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

BMY-28232, an aminothiazolyl imino methoxy cephalosporin which is available as an orally absorbed acetoxyethyl ester, inhibited strains of methicillin-susceptible Staphylococcus aureus, hemolytic streptococci, Streptococcus pneumoniae, Escherichia coli, Klebsiella species, and many strains of Proteus and Providencia stuartii at concentrations less than 1 microgram/ml, including isolates resistant to cephalexin and cefaclor. It had activity similar to that of cefixime, but was more active against methicillin-susceptible staphylococci. BMY-28232 was a poor substrate for beta-lactamases but was destroyed by the new TEM-3 enzyme, and had less activity against Enterobacter species, Citrobacter freundii, and Proteus vulgaris isolates. Methicillin-resistant staphylococci, Pseudomonas species, enterococci, Listeria monocytogenes, Corynebacterium jeikeium, Bacteroides fragilus and some strains of Clostridium species were resistant to BMY-28232.
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PMID:Antimicrobial activity and beta-lactamase stability of BMY-28232, parent compound of an oral cephalosporin. 208 21

Extended-broad-spectrum beta-lactamase TEM-9, detected in a clinical isolate of Klebsiella pneumoniae, confers high-level resistance to recent cephalosporins, in particular ceftazidime, and to the monobactam aztreonam. Using oligonucleotide probes, we found that the plasmid gene blaT-9 encoding TEM-9 differs from characterized blaT genes by a new combination of already known mutations. Gene blaT-9 was further studied by direct sequencing of an amplified 1.1-kb DNA fragment which contained the open reading frame and its promoter. Analysis of the nucleotide and of the deduced amino acid sequence confirmed the hybridization results and indicated that TEM-9 differs from TEM-1 by four amino acid substitutions: Phe at position 19 and Met at position 261, which have been found in TEM-4 and are known not to expand the enzyme substrate range; Lys 102, detected in TEM-3 and TEM-4, and Ser 162, present in TEM-5 and TEM-7. Each of the latter substitutions enlarges the substrate spectrum of the enzymes and they are found associated for the first time in TEM-9.
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PMID:Direct sequencing of the amplified structural gene and promoter for the extended-broad-spectrum beta-lactamase TEM-9 (RHH-1) of Klebsiella pneumoniae. 216 46

The effectiveness of a combination of the recently developed penam sulphone tazobactam with piperacillin was studied in clinical isolates with defined beta-lactamase production. The combination was highly effective against piperacillin-resistant beta-lactamase-producing Staphylococcus aureus, TEM-1-producing Escherichia coli and Proteus vulgaris isolates. It was less effective against E. coli isolates producing the OXA-1 enzyme and marginally active against TEM-1-producing Klebsiella spp. isolates. The presence of tazobactam at a concentration of 10 mg/l markedly reduced the minimal inhibitory concentrations for piperacillin in most of the beta-lactamase-derepressed Enterobacter cloacae, Serratia marcescens and Citrobacter freundii isolates; however, this synergism was much less pronounced in beta-lactamase-derepressed Klebsiella spp. isolates. The selection frequency of resistant clones from clinical E. cloacae and C. freundii isolates could be markedly reduced by the addition of 10 mg/l tazobactam to the piperacillin-containing selective medium. Resistant clones could be obtained only from part of the wild-type strains at 2 or 4 times the MIC of piperacillin in the presence of tazobactam, whereas resistant clones could be selected up to 64 times the MIC of piperacillin without the addition of tazobactam. This aspect deserves attention with respect to the rapid selection of beta-lactamase-derepressed clones from nosocomial pathogens.
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PMID:Antibacterial activity of piperacillin and tazobactam against beta-lactamase-producing clinical isolates. 217 81

