Staphylococcal polysaccharide products inhibitory to Staphylococcus aureus bacteriophage

1975 ◽  
Vol 21 (8) ◽  
pp. 1178-1184
Author(s):  
E. R. Scheer ◽  
B. W. Koft
Keyword(s):  
Amino Acids ◽  
Staphylococcus Aureus ◽  
Inhibitory Activity ◽  
Uronic Acid ◽  
Active Material ◽  
Carbohydrate Content ◽  
Exact Nature ◽  
High Carbohydrate

Four products derived from Staphylococcus aureus cultures were partially purified and tested for inhibitory activity against staphylococcal phage. Phage inhibition, a specific stable phenomenon, was concentration dependent. All inhibitory products contained carbohydrate and amino acids, the most active (phage 73 lysate product) having a high carbohydrate content. Galactose, glucosamine, five or six amino acids, and possibly 3-O-methylglucose and a uronic acid were found as components in all active preparations. However, the exact nature of the active material remains undetermined.

Chemical composition of cell walls of Saccharomyces fragilis

1969 ◽  
Vol 15 (9) ◽  
pp. 989-993 ◽  
Author(s):  
T. Reuvers ◽  
E. Tacoronte ◽  
C. Garcia Mendoza ◽  
M. Novaes-Ledieu
Keyword(s):  
Amino Acids ◽  
Chemical Composition ◽  
Cell Walls ◽  
Carbohydrate Content ◽  
Positive Component ◽  
High Carbohydrate ◽  
Mechanical Disruption

Cell walls of Saccharomyces fragilis grown in two different media were prepared by mechanical disruption, and their chemical composition was studied. A high carbohydrate content (75–80%) was found in these walls. Glucose and mannose were represented in a ratio 1:1 in both cases; cell walls also contained a small amount of glucosamine. Sixteen common amino acids were detected in S. fragilis wall hydrolysates. One unidentified ninhydrin-positive component was present when the organism was grown in Hansen medium. A low percentage of lipid was found in both walls. The significance of all these data is discussed in the light of the difficulties encountered in the preparation and purification of walls.

scholarly journals SosA inhibits cell division inStaphylococcus aureusin response to DNA damage

2018 ◽  
Author(s):  
Martin S. Bojer ◽  
Katarzyna Wacnik ◽  
Peter Kjelgaard ◽  
Clement Gallay ◽  
Amy L. Bottomley ◽  
...  
Keyword(s):  
Amino Acids ◽  
Staphylococcus Aureus ◽  
Dna Damage ◽  
Cell Division ◽  
Inhibitory Activity ◽  
Cell Swelling ◽  
Bacterial Cells ◽  
Human Pathogen ◽  
Cell Division Inhibition ◽  
Cell Division Inhibitor

AbstractInhibition of cell division is critical for cell viability under DNA damaging conditions. In bacterial cells, DNA damage induces the SOS response, a process that inhibits cell division while repairs are being made. In coccoid bacteria, such as the human pathogenStaphylococcus aureus, the process remains poorly understood. Here we have characterized an SOS-induced cell-division inhibitor, SosA, inS. aureus. We find that in contrast to the wildtype,sosAmutant cells continue division under DNA damaging conditions with decreased viability as a consequence. Conversely, overproduction of SosA leads to cell division inhibition and reduced growth. The SosA protein is localized in the bacterial membrane and mutation of an extracellular amino acid, conserved between homologs of other staphylococcal species, abolished the inhibitory activity as did truncation of the C-terminal 30 amino acids. In contrast, C-terminal truncation of 10 amino acids lead to SosA accumulation and a strong cell division inhibitory activity. A similar phenotype was observed upon expression of wildtype SosA in a mutant lacking the membrane protease, CtpA. Thus, the extracellular C-terminus of SosA is required both for cell-division inhibition and for turnover of the protein. Functional studies showed that SosA is likely to interact with one or more divisome components and, without interfering with early cell-division events, halts cell division at a point where septum formation is initiated yet being unable to progress to septum closure. Our findings provide important insights into cell-division regulation in staphylococci that may foster development of new classes of antibiotics targeting this essential process.ImportanceStaphylococcus aureusis a serious human pathogen and a model organism for cell-division studies in spherical bacteria. We show that SosA is the DNA-damage-inducible cell-division inhibitor inS. aureusthat upon expression causes cell swelling and cessation of the cell cycle at a characteristic stage post septum initiation but prior to division plate completion. SosA appears to function via an extracellular activity and is likely to do so by interfering with the essential membrane-associated division proteins, while at the same time being negatively regulated by the membrane protease CtpA. This report represents the first description of the process behind cell-division inhibition in coccoid bacteria. As several pathogens are included in this category, uncovering the molecular details of SosA activity and control can lead to identification of new targets for development of valuable anti-bacterial drugs.

