Haemophilus vaginalis 594, a Gram-negative organism?

1971 ◽  
Vol 17 (7) ◽  
pp. 865-869 ◽  
Author(s):  
B. Sue Criswell ◽  
Judith H. Marston ◽  
Wayne A. Stenback ◽  
S. H. Black ◽  
Herman L. Gardner
Keyword(s):  
Escherichia Coli ◽  
Amino Acids ◽  
Cell Wall ◽  
Bacillus Megaterium ◽  
Teichoic Acid ◽  
Biochemical Properties ◽  
Positive Bacterium ◽  
Gram Negative ◽  
Bacterium Bacillus ◽  
Escherichia Coli B

The fine structure of Haemophilus vaginalis 594 (ATCC 14018) was examined by electron microscopy, and the biochemical composition of its cell wall was determined. For comparison, similar studies were done with a Gram-positive bacterium, Bacillus megaterium KM, and a Gram-negative bacterium, Escherichia coli B. Both Haemophilus vaginalis 594 and Escherichia coli B possessed a multiple-layered cell wall containing 11 to 14 amino acids, a low mucopeptide content, and no teichoic acid. In contrast, Bacillus megaterium KM had a thick, amorphous cell wall with five amino acids, high mucopeptide content, and detectable amounts of teichoic acid. Haemophilus vaginalis 594 resembled Escherichia coli, a member of the Gram-negative group of organisms. The structural and biochemical properties of Haemophilus vaginalis, which are described in detail, may prove useful in determining the ultimate taxonomic position of this species.

Alkaloids of Anuran Skin: Antimicrobial Function?

2005 ◽  
Vol 60 (11-12) ◽  
pp. 932-937 ◽  
Author(s):  
Cyrus Macfoy ◽  
Douglas Danosus ◽  
Raj Sandit ◽  
Tappey H. Jones ◽  
H. Martin Garraffo ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Skin Infections ◽  
Negative Bacterium ◽  
Positive Bacterium ◽  
Gram Negative ◽  
Poison Frogs ◽  
E Coli ◽  
Antimicrobial Function ◽  
Bacterium Bacillus Subtilis ◽  
Bacterium Bacillus

A variety of alkaloids, most of which occur or are structurally related to alkaloids that occur in skin glands of dendrobatid poison frogs, were assayed for antimicrobial activity against the Gram-positive bacterium Bacillus subtilis, the Gram-negative bacterium Escherichia coli and the fungus Candida albicans. Certain pyrrolidines, piperidines and decahydroquinolines, perhydro-histrionicotoxin, and a synthetic pumiliotoxin were active against B. subtilis. Only 2-n-nonylpiperidine was active against E. coli. One pyrrolidine, two piperidines, two decahydroquinolines, and the synthetic pumiliotoxin were active against the fungus C. albicans. The results suggest that certain of the skin alkaloids of poison frogs, in addition to being noxious to predators, may also benefit the frog through protection against skin infections.

Sites of Adsorption of the Bacteriophages T3 and T5 on the Wall of Escherichia Coli B.

1967 ◽  
Vol 25 ◽  
pp. 96-97
Author(s):  
Manfred E. Bayer
Keyword(s):  
Escherichia Coli ◽  
Cell Wall ◽  
Electron Microscope ◽  
Uranyl Acetate ◽  
E Coli ◽  
Receptor Sites ◽  
Rigid Cell Wall ◽  
Host Cell Surface ◽  
Bacterial Viruses ◽  
Escherichia Coli B

Bacterial viruses adsorb specifically to receptors on the host cell surface. Although the chemical composition of some of the cell wall receptors for bacteriophages of the T-series has been described and the number of receptor sites has been estimated to be 150 to 300 per E. coli cell, the localization of the sites on the bacterial wall has been unknown.When logarithmically growing cells of E. coli are transferred into a medium containing 20% sucrose, the cells plasmolize: the protoplast shrinks and becomes separated from the somewhat rigid cell wall. When these cells are fixed in 8% Formaldehyde, post-fixed in OsO4/uranyl acetate, embedded in Vestopal W, then cut in an ultramicrotome and observed with the electron microscope, the separation of protoplast and wall becomes clearly visible, (Fig. 1, 2). At a number of locations however, the protoplasmic membrane adheres to the wall even under the considerable pull of the shrinking protoplast. Thus numerous connecting bridges are maintained between protoplast and cell wall. Estimations of the total number of such wall/membrane associations yield a number of about 300 per cell.

scholarly journals Characterization of the 6'-N-aminoglycoside acetyltransferase gene aac(6')-Im [corrected] associated with a sulI-type integron.

