IN VITRO INFLAMMATORY RESPONSES OF MOUSE MACROPHAGES TO GRAM POSITIVE & GRAM NEGATIVE MICROBES: EFFECT OF ANTIBIOTICS.

Shock ◽  
2001 ◽  
Vol 15 (Supplement) ◽  
pp. 54
Author(s):  
W. Cui ◽  
D. C. Morrison;
Keyword(s):  
Inflammatory Responses ◽  
Gram Positive ◽  
Gram Negative ◽  
Mouse Macrophages

scholarly journals IFN-mediated negative feedback supports bacteria class-specific macrophage inflammatory responses

eLife ◽  
2019 ◽  
Vol 8 ◽  
Author(s):  
Rachel A Gottschalk ◽  
Michael G Dorrington ◽  
Bhaskar Dutta ◽  
Kathleen S Krauss ◽  
Andrew J Martins ◽  
...  
Keyword(s):  
Negative Feedback ◽  
Molecular Mechanisms ◽  
Cytokine Production ◽  
Inflammatory Responses ◽  
Type I ◽  
Gram Negative Bacteria ◽  
Gram Positive ◽  
Gram Negative

Despite existing evidence for tuning of innate immunity to different classes of bacteria, the molecular mechanisms used by macrophages to tailor inflammatory responses to specific pathogens remain incompletely defined. By stimulating mouse macrophages with a titration matrix of TLR ligand pairs, we identified distinct stimulus requirements for activating and inhibitory events that evoked diverse cytokine production dynamics. These regulatory events were linked to patterns of inflammatory responses that distinguished between Gram-positive and Gram-negative bacteria, both in vitro and after in vivo lung infection. Stimulation beyond a TLR4 threshold and Gram-negative bacteria-induced responses were characterized by a rapid type I IFN-dependent decline in inflammatory cytokine production, independent of IL-10, whereas inflammatory responses to Gram-positive species were more sustained due to the absence of this IFN-dependent regulation. Thus, disparate triggering of a cytokine negative feedback loop promotes tuning of macrophage responses in a bacteria class-specific manner and provides context-dependent regulation of inflammation dynamics.

scholarly journals Lipopolysaccharide-Related Stimuli Induce Expression of the Secretory Leukocyte Protease Inhibitor, a Macrophage-Derived Lipopolysaccharide Inhibitor

1998 ◽  
Vol 66 (6) ◽  
pp. 2447-2452 ◽  
Author(s):  
Fenyu Jin ◽  
Carl F. Nathan ◽  
Danuta Radzioch ◽  
Aihao Ding
Keyword(s):  
Protease Inhibitor ◽  
Inflammatory Responses ◽  
Interleukin 10 ◽  
Secretory Leukocyte Protease Inhibitor ◽  
No Production ◽  
Gram Positive ◽  
Gram Negative ◽  
Anti Inflammatory

ABSTRACT Mouse secretory leukocyte protease inhibitor (SLPI) was recently characterized as a lipopolysaccharide (LPS)-induced product of macrophages that antagonizes their LPS-induced activation of NF-κB and production of NO and tumor necrosis factor (TNF) (F. Y. Jin, C. Nathan, D. Radzioch, and A. Ding, Cell 88:417–426, 1997). To better understand the role of SLPI in innate immune and inflammatory responses, we examined the kinetics of SLPI expression in response to LPS, LPS-induced cytokines, and LPS-mimetic compounds. SLPI mRNA was detectable in macrophages by Northern blot analysis within 30 min of exposure to LPS but levels peaked only at 24 to 36 h and remained elevated at 72 h. Despite the slowly mounting and prolonged response, early expression of SLPI mRNA was cycloheximide resistant. Two LPS-induced proteins—interleukin-10 (IL-10) and IL-6—also induced SLPI, while TNF and IL-1β did not. The slow attainment of maximal induction of SLPI by LPS in vitro was mimicked by infection with Pseudomonas aeruginosa in vivo, where SLPI expression in the lung peaked at 3 days. Two LPS-mimetic molecules—taxol from yew bark and lipoteichoic acid (LTA) from gram-positive bacterial cell walls—also induced SLPI. Transfection of macrophages with SLPI inhibited their LTA-induced NO production. An anti-inflammatory role for macrophage-derived SLPI seems likely based on SLPI’s slowly mounting production in response to constituents of gram-negative and gram-positive bacteria, its induction both as a direct response to LPS and as a response to anti-inflammatory cytokines induced by LPS, and its ability to suppress the production of proinflammatory products by macrophages stimulated with constituents of both gram-positive and gram-negative bacteria.

scholarly journals In Vitro and In Vivo Antibacterial Activities of DW-224a, a New Fluoronaphthyridone