The Study of Bacillus Subtils Antimicrobial Activity on Some of the Pathological Isolates

2019 ◽  
Vol 9 (02) ◽  
Author(s):  
Hussein A Kadhum ◽  
Thualfakar H Hasan2
Keyword(s):  
Staphylococcus Aureus ◽  
Pseudomonas Aeruginosa ◽  
Antimicrobial Activity ◽  
Bacillus Subtilis ◽  
Bacterial Growth ◽  
Broad Spectrum ◽  
Inhibitory Activity ◽  
Bacterial Pathogens ◽  
Inhibitory Ability ◽  
Selection Of

The study involved the selection of two isolates from Bacillus subtilis to investigate their inhibitory activity against some bacterial pathogens. B sub-bacteria were found to have a broad spectrum against test bacteria such as Staphylococcus aureus and Pseudomonas aeruginosa. They were about 23-30 mm and less against Klebsiella sp. The sensitivity of some antibodies was tested on the test samples. The results showed that the inhibitory ability of bacterial growth in the test samples using B. subtilis extract was more effective than the antibiotics used.

Inhibitory Activity of Brown Propolis Extracts on a Norfloxacin-Resistant Strain of Staphylococcus aureus

2021 ◽  
Author(s):  
Vanessa Moreira Frota ◽  
Francisco Matheus F. Dias ◽  
Mariana Ferreira do Nascimento ◽  
Lavosyer da Silva Mendonça ◽  
Emanuella Cristina dos Santos Moita ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Inhibitory Activity ◽  
Resistant Strain

scholarly journals Genome-Wide Identification of Resveratrol Intrinsic Resistance Determinants in Staphylococcus aureus

Antibiotics ◽  
2021 ◽  
Vol 10 (1) ◽  
pp. 82
Author(s):  
Liping Liu ◽  
Hanne Ingmer ◽  
Martin Vestergaard
Keyword(s):  
Staphylococcus Aureus ◽  
Stress Response ◽  
Inhibitory Activity ◽  
Bacterial Species ◽  
Dna Integrity ◽  
Intrinsic Resistance ◽  
Potential Health ◽  
Cellular Effects ◽  
Development Of Resistance ◽  
Wide Range

Resveratrol has been extensively studied due to its potential health benefits in multiple diseases, for example, cancer, obesity and cardiovascular diseases. Besides these properties, resveratrol displays inhibitory activity against a wide range of bacterial species; however, the cellular effects of resveratrol in bacteria remain incompletely understood, especially in the human pathogen, Staphylococcus aureus. In this study, we aimed to identify intrinsic resistance genes that aid S. aureus in tolerating the activity of resveratrol. We screened the Nebraska Transposon Mutant Library, consisting of 1920 mutants with inactivation of non-essential genes in S. aureus JE2, for increased susceptibly to resveratrol. On agar plates containing 0.5× the minimum inhibitory concentration (MIC), 17 transposon mutants failed to grow. Of these, four mutants showed a two-fold reduction in MIC, being the clpP protease mutant and three mutants with deficiencies in the electron transport chain (menD, hemB, aroC). The remaining 13 mutants did not show a reduction in MIC, but were confirmed by spot-assays to have increased susceptibility to resveratrol. Several genes were associated with DNA damage repair (recJ, xerC and xseA). Treatment of S. aureus JE2 with sub-inhibitory concentrations of resveratrol did not affect the expression of recJ, xerC and xseA, but increased expression of the SOS–stress response genes lexA and recA, suggesting that resveratrol interferes with DNA integrity in S. aureus. Expression of error-prone DNA polymerases are part of the SOS–stress response and we could show that sub-inhibitory concentrations of resveratrol increased overall mutation frequency as measured by formation of rifampicin resistant mutants. Our data show that DNA repair systems are important determinants aiding S. aureus to overcome the inhibitory activity of resveratrol. Activation of the SOS response by resveratrol could potentially facilitate the development of resistance towards conventional antibiotics in S. aureus.

