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Query: UMLS:C0519030 (
Klebsiella
)
21,988
document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)
Of 775 conjugative plasmids found in enterobacteria mediating antibiotic resistance, 24 (3.1%) were thermosensitive (ts); they were most common in
Klebsiella
pneumoniae. Ts plasmids were also found in all the samples of sewage and river water examined. Over half of 73 ts plasmids from unrelated sources mediated resistance to chloramphenicol in addition to several other antibiotics. Many of them mediated resistance to mercury (53.4%), arsenite (38.4%) and tellurite (79.5%) but not to copper, cobalt and silver. Fifty-eight belonged to incompatibility group H2 and 12 belonged to the H1 group. Resistance to mercury, arsenite and tellurite was common in strains containing H2 plasmids but not in H1 plasmids. The 73 plasmids transferred at high rates at 22 and 28 degrees C and at lower rates at 15 degrees C; they transferred at very low rates or not at all at 37 degrees C. They could be divided into two sets according to whether they transferred at a high or at a low rate at 33 degrees C. Unlike the prototype plasmid, Rts 1, they were solely or mainly ts for transfer and not for replication and only one of them brought about a marked reduction in growth rate of its host organism at 42 degrees C. None of the 73 plasmids mediated colicin or haemolysin production. Three plasmids, all from K. pneumoniae, mediated utilization of lactose, two of sucrose and raffinose and three, all belonging to group H1, of citrate. None of the plasmids increased the pathogenicity of Salmonella typhimurium for chicks or Escherichia coli K12 for mice.
J
Gen
Microbiol 1978 Nov
PMID:Thermosensitive antibiotic resistance plasmids in enterobacteria. 73 Dec 7
A His+ Nif+ Escherichia coli K12, Hfr strain (UNF43) was constructed by an intergeneric mating between a
Klebsiella
pneumoniae donor strain (HF3) and a his-HFR E. coli strain (SBI824) which transfers his as an early marker. An F-prime nif plasmid, FN39, carrying genes which correspond to the E. coli chromosomal region, metG gnd his shiA, but excluding purF and aroD, was isolated from UNF43. Translocation of carbenicillin resistance genes from a P-type R-factor, R68, to FN39 increased the stability of his and nif on the derivative F-prime, FN68. Sedimentation analysis of both F-primes in sucrose gradients revealed our covalently closed circular(CCC) DNA species of molecular weights 279 +/- 9, 136 +/- 3, 90 +/- 1 and 44 +/- 1 megadaltons. It is suggested that the two smallest CCC-DNA species are component replicons of the composite F-primes of molecular weight 136 +/- 3 megadaltons, and that the molecules of 279 +/- 9 megadaltons are CCC-dimers. FN68 was transferable in intergeneric matings to
Klebsiella
aerogenes, K. pneumoniae and Salmonella typhimurium but not to Proteus mirabilis; only carbenicillin resistance and sex factor activity were transferred to Erwinia herbicola. nif genes on FN68 were expressed in a Nif- mutant of K. pneumoniae and also in S. typhimurium, which in conventional tests is naturally non-nitrogen-fixing; expression of the his determinant of FN68 became temperature-sensitive in S. typhimurium.
J
Gen
Microbiol 1976 Mar
PMID:Derivation and properties of F-prime factors in Escherichia coli carrying nitrogen fixation genes from Klebsiella pneumoniae. 77 61
Oxygen-limited (N2-fixing) chemostat cultures of
Klebsiella
pneumoniae supplied with a N-free medium were established by introducing low atmospheric O2 concentrations into the gas supply of anaerobic glucose-limited N2-fixing chemostat cultures; the molar growth yield for glucose and the efficiency of N2 fixation (mug N fixed/mg glucose consumed) were increased (by up to 82%) from the anaerobic values. Acetylene-reducing activity was inhibited reversibly by O2 in samples from O2-limited and anaerobic glucose-limited chemostat cultures. Oxygen uptake rates in samples from these chemostat cultures were similar, but C2-H2-reducing activity in samples from O2-limited chemostat cultures was more tolerant of low atmospheric O2 concentrations, in part because of a higher population density. In the absence of glucose, O2 was required at a low atmospheric concentration for C2H2 reduction in samples from either O2-limited or anaerobic glucose-limited chemostat cultures. The possibility is discussed that ATP generated from oxidative phosphorylation can be used for N2 fixation in K. pneumoniae.