1997 ◽  
Vol 41 (2) ◽  
pp. 314-318 ◽  
Author(s):  
E Hannecart-Pokorni ◽  
F Depuydt ◽  
L de wit ◽  
E van Bossuyt ◽  
J Content ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Amino Acids ◽  
Amino Acid ◽  
Resistance Gene ◽  
Citrobacter Freundii ◽  
Gram Negative ◽  
Gene Environment ◽  
Insert Region ◽  
Klebsiella Spp

The amikacin resistance gene aac(6')-Im [corrected] from Citrobacter freundii Cf155 encoding an aminoglycoside 6'-N-acetyltransferase was characterized. The gene was identified as a coding sequence of 521 bp located down-stream from the 5' conserved segment of an integron. The sequence of this aac(6')-Im [corrected] gene corresponded to a protein of 173 amino acids which possessed 64.2% identity in a 165-amino-acid overlap with the aac(6')-Ia gene product (F.C. Tenover, D. Filpula, K.L. Phillips, and J. J. Plorde, J. Bacteriol. 170:471-473, 1988). By using PCR, the aac(6')-Im [corrected] gene could be detected in 8 of 86 gram-negative clinical isolates from two Belgian hospitals, including isolates of Citrobacter, Klebsiella spp., and Escherichia coli. PCR mapping of the aac(6')-Im [corrected] gene environment in these isolates indicated that the gene was located within a sulI-type integron; the insert region is 1,700 bases long and includes two genes cassettes, the second being ant (3")-Ib.

Purification of an exo-1,3-β-glucanase from Candida utilis

1976 ◽  
Vol 54 (11) ◽  
pp. 927-934 ◽  
Author(s):  
T. G. Villa ◽  
V. Notario ◽  
T. Benítez ◽  
J. R. Villanueva
Keyword(s):  
Amino Acids ◽  
Heavy Metal ◽  
Cell Wall ◽  
Heavy Metal Ions ◽  
Candida Utilis ◽  
Negative Charge ◽  
Hydrolysis Product ◽  
Culture Fluid ◽  
Biochemical Properties ◽  
Acidic Amino Acids

An exo-1,3-β-glucanase (EC 3.2.1.—) has been purified from the culture fluid of the yeast Candida utilis, and its biochemical properties have been studied. The amino acid analysis revealed a high content of acidic amino acids. The purified enzyme had 20% carbohydrate and a net negative charge showing higher affinity for laminarin than for p-nitrophenyl-β-D-glucopyranoside and yeast cell-wall 1,3-β-glucans. In addition, the enzyme hydrolyzed the substrates starting from the nonreducing ends, releasing glucose as the exclusive hydrolysis product. The enzyme activity was strongly inhibited by lactones and also by some heavy-metal ions.

Propriétés physiques et chimiques des tryptophanases de cinq espèces d'Entérobactériaceae

1975 ◽  
Vol 21 (6) ◽  
pp. 828-833 ◽  
Author(s):  
C. Simard ◽  
A. Mardini ◽  
L. M. Bordeleau
Keyword(s):  
Escherichia Coli ◽  
Amino Acids ◽  
Molecular Weight ◽  
Sedimentation Coefficient ◽  
Species Differentiation ◽  
Proteus Vulgaris ◽  
Amino Acids Composition ◽  
Propriétés Physiques ◽  
Tryptophan Content ◽  
Escherichia Coli B

