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 activity of cefbuperazone, a 7 alpha-methoxy ureido cephalosporin, was determined against 726 clinical isolates. Ninety percent of Escherichia coli, Klebsiella pneumoniae, Klebsiella oxytoca, Citrobacter diversus, Proteus mirabilis, Enterobacter aerogenes, Proteus vulgaris, Morganella morganii, Salmonella, and Shigella species were inhibited by less than or equal to 6.3 micrograms/ml. Cefbuperazone was more active than cefamandole, cefoxitin and piperacillin against these species. Concentrations of 25 micrograms/ml of cefbuperazone were needed to inhibit Serratia marcescens and Providencia species, and 50% of Enterobacter cloacae had MICs greater than 25 micrograms/ml. Cefbuperazone was less active by 8 to 32-fold than cefotaxime or moxalactam against most Enterobacteriaceae. Cefbuperazone did not inhibit Acinetobacter or Pseudomonas species. Hemolytic streptococci were inhibited by 12.5 micrograms/ml and staphylococci by 25 micrograms/ml. Cefbuperazone had activity comparable to cefoxitin and moxalactam against Bacteroides fragilis with MIC90s of 6.3 micrograms/ml. Cefbuperazone was not hydrolyzed by plasmid or chromosomal beta-lactamases and was an inhibitor of the P99 E. cloacae beta-lactamase with an I50 of 1 microgram/ml. It was a less effective inhibitor of the K. oxytoca K1 and E. coli TEM-1 beta-lactamases than was clavulanic acid. Cefbuperazone induced beta-lactamases in P. aeruginosa and resistant E. cloacae. A permeability barrier in E. cloacae, C. freundii and P. aeruginosa is suggested by the potentiation of cefbuperazone's activity by EDTA.
 ...
PMID:The activity of cefbuperazone, a 7 alpha-methoxy 7 beta acyl ureido cephalosporin. 387 64

Of nine hundred ampicillin resistant (Amp-R) enterobacteria strains, isolated in hospital between July and December 1981, 73,7% are also carbenicillin-resistant (Carb-R). This particular double resistance varies depending upon the species considered: indole positive Proteus (23%), Enterobacter cloacae (64%), Citrobacter freundii (67%), Acinetobacter calcoaceticus (73%), Proteus mirabilis (75%), Serratia marcescens (90%), Escherichia coli (91%), Providencia stuartii (96%) and Klebsiella pneumoniae (100%). The biochemical and genetic basis of resistance to beta-lactamines was studied in 27 strains belonging to these 9 species. A constitutive beta-lactamase was found in all the strains. These enzymes were identified by determination of the isoelectric point on crude sonic extracts, the enzymic activity profile, the inhibition by clavulanic acid and cloxacillin of enzyme activity. Two types of enzymes were predominant: TEM-1 (20 strains) and TEM-2 (7 strains); two strains of Klebsiella pneumoniae produced both SHV-1 and TEM-1. The transfer by conjugation to E. coli K12 of ampicillin and carbenicillin resistance was obtained with 14 strains: (E. coli: 9, C. freundii: 1, K. pneumoniae: 1, E. cloacae: 2, P. stuartii: 1). In all strains but one E. coli we noted the co-transfer of other antibiotic resistance markers.
 ...
PMID:[Carbenicillin resistance of gram-negative bacteria: incidence, biochemical and genetic determinism]. 390 20

Resistance of bacteria to beta-lactam antibiotics has become a serious problem in the past several decades. Virtually all Staphylococcus aureus, and many Hemophilus influenzae, Branhamella catarrhalis, Neisseria gonorrhoeae, Enterobacteriaceae, and Bacteroides species possess beta-lactamases that hydrolyze penicillins and cephalosporins. The most common plasmid-mediated beta-lactamase is the TEM enzyme (Richmond-Sykes type IIIa), which is present in Hemophilus, Neisseria, and Enterobacteriaceae. One technique to overcome bacterial resistance has been the development of beta-lactamase inhibitors. Clavulanic acid is a beta-lactamase inhibitor that inhibits the beta-lactamases of S. aureus, Hemophilus, Neisseria, Branhamella, Eschericia coli, Klebsiella, and Bacteroides. Clavulanate acts as a "suicide" inhibitor, forming a stable enzyme complex that binds to serine at the active site of the enzyme. Clavulanate readily crosses the outer cell wall of most Enterobacteriaceae to interact with beta-lactamases in the periplasmic space. Clavulanate does not inhibit beta-lactamases such as the Richmond-Sykes type I enzymes found in Pseudomonas aeruginosa, Enterobacter, and Citrobacter species, which are inducible enzymes that function primarily as cephalosporinases.
 ...
PMID:Contribution of beta-lactamases to bacterial resistance and mechanisms to inhibit beta-lactamases. 390 41