J
Gen
Microbiol 1976 Apr
PMID:Influence of atmospheric oxygen concentration on acetylene reduction and efficiency of nitrogen fixation in intact Klebsiella pneumoniae. 77 26
Rabbit antisera were prepared against the heptoseless Re mutants, Salmonella minnesota R595 and S. typhimurium SLI102, as well as against purified R595 glycolipid coated on autologous erythrocytes. The antisera cross-reacted with the endotoxic glycolipids extracted from Re mutants of various bacterial strains, including S. minnesota R595, S. typhimurium SLI102, Escherichia coli D3Im4, E. coli D2If2 and E. coli F515, as shown by passive haemagglutination and gel diffusion tests. The anti-Re sera also cross-reacted with the RESI preparations (a purified 'lipid A' fraction) from the endotoxic lipopolysaccharides of various heterologous smooth Gram-negative bacteria including Serratia marcescens. Psuedomonas fluorescens and E. coli 0127. However, the same antisera failed to protect mice against infection by Gram-negative bacteria such as
Klebsiella
pneumoniae type II, S. typhi 0901, P. aeruginosa 119 and E. coli. The results suggest that although the lipid moieties of the lipopolysaccharides in the cell wall of Gram-negative bacteria share cross-reactive immunodeterminant groups, these groups may not be accessible to antibody against them.
J
Gen
Microbiol 1976 May
PMID:Relationship of structure to function in bacterial endotoxins: serologically cross-reactive components and their effect on protection of mice against some gram-negative infections. 77 29
The apparent ATP requirement for N2 fixation in
Klebsiella
pneumoniae was high (the ATP/N2 molar ratio was 29 when estimated in anaerobic glucose-limited chemostat cultures) compared with that determined previously in Azotobacter chroococcum and in Clostridium pasteurianum. The high value was probably not due to unfavourable temperature, phosphate concentration or pH. The apparent ATP requirement for N2 fixation was probably no lower in 02-limited chemostat cultures than in anaerobic glucose-limited chemostat cultures. When hydrogen was introduced into the atmosphere over the anaerobic glucose-limited chemostate culture, there was an increase in the apparent ATP requirement for N2 fixation and in the activity of nitrogenase in intact organisms. A comparison of these increases suggests that some ATP is wasted by the ATP-dependent H2-evolving activity of nitrogenase.
J
Gen
Microbiol 1976 Aug
PMID:The apparent ATP requirement for nitrogen fixation in growing Klebsiella pneumoniae. 78 6
Two mutants which lacked both capsular and lipopolysaccharide O-antigen polysaccharides were isolated from
Klebsiella
aerogenes serotype 2 by phage selection; these were designated rough mutants. The polysaccharide fractions solubilized by partial acid hydrolysis of the lipopolysaccharide from both the wild type and mutants were chromatographed on Sephadex G-50. Analysis of the fractions obtained confirmed that the rough mutants lacked the galactan portion of the molecule, which is analogous to the Salmonella O-antigen polysaccharide. Membranes prepared from wild-type K. aerogenes, from a non-mucoid strain (lacking capsule only), and from one of the rough mutants were used in incubation mixtures to compare the biosynthesis of polysaccharides by these organisms. The incorporation of sugar nucleotides into both lipid intermediates and polymer was followed. Results show that the transferases were apparently present in all membranes, while the polymerases were absent in both the non-mucoid and rough mutants.