The molecular weight, sedimentation coefficient, and amino acids composition were determined on five tryptophanases (TPases) from Escherichia coli B and E. aurescens, Shigella alkalescens, and Proteus vulgaris and P. morganii. These TPases have identical sedimentation profile and coefficient (9.6 S), and the same molecular weight (220 000). Each enzyme is constituted of four identical subunits having a molecular weight of 55 000. The amino acids composition of these TPases is very similar, with the exception of P. morganii and P. vulgaris TPases which present significative variations in basic amino acids and tryptophan content. The species differentiation of the coli group cannot be made on their TPase characteristics only, contrary to P. morganii and P. vulgaris which can be differentiated between them and from the coli group. [Journal translation]

scholarly journals Interactions between Penicillin-Binding Proteins (PBPs) and Two Novel Classes of PBP Inhibitors, Arylalkylidene Rhodanines and Arylalkylidene Iminothiazolidin-4-ones

2004 ◽  
Vol 48 (3) ◽  
pp. 961-969 ◽  
Author(s):  
Astrid Zervosen ◽  
Wei-Ping Lu ◽  
Zhouliang Chen ◽  
Ronald E. White ◽  
Thomas P. Demuth ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Cell Wall ◽  
Cell Wall Synthesis ◽  
Bacterial Strains ◽  
Gram Negative ◽  
Penicillin Binding Proteins ◽  
E Coli ◽  
Peptidoglycan Biosynthesis ◽  
Vancomycin Resistant ◽  
Inhibitory Activities

ABSTRACT Several non-β-lactam compounds were active against various gram-positive and gram-negative bacterial strains. The MICs of arylalkylidene rhodanines and arylalkylidene iminothiazolidin-4-ones were lower than those of ampicillin and cefotaxime for methicillin-resistant Staphylococcus aureus MI339 and vancomycin-resistant Enterococcus faecium EF12. Several compounds were found to inhibit the cell wall synthesis of S. aureus and the last two steps of peptidoglycan biosynthesis catalyzed by ether-treated cells of Escherichia coli or cell wall membrane preparations of Bacillus megaterium. The effects of the arylalkylidene rhodanines and arylalkylidene iminothiazolidin-4-one derivatives on E. coli PBP 3 and PBP 5, Streptococcus pneumoniae PBP 2xS (PBP 2x from a penicillin-sensitive strain) and PBP 2xR (PBP 2x from a penicillin-resistant strain), low-affinity PBP 2a of S. aureus, and the Actinomadura sp. strain R39 and Streptomyces sp. strain R61 dd-peptidases were studied. Some of the compounds exhibited inhibitory activities in the 10 to 100 μM concentration range. The inhibition of PBP 2xS by several of them appeared to be noncompetitive. The dissociation constant for the best inhibitor (Ki = 10 μM) was not influenced by the presence of the substrate.

scholarly journals Recycling of the Anhydro-N-Acetylmuramic Acid Derived from Cell Wall Murein Involves a Two-Step Conversion to N-Acetylglucosamine-Phosphate

2005 ◽  
Vol 187 (11) ◽  
pp. 3643-3649 ◽  
Author(s):  
Tsuyoshi Uehara ◽  
Kyoko Suefuji ◽  
Noelia Valbuena ◽  
Brian Meehan ◽  
Michael Donegan ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Amino Acids ◽  
Cell Wall ◽  
Deletion Mutant ◽  
Biosynthetic Pathway ◽  
Reverse Genetics ◽  
Side Wall ◽  
Cell Extract ◽  
Amino Sugars ◽  
Kinase Gene

ABSTRACT Escherichia coli breaks down over 60% of the murein of its side wall and reuses the component amino acids to synthesize about 25% of the cell wall for the next generation. The amino sugars of the murein are also efficiently recycled. Here we show that the 1,6-anhydro-N-acetylmuramic acid (anhMurNAc) is returned to the biosynthetic pathway by conversion to N-acetylglucosamine-phosphate (GlcNAc-P). The sugar is first phosphorylated by anhydro- N -acetylmuramic acid kinase (AnmK), yielding MurNAc-P, and this is followed by action of an etherase which cleaves the bond between d-lactic acid and the N-acetylglucosamine moiety of MurNAc-P, yielding GlcNAc-P. The kinase gene has been identified by a reverse genetics method. The enzyme was overexpressed, purified, and characterized. The cell extract of an anmK deletion mutant totally lacked activity on anhMurNAc. Surprisingly, in the anmK mutant, anhMurNAc did not accumulate in the cytoplasm but instead was found in the medium, indicating that there was rapid efflux of free anhMurNAc.

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