A5008981834- Bacterial Genetics and Biotechnology
- Vibrio bacteria research studies
- Escherichia coli research studies
- Microbial Community Ecology and Physiology
- Bacillus and Francisella bacterial research
- Ubiquitin and proteasome pathways
- Cellular transport and secretion
- Antimicrobial Resistance in Staphylococcus
- Probiotics and Fermented Foods
- Bacterial biofilms and quorum sensing
- Inflammasome and immune disorders
- Protein Kinase Regulation and GTPase Signaling
- Clostridium difficile and Clostridium perfringens research
- RNA and protein synthesis mechanisms
- Exercise and Physiological Responses
- Fecal contamination and water quality
- Insect symbiosis and bacterial influences
- Research on Leishmaniasis Studies
- Adipose Tissue and Metabolism
- Connexins and lens biology
- Bacteriophages and microbial interactions
- Insect Resistance and Genetics
- Wastewater Treatment and Nitrogen Removal
- Cell death mechanisms and regulation
- Cell Adhesion Molecules Research
Université Côte d'Azur
2012-2025
Inserm
2012-2025
Centre Méditerranéen de Médecine Moléculaire
2011-2024
Observatoire de la Côte d’Azur
2021-2023
University of Maryland, College Park
1996
Biotechnology Institute
1996
University of Maryland, Baltimore
1996
Abstract Dysregulated immune response is the key factor leading to unfavorable coronavirus disease 2019 (COVID-19) outcome. Depending on pathogen-associated molecular pattern, NLRP3 inflammasome can play a crucial role during innate immunity activation. To date, studies describing severe acute respiratory syndrome 2 infection in patients are lacking. We prospectively monitored caspase-1 activation levels peripheral myeloid cells from healthy donors and with mild critical COVID-19. The...
The adaptation of enteric bacteria in seawater has previously been described terms nutrient starvation. In the present paper, we bring experimental arguments suggesting that survival these microorganisms could also depend on their ability to overcome effects osmotic stress. We analyzed influence osmoregulatory mechanisms (potassium transport, transport and accumulation organic osmolytes) Escherichia coli microcosms by using mutants lacking components stress response. Long-term protection was...
Here we engineered transgenic Leishmania infantum that express luciferase, the objectives being to more easily monitor in real time their establishment either BALB/c mice—the liver and spleen mainly studied—or vitro. Whatever stationary phase L. promastigotes population—wild type or luciferase—the parasite burden was similar at day 30 post intravenous inoculation of mice. Imaging hosting BALB/C mice provided sensitivity range 20,000 40,000 amastigotes/mg tissue, two tissues—liver...
The sigma factor RpoS is essential for stationary-phase-specific, multiple-stress resistance. We compared the viabilities (direct viable counts) and culturabilities (colony in seawater of Escherichia coli Salmonella typhimurium strains those which rpoS was deleted or were deficient guanosine 3',5'-bispyrophosphate (ppGpp) synthesis (relA spoT). RpoS, possibly via ppGpp regulation, positively influenced culturability these bacteria oligotrophic seawater. This influence closely depended,...
The GTPase RhoA is a major regulator of the assembly actin stress fibers and contractility actomyosin cytoskeleton. epidermal cell differentiation inhibitor (EDIN) EDIN-like ADP-ribosyltransferases Staphylococcus aureus catalyze inactivation RhoA, producing cable disruption. We report that purified recombinant EDIN EDIN-producing S. provoke large transcellular tunnels in endothelial cells we have named macroapertures (MAs). These structures open transiently, followed by appearance...
The CNF1 toxin is produced by uropathogenic and meningitis-causing Escherichia coli. penetrates autonomously into cells confers phagocytic properties to epithelial endothelial cells. acts at the molecular level constitutively activating Rho GTPases attenuated their cellular ubiquitin-mediated proteasomal degradation. Here we report relationship between degradation of activated cell response toxin. type intoxication, first screened DNA microarray analysis, revealed launching a program...
Background Motility is an important component of Salmonella enterica serovar Typhimurium (ST) pathogenesis allowing the bacteria to move into appropriate niches, across mucus layer and invade intestinal epithelium. In vitro, flagellum-associated motility closely related invasive properties ST. The probiotic yeast Saccharomyces boulardii BIOCODEX (S.b-B) widely prescribed for prophylaxis treatment diarrheal diseases caused by or antibiotics. case infection, S.b-B has been shown decrease ST...
The detection of the activities pathogen-encoded virulence factors by innate immune system has emerged as a new paradigm pathogen recognition. Much remains to be determined with regard molecular and cellular components contributing this defense mechanism in mammals importance during infection. Here, we reveal central role IL-1β signaling axis Gr1+ cells controlling Escherichia coli burden blood response sensing Rho GTPase-activating toxin CNF1. Consistently, is abrogated...
