Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0519030 (Klebsiella)
 21,988 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The in vitro effects of Bay k 4999 in combination with gentamicin, tobramycin, amikacin sisomicin and netilmicin in bacteriostatic (MIC) and bactericidal (MBC) concentrations were compared using the checkerboard dilution technique against 20 different strains of Pseudomonas aeruginosa, Escherichia coli, Klebsiella pneumoniae and indole-positive-negative Proteus species. On average 63% of Bay k 4999-aminoglycoside (AG) combinations inhibited Pseudomonas, Proteus and Klebsiella strains additively and/or synergistically in bacteriostatic as well as in bactericidal concentrations as compared to only 14% additive or synergistic activity on E. coli. 35% of the combinations tested proved to be synergistic in K. pneumoniae, 20% in Proteus, 13% in Pseudomonas, but only 5% in E. coli. No significant differences between various Bay k 4999-AG combination effects could be demonstrated.
 ...
PMID:In vitro efficacy of Bay k 4999, a new ureido-penicillin, in combination with aminoglycosides against Pseudomonas aeruginosa, Escherichia coli, Klebsiella pneumoniae and Proteus strains. 11 78

The antimicrobial activity of cefaclor, a new orally administered cephalosporin derivative, was studied in vitro against a variety of Gram-positive and Gram-negative clinical isolates. Both penicillin-resistant and penicillin-susceptible strains of Staphylococcus aureus were susceptible to cefaclor, with mean MICs of 1.44 and 0.93 microgram/ml, respectively. However, the MBC for penicillin-resistant S. aureus was higher than that for the penicillin-susceptible strains. All strains of Streptococcus pyogenes, Streptococcus viridans, and Streptococcus pneumoniae tested were highly susceptible to cefaclor; all strains of Streptococcus faecalis were highly resistant to cefaclor. Strains of Escherichia coli, Klebsiella sp., Proteus mirabilis, and Hemophilus influenzae were susceptible to cefaclor. Eighty per cent of strains of H. influenzae were inhibited by 5 micrograms/ml of cefaclor. Most strains of Enterobacter sp., indole-positive Proteus, Pseudomonas sp., and Serratia sp. were resistant to cefaclor.
 ...
PMID:Antimicrobial activity in vitro of cefaclor, a new oral cephalosporin. 62 78

The in-vitro activity of two new quinolone antimicrobials, rufloxacin and MF 961, together with the desmethylated metabolite of rufloxacin (MF 922) were compared with other orally administered agents against 622 bacterial strains. Against Enterobacteriaceae and Pseudomonas aeruginosa rufloxacin was generally active (MIC90 1-8 mg/L) with the exception of Klebsiella and Serratia spp. (MIC90 32 mg/L and Enterobacter spp. (MIC90) 64 mg/L. The respiratory pathogens Haemophilus influenzae and Moraxella catarrhalis were susceptible to rufloxacin (MIC90 0.5 and 1 mg/L respectively) but Streptococcus pneumoniae was less susceptible (MIC90 32 mg/L). Staphylococcus aureus were susceptible to rufloxacin (MIC90 2 mg/L). The rufloxacin metabolite MF 922 was generally as active as its parent. MF 961 was usually two-fold more active than rufloxacin. All three compounds were four to 16 times less active than norfloxacin, but rufloxacin was as active or somewhat more active than norfloxacin against Staphylococcus spp. Any strains showing decreased susceptibility to other quinolones exhibited cross resistance to these new agents. The MBC of rufloxacin and MF 922 was within one dilution of the MIC and human serum had little effect upon the activity of both agents. The protein binding of rufloxacin and MF 922 at 1 and 10 mg/L were 55% and 63.8% and 30.3% and 32.6% respectively. The activity of rufloxacin against four strains of Chlamydia trachomatis and one strain of Chlamydia pneumoniae was determined. The MICs for C. trachomatis were 4-8 mg/L and 4 mg/L for C. pneumoniae.
 ...
PMID:The in-vitro activity of two new quinolones: rufloxacin and MF 961. 132 39

