Publications by authors named "PONS B"

Article Synopsis
  • Bacteria have developed a variety of defensive mechanisms to combat their parasites, resulting in diverse strategies for survival against threats like phages.
  • The newly identified methylation-associated defense system (MADS) appears in various bacterial species and works alongside CRISPR-Cas systems to enhance resistance to viral infections.
  • MADS consists of eight essential genes that equip bacteria to distinguish between self and non-self DNA, providing a sophisticated method for recognizing and responding to infections effectively.
View Article and Find Full Text PDF

Chiral molecules, used in applications such as enantioselective photocatalysis, circularly polarized light detection and emission and molecular switches, exist in two geometrical configurations that are non-superimposable mirror images of each other. These so-called (R) and (S) enantiomers exhibit different physical and chemical properties when interacting with other chiral entities. Attosecond technology might enable influence over such interactions, given that it can probe and even direct electron motion within molecules on the intrinsic electronic timescale and thereby control reactivity.

View Article and Find Full Text PDF

Purpose: The effect of renal replacement therapy (RRT) in comatose patients with acute kidney injury (AKI) remains unclear. We compared two RRT initiation strategies on the probability of awakening in comatose patients with severe AKI.

Methods: We conducted a post hoc analysis of a trial comparing two delayed RRT initiation strategies in patients with severe AKI.

View Article and Find Full Text PDF

The prokaryotic adaptive immune system, CRISPR-Cas (clustered regularly interspaced short palindromic repeats; CRISPR-associated), requires the acquisition of spacer sequences that target invading mobile genetic elements such as phages. Previous work has identified ecological variables that drive the evolution of CRISPR-based immunity of the model organism Pseudomonas aeruginosa PA14 against its phage DMS3vir, resulting in rapid phage extinction. However, it is unclear if and how stable such acquired immunity is within bacterial populations, and how this depends on the environment.

View Article and Find Full Text PDF

Small GTPases are highly regulated proteins that control essential signaling pathways through the activity of their effector proteins. Among the RHOA subfamily, RHOB regulates peculiar functions that could be associated with the control of the endocytic trafficking of signaling proteins. Here, we used an optimized assay based on tripartite split-GFP complementation to localize GTPase-effector complexes with high-resolution.

View Article and Find Full Text PDF

Background: The extent of the consequences of an episode of severe acute kidney injury (AKI) on long-term outcome of critically ill patients remain debated. We conducted a prospective follow-up of patients included in a large multicenter clinical trial of renal replacement therapy (RRT) initiation strategy during severe AKI (the Artificial Kidney Initiation in Kidney Injury, AKIKI) to investigate long-term survival, renal outcome and health related quality of life (HRQOL). We also assessed the influence of RRT initiation strategy on these outcomes.

View Article and Find Full Text PDF

CRISPR-Cas are prokaryotic defence systems that provide protection against invasion by mobile genetic elements (MGE), including bacteriophages. MGE can overcome CRISPR-Cas defences by encoding anti-CRISPR (Acr) proteins. These proteins are produced in the early stages of the infection and inhibit the CRISPR-Cas machinery to allow phage replication.

View Article and Find Full Text PDF

It is becoming increasingly clear that antibiotics can both positively and negatively impact the infectivity of bacteriophages (phage), but the underlying mechanisms often remain unclear. Here we demonstrate that antibiotics that target the protein translation machinery can fundamentally alter the outcome of bacteria-phage interactions by interfering with the production of phage-encoded counter-defense proteins. Specifically, using Pseudomonas aeruginosa PA14 and phage DMS3vir as a model, we show that bacteria with Clustered Regularly Interspaced Short Palindromic Repeat, CRISPR associated (CRISPR-Cas) immune systems have elevated levels of immunity against phage that encode anti-CRISPR (acr) genes when translation inhibitors are present in the environment.

