scholarly journals Antibacterial Effects of Unripe Cephalotaxus harringtonia Fruit Extract on Gram-positive Bacteria

2009 ◽  
Vol 56 (10) ◽  
pp. 533-540 ◽  
Author(s):  
Kentaroh Watanabe ◽  
Tadashi Fukao
Keyword(s):  
Antibacterial Effects ◽  
Fruit Extract ◽  
Gram Positive ◽  
Gram Positive Bacteria

scholarly journals Antibacterial effects of commercially available phosphates on selected microorganisms

2008 ◽  
Vol 56 (5) ◽  
pp. 19-24 ◽  
Author(s):  
Leona Buňková ◽  
Pavel Pleva ◽  
František Buňka ◽  
Pavel Valášek ◽  
Stanislav Kráčmar
Keyword(s):  
Inhibitory Effect ◽  
Gram Negative Bacteria ◽  
Bacterial Strains ◽  
Inhibitory Effects ◽  
Antibacterial Effects ◽  
Gram Positive ◽  
Gram Negative ◽  
Gram Positive Bacteria ◽  
The Individual ◽  
Phosphate Salts

In the food industry, phosphates, polyphosphates and their salts are used, for example, as emul­si­fying agents in the production of processed cheese. The inhibitory effects of three commercially avai­la­ble phosphates and polyphosphates differing in their chain length (690, S9 and HBS) were tested on a set of 15 gram-positive or gram-negative CCM (Czech Collection of Microorganisms) strains and on 12 bacterial strains isolated from processed cheeses. Five different concentrations of each phosphate were chosen (0.1, 0.2, 0.3, 0.4 and 0.5% w/v) in order to observe the inhibitory effects of the phosphate salts on the growth of the microorganisms tested. Sensitivity of the individual bacterial strains to phosphates was observed of a liquid cultivation medium which was supplemented with applied salts. Subsequently, the growth in cells was determined by measuring optical density at a wavelength of 600 nm. According to the results, 690 and S9 phosphates, containing mainly orthophosphates, diphosphates (pyrophosphates) and short-chain polyphosphates, do not have a significant inhibitory effect on the growth of the tested bacteria. Significant inhibitory effects were observed only in HBS salt (a mixture of long-chain polyphosphates), which showed antibacterial effects on all gram-positive bacteria tested (both the CCM strains and those isolated from processed cheeses). The antibacterial effect of phosphates on gram-positive microorganisms is growing with the increasing length of the polyphosphate chain. This study has not proved a significant effect of the phosphates tested on the growth of gram-negative bacteria used.

scholarly journals Two Proteins From Snake Venom Have Potent Antibacterial Effects Against Bacillus Anthracis and Streptococcus Pneumoniae

2020 ◽  
Vol 14 (3) ◽  
pp. 139-144
Author(s):  
Mahboobeh Talebi Mehrdar ◽  
Keyword(s):  
Streptococcus Pneumoniae ◽  
Bacillus Anthracis ◽  
Snake Venom ◽  
Inhibitory Effects ◽  
Antibacterial Effects ◽  
Gram Positive ◽  
E Coli ◽  
Molecular Weights ◽  
Gram Positive Bacteria ◽  
Sds Page

Background: Antibacterial proteins are widely expressed in snake venoms. Previously, we have isolated two immunodominant proteins with molecular weights of 14 and 65 kD from the snake venom of Naja naja oxiana (N. oxiana). It was demonstrated that they had potent inhibitory effects against gram-positive bacteria, S. aureus and B. subtilis but were less effective against gram-negative bacteria, such as E. coli and P. aeruginosa. This study aimed at investigating the potential antibacterial effects of the two proteins against Bacillus anthracis and Streptococcus pneumoniae. Methods: The proteins were identified by SDS-PAGE and western blot analysis, and isolated by Gel Electrophoresis (Electro-elution). The antibacterial effects were tested against the strains of Bacillus anthracis and Streptococcus pneumoniae, using broth microdilution and disc-diffusion assays. For comparison, the antibacterial effects of standard antibiotics, such as Gentamicin, Ampicillin, Penicillin, Amoxicillin and Ciprofloxacin were also tested on the same B. anthracis and S. pneumoniae batches under identical laboratory conditions. Results: The two proteins showed high immunogenicity and strongly inhibited the growth of gram-positive bacteria, B. anthracis, and to a lesser extent S. pneumoniae. Conclusion: The isolated proteins demonstrated strong antibacterial effects against Gram-positive bacteria, B. anthracis and S. pneumoniae, in addition to their previously known effects against S. aureus and B. subtilis.

