scholarly journals Innate Immune Responses of Human Neonatal Cells to Bacteria from the Normal Gastrointestinal Flora

2002 ◽  
Vol 70 (12) ◽  
pp. 6688-6696 ◽  
Author(s):  
Helen Karlsson ◽  
Christina Hessle ◽  
Anna Rudin
Keyword(s):  
Immune System ◽  
Mononuclear Cells ◽  
Innate Immune ◽  
Enzyme Linked Immunosorbent Assay ◽  
Bacterial Strains ◽  
Gram Positive ◽  
Gram Negative ◽  
Gram Positive Bacteria ◽  
Tnf Α ◽  
Adult Cells

ABSTRACT The hygiene hypothesis postulates that the prevalence of allergy has increased due to decreased microbial stimulation early in life, leading to delayed maturation of the immune system. The aim of this study was to examine the cytokine pattern produced from cord blood mononuclear cells relative to adult cells after stimulation with bacterial strains from the normal flora. Mononuclear cells from cord and adult blood samples were stimulated with the following bacteria: Bifidobacterium adolescentis, Enterococcus faecalis, Lactobacillus plantarum, Streptococcus mitis, Corynebacterium minutissimum, Clostridium perfringens, Bacteroides vulgatus, Escherichia coli, Pseudomonas aeruginosa, Veillonella parvula, and Neisseria sicca. The levels of interleukin 12 (IL-12), tumor necrosis factor alpha (TNF-α), IL-10, and IL-6 were measured by enzyme-linked immunosorbent assay. The TNF-α production was also analyzed after blocking CD14, Toll-like receptor 2 (TLR-2), and TLR-4 prior to stimulation with bacteria. The levels of IL-12 and TNF-α were similar in cord and adult cells. Gram-positive bacteria induced considerably higher levels of IL-12 and TNF-α than gram-negative bacteria in both cord and adult cells. The levels of IL-6 were significantly higher in newborns than in adults, whereas the levels of IL-10 were similar in newborns and adults. Gram-negative and gram-positive bacteria induced similar levels of IL-6 and IL-10 in cord cells. L. plantarum bound or signaled through CD14, TLR-2, and TLR-4, whereas E. coli acted mainly through CD14 and TLR-4. These results indicate that the innate immune response in newborns to commensal bacteria is strong and also suggest that different bacterial strains may have differential effects on the maturation of the immune system of infants.

scholarly journals Differential Cytokine Response in Host Defence Mechanisms Triggered by Gram-Negative and Gram-Positive Bacteria, and the Roles of Gabexate Mesilate, a Synthetic Protease Inhibitor

2002 ◽  
Vol 30 (2) ◽  
pp. 99-108 ◽  
Author(s):  
H Iwadou ◽  
Y Morimoto ◽  
H Iwagaki ◽  
S Sinoura ◽  
Y Chouda ◽  
...  
Keyword(s):  
Protease Inhibitor ◽  
Bacterial Infections ◽  
Mononuclear Cells ◽  
Cytokine Production ◽  
Gabexate Mesilate ◽  
Gram Positive ◽  
Peripheral Blood Mononuclear ◽  
Gram Negative ◽  
Gram Positive Bacteria ◽  
Tnf Α

Bacterial infection results in the production of inflammatory mediators and may be involved in the pathogenesis of sepsis and/or systemic inflammatory response syndrome. The effect of lipopolysaccharide (LPS), a major component of the outer surface of Gram-negative bacteria, and Staphylococcal enterotoxin B (SEB), a superantigen of Gram-positive bacteria, on cytokine production in peripheral blood mononuclear cells (PBMCs) was examined. LPS significantly increased the production of proinflammatory and anti-inflammatory cytokines, and SEB enhanced the production of helper T lymphocyte type cytokines. These results illustrated the different responses to Gram-negative and Gram-positive bacterial infections. The effect of gabexate mesilate, a synthetic protease inhibitor, on cytokine production and expression of the toll-like receptor (TLR) was also examined. The results suggest that gabexate mesilate-induced inhibition of tumour necrosis factor-α (TNF-α) and interleukin-18 (IL-18) production in LPS-stimulated PBMCs is due to the inhibition of the nuclear factor-κB activation pathway and/or inhibition of the processing pathway of pro-TNF-α and pro-IL-18, not to down-regulation of TLR-2 or TLR-4.

