Gram-negative bacteria Pseudomonas

The effects of ultrasound upon the permeability of the cell walls of the gram-negative bacteria Pseudomonas aeruginosa toward hydrophobic compounds particularly antibiotics have been examined [8]. The penetration and distribution of 16-dosylstearic acid (16-DS) in the cell membranes of the bacteria was quantified by a spin-labeling electron spin resonance (ESR) method. The results indicated that the intracellular concentration of 16- D S was higher in insonated cells and increased linearly with the sonication power. 

Gram (Gram s Stain) A method for separating bacteria whereby bacteria are stained first with crystal violet (a red dye) and then washed with an iodine solution. Gram positive bacteria (Bacillus) retain the dye. Gram negative bacteria (Pseudomonas and some Bacillus) lose the dye. 

Natural Products and Related Substances - A basic peptide fraction of bee venom exhibits powerful antllnflanmatory effects In the carrageenln paw and adjuvant rat tests 13 vdiole bee venom is Ineffective in adjuvant arthritis in adrenalectomlzed rats 135 lymphocyte chalone concentrate from spleen exhibits immunosuppressive properties 13 vitamin A stimulates humoral and cell-mediated responsel37 and vitamin E exerts antiinflammatory effects in rats and on htiman skin.138 Improved methods of purification preparation and characterization of immunosuppressive material derived from bovine serum l39 antiinflammatory material from human plasma or gram-negative bacteria (Pseudomona aeruginosa),1 1 were described. 

Fosfadecin (186) and fosfocytocin (187) are adenine and cytosine nucleotide antibiotics isolated from the culture filtrates of Pseudomonas viridiflava PK-5 and P. fluorescens PK-52, respectively (283). Hydrolysis produces fosfoxacin which is also isolated from the culture filtrates. Compounds (186) and (187) inhibit gram-positive and gram-negative bacteria. 

Gram negative Bacteria cells which lose the crystal violet during the decolorizing step and are then colored by the counterstain. Pseudomonas and Thiobacillus are examples of gram negative strains. 

These compounds showed a remarkable activity toward Gram-positive (e.g.. Bacillus cereus, Staphylococcus aureus, Sarcina luted) and Gram-negative bacteria (e.g.. Pseudomonas sp.) the activity was somewhat lower in the styryl derivatives (82MI2). 

The combined intrinsic activities of different efflux pumps play a major role for the intrinsic resistance of Gram-negative bacteria to macrolides and oxazolidi-nones as well as to the intrinsic resistance of Pseudomonas aeruginosa against a broad range of disinfectants and antibiotics. 

In Gram-negative bacteria, diffusion of (3-lactam antibiotics into the periplasm (where the activity of PBPs takes place) occurs via the channels that porins create in the outer membrane. The number and properties of the porin molecules are such that diffusion is relatively rapid in E. coli but much slower in Enterobacter and Pseudomonas. Mutants can be selected after the permeability of porin channels or their number has been decreased. A slow diffusion into... 

A. Kleeberger, H. Castorph, and W. Klingmuller, The rhizosphere microflora of wheat and barley with special reference to gram-negative bacteria (Enterohacter agglomerans. Pseudomonas ]iuore.scens). Arch. Microbiol. 136 306 (1983). 

Endotoxin. Endotoxin is the lipopolysaccharide that comprises a major portion of the cell wall of the gram-negative bacteria. The endotoxins from each species of bacteria are different but the lipid A moiety is similar for the Enterobacterlaceae, and has a similar series of biological actions regardless of its source. The lipid A material is different in some of the gram-negative rods present in cotton (i.e. in the Pseudomonas species). This variety of compounds makes quantitation of endotoxin difficult. Hence, it is usually measured by its biological activity as compared to a standard endotoxin (usually that of E. coll). (See Table VIII.)... 

It is nearly 50 years since a c-type cytochrome was shown to catalyze peroxidase activity in crude extracts of Pseudomonas fluorescens (40). The enzyme responsible was first purified some 20 years later by Ell-folk and Soninen from the closely related P. aeruginosa and shown to be a diheme cytochrome c peroxidase (CCP) (41). These bacterial diheme CCPs are quite distinct from the superfamily of plant and yeast peroxidases (42) and are widely distributed among the Gram-negative bacteria (41, 43 6). Diheme CCPs are located in the periplasm (Fig. 2), where they catalyze the two-electron reduction of H2O2 to H2O by soluble one-electron donors such as cytochromes c and cupredoxins. 

Urinary tract infections are very commonly caused by Gram-negative bacteria such as Escherichia coli, the Proteus species and Pseudomonas species. 

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