SBA against piperacillin-susceptible Serratia spp. (1:256), Enterobacter spp. (1:128), and P. aeruginosa (1:32) were significantly higher than against piperacillin-resistant strains (1:32, 1:8, and 1:4, respectively). Killing curves confirmed the high bactericidal activities obtained against the majority of strains. In the case of one Enterobacter sp. and one P. aeruginosa isolate with an MBC greater than or equal to 32, the absence of killing was noted.
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PMID:BRL-36650: in vitro studies and assessment of serum bactericidal activity after single-dose administration in volunteers. 375 14

The in vitro activity of a quinolinecarboxylic acid compound, norfloxacin, was compared with those of amikacin, carbenicillin, cefazolin, cefoxitin, gentamicin, nalidixic acid, and oxolinic acid against 243 Gram-positive and Gram-negative amoxicillin-resistant (MIC 800 greater than or equal to micrograms/ml) uropathogenic isolates. Norfloxacin showed remarkable activity against the majority of the bacteria tested. Ninety percent of strains of Staphylococcus aureus, Streptococcus faecalis, Citrobacter freundii and Serratia spp. were inhibited by 3.12 micrograms/ml or less. Among the Gram-negative urinary isolates, only a few Enterobacter, Escherichia coli, Klebsiella, Proteus and Pseudomonas aeruginosa strains required norfloxacin levels between 12.5 and 25 micrograms/ml. The MBC was within one dilution of the MIC for 100% of the Gram-positive strains and 95% of the Gram-negative isolates against norfloxacin and aminoglycosides. Norfloxacin had a markedly higher inhibitory index than all other antimicrobial agents for Gram-positive cocci and Gram-negative bacteria. From its in vitro activity, norfloxacin appears to be a potentially valuable agent for the treatment of serious urinary tract infections.
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PMID:Study of the in vitro activity of norfloxacin and other drugs on amoxicillin-resistant uropathogenic isolates. 624 5

Pefloxacin is a new methyl-4-piperazinyl quinolone. It had MIC90 values of less than 0.01 to 0.8 micrograms/ml for the majority of Escherichia coli, Klebsiella, oxytoca, Citrobacter, Providencia, Enterobacter cloacae, Enterobacter aerogenes, Morganella and Proteus mirabilis. It inhibited ampicillin, cephalexin and nalidixic acid resistant isolates of these species. Against Pseudomonas the pefloxacin MIC90 was 3.1 micrograms/ml. Staphylococcus aureus had a MIC50 of 0.4 micrograms/ml and a MIC90 of 0.8 micrograms/ml and S. faecalis had a MIC90 of 3.1 micrograms/ml. Pefloxacin inhibited Salmonella spp., Salmonella typhi, Shigella spp., Yersinia, Aeromonas, toxigenic E. coli at concentrations of less than 0.05 to 1.6 micrograms/ml, including ampicillin and trimethoprim resistant strains. There was a minimal difference in MIC and MBC values in broth or serum, but major changes in MIC and MBC values occurred in acid urine. Increase in MIC values occurred with repeated transfer in broth or urine.
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PMID:In vitro activity of pefloxacin compared to that of quinolones and other antimicrobial agents. 624 47


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