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

We extracted an R-form lipopolysaccharide (LPS) by the phenol-water method from Klebsiella sp. strain LEN-111 (O3-:KI-) and followed the changes in ultrastructure of the LPS during the extraction procedure. When the LPS was obtained from the water phase of an extract by addition of 2 volumes of 10 mM MgCI2-ethanol, it consisted of membrane pieces with a hexagonal lattice structure with a lattice constant of 14 to 15 nm. The lattice structure of the LPS was disrupted into short rods with sodium dodecyl sulfate, but the same hexagonal lattice structure was again formed by precipitation with 2 volumes of 10 mM MgCI2-ethanol. The LPS preparation after two cycles of treatment by the phenol-water method, which contained no detectable amounts of proteins, kept an unaltered ability to form the hexagonal lattice structure. Extensive treatment with pronase and extraction with chloroform did not impair the ability of the LPS preparation to form the lattice structure. When the other salts, NaCI, CaCI2 or Zn(CH3COO)2, were used for precipitation of the LPS with ethanol in place of MgCI2, the LPS did not form the hexagonal lattice structure. However, if the LPS precipitated with NaCI-ethanol was converted to the magnesium salt form after it was electrodialyzed, it formed the same hexagonal lattice structure as the LPS precipitated with MgCI2-ethanol. From these results, it was concluded that the R-form LPS has the ability of in vitro self-assembly into a hexagonal lattice structure in the presence of Mg2+ without the help of other components such as proteins and free lipids from outer membrane.
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PMID:Formation of a hexagonal lattice structure by an R-form lipopolysaccharide of Klebsiella sp. 399 76

Various uniform salt forms of an R-form lipopolysaccharide (LPS) extracted from Klebsiella strain LEN-111 (O3-:K1-) were prepared and their ultrastructure was examined. The LPS, which was extracted by the phenol-water method, freed from contamination with RNA by treatment with RNase, and precipitated by addition of two volumes of 10 mM MgCl2-ethanol, was used as the original preparation for uniform salt forms. The original LPS preparation formed a hexagonal lattice structure with a lattice constant of 14.9 +/- 0.2 nm. The LPS after electrodialysis retained the ability to form a hexagonal lattice structure, although its lattice constant was large (18.7 +/- 0.5 nm) and the lattice structure of the electrodialyzed LPS was labile at pH 8.0 in contrast to that of the original LPS preparation. The magnesium salt form of the LPS formed essentially the same ordered hexagonal lattice structure (lattice constant of 15.0 +/- 0.2 nm) as that of the original LPS preparation. The calcium and ammonium salt forms formed a hexagonal lattice structure, but the lattice constants of the calcium and ammonium salt forms were larger (18.6 +/- 0.6 nm and 19.3 +/- 0.4 nm, respectively) than that of the magnesium salt form. The sodium and potassium salt forms consisted of freely branching ribbon-like structures with an average width of 13 nm and an average thickness of 9 nm. The triethylamine salt form consisted principally of short rods (10 nm X 9-13 nm).
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PMID:Formation of a hexagonal lattice structure by an R-form lipopolysaccharide of Klebsiella: relationship between lattice formation and uniform salt forms. 409 71

The presence of acetate and pyruvate groups in Klebsiella capsular polysaccharides may be demonstrated and estimated quantitatively by running the proton magnetic resonance spectrum of the polysaccharide (as sodium salt) in deuterium oxide at 95 C. Such spectra also permit an assessment to be made of the number of alpha- and beta-linkages in the repeat unit of the polysaccharide structure.
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PMID:Proton magnetic resonance spectroscopy of Klebsiella capsular polysaccharides. 434 70

1. The permeability barrier against benzylpenicillin has been found to be passive in four strains of penicillinase-producing Gram-negative bacteria (three of Klebsiella aerogenes and one of Escherichia coli). 2. If the three K. aerogenes strains are grown in the presence of sub-inhibitory concentrations of benzylpenicillin, ampicillin or phenethicillin the resultant bacterial cells have deficient permeability barriers. Concentrations of ampicillin or benzylpenicillin less than one-tenth of those required to inhibit growth cause destruction of more than half the permeability barrier in these strains. 3. Benzylpenicillin, ampicillin and phenethicillin have no effect upon the permeability barriers of resting cells from the three K. aerogenes strains. 4. Treatment of resting cells with trisodium EDTA, although failing to sensitize K. aerogenes to lysozyme, severely damages permeability barriers in this species. 5. The magnesium and calcium salts of EDTA do not have the same capacity as the sodium salt for causing damage to permeability barriers in K. aerogenes and E. coli. Damage caused by trisodium EDTA can be at least partially reversed by treatment with Ca(2+) or Mg(2+) ions. It is suggested that EDTA damage is caused by removal of either Ca(2+) or Mg(2+) ions, or both, from the bacterial cell envelope. 6. Bacterial cells with deficient permeability barriers as a result of either growth in the presence of a penicillin or treatment with EDTA remain viable, and revert to their usual permeability after growth in nutrient broth.
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PMID:Damaging effects of ethylenediaminetetra-acetate and penicillins on permeability barriers in Gram-negative bacteria. 496 52

