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

A procedure for the simultaneous large-scale isolation of pullulanase and 1,4-alpha-glucan phosphorylase from Klebsiella pneumoniae is described. The pullulanase is solubilized from the cell wall by cholate treatment; cells and cell debris are removed by partition in a poly(ethylene glycol) (PEG)-dextran two-phase system and from the upper (PEG) phase of this system the pullulanase is isolated by ultrafiltration and precipitation with N-cetyl,N-,N-,N-trimethyl ammonium bromide to a purity of about 80% with a yield of 70%. The preparations are free of alpha-amylase activity. The cell containing dextran-rich phase is passed through a Manton-Gaulin homogenizer. Then the phosphorylase is separated from the cell debris by partition in a second PEG-dextran system. From the top phase of this system the phosphorylase is isolated by distribution in a PEG-salt two-phase system followed by batch adsorption on carboxymethyl-Sephadex in a yield of 55%, a purity of around 90%, and nearly free of glycosyltransferase activity. All steps in the isolation of the two enzymes can be performed easily in a large scale.
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PMID:Procedure for the simultaneous large-scale isolation of pullulanase and 1,4-alpha-glucan phosphorylase from Klebsiella pneumoniae involving liquid-liquid separations. 36 57

This study reports the extent and character of plasmolysis and other morphological changes as shown by electron microscopy in a strain of Klebsiella pneumoniae and with sucrose or polyethylene glycol 400 (PEG-400) as the plasmolysing agent at a water activity of 0.935. Both solutes produced severe plasmolysis in K. pneumoniae cells; PEG-400 also caused some cell wall collapse and finger like extrusions to emerge from the bacterial cell.
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PMID:Submicroscopical changes in Klebsiella pneumoniae cells treated with concentrated sucrose and polyethylene glycol 400 solutions. 352 23

It was found that concentrated polyethylene glycol 400 (PEG 400) solutions have significant antibacterial activity against various pathogenic bacteria, including Klebsiella pneumoniae, Pseudomonas aeruginosa, Escherichia coli, and Staphylococcus aureus. This effect might be attributed to two effects: lowering of water activity and, superimposed on this, the specific action of PEG-400 molecules on bacterial cells. Phase-contrast microscopic observations of cells placed in contact with PEG 400 revealed clumping and morphological changes of bacterial cells. The larger changes in appearance were evidenced by the species which were more rapidly killed by PEG 400. The results obtained suggested that concentrated PEG 400 solutions may have a potential value in medicine as a topical antibacterial agent. The feasibility of this application is the subject of present investigation.
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PMID:In vitro antibacterial activity of concentrated polyethylene glycol 400 solutions. 663 96

Polymer (PEG-PE)-coated liposomes exhibit prolonged circulation time in blood and substantial localization in Klebsiella pneumoniae-infected lung tissue in rats. Therefore, to determine the therapeutic effect, gentamicin and ceftazidime were entrapped in these liposomes and administered to rats experimentally infected with pneumonia: Relatively high and sustained concentrations of liposome-associated antibiotic in blood were observed. Compared with antibiotics alone, one dose of liposome-entrapped gentamicin or ceftazidime increased the therapeutic effect of the drugs, survival of rats, and bacterial killing in lungs. One dose of liposome-entrapped ceftazidime was as effective as a continuous 2-day infusion of nonentrapped ceftazidime. Since antibiotic-containing liposomes are stable during circulation and liposome-entrapped ceftazidime and gentamicin have low bactericidal activity in vitro, the superior therapeutic effect of the liposome-encapsulated antibiotics results from localization and subsequent degradation of liposomes and the resulting release of entrapped antibiotic at the infection site.
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PMID:Efficacy of gentamicin or ceftazidime entrapped in liposomes with prolonged blood circulation and enhanced localization in Klebsiella pneumoniae-infected lung tissue. 770 22

Sterically stabilized liposomes are able to localize at sites of infection and could serve as carriers of antimicrobial agents. For a rational optimization of liposome localization, the blood clearance kinetics and biodistribution of liposomes differing in poly(ethylene glycol) (PEG) density, particle size, bilayer fluidity or surface charge were studied in a rat model of a unilateral pneumonia caused by Klebsiella pneumoniae. It is shown that all liposome preparations studied localize preferentially in the infected lung compared to the contralateral non-infected lung. A reduction of the PEG density or rise in particle size resulted in a higher uptake by the mononuclear phagocyte system, lower blood circulation time and lower infected lung localization. Differences in bilayer fluidity did not affect blood clearance kinetics or localization in the infected lung. Increasing the amount of negatively charged phospholipids in the liposome bilayer did not affect blood clearance kinetics, but did reduce localization of this liposome preparation at the site of lung infection. In conclusion, the degree of localization at the infected site is remarkably independent of the physicochemical characteristics of the PEG liposomes. Substantial selective liposome localization can be achieved provided that certain criteria regarding PEG density, size and inclusion of charged phospholipids are met. These properties seem to be a direct consequence of the presence of the polymer coating operating as a repulsive steric barrier opposing interactions with biological components.
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PMID:Localization of sterically stabilized liposomes in Klebsiella pneumoniae-infected rat lung tissue: influence of liposome characteristics. 1051 2