View Article and Find Full Text PDF
Article Synopsis
  • Bacteria defend against viruses (bacteriophages) using mechanisms like the CRISPR-Cas system, which remembers past infections for immunity.
  • Phages can counteract this defense by producing anti-CRISPR (Acr) proteins that inhibit the CRISPR-Cas system, although this often leads to failed infections.
  • The proposed method seeks to evaluate how Acr-induced inhibition of the CRISPR-Cas system persists by infecting bacteria, removing the phage, and testing transformation efficiency of targeted versus non-targeted plasmids.
View Article and Find Full Text PDF

Background: Intermittent hemodialysis (IHD) and continuous renal replacement therapy (CRRT) are the two main RRT modalities in patients with severe acute kidney injury (AKI). Meta-analyses conducted more than 10 years ago did not show survival difference between these two modalities. As the quality of RRT delivery has improved since then, we aimed to reassess whether the choice of IHD or CRRT as first modality affects survival of patients with severe AKI.

View Article and Find Full Text PDF

The resonance-enhanced multiphoton ionization of chiral molecules by elliptically polarized laser pulses produces photoelectron angular distributions that are forward/backward asymmetric with respect to the light propagation axis. We investigate this photoelectron elliptical dichroism in the (2 + 1)-photon ionization of fenchone molecules, using wavelength tunable femtosecond UV pulses. We show that the photoelectron elliptical asymmetry is extremely sensitive to the intermediate resonant states involved in the ionization process, and enables electronic couplings to be revealed that do not show up so clearly when using circularly polarized light.

View Article and Find Full Text PDF

We study the isomeric effects using time resolved photoelectron circular dichroism (TR-PECD). Using a (1 + 1') pump-probe ionisation scheme with photoelectrons collected by the velocity map imaging technique, we compare the relaxation dynamics from the 3s-Rydberg state in 1,4-(+)-camphor with the one in its chiral isomer, 1,4-(-)-fenchone [Comby , 2016, , , 4514]. Our measurements revealed a similar lifetime for both isomers.

View Article and Find Full Text PDF

We commonly acknowledge that bacterial viruses (phages) shape the composition and evolution of bacterial communities in nature and therefore have important roles in ecosystem functioning. This view stems from studies in the 1990s to the first decade of the twenty-first century that revealed high viral abundance, high viral diversity and virus-induced microbial death in aquatic ecosystems as well as an association between collapses in bacterial density and peaks in phage abundance. The recent surge in metagenomic analyses has provided deeper insight into the abundance, genomic diversity and spatio-temporal dynamics of phages in a wide variety of ecosystems, ranging from deep oceans to soil and the mammalian digestive tract.

View Article and Find Full Text PDF

Background: High-level antibiotic consumption plays a critical role in the selection and spread of extended-spectrum beta-lactamase-producing Enterobacteriaceae (ESBL-E) in the ICU. Implementation of a stewardship program including a restrictive antibiotic policy was evaluated with respect to ESBL-E acquisition (carriage and infection).

Methods: We implemented a 2-year, before-and-after intervention study including all consecutive adult patients admitted for > 48 h in the medical-surgical 26-bed ICU of Guadeloupe University Hospital (French West Indies).

View Article and Find Full Text PDF
Article Synopsis
  • The Cytolethal Distending Toxin (CDT) is a bacterial genotoxin linked to significant foodborne diseases, activating DNA Damage Response and influencing immune responses.
  • Chronic exposure to CDT in cells leads to a strong type I interferon (IFN) response through the cytoplasmic sensor cGAS, emphasizing the role of DNA damage recognition.
  • The study indicates that CDT exposure causes extensive DNA damage and genetic instability during cell division, with varying effects on immune response based on tissue and cell type, which is crucial for understanding its role in chronic inflammation and cancer development.
View Article and Find Full Text PDF

Background: Critically ill patients with obesity may have an increased risk of difficult intubation and subsequent severe hypoxemia. We hypothesized that pre-oxygenation with noninvasive ventilation before intubation as compared with high-flow nasal cannula oxygen may decrease the risk of severe hypoxemia in patients with obesity.

