Isolation And Characterization Of The Outer And Cytoplasmic Membranes Of Pseudomonas cepacia

Summary.A clinical isolate of Pseudomonas cepacia from a cystic fibrosis patient was examined for its ability to produce extracellular toxic material. The organism was grown to stationary phase in a defined medium and toxic material was isolated by ultrafiltration, ion-exchange chromatography on DEAE-Sephacel and gel-filtration chromatography on Sepharose 4B. It consisted of a surface carbohydrate antigen, lipopolysaccharide and protein, and had an LD50 (when injected intraperitoneally into mice) of 395k2Opg. The toxicity appeared to be associated with the lipopolysaccharide portion of the complex, because boiling for 15 min and exposure to proteolytic enzymes had no effect on toxicity. However, saponification destroyed the toxicity of the compound. Studies employing radial immunodiffusion with the sera of mice infected with this organism demonstrated production of the complex in uiuo at levels approaching those sufficient to produce death. When sublethal amounts of this complex were placed in the lungs of specific-pathogen-free rats, the lung pathology observed after 12, 24, 36 and 48 h was extensive. However, antibody generated in rabbits against this material could protect mice against the complex, as well as against challenge by the homologous organism. These data indicate that extracellular toxic material produced by P . cepacia may be responsible for the lethality and lung tissue destruction normally associated with an active pneumonia caused by this organism.

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“…This finding was supported by Anwar et al (1983a) in the isolation and characterisation of the outer membrane of P . cepacia.…”

Section: Discussionsupporting

confidence: 72%

The importance of extracellular antigens in Pseudomonas cepacia infections

Straus

Woods²,

Lonon³

et al. 1988

Journal of Medical Microbiology

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“…Manniello et al (1979) were the first to report that there was no detectable KDO in biologically active LPS preparations extracted from the strains of P. cepacia, as determined by the procedure of Osborn (1963). This conclusion was supported by Anwar et al (1983a) in their studies on the outer membrane of one strain of P. cepacia. In this study, we treated the ETC with sweet potato acid phosphatase (Uehara et al, 1974) before examination for KDO by the procedure described by Osborn (1963).…”

Section: Discussionmentioning

confidence: 92%

Production of an Extracellular Toxic Complex by Various Strains of Pseudomonas Cepacia

Straus

Lonon

Woods

et al. 1989

Journal of Medical Microbiology

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Summary. Six isolates of Pseudomonas cepacia, representing various serotypes of the organism and possessing similar degrees of virulence in mice, were examined for their production of an extracellular toxic complex (ETC) in vitro. This compound is lethal for mice and produces extensive lung pathology in rats; it is composed of a surface carbohydrate antigen, lipopolysaccharide and protein. All six isolates produced the ETC. The LD50 values for the six ETC preparations ranged from 395 pg for strain 61g to 1750 pg for strain 90ee. Only two of the six ETC preparations contained ketodeoxyoctonate detectable by the methods used, and these two were the most toxic. Rabbit antiserum to the ETC of a serotype D strain could significantly protect mice only against serotype D strains. Examination of the various phases of growth of P. cepacia showed that there was extracellular release of the ETC beginning in the early logarithmic phase and continuing through the late stationary phase. The presence of the ETC in the supernatant fluids was due to release of this material rather than to cell lysis. In addition, at least one strain of P. cepacia was shown to produce an alginic acid-like compound.

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“…Burkholderia cepacia expresses a 66 kDa protein in large amounts when grown as a planktonic culture under iron limitation (Anwar et al 1983a). The bacteria also expressed this protein when grown on CDM 12 agar as a biofilm under iron-restricted conditions but only in very small amounts with iron supplementation (data not shown).…”

Section: Growth Of Burkholderia Cepacia Dependent On the Iron Concentmentioning

confidence: 84%

Generation of a reproducible nutrient‐depleted biofilm of Escherichia coli and Burkholderia cepacia

Bühler

Ballestero

Desai

et al. 1998

Journal of Applied Microbiology

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An in vitro method of growing bacteria as a defined nutrient‐depleted biofilm is proposed. The medium was defined nutritionally in terms of the quantitative composition and by the total amount of nutrient required to achieve a defined population size. Escherichia coli and Burkholderia cepacia were incubated on a filter support placed on a defined volume of solid medium. The change of biomass of the biofilm population was compared with the change in a planktonic culture. The size of the population in stationary phase was proportional to the concentration of limiting substrate up to 40 μmol cm−2 glucose for E. coli and up to 2·7 × 10−9 mol cm−2 iron for B. cepacia. Escherichia coli growing exponentially had a growth rate of μ = 0·30 h−1 in a biofilm and μ = 0·96 h−1 in planktonic culture. The growth rate, μ, for exponentially growing B. cepacia in a biofilm was 1·12 h−1 and in planktonic culture 0·78 h−1. This method allows the limitation of the size of a biofilm population to a chosen value.

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Isolation And Characterization Of The Outer And Cytoplasmic Membranes Of Pseudomonas cepacia

Cited by 26 publications

References 31 publications

The importance of extracellular antigens in Pseudomonas cepacia infections

The importance of extracellular antigens in Pseudomonas cepacia infections

Production of an Extracellular Toxic Complex by Various Strains of Pseudomonas Cepacia

Generation of a reproducible nutrient‐depleted biofilm of Escherichia coli and Burkholderia cepacia

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