scholarly journals Purification of Bioactive Peptide with Antimicrobial Properties Produced by Saccharomyces cerevisiae

Foods ◽  
2020 ◽  
Vol 9 (3) ◽  
pp. 324 ◽  
Author(s):  
Shayma Thyab Gddoa Al-sahlany ◽  
Ammar Altemimi ◽  
Alaa Al-Manhel ◽  
Alaa Niamah ◽  
Naoufal Lakhssassi ◽  
...  
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Antimicrobial Properties ◽  
Antibacterial Peptide ◽  
Inhibition Activity ◽  
Bacterial Strains ◽  
Gram Positive ◽  
Gram Negative ◽  
Gram Positive Bacteria ◽  
Viable Cells ◽  
Ph Range

A variety of organisms produce bioactive peptides that express inhibition activity against other organisms. Saccharomyces cerevisiae is considered the best example of a unicellular organism that is useful for studying peptide production. In this study, an antibacterial peptide was produced and isolated from Saccharomyces cerevisiae (Baker’s yeast) by an ultrafiltration process (two membranes with cut-offs of 2 and 10 kDa) and purified using the ÄKTA Pure 25 system. Antibacterial peptide activity was characterized and examined against four bacterial strains including Gram-positive and Gram-negative bacteria. The optimum condition for yeast growth and antibacterial peptide production against both Escherichia. coli and Klebsiella aerogenes was 25–30 °C within a 48 h period. The isolated peptide had a molecular weight of 9770 Da, was thermostable at 50–90 °C for 30 min, and tolerated a pH range of 5–7 at 4 °C and 25 °C during the first 24 h, making this isolated antibacterial peptides suitable for use in sterilization and thermal processes, which are very important aspect in food production. The isolated antibacterial peptide caused a rapid and steady decline in the number of viable cells from 2 to 2.3 log units of gram-negative strains and from 1.5 to 1.8 log units of gram-positive strains during 24 h of incubation. The isolated antibacterial peptide from Saccharomyces cerevisiae may present a potential biopreservative compound in the food industry exhibiting inhibition activity against gram-negative and gram-positive bacteria.

Contribution of Toll-like receptors to the innate immune response to Gram-negative and Gram-positive bacteria

Blood ◽  
2006 ◽  
Vol 109 (4) ◽  
pp. 1574-1583 ◽  
Author(s):  
Greg Elson ◽  
Irène Dunn-Siegrist ◽  
Bruno Daubeuf ◽  
Jérome Pugin
Keyword(s):  
Cell Activation ◽  
Dependent Manner ◽  
Toll Like Receptors ◽  
Bacterial Strains ◽  
Gram Positive ◽  
Independent Manner ◽  
Gram Negative ◽  
Gram Positive Bacteria ◽  
Molecular Pattern ◽  
High Concentrations

Abstract Innate recognition of bacteria is a key step in the activation of inflammation and coagulation, and it is dependent on pathogen-associated molecular pattern (PAMP) ligation to Toll-like receptors (TLRs) and CD14. The dominant receptors activated when cells encounter a whole bacterium, which express several PAMPs, are poorly defined. Herein, we have stimulated various human cells with prototypic Gram-negative and Gram-positive bacteria. Receptor-dependent responses to whole bacteria were assessed using both TLR-transfected cells and specific monoclonal antibodies against TLRs, MD-2, and CD14. Enterobacteria-activated leukocytes and endothelial cells in a TLR4/MD-2–dependent manner, most likely via lipopolysaccharide (LPS). TLR2 activation was observed with a high bacterial inoculum, and in epithelial cells expressing TLR2 but not TLR4. Pseudomonas aeruginosa stimulated cells by both TLR2 and TLR4/MD-2. Gram-positive bacteria activated cells only at high concentrations, in a partially TLR2-dependent but TLR4/MD-2–independent manner. Either TLR or CD14 neutralization blocked activation to all bacterial strains tested with the exception of some Gram-positive strains in whole blood in which partial inhibition was noted. This study identifies dominant TLRs involved in responses to whole bacteria. It also validates the concept that host cell activation by bacterial pathogens can be therapeutically reduced by anti-TLR4, -TLR2, and -CD14 mAbs.