J
Gen
Microbiol 1976 Sep
PMID:Isolation of rough mutants of Klebsiella aerogenes and their synthesis of polysaccharides. 78 14
Fluorescent antibodies (FA) prepared against the Mo-Fe and Fe proteins of nitrogenase from
Klebsiella
pneumoniae M5aI were used to detect these protein components in toluene-treated whole cells that were actively reducing acetylene. The FA were highly specific, staining only nitrogenase component proteins originating from
Klebsiella
. Cross-reactions between the FA and purified nitrogenase proteins from other dinitrogen-fixing micro-organisms did not occur, except in the case of Bacillus polymyxa. The tests rapidly and accurately assayed the component proteins in
Klebsiella
mutants and derivatives to which
Klebsiella
nif genes had been transferred either by plasmid or by other means. Cross-reactions also indicated the degree of relatedness between nitrogenase proteins from dinitrogen-fixing micro-organisms of various origins.
J
Gen
Microbiol 1976 Dec
PMID:Immunofluorescence detection of nitrogenase proteins in whole cells. 79 12
Urease activity in the sheep rumen varied with the diet of the sheep, but appeared to be largely or entirely present in the small bacterial fraction. Screening of over 1000 strains of rumen bacteria isolated on different media showed that urease activity was apparently confined to species of Staphylococcus, Lactobacillus casei var. casei and
Klebsiella
aerogenes. Consideration of the numbers in which these occurred and their activities suggested that the bacteria could not be responsible for the total rumen urease activity. By enrichment culture a ureolytic strain of Streptococcus faecium was isolated. This had a higher urease activity than the other bacteria and occurred in higher numbers in the rumen. It could live with other bacteria in the rumen of a gnotobiotic lamb in numbers, and with a urease activity, comparable with those in the normal sheep rumen. The other properties of the bacterium also suggested that it would grow and produce urease in the rumen, but was unlikely to retain its urease activity after isolation. It was concluded that this bacterium was the main source of rumen urease in roughage-fed, and probably other, sheep.
J
Gen
Microbiol 1976 Jan
PMID:Urease activity in the rumen of sheep and the isolation of ureolytic bacteria. 81 52
beta-Lactamases (EC. 3.5.2.6) can be directly compared by analytical isoelectric focusing. Using this technique, 242 strains from five Gram-positive and 16 Gram-negative genera were examined. A preparation of each strain focused as a single group of bands which did not match the pattern of any R factor-associated beta-lactamase. None of the strains was known to carry an R factor and resistance transfer experiments were unsuccessful. The enzymes studied were therefore thought to be chromosomally mediated. The isoelectric points ranged from 3.9 to 8.7 and were not related to the substrate profiles or other biochemical properties. The chromosomal beta-lactamases appeared to be specific for genus, species and sub-species, and strains that produced identical beta-lactamases had identical bacterial characteristics. Correlation of bacteriological differences with differences in beta-lactamase patterns is discussed with particular reference to strains of Escherichia coli and
Klebsiella
spp. Since beta-lactamases may be universally produced by bacteria, separation of the enzymes by analytical isoelectric focusing could be used in bacterial taxonomy.
J
Gen
Microbiol 1976 May
PMID:Identification of beta-lactamases by analytical isoelectric focusing: correlation with bacterial taxonomy. 81 25
Two phage-bound polysaccharide hydrolases specific for
Klebsiella
aerogenes type 8 exopolysaccharides were isolated. Each enzyme was specific for the polysaccharide produced by the host strain. One enzyme hydrolysed a pyruvylated and acetylated polymer, while the other only acted on the substrate lacking these substituents. Both enzymes were endogalactosidases releasing tetrasaccharides from their substrates which were only hydrolysed to a limited extent.
J
Gen
Microbiol 1976 May
PMID:Highly specific bacteriophage-associated polysaccharide hydrolases for Klebsiella aerogenes type 8. 93 88
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