The natriuretic peptide receptor agonist osteocrin disperses biofilm.

Biofilms are highly tolerant to antimicrobials and host immune defense, enabling pathogens to thrive in hostile environments. The diversity of microbial biofilm infections requires alternative and complex treatment strategies. In a previous work we demonstrated that the human Atrial Natriuretic Peptide (hANP) displays a strong anti-biofilm activity toward and that the binding of hANP by the AmiC protein supports this effect.

Effect of Phthalates and Their Substitutes on the Physiology of .

Phthalates are used in a variety of applications-for example, as plasticizers in polyvinylchloride products to improve their flexibility-and can be easily released into the environment. In addition to being major persistent organic environmental pollutants, some phthalates are responsible for the carcinogenicity, teratogenicity, and endocrine disruption that are notably affecting steroidogenesis in mammals. Numerous studies have thus focused on deciphering their effects on mammals and eukaryotic cells.

Pf4 Phage Variant Infection Reduces Virulence-Associated Traits in .

Pf4 is a filamentous bacteriophage integrated as a prophage into the genome of Pseudomonas aeruginosa PAO1. Pf4 virions can be produced without killing P. aeruginosa.

Pseudomonas aeruginosa Biofilm Dispersion by the Human Atrial Natriuretic Peptide.

Pseudomonas aeruginosa biofilms cause chronic, antibiotic tolerant infections in wounds and lungs. Numerous recent studies demonstrate that bacteria can detect human communication compounds through specific sensor/receptor tools that modulate bacterial physiology. Consequently, interfering with these mechanisms offers an exciting opportunity to directly affect the infection process.

Identification of Tse8 as a Type VI secretion system toxin from Pseudomonas aeruginosa that targets the bacterial transamidosome to inhibit protein synthesis in prey cells.

The Type VI secretion system (T6SS) is a bacterial nanomachine that delivers toxic effectors to kill competitors or subvert some of their key functions. Here, we use transposon directed insertion-site sequencing to identify T6SS toxins associated with the H1-T6SS, one of the three T6SS machines found in Pseudomonas aeruginosa. This approach identified several putative toxin-immunity pairs, including Tse8-Tsi8.

Study of key RNA metabolism proteins in .

The control of mRNA turnover is essential in bacteria to allow rapid adaptation, especially in opportunistic pathogen like . This mechanism involves RNase and DEAD-box helicases that are key elements in RNA processing and their associations form the degradosome with accessory proteins. In this study, we investigated the function of four RNases (J1, J2, Y and III) and three DEAD-box helicases (CshA, CshB, CshC) present in most Enterococci.

Role of the LytSR Two-Component Regulatory System in Biofilm Formation and Pathogenesis.

is a coagulase negative recognized as a virulent pathogen. It is responsible for a wide variety of infections, some of which are associated with biofilm production, such as implanted medical device infections or endocarditis. However, little is known about regulation of virulence factor expression.

Heterogeneous-phase Sonogashira cross-coupling reaction on COC surface for the grafting of biomolecules - Application to isatin.

The grafting of 5-iodoisatin heterocycle on a cyclic olefin copolymer (COC) and a gold surface was performed using a heterogeneous phase Sonogashira reaction consisting of coupling 5-iodoisatin with an arylalkyne previously introduced onto the surfaces. This optimized strategy takes advantage of the well-established methodology to functionalize COC or gold surfaces using aryldiazonium surface chemistry. Herein, we reported the first example of an isatin decorated polymeric or metallic surface.

Mechanism of action of the moonlighting protein EfTu as a Substance P sensor in Bacillus cereus.

The striking feature of the ubiquitous protein EfTu (Thermo unstable ribosomal Elongation factor) is its moonlighting (multifunctional) activity. Beyond its function at the ribosomal level it should be exported to the bacterial surface and act as an environmental sensor. In Bacillus cereus, and other cutaneous bacteria, it serves as a Substance P (SP) receptor and is essential for bacterial adaptation to the host.