New plasmidic beta-lactamases inactivating so far stable cephalosporins, aztreonam and cephamycins restrict the use of these antibiotics in therapy of infections, e.g., by Escherichia coli and Klebsiella. Thus, combinations of beta-lactamase inhibitors and beta-lactam antibiotics were investigated in vitro with regard to their therapeutic perspectives. Minimal inhibitory concentrations and the kinetics of killing in a pharmacodynamic model were determined. Extended broad spectrum beta-lactamases (EBS-beta-lactamases) representative both for the TEM- and SHV-type were included. None of the available fixed combinations of penicillins and beta-lactamase inhibitors appears useful for therapy of infections caused by producers of EBS-beta-lactamases. In contrast, combinations of piperacillin and tazobactam or sulbactam plus cephalosporins (cefoperazone, cefotaxime, ceftazidime) or aztreonam are highly active (both by their MICs and bactericidal activity) against TEM-type EBS-beta-lactamases, but less promising for the SHV-type EBS-beta-lactamases, and plasmidic cephamycinase. Of the beta-lactams available, the monobactam carumonam and the carbapenems (imipenem, meropenem) remain safe in infections caused by E. coli and Klebsiella EBSBase producers.
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PMID:Perspectives of beta-lactamases inhibitors in therapy of infections caused by Escherichia coli or Klebsiella with plasmidic resistance to third generation cephalosporins. 217 38

A strain of Klebsiella oxytoca, originally isolated in Liverpool in 1982, has been found to produce a novel transferable beta-lactamase, TEM-E2. This enzyme confers resistance to ceftazidime and focused as a doublet band with an iso-electric point (pI) of 5.3. The strain also produced the TEM-1 beta-lactamase. Both TEM-1 and TEM-E2 beta-lactamases were encoded by a transferable 103 kb plasmid; these two enzymes also had similar molecular weights, were inhibited by clavulanic acid, and hydrolysed ampicillin, carbenicillin and cephaloridine at similar rates. However, unlike the TEM-1 enzyme, the TEM-E2 beta-lactamase hydrolysed ceftazidime and cefotaxime with similar efficiency, although it conferred much greater resistance to ceftazidime in the host strain. This is the earliest documented example of a TEM-like enzyme which confers transferable resistance to ceftazidime and related cephalosporins.
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PMID:Characterisation of a unique ceftazidime-hydrolysing beta-lactamase, TEM-E2. 219 63

The enzymatic and plasmid-encoded resistance towards oxyimino-beta-lactams has been recently reported as related to the production of an extended-spectrum beta-lactamase (e.g. SHV-2, CTX-1 or TEM-3), in particular in our hospital since 1984. The prevalence of that resistance has been examined from January 1984 to December 1988 in function of specimen, unit and type of enzyme among 8,421 isolates of Klebsiella spp., E. coli, Salmonella spp. Each isolate showing a diameter of inhibition zone size inferior or equal to 25 mm for cefotaxime, the double disk synergy test was performed between a disk of amoxicillin and a clavulanic acid disk of cefotaxime, ceftriaxone, ceftazidime and aztreonam. In case of synergy, sonicated extracts have been prepared and examined by isoelectrofocusing with the detection of beta-lactamase activity by ceftriaxone and nitrocefin. 56 isolates (K. pneumoniae, K. oxytoca, E. coli, S. wien, S. typhimurium scored positive including 27 in pediatrics, 18 in surgery, and 8 in medicine. 41% of isolates have been obtained from blood cultures and 26.8% from urines. A majority of isolates (49/56) produced the SHV-2 type, but other types mediating the resistance phenotype CTX have been individualized initially by their isoelectric points e.g. 5.4 (TEM-20 in K. pneumoniae in July 1986), 6.4 (TEM-21 in E. coli, 1 K. pneumoniae in July 1988). The prevalence of resistance to cefotaxime from 1984 to 1988 has increased (from 0.3 to 1.4%), the highest rate being observed in pediatrics (5.6% in 1984 and 22.1% in 1988).
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PMID:[Enzymatic resistance to cefotaxime in 56 strains of Klebsiella spp., Escherichia coli and Salmonella spp. at a Tunisian hospital (1984-1988)]. 219 57

A multiple trauma patient failed treatment with ceftazidime and amikacin for bacteremia and meningitis due to a Klebsiella pneumoniae strain that produced a novel, plasmid-mediated beta-lactamase. Both pre- and posttreatment isolates were resistant to ceftazidime (MIC, greater than or equal to 64 micrograms/ml) and various penicillins but not to other expanded-spectrum cephalosporins. The beta-lactamase had a pI of 5.25 and was encoded on a conjugal plasmid of approximately 150 kilobases. DNA hybridization studies indicated that the enzyme was a TEM derivative.
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PMID:Failure of ceftazidime-amikacin therapy for bacteremia and meningitis due to Klebsiella pneumoniae producing an extended-spectrum beta-lactamase. 220 6

