Characterization of a dynamic S layer on Bacillus thuringiensis.

The surfaces of three Bacillus thuringiensis strains possess an S layer composed of linear arrays of small particles arranged with p2 symmetry and with a = 8.5 nm, b = 7.2 nm, and gamma = 73 degrees.

Bacterial sorption of heavy metals.

Four bacteria, Bacillus cereus, B. subtilis, Escherichia coli, and Pseudomonas aeruginosa, were examined for the ability to remove Ag+, Cd2+, Cu2+, and La3+ from solution by batch equilibration methods. Cd and Cu sorption over the concentration range 0.

Physicochemical interaction of Escherichia coli cell envelopes and Bacillus subtilis cell walls with two clays and ability of the composite to immobilize heavy metals from solution.

Isolated Escherichia coli K-12 cell envelopes or Bacillus subtilis 168 cell walls were reacted with smectite or kaolinite clay in distilled deionized water (pH 6.0); unbound envelopes or walls were separated by sucrose density gradient centrifugation, and the extent of adsorption was calculated. At saturation, both clays adsorbed approximately 1.

Metal Interactions with Microbial Biofilms in Acidic and Neutral pH Environments.

Microbial biofilms were grown on strips of epoxy-impregnated filter paper submerged at four sites in water contaminated with metals from mine wastes. At two sample stations, the water was acidic (pH 3.1); the other sites were in a lake restored to a near neutral pH level by application of a crushed limestone slurry.

[Initial clinical experiences in the treatment of chronic polyarthritis with a new monokine release inhibitor].

Cytokines such as Interleukin-1 (IL-1) are important modulators of the cell-mediated immune response and play a paramount role in inflammatory autoimmune disease. We report on preliminary clinical experiences with a new, tricyclic substance [( 10-Methoxy-4H-benzo[4,5]cyclo-hepta-[1,2-b]thiophene-4- ylidene]acetic acid, MW 284), which inhibits the release of interleukin-1 alpha and -beta from cultured murine macrophages or human mononuclear cells. The study included 12 patients (rheumatoid arthritis, n = 9; hemochromatotic arthropathy, n = 1; psoriatic arthropathy, n = 1; seronegative spondylarthropathy, n = 1).

Observations of the ultrastructure of infected kidney stones.

Struvite stones are formed as the result of urinary tract infection by urease-producing bacteria. Ultrastructural examination of calculi removed from a patient revealed bacteria incorporated throughout the stone matrix. Exopolysaccharide stained by ruthenium red was associated with most of the bacteria, but it represented only a small portion of the organic matrix in the stone.

Structural and biochemical analyses of a surface array protein of Campylobacter fetus.

Electron microscopic examination of ultrathin sections and freeze-etched and shadow cast preparations of a bovine prepuce isolate of Campylobacter fetus VC119 showed an S layer with subunits in an apparent linear arrangement. Surface radioiodination, enzyme digestion, low-pH extraction, and Western immunoblotting showed that the layer was composed mainly of one protein which is the predominant protein antigen of C. fetus.

Serotype-specific monoclonal antibodies against the H12 flagellar antigen of Escherichia coli.

The flagellar filaments of morphotype E isolates of Escherichia coli characteristically possess an apparent helically arranged sheath structure, surrounding the central core of the filament. Re-examination of the type strains of H-serotypes belonging to morphotype E showed that all but serotype H34 possessed the expected morphology. Heterogeneity was observed in both the diameter of filaments from individual morphotype E strains and in the Mr of individual flagellins.

The bacterial surface: general considerations towards design and function.

The shape of bacteria is determined by the wall which surrounds the protoplast. This enveloping structure resides in diverse chemical and organizational forms and is of fundamental importance for several aspects of cellular life and growth. This article discusses these general aspects and serves as an introduction to the journal issue and to the more specific papers which follow in the section.

Pharmacokinetics of cyclosporine G in patients with renal failure.

The pharmacokinetics of the cyclosporine A (CsA, Sandimmune) analogue Nva2-cyclosporine, or cyclosporine G (CsG) was investigated in 6 patients with terminal renal failure after a 4-hr intravenous infusion (3.5 mg/kg) and after oral administration (600 mg) of the drug. Blood samples were collected up to 38 hr and CsG concentrations were measured by radioimmunoassay and high-performance liquid chromatography.