RNA polymerase molecules pause at a single site during in vitro transcription of the tryptophan (trp) operon leader region. Pausing was observed when DNA templates derived from Escherichia coli. Salmonella typhimurium, and Klebsiella aerogenes were used. Fingerprint analyses showed that the major RNA species produced by the transcriptional pause is 91 nucleotides long. A minor RNA species 90 nucleotides long was also detected. Single-round transcription experiments were used to study the kinetics of pausing. Time course, pulse-chase, and delayed-labeling experiments suggest that every RNA polymerase molecule transcribing the trp leader region pauses. A suboptimal ribonucleoside triphosphate concentrations, the half-life of paused-leader RNA was approximately 3 min at 22 degrees C and 0.7 min at 37 degrees C. At near-optimal ribonucleoside triphosphate concentrations, the half-time of the paused species dropped to about 0.3 min at 22 degrees C. The appearance and half-life of the paused species were unaffected by salt concentration, rho factor, guanosine 3'-5'-bis(diphosphate), or point mutations in the trp attenuator region. It is postulated that transcriptional pausing may play a role in maintaining the synchronization of transcription and translation that is vital in the control of transcription termination at the trp operon attenuator.
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PMID:Pausing of RNA polymerase during in vitro transcription of the tryptophan operon leader region. 616 81

The in vitro activity, pharmacokinetics, adverse effects, and clinical efficacy of cefonicid are reviewed. Also discussed are formulary considerations and bacterial resistance. Cefonicid, an investigational agent near approval, is less active than other currently available first- and second-generation cephalosporins against gram-positive cocci, particularly Staphylococcus. Cefonicid and cefamandole have similar activity that is superior to the first-generation cephalosporins against Escherichia coli, Klebsiella, Citrobacter spp., Enterobacter spp., indole-negative Proteus spp., and Providencia spp. Organisms such as Serratia marcescens, Acinetobacter, Pseudomonas, and Bacteroides fragilis are resistant to cefonicid. Despite a small volume of distribution and high protein binding, cefonicid achieves high tissue concentrations. Approximately 90% of an administered dose is excreted unchanged in the urine, and the elimination half-life is approximately four hours. Cefonicid is usually well tolerated. In treating skin infections, cefonicid was usually less effective than cefazolin against Staphylococcus aureus. In genitourinary infections, cefonicid 1 g daily (as the sodium salt) in a single dose has shown comparable efficacy to cefamandole or amoxicillin given in multiple daily doses. Based on available data, single daily dosing of cefonicid in the therapy of Staph. aureus endocarditis is not effective. In studies of patients undergoing hysterectomy, cesarean section, cholecystectomy, and colorectal surgery, cefonicid 1 g given as a single preoperative dose has produced results comparable with those of cefoxitin 1-2 g (as the sodium salt) given preoperatively and for several doses postoperatively. The major clinical uses of cefonicid will probably be as a possible cost-reducing alternative (based on a single daily dose) to currently available first- and second-generation cephalosporins for the treatment of community-acquired pneumonia and infections caused by enteric organisms. It may also be useful as a possible cost-reducing alternative to cefoxitin for prophylaxis in hysterectomy and biliary tract surgery.
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PMID:Review of cefonicid, a long-acting cephalosporin. 636 14