The efficacy of tazobactam, a beta-lactamase inhibitor, in combination with piperacillin, was studied in vitro and in rabbit experimental endocarditis due to a Klebsiella pneumoniae strain (KpR) producing an extended-spectrum beta-lactamase, TEM-3, or its nonproducing variant (KpS). In vitro, piperacillin was active against KpS (MIC = 4 micrograms/ml, MBC = 8 micrograms/ml with 10(7)-CFU/ml inoculum) but not against KpR (MIC = MBC = 256 micrograms/ml). Tazobactam (1 microgram/ml) restored the activity of piperacillin against KpR (MIC = 2 micrograms/ml, MBC = 4 micrograms/ml). Gentamicin was active against both strains (MIC = 0.25 and 0.5 micrograms/ml for KpS and KpR, respectively). The piperacillin-tazobactam-gentamicin combination was synergistic in vitro. The piperacillin/tazobactam ratio in plasma and in vegetations was always lower than the 4/1 injected dose ratio. In vivo, piperacillin (300 mg/kg of body weight four times a day [QID]) was active against KpS but not against KpR. Tazobactam (75 mg/kg QID) was able to restore the in vivo effect of piperacillin (300 mg/kg QID) against KpR (-3.0 log10 CFU/g of vegetation versus that of controls). Gentamicin (4 mg/kg twice a day [BID]) was active against both strains. Compared with controls, the combination of gentamicin plus piperacillin against KpS (-5.6 log10 CFU/g of vegetation), and the gentamicin-piperacillin-tazobactam combination against KpR (-4.4 log10 CFU/g of vegetation) achieved the greatest decrease in bacterial counts in vegetations and were the only regimens that significantly increased the proportion of sterile vegetations. It is concluded that (i) tazobactam was able to restore the effect of piperacillin against a TEM-3 extended-spectrum Beta-lactamase-producing strain of K. pneumoniae, both in vitro and in a severe experimental infection with high inoculum, when used in a 4/1 piperacillin/tazobactam dose ratio; (ii) gentamicin alone was effective because of the high peak/MBC ratio in plasma; (iii) piperacillin-tazobactam-gentamicin, probably because of the effect of gentamicin in reducing bacterial inoculum in vivo, as stressed by the results obtained by piperacillin-gentamicin against KpS, may be the most effective regimen against KpR.
 ...
PMID:Piperacillin, tazobactam, and gentamicin alone or combined in an endocarditis model of infection by a TEM-3-producing strain of Klebsiella pneumoniae or its susceptible variant. 132 34

The ability of brobactam to inhibit beta-lactamases and the in vitro activity of ampicillin combined with brobactam was compared with another beta-lactamase inhibitor, clavulanic acid, and other beta-lactam antibiotics. Both inhibitors showed good and similar activity against staphylococcal penicillinase and most broad-spectrum beta-lactamases found in the Enterobacteriaceae, whether plasmid or chromosomally mediated. Both inhibitors were less active against chromosomally mediated cephalosporinases in Enterobacteriaceae, but brobactam was 8-50 times more potent than clavulanic acid. The amount and type of beta-lactamase produced by a particular bacterial strain was reflected in its sensitivity to a combination of ampicillin and brobactam, and correlated well with the sensitivity of extracted beta-lactamase to inhibition by brobactam. The in-vitro activity of ampicillin/brobactam in a 3:1 ratio was compared to amoxycillin/clavulanic acid (4:1 ratio), amoxycillin, cefaclor and cefuroxime. The two inhibitor combinations were generally of similar activity, but the brobactam combination had superior activity against Proteus vulgaris, Morganella morganii, Citrobacter freundii and Yersinia enterocolitica. The cephalosporins were less effective against the Bacteroides fragilis group, Prot. vulgaris and M. morganii, but had advantages in the case of Escherichia coli, Klebsiella spp. and C. diversus. The MBC of ampicillin/brobactam was similar to the MIC. No resistant sub-populations were observed amongst the staphylococcal strains investigated. Exposure of bacteria to sub-inhibitory levels of ampicillin/brobactam did not lead generally to the development of resistance.
 ...
PMID:In-vitro evaluation of ampicillin/brobactam and comparison with other beta-lactam antibiotics. 164 79