Some metabolic modifications of Escherichia coli cells during starvation in seawater were studied laboratory microcosms. The apparent die-off this bacterium under such conditions, as observed by comparing the enumeration CFU conventional freshwater media and direct epifluorescence counts, was partially prevented when previously grown salted organic medium or on seawater-wastewater agar. beta-Galactosidase activity starved disappeared gradually with time, even though some other enzymatic...
Inactivation of the host GTPase RhoA by staphylococcal epidermal cell differentiation inhibitor (EDIN) exotoxins triggers formation large transcellular tunnels, named macroapertures, in endothelial cells. We used bioluminescent strains Staphylococcus aureus to monitor infection foci during first 24 h hematogenous bacterial dissemination. Clinically derived EDIN-expressing S. S25 and Xen36 produced many disseminated foci. EDIN had no detectable impact on terms histopathology or intensity...
Salmonella enterica serovar Typhimurium (ST) is an enteropathogenic Gram-negative bacterium that causes infection following oral ingestion. ST spreads rapidly along the gastrointestinal tract (GIT) and invades intestinal epithelium to ultimately reach internal body organs. The probiotic yeast Saccharomyces boulardii BIOCODEX (S.b-B) prescribed for prophylaxis of diarrheal infectious diseases. We previously showed S.b-B prevents weight loss in ST-infected mice significantly decreases...
Transcription factor EB (TFEB) is a key transcription that orchestrates the cellular response to stress. Dysregulation of TFEB associated with range human diseases, and understanding regulatory mechanisms crucial for identifying potential drug targets. In this study, we used Caenorhabditis elegans screen E3 ubiquitin ligases regulating activity TFEB's homolog, HLH-30, upon pathogenic infection. We identified WWP-1 as regulator HLH-30-dependent immune controlling HLH-30 stability mediate host...
Systemic injection of Bacillus anthracis lethal toxin (LT) produces vascular leakage and animal death. Recent studies suggest that LT triggers direct endothelial cell cytotoxicity is responsible for the leakage. composed heptamers protective antigen (PA), which drives endocytosis translocation into host cells factor (LF), a mitogen-activated protein kinase protease. Here we investigated consequences an endothelium-permeabilizing using as "molecular syringe." To this end, generated chimeric...
Cherubism is a rare autoinflammatory bone disorder that associated with point mutations in the SH3-domain binding protein 2 (SH3BP2) gene, which encodes adapter 3BP2. Individuals cherubism present symmetrical fibro-osseous lesions of jaw, are attributed to exacerbated osteoclast activation and defective osteoblast differentiation. Although it dominant trait humans, appears be recessively transmitted mice, suggesting existence additional factors pathogenesis cherubism. Here, we report...
Exolysin (ExlA) is a recently-identified pore-forming toxin secreted by subset of Pseudomonas aeruginosa strains identified worldwide and devoid Type III secretion system (T3SS), major virulence factor. Here, we characterized at the ultrastructural level lesions caused an ExlA-secreting strain, CLJ1, in mouse infected lungs. CLJ1 induced necrotic pneumocytes endothelial cells, resulting alveolo-vascular barrier breakdown. Ectopic expression ExlA exlA-negative strain similar tissue injuries....
A growing number of patients presenting severe combined immunodeficiencies attributed to monoallelic RAC2 variants have been identified. The expression the RHO GTPase is restricted hematopoietic lineage. described cause associated with high frequency infection, leukopenia, and autoinflammatory features. Here, we show that specific activating mutations induce NLRP3 inflammasome activation leading secretion IL-1β IL-18 from macrophages. This depends on state variant mediated by downstream...
By use of experimental microcosms, it was demonstrated that the survival Escherichia coli in nutrient-free seawater depended on age cells and some physicochemical conditions during their prior growth. Cells grown a bacteriological medium, with an acid or alkaline pH, at high temperature (44 °C), absence oxygen were more sensitive to exposure low nutrient content. In contrast, complex media allowed production adapting rapidly seawater. urine far than those all tested. The sensitivity highest...
It is crucial to define risk factors that contribute host invasion by Staphylococcus aureus. Here, we demonstrate the chromosomally encoded EDIN-B isoform from S. aureus contributes onset of bacteremia during course pneumonia. Deletion edinB in a European lineage community-acquired methicillin resistant (CA-MRSA) strain (ST80-MRSA-IV) dramatically decreased frequency and magnitude mice suffering This deletion had no effect on bacterial burden both blood circulation lung tissues....