Characterization of the bacterial magnetosome membrane.

Intact magnetosomes of Aquaspirillum magnetotacticum were purified from broken cells by a magnetic separation technique. Electron microscopic and chemical analyses revealed the magnetite to be enclosed by a lipid bilayer admixed with proteins. Lipids were recovered in fractions expected to contain (i) neutral lipids and free fatty acids, (ii) glycolipids and sulfolipids, and (iii) phospholipids (in a weight ratio of 1:4:6).

Amikacin disrupts the cell envelope of Pseudomonas aeruginosa ATCC 9027.

Amikacin, an aminoglycoside known to inhibit protein synthesis, was found to perturb the outer membrane of a sensitive Pseudomonas aeruginosa strain (ATCC 9027). This perturbation was monitored using electron microscopy and biochemical analyses. Following exposure to 20 micrograms amikacin/mL for 15 min, the outer membrane of exponentially growing cells lost 15% of its protein, 18% of its lipopolysaccharide, and 18% of its phosphate.

Isolation and characterization of monoclonal antibodies to proline dehydrogenase from Escherichia coli K-12.

The PutA protein of Escherichia coli K-12 serves as both proline dehydrogenase and the repressor controlling the expression of genes putP and putA. Thirty-eight hybridoma cell lines were isolated using mice immunized with proline dehydrogenase purified from a bacterial membrane extract. The monoclonal antibodies secreted by those cells showed varying affinities for proline dehydrogenase by enzyme-linked immunosorbent assay (ELISA).

Cloning of a serotype-specific antigen from Pasteurella haemolytica A1.

Recombinant plasmids coding for a soluble (or surface) antigen of Pasteurella haemolytica A1 were identified. Two plasmids, both containing the same 5.4 kilobase pairs of insert DNA, were recovered independently by screening a clone band of P.

Physicochemical roles of soluble metal cations in the outer membrane of Escherichia coli K-12.

Atomic absorption spectroscopy of isolated native and EDTA-modified (lipopolysaccharide-depleted) outer membrane revealed trace amounts of potassium, manganese, and iron (1.0-7.0 nmol/mg dry weight outer membrane).

Gentamicin interaction with Pseudomonas aeruginosa cell envelope.

Gentamicin, an aminoglycoside antibiotic known to inhibit protein synthesis, had a detrimental effect on the integrity of the cell wall of Pseudomonas aeruginosa ATCC 9027 (a susceptible strain) as shown by electron microscopy using negative-staining, thin-sectioning, and freeze-fracture techniques. The disruption occurred in a sequential manner, moving from the outer membrane to the inner membrane, and could result in lysis of the cell. During this process the outer membrane lost 34% of its total protein and 30% of its lipopolysaccharide (measured as 2-keto-3-deoxyoctonate) upon exposure to 25 micrograms of gentamicin per ml for 15 min.

Two patterns in the Aeromonas salmonicida A-layer may reflect a structural transformation that alters permeability.

Electron micrographs of negatively stained regular surface layers (A-layers) of Aeromonas salmonicida showed two square patterns having p4 symmetry. Computer image processing demonstrated that, at a resolution of 2.3 nm, both square arrays were composed of two different morphological units arranged alternatively to give a face-centered lattice in which the four nearest neighbors of each unit were the other type of unit.

Lipopolysaccharide changes and cytoplasmic polyphosphate granule accumulation in Pseudomonas aeruginosa during growth on hexadecane.

Pseudomonas aeruginosa ATCC 9027 grew on 0.5% (v/v) hexadecane as a sole carbon source in a chemically defined medium which required the addition of Fe3+ and Ca2+. There was a variable and extended lag period before an active growth rate was attained.

Site specificity of metallic ion binding in Escherichia coli K-12 lipopolysaccharide.

The site specificity of metallic ion binding in Escherichia coli K-12 lipopolysaccharide was assessed by collecting high-resolution phosphorus nuclear magnetic resonance spectra in the presence of manganese, a paramagnetic divalent cation. This technique revealed high-affinity interactions between the cation and all of the lipopolysaccharide phosphoryl groups. To ascertain whether the carboxyl groups of 2-keto-3-deoxyoctonate contributed to the metal cation binding, lipopolysaccharide was chemically modified using a glycine ethyl ester - carbodiimide reaction.