Preferential localization of liposomes at sites of infection or inflammation has been demonstrated in a variety of experimental models. Most studies report enhanced localization at the target site of poly(ethyelene) glycol (PEG)-coated liposomes as compared to conventional non-coated liposomes. It is generally accepted that the prolonged circulation time of PEG-coated liposomes increases target site exposure, which results in increased target localization. A quantitative relationship between circulation kinetics and localization at the pathological site has not been defined as yet. Besides, an effect of the PEG coating itself has been suggested, as theoretically the PEG coating may facilitate liposome extravasation. In the present study, in a rat model of an acute unilateral Klebsiella pneumoniae pneumonia, circulation kinetics of PEG-coated liposomes were manipulated by incorporation of different amounts of phosphatidylserine (PS) and variation of lipid dose, additionally allowing evaluation of the saturability of the localization process. In addition, this paper addresses the effect of the PEG coating, by comparing the circulation kinetics and target localization of long-circulating 'PEG-free' and PEG-coated liposomes. It is shown that the degree of liposome localization at the target site is positively linearly related to the area under the blood concentration time curve (AUC) of the liposome formulations, irrespective of PEG coating. This finding is discussed in relation to the equation of Kedem and Katchalsky, which describes protein influx into sites of infection or inflammation.
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PMID:Localization of sterically stabilized liposomes in experimental rat Klebsiella pneumoniae pneumonia: dependence on circulation kinetics and presence of poly(ethylene)glycol coating. 1101 69

CysB is a positive regulator of transcription of genes involved in cysteine biosynthesis in Gram-negative bacteria and belongs to the large family of LysR-type transcriptional regulators. The full-length protein from Klebsiella aerogenes has been crystallized from solutions containing PEG 8000 in the presence and in the absence of the inducer N-acetylserine by the method of vapour diffusion in hanging drops. For the complexed protein different crystal forms appear in the same drops.
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PMID:Crystallization of full-length CysB of Klebsiella aerogenes, a LysR-type transcriptional regulator. 1117 73

OXY-1a is an extended-spectrum beta-lactamase from the conditional pathogenic bacterium Klebsiella oxytoca. OXY-1a is responsible for the antibiotic resistance of this pathogen. A soluble form of OXY-1a with a His tag at its C-terminus was overexpressed in Escherichia coli. The recombinant protein was purified and crystallized at room temperature using PEG 4000 as the main precipitant. Two crystal forms were obtained from the same growth conditions. One was orthorhombic, with crystals that diffracted to better than 1.9 A, while the other was tetragonal, with crystals that only diffracted to about 3.0 A. Complete data sets were collected from both crystal forms. The orthorhombic crystal belongs to space group P2(1)2(1)2(1), with unit-cell parameters a = 46.54, b = 73.43, c = 84.56 A, while the tetragonal crystal has unit-cell parameters a = b = 73.72, c = 96.81 A. The asymmetric unit of the orthorhombic crystal is estimated to contain one OXY-1a molecule, giving a crystal volume per protein weight (V(M)) of 2.25 A(3) Da(-1) and a solvent content of 45%.
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PMID:Expression, purification and crystallization of an extended-spectrum beta-lactamase from Klebsiella oxytoca. 1474 13

The purpose of this study was to ascertain the prevalence of extended-spectrum beta-lactamases (ESBLs) among Escherichia coli and Klebsiella pneumoniae strains obtained from urine samples of residents of a long-term care facility and to determine the risk factors for acquisition of ESBL-producing strains. All urine samples collected from January 2003 to October 2003 that were positive for E. coli or K. pneumoniae were tested for the presence of ESBL. Records of patients with ESBL-positive (ESBL-P) samples were analyzed for clinical and demographic data. The records of a matched control group of patients whose urine samples were positive for E. coli or K. pneumoniae but were ESBL-negative (ESBL-N) were also analyzed. The overall rate of ESBLs among the E. coli and K. pneumoniae samples was 25.6%. Of 350 urine samples that grew E. coli, 77 (22%) were positive for ESBL; 34 of 84 (40.5%) samples that grew K. pneumoniae were ESBL-P. Male sex, treatment in the subacute care unit, recent antimicrobial treatment, pressure sores, (percutaneous endoscopic gastrostomy) PEG tube, anemia, hypoalbuminemia, permanent urinary catheter, and any recent invasive procedure were all associated with ESBL-P bacteria in the univariate analysis. The multivariate analysis revealed three independent risk factors for the presence of an ESBL-producing strain: anemia, permanent urinary catheter, and previous antibiotic use. Fluoroquinolones were most strongly associated with the development of ESBL-producing bacteria. The prevalence of ESBL-producing E. coli and K. pneumoniae in the long-term care facility investigated was unexpectedly high and corroborates the notion that long-term care facilities could be important reservoirs of resistant bacteria. Identification of the risk factors for ESBLs is the first step in formulating an effective strategy to curtail the spread of ESBL resistance in long-term care facilities.
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PMID:Prevalence and risk factors of extended-spectrum beta-lactamase-producing Escherichia coli and Klebsiella pneumoniae in an Israeli long-term care facility. 1566 Feb 55

Comparative antimicrobial activity of four ointments, i. e. stellanin-PEG, levomecole, dioxydin 5% ointment and betadin was studied with the use of collection microbial strains and the most frequent pathogens of pyoinflammary processes in surgical patients. Clinical strains of gram positive and gram negative organisms were used as the test cultures. Stellanin-PEG 3% ointment showed high antimicrobial activity against both the gram positive and the gram negative organisms, including methicillin resistant staphylococci, E. faecalis, E. faecium, as well as E. coli and Klebsiella spp. producing extended spectrum beta-lactamases. As a whole, stellanin-PEG 5% ointment was inferior only to 5% dioxydin ointment.
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PMID:[Stellanin-PEG 3% ointment: comparative antimicrobial activity against surgical infection pathogens]. 1944 51


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