2006 ◽  
Vol 50 (6) ◽  
pp. 2261-2264 ◽  
Author(s):  
Hee-Soo Park ◽  
Hyun-Joo Kim ◽  
Min-Jung Seol ◽  
Dong-Rack Choi ◽  
Eung-Chil Choi ◽  
...  
Keyword(s):  
Antibacterial Activities ◽  
The Other ◽  
Vitro Activity ◽  
Gram Negative Bacteria ◽  
In Vitro Activity ◽  
Gram Positive ◽  
Gram Negative ◽  
Gram Positive Bacteria

ABSTRACT DW-224a showed the most potent in vitro activity among the quinolone compounds tested against clinical isolates of gram-positive bacteria. Against gram-negative bacteria, DW-224a was slightly less active than the other fluoroquinolones. The in vivo activities of DW-224a against gram-positive bacteria were more potent than those of other quinolones.

scholarly journals Factors Influencing the Microbial Composition of Metalworking Fluids and Potential Implications for Machine Operator's Lung

2011 ◽  
Vol 78 (1) ◽  
pp. 34-41 ◽  
Author(s):  
Jean-Benjamin Murat ◽  
Frédéric Grenouillet ◽  
Gabriel Reboux ◽  
Emmanuelle Penven ◽  
Adam Batchili ◽  
...  
Keyword(s):  
Metal Cutting ◽  
Hypersensitivity Pneumonitis ◽  
Environmental Parameters ◽  
Metalworking Fluids ◽  
Microbial Composition ◽  
Gram Positive ◽  
Gram Negative ◽  
Content Type ◽  
Kinetics Of

ABSTRACTHypersensitivity pneumonitis, also known as “machine operator's lung” (MOL), has been related to microorganisms growing in metalworking fluids (MWFs), especiallyMycobacterium immunogenum. We aimed to (i) describe the microbiological contamination of MWFs and (ii) look for chemical, physical, and environmental parameters associated with variations in microbiological profiles. We microbiologically analyzed 180 MWF samples from nonautomotive plants (e.g., screw-machining or metal-cutting plants) in the Franche-Comté region in eastern France and 165 samples from three French automotive plants in which cases of MOL had been proven. Our results revealed two types of microbial biomes: the first was from the nonautomotive industry, showed predominantly Gram-negative rods (GNR), and was associated with a low risk of MOL, and the second came from the automotive industry that was affected by cases of MOL and showed predominantly Gram-positive rods (GPR). Traces ofM. immunogenumwere sporadically detected in the first type, while it was highly prevalent in the automotive sector, with up to 38% of samples testing positive. The use of chromium, nickel, or iron was associated with growth of Gram-negative rods; conversely, growth of Gram-positive rods was associated with the absence of these metals. Synthetic MWFs were more frequently sterile than emulsions. Vegetable oil-based emulsions were associated with GNR, while mineral ones were associated with GPR. Our results suggest that metal types and the nature of MWF play a part in MWF contamination, and this work shall be followed by furtherin vitrosimulation experiments on the kinetics of microbial populations, focusing on the phenomena of inhibition and synergy.

Biosynthesis of Silver Nanoparticles by Punica Granatum Peel Extract and their Biological Activity on different Pathogenic Bacteria

2021 ◽  
Vol 19 (9) ◽  
pp. 38-45
Author(s):  
Hussein H. Al-Turnachy ◽  
Fadhilk. alibraheemi ◽  
Ahmed Abd Alreda Madhloom ◽  
Zahraa Yosif Motaweq ◽  
Nibras Yahya Abdulla
Keyword(s):  
Antimicrobial Activity ◽  
Silver Nanoparticles ◽  
Biological Activity ◽  
Pathogenic Bacteria ◽  
Punica Granatum ◽  
Gram Positive ◽  
Gram Negative ◽  
Inhibition Zones ◽  
Peel Extract

The present study was included the assessment of the antimicrobial activity of AgNPs synthesized by Punica granatum peel extract against pathogenic bacteria by testing warm aqueous P. granatum peel extract and silver nanoparticles. Punica granatum indicated potency for AgNP extracellular nanobiosynthesis after addition of silver nitrate (AgNO3) 4mM to the extract supernatant, in both concentrations (100mg and 50mg). The biogenic AgNPs showed potency to inhibit both gram-negative and gram-positive bacterial growth. Zons of inhibition in (mm) was lesser in gram-positive than gram-negative bacteria. The resulted phytogenic AgNPs gave higher biological activity than warm aqueous Punica granatum peel extract. The inhibition zone of the phytogenic AgNPs on E. coli reached 17.53, 22.35, and 26.06 mm at (0.1, 0.5, and 1) mg/ml respectively. While inhibition zones of Punica warm aqueous extract reached 5.33, 10.63, and 16.08 mm at the same concentrations. phytogenic AgNPs gave smaller inhibition zones in gram-positive than gram- negative. Cytotoxic activity of the phytogenic AgNPs was assayed in vitro agaist human blood erythrocytes (RBCs), spectroscopic results showed absorbance at 540 nm hemolysis was observed. In general, AgNPs showed least RBCs hemolysis percentage, at 1 mg/ml concentration, hemolysis percentage was (4.50%). This study, concluded that the Punica granatum peel extract has the power of synthses of AgNPs characterized by broad spectrum antimicrobial activity with cyto-toxicity proportional to AgNPs concentration.