Methods: Post hoc subgroup analysis of critically ill patients with obesity (body mass index ≥ 30 kg·m) from a multicenter randomized controlled trial comparing preoxygenation with noninvasive ventilation and high-flow nasal oxygen before intubation of patients with acute hypoxemic respiratory failure (PaO/FiO < 300 mm Hg).

View Article and Find Full Text PDF

Background: Vascular access for renal replacement therapy (RRT) is routine question in the intensive care unit. Randomized trials comparing jugular and femoral sites have shown similar rate of nosocomial events and catheter dysfunction. However, recent prospective observational data on RRT catheters use are scarce.

View Article and Find Full Text PDF
Article Synopsis
  • The study explored whether delaying renal replacement therapy (RRT) initiation in critically ill patients with severe acute kidney injury could lead to more days without the need for RRT.
  • Conducted in 39 intensive care units in France, the trial randomized 278 patients into two groups: an immediate RRT group and a more-delayed group that only started RRT based on specific clinical indicators.
  • Results showed similar complications and a median of 12 RRT-free days for the delayed group compared to 10 days for the more-delayed group, leading to a conclusion that delaying RRT does not significantly enhance patient outcomes.
View Article and Find Full Text PDF

Aim: The antibody levels against a broad spectrum of pathogens were assessed in commercial intravenous immunoglobulin (IVIG) manufactured from pooled plasma obtained from different global regions.

Methods: Twenty-four IVIG commercial lots from eight manufacturers corresponding to 12 brands were analyzed. The plasma was collected in 10 countries/regions.

View Article and Find Full Text PDF

The Cytolethal Distending Toxin (CDT) is produced by many Gram-negative pathogenic bacteria responsible for major foodborne diseases worldwide. CDT induces DNA damage and cell cycle arrest in host-cells, eventually leading to senescence or apoptosis. According to structural and sequence comparison, the catalytic subunit CdtB is suggested to possess both nuclease and phosphatase activities, carried by a single catalytic site.

View Article and Find Full Text PDF

Background: The Artificial Kidney Initiation in Kidney Injury (AKIKI) trial showed that a delayed renal replacement therapy (RRT) strategy for severe acute kidney injury (AKI) in critically ill patients was safe and associated with major reduction in RRT initiation compared with an early strategy. The five criteria which mandated RRT initiation in the delayed arm were: severe hyperkalemia, severe acidosis, acute pulmonary edema due to fluid overload resulting in severe hypoxemia, serum urea concentration > 40 mmol/l and oliguria/anuria > 72 h. However, duration of anuria/oliguria and level of blood urea are still criteria open to debate.

View Article and Find Full Text PDF

Background: Data on outcomes of critically ill patients requiring mechanical ventilation at the onset of stroke are limited.

Objective: To assess the hospital and long-term functional outcomes of patients with stroke who require mechanical ventilation.

Methods: This retrospective single-center cohort study performed from 1994 to 2008 involved adult patients within 7 days of stroke onset and who required intensive care unit admission and mechanical ventilation.

View Article and Find Full Text PDF

The Cytolethal Distending Toxin (CDT) is a bacterial virulence factor produced by several Gram-negative pathogenic bacteria. These bacteria, found in distinct niches, cause diverse infectious diseases and produce CDTs differing in sequence and structure. CDTs have been involved in the pathogenicity of the associated bacteria by promoting persistent infection.

View Article and Find Full Text PDF

The Cytolethal Distending Toxin (CDT) is produced by many pathogenic bacteria. CDT is known to induce genomic DNA damage to host eukaryotic cells through its catalytic subunit, CdtB. CdtB is structurally homologous to DNase I and has a nuclease activity, dependent on several key residues.

View Article and Find Full Text PDF