Transfer of Cefamandole resistance was demonstrated from strains of Citrobacter freundii as well as from individual strains of Enterobacter cloacae, Acinetobacter anitratus and Klebsiella pneumoniae isolated from patients in two newborn units. In Citrobacter freundii, Cefamandole resistance was transferred always with Cephalotin resistance as well as with a TEM-like beta lactamase (conferring resistance to Ampicillin, Carbenicillin and Azlocillin). Citrobacter freundii strains from Hospital I were completely susceptible to gentamicin, while strains of other species, resistant to Cefamandole plus Cephalotin, were resistant to Gentamicin as well, and transferred this resistance, too. In one Enterobacter cloacae strain from Hospital I, Cefamandole resistance could be separated from resistance to Cephalotin, but only in clones selected with gentamicin and not with any of the cephalosporins. Acinetobacter anitratus strain was also resistant to Cefotaxime, but did not transfer this resistance. It might be concluded that special nosocomial bacteria may carry plasmids conferring a transferable type of resistance to Cefamandole together with resistance to classical cephalosporines. Second cycle of transfers, i.e. between two variants of E. coli K-12 strains confirmed the contransferability of Cefamandole and Cephalotin resistance.
 ...
PMID:Cefamandole resistance transfer in bacterial strains from two newborn units. 391 Jul 23

The in vitro activity of cefpirome, a new cyclopyridinium cephalosporin, was evaluated against 947 aerobic and anaerobic bacteria. Cefpirome inhibited 90% of Escherichia coli, Klebsiella spp., Citrobacter diversus, Morganella morganii, Proteus vulgaris, Proteus mirabilis, Aeromonas spp., Salmonella spp., Shigella spp. and Haemophilus and Neisseria species at less than or equal to 0.4 mg/l. It had activity comparable to that of cefotaxime, ceftizoxime, ceftazidime, aztreonam, and moxalactam against these species. Only a few Citrobacter freundii, Enterobacter spp. and Serratia marcescens had MICs above 3.1 mg/l. The activity of cefpirome against Pseudomonas aeruginosa, 90% MIC of 12.5 mg/l, was superior to piperacillin, moxalactam, cefotaxime and cefoperazone. The 90% MIC against Staphylococcus aureus was 0.8 mg/l, but methicillin-resistant staphylococci were not inhibited. Cefpirome was not significantly hydrolyzed by most plasmid beta-lactamases (TEM, SHV-1, PSE, OXA) nor by chromosomal enzymes (P99, Branhamella catarrhalis, K1). Cefpirome did not inhibit chromosomal or plasmid beta-lactamases. Mice systemically infected with E. coli, Klebsiella pneumoniae, P. aeruginosa and S. aureus were protected by concentrations of cefpirome ranging from 0.85 mg/kg for K. pneumoniae to 4.467 mg/kg for P. aeruginosa.
 ...
PMID:The in vitro activity and beta-lactamase stability of cefpirome (HR 810), a pyridine cephalosporin agent active against staphylococci, Enterobacteriaceae and Pseudomonas aeruginosa. 392 97

1. The beta-lactamases specified by Klebsiella aerogenes 418 and the R-factor R-7268 have been partially purified. 2. The molecular weights of the K. aerogenes strains 418 and 373, Aerobacter cloacae 53, R-7268 and R-TEM beta-lactamases were all about 20000; that of the enzymes from Escherichia coli strains 419 and 214T was about 31000. 3. These enzymes were also compared by means of their K(m) values for benzylpenicillin and ampicillin, and their behaviour on starch-gel electrophoresis. 4. The beta-lactamases specified by the two Klebsiella strains, the Aerobacter strain, and the R-factors R-TEM and R-7268 were found to comprise a broadly similar group. However, within this group, only two enzymes seemed to be identical, namely those specified by the two R-factors. The two E. coli strains produce identical beta-lactamases which are very different from the ;Klebsiella/Aerobacter-type' enzymes.
 ...
PMID:Some relationships between R-factor and chromosomal -lactamase in Gram-negative bacteria. 494 48

1. The penicillinase (beta-lactamase) from Escherichia coli strain TEM has been purified and its activity against a range of penicillin and cephalosporin derivatives measured. 2. The enzyme shows little resemblance to penicillinases from Bacillus cereus, Bacillus licheniformis and Staphylococcus aureus. 3. The molecular weight of the enzyme is 16700+/-5%, which is about half the value obtained for other penicillinases. 4. The enzyme is most similar in properties to a crude preparation of a penicillinase from Klebsiella (Aerobacter) aerogenes, but clearly different from crude enzyme preparations from other strains of E. coli. 5. Since penicillinase synthesis in E. coli strain TEM is mediated by an R-factor known to infect many other species of Enterobacteriaceae, the appearance of similar enzymes in other Gramnegative species is not surprising.
 ...
PMID:The purification and properties of a penicillinase whose synthesis is mediated by an R-factor in Escherichia coli. 532 67