Growth of human diploid cells (strain MRC-5) in defined medium; replacement of serum by a fraction of serum ultrafiltrate

1979 ◽  
Vol 35 (1) ◽  
pp. 381-392
Author(s):  
K. Lambert ◽  
S.J. Pirt
Keyword(s):  
Amino Acids ◽  
Active Material ◽  
Maximum Yield ◽  
Calf Serum ◽  
Defined Medium ◽  
Cell Yield ◽  
Maximum Cell ◽  
Macromolecular Component ◽  
Human Diploid Cells ◽  
Diploid Cells

A calf serum ultrafiltrate fraction permitted growth for at least 3.5 generations, including one subculture, of MRC-5 cells in defined medium in the absence of whole serum. The active material has a molecular weight of 10 000 Daltons or less. This suggests that there may be no requirement for a large macromolecular component of serum. The ultrafiltrate was assayed by maximum cell yield from a serum-limited inoculum in a defined medium containing non-limiting amounts of vitamins, amino acids, glucose, a 68-component supplement, iron and methylcellulose. The levels of vitamins, amino acids and glucose were based on quantitative measurements of uptake and the levels of the other components by minimum amount required for maximum yield in defined medium without ultrafiltrate or serum. With excess ultrafiltrate maximum cell yield was limited by the defined part of the medium, probably the supplement. The cell doubling time in defined medium with ultrafiltrate fractions was 70 h compared with 27 h in the medium with serum. Excess ultrafiltrate did not inhibit growth. The lowered growth rate is attributed to a nutritional deficiency in the supplement.

Differential Effects of High-fat and High-carbohydrate Content Isoenergetic Meals on Plasma Active Ghrelin Concentrations in Lean and Obese Women

2004 ◽  
Vol 36 (8) ◽  
pp. 559-563 ◽  
Author(s):  
N. Tentolouris ◽  
A. Kokkinos ◽  
C. Tsigos ◽  
D. Kyriaki ◽  
J. Doupis ◽  
...  
Keyword(s):  
Carbohydrate Content ◽  
Obese Women ◽  
High Fat ◽  
Differential Effects ◽  
High Carbohydrate

scholarly journals The anti hypertensive nutraceuticals of Vigna sp bean protein hydrolized by alcalase and flavourzyme

2020 ◽  
Vol 2 (1) ◽  
pp. 63-73
Author(s):  
Tejasari ◽  
Sih Yuwanti ◽  
Mohammad Bazar Ahmadi ◽  
Yuna Luki Afsari
Keyword(s):  
Amino Acids ◽  
G Protein ◽  
Inhibitory Activity ◽  
Protein Hydrolysate ◽  
Protein Hydrolysates ◽  
Small Molecular Weight ◽  
Hydrophobic Amino Acids ◽  
Prevention Of Hypertension ◽  
Hydrolysis Of ◽  
Bean Protein

Peptide with hydrophobic amino acids had been studied for their inhibitory activity against angiotensin-I converting enzyme (ACE-1) transformation into ACE-2 and prevention of hypertension. The active peptides may come from alcalase and flavourzyme hydrolysis of bean protein. This study aimed to measure ACE-1 inhibitory of protein hydrolysates from Vigna sp. bean (mung bean and cowpea) that grew in Indonesia, and its solubility. The bean protein (22.9 - 23.6 %) was extracted using isoelectric precipitation at pH 4-4.6. The extracts were hydrolyzed at pH 8 for alcalase and pH 7 for flavourzyme, followed with inactivation at 80-85 oC. ACE-1 inhibitory activity was calculated based on the amount of hippuric acid (HA) formed by the hydrolysis of Hippuryl-His-Leu (HHL), in spectrophotometry detection method (228 nm). Ultrachromatography evaluation showed that the protein hydrolysates of mungbean contained higher hydrophobic amino acids (382 mg/g protein) compared to those of cowpea (329 mg/g protein). Protein hydrolysates of both beans from alcalase hydrolysis have higher ACE-1 inhibitory activity rather than those from flavourzyme. Protein hydrolysate from Vigna spp bean protein hydrolysis by alcalase, contained small molecular weight peptides (3.9-4.63 kDa) and high ACE-1 inhibition ability (80-93 %), and therefore suggested as antihypertensive nutraceuticals. Highest solubility of protein hydrolysates resulted from alcalase hydrolysis of both beans were observed at pH 8, while those resulted from flavorzyme hydrolysis were at pH 7, respectively.

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