scholarly journals Recognition of Streptococcus pneumoniae and Muramyl Dipeptide by NOD2 Results in Potent Induction of MMP-9, Which Can Be Controlled by Lipopolysaccharide Stimulation

2014 ◽  
Vol 82 (12) ◽  
pp. 4952-4958 ◽  
Author(s):  
Marloes Vissers ◽  
Yvonne Hartman ◽  
Laszlo Groh ◽  
Dirk J. de Jong ◽  
Marien I. de Jonge ◽  
...  
Keyword(s):  
Streptococcus Pneumoniae ◽  
Mononuclear Cells ◽  
Muramyl Dipeptide ◽  
Tissue Inhibitor Of Metalloproteinase ◽  
Gram Negative Bacteria ◽  
Gram Positive ◽  
Potent Inducer ◽  
Gram Negative ◽  
Content Type ◽  
Gram Positive Bacteria

ABSTRACTMatrix metallopeptidase 9 (MMP-9) is a protease involved in the degradation of extracellular matrix collagen. Evidence suggests that MMP-9 is involved in pathogenesis duringStreptococcus pneumoniaeinfection. However, not much is known about the induction of MMP-9 and the regulatory processes involved. We show here that the Gram-positive bacteria used in this study induced large amounts of MMP-9, in contrast to the Gram-negative bacteria that were used. An important pathogen-associated molecular pattern (PAMP) for Gram-positive bacteria is muramyl dipeptide (MDP). MDP is a very potent inducer of MMP-9 and showed a dose-dependent MMP-9 induction. Experiments using peripheral blood mononuclear cells (PBMCs) from Crohn's disease patients with nonfunctional NOD2 showed that MMP-9 induction byStreptococcus pneumoniaeand MDP is NOD2 dependent. Increasing amounts of lipopolysaccharide (LPS), an important PAMP for Gram-negative bacteria, resulted in decreasing amounts of MMP-9. Moreover, the induction of MMP-9 by MDP could be counteracted by simultaneously adding LPS. The inhibition of MMP-9 expression by LPS was found to be regulated posttranscriptionally, independently of tissue inhibitor of metalloproteinase 1 (TIMP-1), an endogenous inhibitor of MMP-9. Collectively, these data show thatStreptococcus pneumoniaeis able to induce large amounts of MMP-9. These high MMP-9 levels are potentially involved inStreptococcus pneumoniaepathogenesis.

scholarly journals The antimicrobial potentialities of (Nk-lysin peptides of chicken, bovine, and human) against bacteria and rotavirus

2021 ◽  
Author(s):  
Maged. M Mahmoud ◽  
Ahmed M. Al-Hejin ◽  
Turki S Abujaml ◽  
S Abd-Elmaksoud ◽  
Salem M. El-Hamidy ◽  
...  
Keyword(s):  
Antiviral Activity ◽  
Klebsiella Oxytoca ◽  
Bacterial Strains ◽  
Gram Positive ◽  
Gram Negative ◽  
Beta Lactamases ◽  
Gram Positive Bacteria ◽  
The Past ◽  
Antiviral Activities ◽  
First Time