The absence of SigX results in impaired carbon metabolism and membrane fluidity in Pseudomonas aeruginosa.

In Pseudomonas aeruginosa, SigX is an extra-cytoplasmic function σ factor that belongs to the cell wall stress response network. In previous studies, we made the puzzling observation that sigX mutant growth was severely affected in rich lysogeny broth (LB) but not in minimal medium. Here, through comparative transcriptomic and proteomic analysis, we show that the absence of SigX results in dysregulation of genes, whose products are mainly involved in transport, carbon and energy metabolisms.

Host Peptidic Hormones Affecting Bacterial Biofilm Formation and Virulence.

Bacterial biofilms constitute a critical problem in hospitals, especially in resuscitation units or for immunocompromised patients, since bacteria embedded in their own matrix are not only protected against antibiotics but also develop resistant variant strains. In the last decade, an original approach to prevent biofilm formation has consisted of studying the antibacterial potential of host communication molecules. Thus, some of these compounds have been identified for their ability to modify the biofilm formation of both Gram-negative and Gram-positive bacteria.

Extracytoplasmic function sigma factors in Pseudomonas aeruginosa.

The opportunistic pathogen Pseudomonas aeruginosa, like all members of the genus Pseudomonas, has the capacity to thrive in very different environments, ranging from water, plant roots, to animals, including humans to whom it can cause severe infections. This remarkable adaptability is reflected in the number of transcriptional regulators, including sigma factors in this bacterium. Among those, the 19 to 21 extracytoplasmic sigma factors (ECFσ) are endowed with different regulons and functions, including the iron starvation σ (PvdS, FpvI, HasI, FecI, FecI2 and others), the cell wall stress ECFσ AlgU, SigX and SbrI, and the unorthodox σ involved in the expression of virulence.

Different Dose-Dependent Modes of Action of C-Type Natriuretic Peptide on Biofilm Formation.

We have previously shown that the C-type Natriuretic Peptide (CNP), a peptide produced by lungs, is able to impact physiology. In the present work, the effect of CNP at different concentrations on biofilm formation was studied and the mechanisms of action of this human hormone on were deciphered. CNP was shown to inhibit dynamic biofilm formation in a dose-dependent manner without affecting the bacterial growth at any tested concentrations.

Development of a novel functional core-shell-shell nanoparticles: From design to anti-bacterial applications.

This article reports the synthesis and functionalization of a novel CuO@SiO-APTES@Ag core-shell-shell material using a simple and low-cost process. The growth, design strategies and synthesis approach are the key factors for the development of CuO@SiO-APTES@Ag as efficient material with enhanced antibacterial activity. We investigated the morphology, surface charge, structure and stability of our new core-shell-shell by atomic force microscopy, scanning electron microscopy, energy dispersive X-ray, Fourier transform infrared and UV-visible spectroscopies, zeta potential measurements, and differential scanning calorimetry.

The aliphatic amidase AmiE is involved in regulation of Pseudomonas aeruginosa virulence.

We have previously shown that the eukaryotic C-type natriuretic peptide hormone (CNP) regulates Pseudomonas aeruginosa virulence and biofilm formation after binding on the AmiC sensor, triggering the amiE transcription. Herein, the involvement of the aliphatic amidase AmiE in P. aeruginosa virulence regulation has been investigated.

Pseudomonas aeruginosa Expresses a Functional Human Natriuretic Peptide Receptor Ortholog: Involvement in Biofilm Formation.

Unlabelled: Considerable evidence exists that bacteria detect eukaryotic communication molecules and modify their virulence accordingly. In previous studies, it has been demonstrated that the increasingly antibiotic-resistant pathogen Pseudomonas aeruginosa can detect the human hormones brain natriuretic peptide (BNP) and C-type natriuretic peptide (CNP) at micromolar concentrations. In response, the bacterium modifies its behavior to adapt to the host physiology, increasing its overall virulence.