In Vitro Activity of Gepotidacin Against Gram-negative and Gram-positive Anaerobes

2021 ◽  
Author(s):  
Meredith A. Hackel ◽  
James A. Karlowsky ◽  
Michele A. Canino ◽  
Daniel F. Sahm ◽  
Nicole E. Scangarella-Oman
Keyword(s):  
Clinical Trials ◽  
Vitro Activity ◽  
Phase Iii ◽  
In Vitro Activity ◽  
Gram Positive ◽  
Gram Negative ◽  
Phase Iii Clinical Trials ◽  
Agar Dilution

Gepotidacin (formerly GSK2140944) is a first in class triazaacenaphthylene antibacterial currently in Phase III clinical trials. When tested against Gram-negative ( n =333) and Gram-positive ( n =225) anaerobes by agar dilution, gepotidacin inhibited 90% of isolates (MIC 90 ) at concentrations of 4 and 2 μg/ml, respectively. Given gepotidacin’s in vitro activity against the anaerobic isolates tested, further study is warranted to better understand gepotidacin’s utility in the treatment of infections caused by clinically relevant anaerobic organisms.

scholarly journals In vitro activity of tigecycline against 313 Gram-positive and Gram-negative clinical isolates

2010 ◽  
Vol 25 (1) ◽  
Author(s):  
Elisabetta Maioli ◽  
Erika Coppo ◽  
Ramona Barbieri ◽  
Elisabetta Canepa ◽  
Laura Gualco ◽  
...  
Keyword(s):  
Vitro Activity ◽  
Clinical Isolates ◽  
In Vitro Activity ◽  
Gram Positive ◽  
Gram Negative

PTS 50: Past, Present and Future, or Diauxie Revisited

2015 ◽  
Vol 25 (2-3) ◽  
pp. 79-93 ◽  
Author(s):  
Joseph W. Lengeler
Keyword(s):  
Catabolite Repression ◽  
Biological Significance ◽  
Cellular Growth ◽  
Gram Positive ◽  
Gram Negative ◽  
Inducer Exclusion ◽  
Gram Positive Bacteria ◽  
Cellular Control

<b><i>Past:</i></b> The title ‘PTS 50 or The PTS after 50 years' relies on the first description in 1964 of the phosphoenolpyruvate-dependent carbohydrate:phosphotransferase system (PTS) by Kundig, Gosh and Roseman [Proc Natl Acad Sci USA 1964;52:1067-1074]. The system comprised proteins named Enzyme I, HPr and Enzymes II, as part of a novel PTS for carbohydrates in Gram-negative and Gram-positive bacteria, whose ‘biological significance remained unclear'. In contrast, studies which would eventually lead to the discovery of the central role of the PTS in bacterial metabolism had been published since before 1942. They are primarily linked to names like Epps and Gale, J. Monod, Cohn and Horibata, and B. Magasanik, and to phenomena like ‘glucose effects', ‘diauxie', ‘catabolite repression' and carbohydrate transport. <b><i>Present:</i></b> The pioneering work from Roseman's group initiated a flood of publications. The extraordinary progress from 1964 to this day in the qualitative and in vitro description of the genes and enzymes of the PTS, and of its multiple roles in global cellular control through ‘inducer exclusion', gene induction and ‘catabolite repression', in cellular growth, in cell differentiation and in chemotaxis, as well as the differences of its functions between Gram-positive and Gram-negative bacteria, was one theme of the meeting and will not be treated in detail here. <b><i>Future:</i></b> At the 1988 Paris meeting entitled ‘The PTS after 25 years', Saul Roseman predicted that ‘we must describe these interactions [of the PTS components] in a quantitative way [under] in vivo conditions'. I will present some results obtained by our group during recent years on the old phenomenon of diauxie by means of very fast and quantitative tests, measured in vivo, and obtained from cultures of isogenic mutant strains growing under chemostat conditions. The results begin to hint at the problems relating to future PTS research, but also to the ‘true science' of Roseman.

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