Abstract For the first time, this study was carried out to investigate and evaluate the relative antibacterial activity of three different Nk-lysin peptides from human, chicken, and bovine activity compared to Gram-negative and Gram-positive bacteria as well as antiviral activity against rotavirus (strain SA-11) and finally mechanisms of action optionality. This report is the first of its kind that investigates the increased antimicrobial ability of (Nk-lysin + AgNPs) and (Nk-lysin + human IL-2) combinations against S. typhi activity by carrying out direct comparison under similar experimental settings. Our results showed that gram-negative and gram-positive microorganisms, including Streptococcus pyogenes, Streptococcus mutans, Escherichia coli, Pseudomonas aeruginosa, Klebsiella oxytoca, Shigella sonnei, Klebsiella pneumoniae and Salmonella typhimurium, are susceptible to NK-lysin treatment. It was shown in our findings that there was equal potentiality in mixture (Nk-lysin + AgNPs) and (Nk-lysin + human IL-2) for preventing the growth of S. typhi, however, when added together, there was minor increase in the level of action. In our study, the TOHO-1 gene was absent in treated bacteria. Following treatment with Nk-lysin peptides, the beta-lactamases genes (CTX-M-1, M-8, and M-9) were not found in any bacterial strains. The examination did not find any of the plasmid mediated quinolone resistance genes in the bacterial strains as a response to NK-lysin treatment. Nonetheless, no study has been carried out in the past that characterized the antiviral activity of bovine, human and chicken Nk-lysin peptides. Hence, this is the foremost study on the enhanced antimicrobial activity of human, bovine and chicken Nk-lysin peptides against Rotavirus (strain SA-11). The findings of the study demonstrated that the powerful antiviral activities were exhibited by Nk-lysin peptides against Rotavirus (strain SA-11). Based on the comparison between these peptides, it can be concluded that there is an evident potent antiviral activity of bovine Nk-lysin against Rotavirus (strain SA-11) as it restrains infection by up to 90%. However, growth was restricted by 80% by chicken Nk-lysin and by 50% by the human peptide.

scholarly journals Antibacterial activity of Beta vulgaris L. pomace extract

2011 ◽  
pp. 263-269 ◽  
Author(s):  
Aleksandra Velicanski ◽  
Dragoljub Cvetkovic ◽  
Sinisa Markov ◽  
Jelena Vulic ◽  
Sonja Djilas
Keyword(s):  
Antibacterial Activity ◽  
Beta Vulgaris ◽  
Staphylococcus Epidermidis ◽  
Control Sample ◽  
Diffusion Method ◽  
Bacterial Strains ◽  
Gram Positive ◽  
Gram Negative ◽  
Gram Positive Bacteria ◽  
Natural Isolates

Antibacterial activity of Beta vulgaris L. (beetroot) pomace extract (concentration 100 mg/ml) was tested against five Gram positive and seven Gram negative bacterial strains (reference cultures and natural isolates). Disc diffusion method with 15 ?l of extract and agar-well diffusion method with 50 and 100 ?l were used. Antibiotic (cefotaxime/clavulanic acid) was used as a control sample. The tested extract showed the highest activity against Staphylococcus aureus and Bacillus cereus, where clear zones (without growth) appeared. There was no any activity against other tested Gram-positive bacteria, except for Staphylococcus epidermidis, with a small zone of reduced growth. Growth of all tested Gram-negative bacteria was inhibited usually with 100 ?l of extract. The most susceptible were Citrobacter freundii and Salmonella typhymurium. The tested antibiotic gave clear, usually large zones for all tested strains except for Staphylococcus cohni spp. cohni, where only a zone of reduced growth appeared.

scholarly journals Comparative Study of the Bacteriological Activity of Zinc Oxide and Copper Oxide Nanoparticles

2019 ◽  
Vol 6 (1) ◽  
pp. 63-72
Author(s):  
Abdelali Merah ◽  
Abdenabi Abidi ◽  
Hana Merad ◽  
Noureddine Gherraf ◽  
Mostepha Iezid ◽  
...  
Keyword(s):  
Zinc Oxide ◽  
Copper Oxide ◽  
Metal Oxides ◽  
Bactericidal Effect ◽  
Cuo Nanoparticles ◽  
Gram Negative Bacteria ◽  
Bacterial Strains ◽  
Gram Positive ◽  
Gram Negative ◽  
Gram Positive Bacteria

Abstract Interest in nanomaterials, especially metal oxides, in the fight against resistant and constantly changing bacterial strains, is more and more expressed. Their very high reactivity, resulting from their large surface area, promoted them to the rank of potential successors of antibiotics. Our work consisted of the synthesis of zinc oxide (ZnO) and copper oxide (CuO) in the nanoparticle state and the study of their bactericidal effect on various Gram-negative and Gram-positive bacterial strains. The nanoparticles of metal oxides have been synthesized by sol-gel method. Qualitative analysis and characterization by UV / Visible and infrared spectrophotometry and X-ray diffraction confirmed that the synthetic products are crystalline. The application of the Scherrer equation allows to determine the size of the two metal oxides, namely: 76.94 nm for ZnO and 24.86 nm for CuO. The bactericidal effect of ZnO and CuO nanoparticles was tested on Gram-positive bacteria (Staphylococcus aureus, Staphylococcus hominis, Staphylococcus haemolyticus, Enterococcus facials) and Gram-negative bacteria (Escherichia coli, Schigella, Klepsiella pneumoniae and Pseudomonas aeruginosa). The results indicate that the tested metal oxides nanoparticles have an effect that varies depending on bacterial species. Indeed, Gram-positive bacteria show greater sensitivity to ZnO nanoparticles whereas Gram-negative bacteria are more sensitive to CuO nanoparticles.