The pathogenesis, clinical signs and symptoms, diagnosis and treatment of chronic bacterial prostatitis (CBP) are reviewed. The most common organism associated with CBP is Escherichia coli, although infections with Klebsiella, Enterobacter, Proteus, Pseudomonas, and enterococci have also been documented. The only symptoms of CBP may be those of an acute urinary-tract infection. The use of simultaneous quantitative urine cultures represents the most accurate method for diagnosing CBP. The use of trimethoprim-sulfamethoxazole, the current drug of choice for CBP, is based on results in animals showing good penetration of trimethoprim into acidic prostatic fluid and the knowledge that normal human prostatic fluid is acidic. Studies in patients with CBP, who have alkaline prostatic fluid, have demonstrated poor penetration of trimethoprim into prostatic fluid, which may explain the cure rate of about 40% seen with trimethoprim-sulfamethoxazole. A few patients have been treated successfully with kanamycin and streptomycin, but these drugs must be given by injection. Carbenicillin indanyl sodium has been associated with cure rates of almost 70% in a small number of studies. Both doxycycline and minocycline have been used to treat CBP, but inadequate urine-culture data make these studies difficult to evaluate. Erythromycin produced a cure rate of 88% in one study in patients who received 500 mg (as the stearate salt) four times daily for 14 days. Local injection of antibiotics into the prostate has been reported to be effective in a few cases. Although controlled comparative trials with trimethoprim-sulfamethoxazole are needed, carbenicillin indanyl sodium and erythromycin appear to be the drugs of choice for treating CBP; trimethoprim-sulfamethoxazole should be reserved for patients with CBP unable to tolerate or unresponsive to therapy with these agents.
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PMID:Treatment of chronic bacterial prostatitis. 636 16

The pharmacokinetics and antibacterial activity of two injectable gentamicin products given i.m. were compared. Ten healthy men randomly received either Schering or Invenex gentamicin 1 mg/kg (as the sulfate salt) by intramuscular injection into the deltoid muscle. Four to six weeks later, subjects received the alternate preparation at the same dose in the opposite arm. Blood samples for gentamicin concentrations were obtained before drug administration and at various times for up to four hours after drug administration; urine from each subject was also collected before and after drug administration. Values for area under the curve, elimination rate constant, peak serum gentamicin concentration and time to peak concentration, clearance, half-life, and percentage of drug excreted in the urine over four hours were compared for each preparation in each subject. The serum inhibitory and bactericidal activities of each gentamicin preparation against Escherichia coli and Klebsiella pneumoniae were also evaluated. None of the pharmacokinetic values for the two preparations was significantly different. The inhibitory and bactericidal activities resulting from each product were also comparable and adequate. No clinically important differences in pharmacokinetic behavior or inhibitory or bactericidal activity were found between gentamicin products of Schering and Invenex.
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PMID:Pharmacokinetics and antibacterial activity of two gentamicin products given intramuscularly. 638 Sep 3

Previously we showed that Klebsiella O3 lipopolysaccharide (KO3 LPS) is much more potent than other kinds of LPS including Escherichia coli O127 LPS (EO127 LPS) in adjuvant activity in augmenting antibody response and delayed-type hypersensitivity to protein antigens and in the ability to enlarge the regional lymph node. Various defined uniform salt forms, the triethylamine, sodium, potassium, ammonium, tris(hydroxymethyl)aminomethane, and calcium salt forms, of KO3 LPS and EO127 LPS were prepared by removing basic materials present in LPS preparations by electrodialysis and neutralizing the electrodialyzed LPS preparations with various kinds of alkali. The triethylamine salt form showed the best solubility and consisted of the smallest granules and, on the other hand, the calcium salt form showed the lowest solubility, compared with the natural form and the other uniform salt forms. Even if the natural forms of KO3 LPS and EO127 LPS were converted to the defined uniform salt forms, adjuvanticity of KO3 LPS and EO127 LPS in augmenting delayed-type hypersensitivity to ovalbumin and the ability to enlarge the regional lymph node did not significantly differ from those of the respective natural forms. From these results it is concluded that the difference in strength of the adjuvanticity between KO3 LPS and EO127 LPS is not due to the difference in their salt forms, solubility or physical state. Moreover, there were no significant differences in lethal toxicity for mice by the intraperitoneal route among the natural form and all the uniform salt forms of KO3 LPS tested.
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PMID:Adjuvant activity of Klebsiella O3 lipopolysaccharide: comparative study using defined uniform salt forms. 638 41

The production of a dialyzable peptidic antibacterial named microcin E492 by the strain of faecal origin Klebsiella pneumoniae RYC492 has previously been reported. In this paper, a procedure to extract this antibiotic from liquid cultures of the producer strain is described. This method was based in the quantitative retention of the microcin on the hydrophobic matrix Bondapak C18 and led to highly active pigment- and salt-free concentrates appropriate for further purification by high pressure liquid chromatography. The characterization of purified preparations indicated that microcin E492 was a basic and hydrophobic peptide with an apparent molecular mass of about 5,000, acid- and heat-resistant and much more active in minimal than in rich medium. These properties are discussed with regard to the likely ecological role of the microcin in the microbial ecosystem of the intestine.
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PMID:Isolation and characterization of microcin E492 from Klebsiella pneumoniae. 638 3


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