We have devised a reliable procedure for the separation of three beta-lactamases of isoelectric focusing points (pI), 5.4, 6.5, and 7.9 by Fast Protein Liquid Chromatography (FPLC System). All of these enzymes were transferable and originated from a ceftazidime and cefotaxime resistant Klebsiella pneumoniae isolated in Bombay, India. The complete separation of the enzymes, achievable by this method, allowed each of the different individual beta-lactamases to be characterized biochemically. This analysis revealed that the enzymes of pI 6.5 and pI 7.9 hydrolysed ceftazidime and cefotaxime, and were responsible for the resistance of K. pneumoniae, and its Escherichia coli J53-2 transconjugant to third generation cephalosporins. The enzyme of pI 5.4 was the TEM-1 beta-lactamase. The beta-lactamase of pI 7.9 appears quite different from any previously reported third generation cephalosporin hydrolysing beta-lactamase, and consequently given the preliminary designation DJP-1. This is also the first example of extended spectrum hydrolysing beta-lactamases found in Asia.
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PMID:Separation of plasmid-mediated extended spectrum beta-lactamases by fast protein liquid chromatography (FPLC system). 221 Mar 30

The antibacterial activity of cefpodoxime proxetil was studied in an in-vitro model simulating doses of 100, 200 and 400 mg. Strains of Klebsiella spp. Proteus mirabilis, Escherichia coli, Streptococcus pyogenes, and Haemophilus influenzae were effectively reduced by a dose of 200 mg. While for Esch. coli no dose-activity relationship was observed--the maximal effect was achieved with a simulated dose of 100 mg--Staphylococcus aureus could be reduced effectively only by a simulated dose of 400 mg. The lower doses showed stepwise lower activities. Apart from broad spectrum beta-lactamases like SHV 2 or TEM 5 the presence of plasmid coded beta-lactamases in Esch. coli and H. influenzae did not affect the antibacterial activity of cefpodoxime proxetil. The results show that cefpodoxime was more active against Gram-negative bacteria than amoxycillin, and comparable activity to intramuscular cefotiam in the in-vitro model.
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PMID:Antibacterial activity of cefpodoxime proxetil in a pharmacokinetic in-vitro model. 221 49

The activity of the new oral cephalosporin Bay v 3522 was compared to that of six other beta-lactam agents. Bay v 3522 inhibited methicillin-susceptible Staphylococcus aureus and Staphylococcus epidermidis at less than or equal to 2 micrograms/ml, compared to MICs of greater than or equal to 8 micrograms/ml for the other cephalosporins tested. It was more active against Streptococcus pyogenes (MIC less than or equal to 0.06 microgram/ml) than cefuroxime, cefixime, cephalexin and cefaclor. Groups B, C and G streptococci were inhibited at less than or equal to 0.12 microgram/ml, while the MI"90 for Streptococcus bovis and viridans streptococci was 0.5 and 2 micrograms/ml, respectively. The MIC90 for enterococci and Listeria monocytogenes was 8 micrograms/ml. Clostridium perfringens was inhibited by 0.12 microgram/ml, but most Bacteroides spp. were resistant. The MIC90 for beta-lactamase positive Escherichia coli (producing primarily TEM-1) was greater than 64 micrograms/ml and for beta-lactamase negative strains 16 micrograms/ml. The MIC90 for high-level beta-lactamase producing Klebsiella pneumoniae was greater than 64 micrograms/ml versus 4 micrograms/ml for other isolates. The MIC90 for Moraxella catarrhalis was 2 micrograms/ml, for Haemophilus influenzae 1 micrograms/ml, and for Neisseria gonorrhoeae 4 micrograms/ml. Enterobacter cloacae, Citrobacter freundii, Proteus mirabilis, Providencia spp. and Pseudomonas aeruginosa were resistant. Bay v 3522 was destroyed by TEM-1, SHV-1, TEM-3 and P99 beta-lactamases.
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PMID:In vitro activity and beta-lactamase stability of the new oral cephalosporin Bay v 3522. 222 99


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