scholarly journals Antibacterial Properties of Propolis

Molecules ◽  
2019 ◽  
Vol 24 (11) ◽  
pp. 2047 ◽  
Author(s):  
Izabela Przybyłek ◽  
Tomasz M. Karpiński
Keyword(s):  
Escherichia Coli ◽  
Staphylococcus Aureus ◽  
Antimicrobial Activity ◽  
Antibacterial Properties ◽  
Bacterial Strains ◽  
Complex Composition ◽  
Gram Positive ◽  
Gram Negative ◽  
Gram Positive Bacteria ◽  
The World

Researchers are continuing to discover all the properties of propolis due to its complex composition and associated broad spectrum of activities. This review aims to characterize the latest scientific reports in the field of antibacterial activity of this substance. The results of studies on the influence of propolis on more than 600 bacterial strains were analyzed. The greater activity of propolis against Gram-positive bacteria than Gram-negative was confirmed. Moreover, the antimicrobial activity of propolis from different regions of the world was compared. As a result, high activity of propolis from the Middle East was found in relation to both, Gram-positive (Staphylococcus aureus) and Gram-negative (Escherichia coli) strains. Simultaneously, the lowest activity was demonstrated for propolis samples from Germany, Ireland and Korea.

scholarly journals Pattern of Cytokine Responses to Gram-Positive and Gram-Negative Commensal Bacteria Is Profoundly Changed when Monocytes Differentiate into Dendritic Cells

2004 ◽  
Vol 72 (5) ◽  
pp. 2671-2678 ◽  
Author(s):  
Helen Karlsson ◽  
Pia Larsson ◽  
Agnes E. Wold ◽  
Anna Rudin
Keyword(s):  
Dendritic Cells ◽  
Bacterial Flora ◽  
Surface Expression ◽  
Commensal Bacteria ◽  
Enzyme Linked Immunosorbent Assay ◽  
Bacterial Strains ◽  
Gram Positive ◽  
Bifidobacterium Adolescentis ◽  
Gram Negative ◽  
E Coli

ABSTRACT The normal gastrointestinal bacterial flora is crucial for the maturation of acquired immunity via effects on antigen-presenting cells (APCs). Here we investigated how two types of APCs, monocytes and dendritic cells (DCs), react to different bacterial strains typical of the commensal intestinal microflora. Purified human monocytes and monocyte-derived DCs were stimulated with UV-inactivated gram-positive (Lactobacillus plantarum and Bifidobacterium adolescentis) and gram-negative (Escherichia coli and Veillonella parvula) bacterial strains. Monocytes produced higher levels of interleukin 12p70 (IL-12p70) and tumor necrosis factor (TNF), as detected by an enzyme-linked immunosorbent assay, in response to L. plantarum than in response to E. coli and V. parvula. In contrast, DCs secreted large amounts of IL-12p70, TNF, IL-6, and IL-10 in response to E. coli and V. parvula but were practically unresponsive to L. plantarum and B. adolescentis. The lack of a response to the gram-positive strains correlated with lower surface expression of Toll-like receptor 2 (TLR2) on DCs than on monocytes. The surface expression of TLR4 on DCs was undetectable when it was analyzed by flow cytometry, but blocking this receptor decreased the TNF production in response to V. parvula, indicating that TLR4 is expressed at a low density on DCs. Gamma interferon increased the expression of TLR4 on DCs and also potentiated the cytokine response to the gram-negative strains. Our results indicate that when monocytes differentiate into DCs, their ability to respond to different commensal bacteria dramatically changes, and they become unresponsive to probiotic gram-positive bacteria. These results may have important implications for the abilities of different groups of commensal bacteria to regulate mucosal and systemic immunity.

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