We studied the activity of the combination of sulbactam and ceftriaxone against a Klebsiella pneumoniae strain producing TEM-3, a new extended-broad-spectrum beta-lactamase, in an endocarditis model. In vitro, ceftriaxone was strongly inactivated in the presence of TEM-3 (MBC, 128 micrograms/ml with an inoculum of 5 x 10(5) CFU/ml). A marked inoculum effect was demonstrated with sulbactam: effective concentrations of inhibitor needed to reduce the MIC and MBC of ceftriaxone to similar levels increased from 1 microgram/ml in the presence of an inoculum of 5 x 10(5) CFU/ml to 20 micrograms/ml in the presence of an inoculum of 1 x 10(7) CFU/ml. In vivo, sulbactam given at 200 mg/kg of body weight every 12 h, a dosage higher than that previously reported to be effective against rabbit endocarditis caused by other microorganisms, was not sufficient to restore the complete activity of ceftriaxone given at 30 mg/kg once daily for 4 days. This insufficient activity may be correlated with the presence of a high level of beta-lactamase inside the vegetations, as indicated by a quantitative in vitro assay of beta-lactamase activity in the cardiac vegetation, suggesting an insufficient inactivation of the extended-broad-spectrum beta-lactamase in vivo.
 ...
PMID:Ceftriaxone-sulbactam combination in rabbit endocarditis caused by a strain of Klebsiella pneumoniae producing extended-broad-spectrum TEM-3 beta-lactamase. 207 99

Sixteen patients with acute meningitis caused by Gram-negative bacteria were treated with pefloxacin intravenously. The age range of the patient group was six months to 85 years with a mean age of 40 years; three patients were children. In all but two patients meningitis was a complication of neurosurgical operations and fourteen of the sixteen had received prior therapy which was not successful. The causative organisms were: Pseudomonas aeruginosa (5), Acinetobacter calcoaceticus (4), Klebsiella pneumoniae (3), Enterobacter cloacae (2), Citrobacter diversus (1) and Salmonella group C (1). Pefloxacin was administered intravenously 800 mg twice a day to the adult patients (mean dosage of 21( +/- 6.7) mg/kg body weight) for a mean period ( +/- S.D.) of 11( +/- 4) days. The mean cerebrospinal fluid concentration of pefloxacin was 8.8( +/- 5.0) mg/l which was 54% of the mean peak serum concentration (16.3( +/- 8.8]. The mean MIC and MBC of the causative organisms were 1.1( +/- 1.2) mg/l and 1.64( +/- 1.2) mg/l. Thirteen patients (87%) were cured or clinically improved and twelve (80%) were bacteriologically cured. One patient failed, another patient had reinfection and one was not assessable. No side effects were observed. In the present study pefloxacin offered an efficacious and safe treatment of Gram-negative meningitis following failure of other antibiotic therapy.
 ...
PMID:Pefloxacin efficacy in gram-negative bacillary meningitis. 225 48

Isolates of Staphylococcus aureus, Streptococcus pneumoniae, Haemophilus influenzae and Klebsiella pneumoniae were tested for their bactericidal activity and postantibiotic effect (PAE) with the new penem FCE 22101. The tissue cage model in rabbits was used to study PAE in vivo. The bactericidal activity against all four species was shown to be in the range of 0.05-4.0 mg/l. A 99.9% killing effect at MBC concentrations was reached within 2 hours with S. pneumoniae and K. pneumoniae and within 6-8 hours with S. aureus and H. influenzae. After in vitro exposure by FCE 22101 a PAE in vitro and in vivo was obtained against S. aureus, S. pneumoniae and H. influenzae strains but no PAE could be demonstrated against K. pneumoniae. FCE 22101 showed a good bactericidal activity and PAE against the strains investigated, except for K. pneumoniae.
 ...
PMID:Postantibiotic effect of the penem FCE 22101 against selected gram-positive and gram-negative bacteria in vitro and in vivo by the use of a tissue cage model in rabbits. 231 48

