BacA: a possible regulator that contributes to the biofilm formation of .

Previously, we pointed out in PAO1 biofilm cells the accumulation of a hypothetical protein named PA3731 and showed that the deletion of the corresponding gene impacted its biofilm formation capacity. PA3731 belongs to a cluster of 4 genes ( to ) that we named for "Biofilm Associated Cluster." The present study focuses on the PA14_16140 protein, i.

Lysine Trimethylation in Planktonic and Pellicle Modes of Growth in .

Over the past 30 years, has been described as an important nosocomial pathogen due to frequent ventilator-associated infections. Many biological processes of remain elusive, such as the formation of an air-liquid biofilm (pellicle). Several studies demonstrated the importance of post-translational modifications (PTMs) in physiology.

Hepatoprotective Effect of Grape Seed and Skin Extract Against Lithium Exposure Examined by the Window of Proteomics.

Context: The liver is the organ by which the majority of substances are metabolized, including psychotropic drugs. Lithium (Li) used as drug for many neurological disorders such as bipolar disorders.

Objective: This study aims to assess lithium toxicity and to evaluate the hepatic-protective properties of a grape skin seed and extract (GSSE).

Biofilm Formation, Motion and Protein Patterns on Hyaluronic Acid and Polydimethylsiloxane Depend on Surface Stiffness.

The surface stiffness of the microenvironment is a mechanical signal regulating biofilm growth without the risks associated with the use of bioactive agents. However, the mechanisms determining the expansion or prevention of biofilm growth on soft and stiff substrates are largely unknown. To answer this question, we used PDMS (polydimethylsiloxane, 9-574 kPa) and HA (hyaluronic acid gels, 44 Pa-2 kPa) differing in their hydration.

Cytoskeletal components can turn wall-less spherical bacteria into kinking helices.

Bacterial cell shape is generally determined through an interplay between the peptidoglycan cell wall and cytoplasmic filaments made of polymerized MreB. Indeed, some bacteria (e.g.

Detoxification Response of MFAF76a to Gaseous Pollutants NO and NO.

Bacteria are often exposed to nitrosative stress from their environment, from atmospheric pollution or from the defense mechanisms of other organisms. Reactive nitrogen species (RNS), which mediate nitrosative stress, are notably involved in the mammalian immune response through the production of nitric oxide (NO) by the inducible NO synthase iNOS. RNS are highly reactive and can alter various biomolecules such as lipids, proteins and DNA, making them toxic for biological organisms.

Gaseous NO induces various envelope alterations in Pseudomonas fluorescens MFAF76a.

Anthropogenic atmospheric pollution and immune response regularly expose bacteria to toxic nitrogen oxides such as NO and NO. These reactive molecules can damage a wide variety of biomolecules such as DNA, proteins and lipids. Several components of the bacterial envelope are susceptible to be damaged by reactive nitrogen species.

Impact of Carbon Source Supplementations on Physiology.

is an opportunistic pathogen highly resistant to a wide range of antimicrobial agents, making its infections very difficult to treat. Since microorganisms need to perpetually adapt to their surrounding environment, understanding the effect of carbon sources on physiology is therefore essential to avoid increasing drug-resistance and better fight this pathogen. By a global proteomic approach and phenotypic assays, we investigated the impact of various carbon source supplementations (glucose, glutamate, succinate, and citrate) on the physiology of the PA14 strain.

Comparative Proteomic Analysis of the Diatom Reveals New Insights Into Intra- and Extra-Cellular Protein Contents of Its Oval, Fusiform, and Triradiate Morphotypes.

is an atypical diatom since it can display three main morphotypes: fusiform, triradiate, and oval. Such pleomorphism is possible thanks to an original metabolism, which is tightly regulated in order to acclimate to environmental conditions. Currently, studies dedicated to the comparison of each morphotype issued from one specific strain are scarce and little information is available regarding the physiological significance of this morphogenesis.

MacAB-TolC Contributes to the Development of Biofilm at the Solid-Liquid Interface.

has emerged as one of the most problematic bacterial pathogens responsible for hospital-acquired and community infections worldwide. Besides its high capacity to acquire antibiotic resistance mechanisms, it also presents high adhesion abilities on inert and living surfaces leading to biofilm development. This lifestyle confers additional protection against various treatments and allows it to persist for long periods in various hospital niches.

Phosphorylation of Extracellular Proteins in in Sessile Mode of Growth.

is a problematic nosocomial pathogen owing to its increasing resistance to antibiotics and its great ability to survive in the hospital environment, which is linked to its capacity to form biofilms. Structural and functional investigations of post-translational modifications, such as phosphorylations, may lead to identification of candidates for therapeutic targets against this pathogen. Here, we present the first S/T/Y phosphosecretome of two strains, the reference strain ATCC 17978 and the virulent multi-drug resistant strain AB0057, cultured in two modes of growth (planktonic and biofilm) using TiO chromatography followed by high resolution mass spectrometry.