The sizes of the zones of inhibition around routinely tested antibiotic disks classified gentamicin-resistant isolates of Klebsiella pneumoniae from one hospital into four major antibiotype classes. From each isolate of the prevalent class (A1), two plasmids could be transferred conjugally. One carried genes for resistance to tetracycline, sulfonamides, and chloramphenicol, and for the SHV beta lactamase. The other carried genes for two aminoglycoside-inactivating enzymes, APH (3')-I and AAC (3)-III, for the TEM 1 beta lactamase, and for resistance to sulfonamides. Transconjugants of either plasmid from any A1 isolate yielded the same DNA fragments after restriction endonuclease digestion, but the two plasmids had no fragments in common. Fragments or genes from either plasmid were variously combined or lacking in plasmids from variant isolates (A2, A3, and A4). Plasmids transferable from isolates of classes B and C shared no common DNA restriction fragments with each other or with either plasmid from Class A. Fragments and genes of the plasmids from C isolates, however, were identical with those of a plasmid endemic in a nearby hospital. Routine monitoring by diagnostic microbiology laboratories of distinctive antibiotypes and of the plasmids that produce them would aid infection control and antibiotic usage policy.
 ...
PMID:Diagnostic microbiology laboratory susceptibility test results discriminate distinctive antibiotic resistance plasmids. 609 87

The activity of cefmenoxime, an aminothiazolyl cephalosporin, was studied against 650 bacteria. It was slightly less active than cefotaxime and more active than moxalactam against staphylococci. It had activity similar to that of cefotaxime and ceftizoxime against group A and B streptococci and Streptococcus pneumoniae. It did not inhibit Streptococcus faecalis or Listeria spp. Cefmenoxime had activity similar to that of cefotaxime, ceftizoxime, ceftazidime, and moxalactam against Escherichia coli, Citrobacter diversus, Klebsiella, Proteus mirabilis, Salmonella, and Shigella. It inhibited beta-lactamase-positive and -negative isolates at less than or equal to 0.4 microgram/ml. Cefmenoxime was somewhat less active than moxalactam or ceftizoxime against Enterobacter cloacae, Enterobacter aerogenes, and Enterobacter agglomerans, but was more active than cefotaxime, ceftizoxime, or ceftazidime against Morganella (minimum inhibitory concentration for 90% of isolates, 0.1 microgram/ml.), Proteus vulgaris and Providencia spp. It was as active as ceftizoxime was against Serratia. Pseudomonas spp. and Bacteroides spp. were relatively resistant (minimum inhibitory concentration for 90% of isolates, greater than 100 micrograms/ml). The compound was stable to the common plasmid beta-lactamases, such as that of TEM. It was stable to most chromosomally mediated beta-lactamases, which act primarily as cephalosporinases, but was hydrolyzed by Bacteroides and Acinetobacter.
 ...
PMID:In vitro activity and beta-lactamase stability of cefmenoxime. 610 Apr 27

Examination of the activity of cefoperazone against ampicillin-resistant, gramnegative bacteria in agar dilution and simultaneously in broth dilution revealed that strains could be divided into three classes: class I strains were susceptible in agar (mean minimal inhibitory concentration [MIC], 0.5 mg/liter) as well as in broth dilution (mean MIC, 1.5 mg/liter), class II strains were susceptible in agar (MIC, 0.9 mg/liter), but resistant in broth dilution (MIC, 182 mg/liter); and class III strains were highly resistant in both test systems. Among 100 randomly selected ampicillin-resistant Escherichia coli cultures, 51 belonged to class I and 49 belonged to class II. Class III E. coli strains were much rarer. Similar results were obtained with cefamandole and cephalothin, but not with six other second-and third-generation cephalosporins. MICs of cefoperazone against cultures of all three classes were influenced by initial inoculum size. The inoculum effect was greatest with class II strains. Examination of bactericidal activity by cefoperazone showed killing of class I and class II E. coli strains and of class III strains of other genera during the first hours of incubation and regrowth after the drug was destroyed by the action of TEM beta-lactamase (penicillinase). Representative class I bacteria produced 10 to 100 times less TEM beta-lactamase than did class II strains. It appeared that the quantitative difference in TEM production was the reason for the different resistance phenotypes in class I and class II strains. Salmonella and Klebsiella strains of class III produced the same amounts of TEM beta-lactamase as did class II E. coli strains. Probably, some factors other than beta-lactamase contributed to the class III phenotype in these species.
 ...
PMID:Activity of cefoperazone against ampicillin-resistant bacteria in agar and broth dilution tests. 621 94


<< Previous 1 2 3 4 5 6 7 8 9 10