The impact of the dosage schedule on the therapeutic efficacy of antibiotics was investigated in experimental Klebsiella pneumoniae pneumonia and septicemia in leukopenic rats. The daily doses (mg/kg) that protected 50% of the animals from death, when calculated for administration at 6 h intervals or by continuous infusion, were as follows: ceftazidime 24.4 and 1.5 (p less than 0.001), gentamicin 2.8 and 3.8 (p greater than 0.05), and ciprofloxacin 3.3 and 6.5 (p less than 0.05), respectively. This correlates with the observation that ceftazidime killed Klebsiella pneumoniae slowly but constantly, and relatively independently of concentration, whereas killing by gentamicin or ciprofloxacin was rapid, and markedly dependent on antibiotic concentration. Exposure of bacteria for 1 h to concentrations of fivefold the MBC did not give rise to a postantibiotic effect for any of the drugs. In our model ceftazidime was far more effective when given continuously than when administered at 6 h intervals. On the other hand, the activity of gentamicin was not influenced by the mode of administration, whereas ciprofloxacin was slightly more effective when given intermittently. However, to avoid misleading conclusions regarding the use of antibiotics in humans, the pharmacokinetic differences between rats and man must be considered when interpreting these results.
 ...
PMID:Impact of the dosage schedule on the efficacy of ceftazidime, gentamicin and ciprofloxacin in Klebsiella pneumoniae pneumonia and septicemia in leukopenic rats. 251 32

Cefixime (CFM) is a new hemi-synthetic orally active cephalosporin which exhibits a particular affinity for PBPs 3, 1a, 1bs. Its penetration through the Gram negative bacilli outer membrane is similar to that of third generation cephalosporins. The MICs were assessed by the agar dilution method against 2,489 bacterial strains collected in 10 hospitals. Against Enterobacteriaceae, MICs50 and 90 are respectively (mg/l): naturally non beta-lactamase-producing species: E. coli and Shigella: 0.25-0.5, Salmonella: 0.06 - 0.25, P. mirabilis: 0.008 - 0.0.32; chromosomal penicillinase producing species: Klebsiella: 0.06 - 2; chromosomal cephalosporinase producing species: E. cloacae and C. freundii: 1 - greater than 128, S. marcescens: 0.25 - 16, Proteus indole: + 0.06 - 4, P. stuartii: 0.032 - 0.5. CFM activity is not altered in strains producing an acquired penicillinase. On the other hand, CFM appears to be inactive against cephalosporinase hyperproducing mutants and its activity is variably decreased against expanded spectrum beta-lactamase producing strains. CFM is inactive against P. aeruginosa (MIC50 and 90: 64 - 128) and against A. baumannii (16 - 128). Haemophilus and gonococci, beta-lactamase producing or not, as well as meningococci, are highly susceptible to CFM (MIC 0.008 - 0.12). B. catarrhalis is usually inhibited by 0.03 to 0.5. CFM is moderately active against meticillin-sensitive staphylococci (MIC50 and 90: 1-64), and inactive against meticillin-resistant strains. Enterococci are usually resistant, whereas streptococci and pneumococci are inhibited by low concentrations: 0.08 to 1. CFM is a bactericidal antibiotic, as shown by MBC and killing curves determination. These antibacterial properties relate CFM to the third generation cephalosporins and position the compound in an excellent place among the orally active cephalosporins.
 ...
PMID:[Antibacterial effect of cefixime]. 253 May 28


1 2 3 4 5 6 7 8 Next >>