Variability of the response of human vaginal Lactobacillus crispatus to 17β-estradiol.

We previously showed that the physiological concentration of 17β-estradiol in the vaginal environment is sufficient to affect the membrane dynamics and adhesion phenotype of the Lactobacillus crispatus strain CIP104459. However, L. crispatus is a heterogeneous species.

Exoproteomics for Better Understanding Virulence.

is the most common human opportunistic pathogen associated with nosocomial diseases. In 2017, the World Health Organization has classified as a critical agent threatening human health, and for which the development of new treatments is urgently necessary. One interesting avenue is to target virulence factors to understand pathogenicity.

Crosstalk between the Type VI Secretion System and the Expression of Class IV Flagellar Genes in the MFE01 Strain.

Type VI secretion systems (T6SSs) are contractile bacterial multiprotein nanomachines that enable the injection of toxic effectors into prey cells. The MFE01 strain has T6SS antibacterial activity and can immobilise competitive bacteria through the T6SS. Hcp1 (hemolysin co-regulated protein 1), a constituent of the T6SS inner tube, is involved in such prey cell inhibition of motility.

Epinephrine affects motility, and increases adhesion, biofilm and virulence of Pseudomonas aeruginosa H103.

Microbial endocrinology has demonstrated for more than two decades, that eukaryotic substances (hormones, neurotransmitters, molecules of the immune system) can modulate the physiological behavior of bacteria. Among them, the hormones/neurotransmitters, epinephrine (Epi) and norepinephrine (NE), released in case of stress, physical effort or used in medical treatment, were shown to be able to modify biofilm formation in various bacterial species. In the present study, we have evaluated the effect of Epi on motility, adhesion, biofilm formation and virulence of Pseudomonas aeruginosa, a bacterium linked to many hospital-acquired infections, and responsible for chronic infection in immunocompromised patients including persons suffering from cystic fibrosis.

A versatile and recyclable molecularly imprinted polymer as an oxidative catalyst of sulfur derivatives: a new possible method for mustard gas and V nerve agent decontamination.

A molecularly imprinted polymer containing a porphyrin unit was developed as a biomimetic heterogenous catalyst for the oxidation of sulfur derivatives. Its catalytic efficiency under mild conditions and its easy recovery represent a great asset for the design of new decontamination tools for yperite and VX.

Protein post-translational modifications in bacteria.

Over the past decade the number and variety of protein post-translational modifications that have been detected and characterized in bacteria have rapidly increased. Most post-translational protein modifications occur in a relatively low number of bacterial proteins in comparison with eukaryotic proteins, and most of the modified proteins carry low, substoichiometric levels of modification; therefore, their structural and functional analysis is particularly challenging. The number of modifying enzymes differs greatly among bacterial species, and the extent of the modified proteome strongly depends on environmental conditions.

Composition of the Biofilm Matrix of Acneic Strain RT5.

In skin, (former ) can behave as an opportunistic pathogen, depending on the strain and environmental conditions. Acneic strains of form biofilms inside skin-gland hollows, inducing inflammation and skin disorders. The essential exogenous products of accumulate in the extracellular matrix of the biofilm, conferring essential bacterial functions to this structure.

Extracellular DNA release, quorum sensing, and PrrF1/F2 small RNAs are key players in tobramycin-enhanced biofilm formation.

Biofilms are structured microbial communities that are the leading cause of numerous chronic infections which are difficult to eradicate. Within the lungs of individuals with cystic fibrosis (CF), causes persistent biofilm infection that is commonly treated with aminoglycoside antibiotics such as tobramycin. However, sublethal concentrations of this aminoglycoside were previously shown to increase biofilm formation by , but the underlying adaptive mechanisms still remain elusive.

Adaptation of acneic and non acneic strains of Cutibacterium acnes to sebum-like environment.

Cutibacterium acnes, former Proprionibacterium acnes, is a heterogeneous species including acneic bacteria such as the RT4 strain, and commensal bacteria such as the RT6 strain. These strains have been characterized by metagenomic analysis but their physiology was not investigated until now. Bacteria were grown in different media, brain heart infusion medium (BHI), reinforced clostridial medium (RCM), and in sebum like medium (SLM) specifically designed to reproduce the lipid rich environment of the sebaceous gland.

LasB and CbpD Virulence Factors of Pseudomonas aeruginosa Carry Multiple Post-Translational Modifications on Their Lysine Residues.

Pseudomonas aeruginosa is a multi-drug resistant human pathogen largely involved in nosocomial infections. Today, effective antibacterial agents are lacking. Exploring the bacterial physiology at the post-translational modifications (PTM) level may contribute to the renewal of fighting strategies.

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.