Influence of Cell Wall Composition on the Fossilisation of Bacteria and the Implications for the Search for Early Life Forms

1997 ◽  
Vol 161 ◽  
pp. 491-504 ◽  
Author(s):  
Frances Westall
Keyword(s):  
Cell Wall ◽  
Life Forms ◽  
Cation Binding ◽  
Positive Bacterium ◽  
Gram Positive ◽  
Gram Positive Bacteria ◽  
Transmission Electron ◽  
Hydrothermal Sediments ◽  
Identification Of Bacteria ◽  
The Difference

AbstractThe oldest cell-like structures on Earth are preserved in silicified lagoonal, shallow sea or hydrothermal sediments, such as some Archean formations in Western Australia and South Africa. Previous studies concentrated on the search for organic fossils in Archean rocks. Observations of silicified bacteria (as silica minerals) are scarce for both the Precambrian and the Phanerozoic, but reports of mineral bacteria finds, in general, are increasing. The problems associated with the identification of authentic fossil bacteria and, if possible, closer identification of bacteria type can, in part, be overcome by experimental fossilisation studies. These have shown that not all bacteria fossilise in the same way and, indeed, some seem to be very resistent to fossilisation. This paper deals with a transmission electron microscope investigation of the silicification of four species of bacteria commonly found in the environment. The Gram positiveBacillus laterosporusand its spore produced a robust, durable crust upon silicification, whereas the Gram negativePseudomonas fluorescens, Ps. vesicularis, andPs. acidovoranspresented delicately preserved walls. The greater amount of peptidoglycan, containing abundant metal cation binding sites, in the cell wall of the Gram positive bacterium, probably accounts for the difference in the mode of fossilisation. The Gram positive bacteria are, therefore, probably most likely to be preserved in the terrestrial and extraterrestrial rock record.

Microanatomy of the Periplasm of Bacillus Licheniformis

1971 ◽  
Vol 29 ◽  
pp. 262-263
Author(s):  
B.K. Ghosh
Keyword(s):  
Cell Wall ◽  
Plasma Membrane ◽  
Bacillus Licheniformis ◽  
External Environment ◽  
Permeability Barrier ◽  
Periplasmic Space ◽  
Modified Technique ◽  
Gram Positive ◽  
Gram Negative ◽  
Gram Positive Bacteria

Periplasm of bacteria is the space outside the permeability barrier of plasma membrane but enclosed by the cell wall. The contents of this special milieu exterior could be regulated by the plasma membrane from the internal, and by the cell wall from the external environment of the cell. Unlike the gram-negative organism, the presence of this space in gram-positive bacteria is still controversial because it cannot be clearly demonstrated. We have shown the importance of some periplasmic bodies in the secretion of penicillinase from Bacillus licheniformis.In negatively stained specimens prepared by a modified technique (Figs. 1 and 2), periplasmic space (PS) contained two kinds of structures: (i) fibrils (F, 100 Å) running perpendicular to the cell wall from the protoplast and (ii) an array of vesicles of various sizes (V), which seem to have evaginated from the protoplast.

Rapid demonstration of septic or infectious arthritis due to Gram-negative bacteria

1992 ◽  
Vol 50 (1) ◽  
pp. 686-687
Author(s):  
Jacob S. Hanker ◽  
Paul R. Gross ◽  
Beverly L. Giammara
Keyword(s):  
Chronic Arthritis ◽  
Blood Cultures ◽  
Gram Negative Bacteria ◽  
Infectious Arthritis ◽  
Bacterial Arthritis ◽  
Gram Positive ◽  
Gram Negative ◽  
Gram Positive Bacteria

Blood cultures are positive in approximately only 50 per cent of the patients with nongonococcal bacterial infectious arthritis and about 20 per cent of those with gonococcal arthritis. But the concept that gram-negative bacteria could be involved even in chronic arthritis is well-supported. Gram stains are more definitive in staphylococcal arthritis caused by gram-positive bacteria than in bacterial arthritis due to gram-negative bacteria. In the latter situation where gram-negative bacilli are the problem, Gram stains are helpful for 50% of the patients; they are only helpful for 25% of the patients, however, where gram-negative gonococci are the problem. In arthritis due to gram-positive Staphylococci. Gramstained smears are positive for 75% of the patients.

Antibacterial activity of magnesium oxide nanoparticles prepared by Calcination method

2019 ◽  
Vol 10 (03) ◽  
Author(s):  
Elaf Ayad Kadhem ◽  
Miaad Hamzah Zghair ◽  
Sarah , Hussam H. Tizkam, Shoeb Alahmad Salih Mahdi ◽  
Hussam H. Tizkam ◽  
Shoeb Alahmad
Keyword(s):  
Antibacterial Activity ◽  
Magnesium Oxide ◽  
Diffusion Method ◽  
Oxide Nanoparticles ◽  
Gram Negative Bacteria ◽  
Gram Positive ◽  
Gram Negative ◽  
Gram Positive Bacteria ◽  
Magnesium Oxide Nanoparticles ◽  
Agar Disc

magnesium oxide nanoparticles (MgO NPs) were prepared by simple wet chemical method using different calcination temperatures. The prepared NPs were characterized by Electrostatic Discharge (ESD), Scanning Electron Microscope (SEM) and X-ray Diffraction (XRD). It demonstrates sharp intensive peak with the increase of crystallinty and increase of the size with varying morphologies with respect to increase of calcination temperature. Antibacterial studies were done on gram negative bacteria (E.coli) and gram positive bacteria (S.aureus) by agar disc diffusion method. The zones of inhibitions were found larger for gram positive bacteria than gram negative bacteria, this mean, antibacterial MgO NPs activity more active on gram positive bacteria than gram negative bacteria because of the structural differences. It was found that antibacterial activity of MgO NPs was found it has directly proportional with their concentration.

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