The Mla system of diderm Firmicute Veillonella parvula reveals an ancestral transenvelope bridge for phospholipid trafficking.

E. coli and most other diderm bacteria (those with two membranes) have an inner membrane enriched in glycerophospholipids (GPLs) and an asymmetric outer membrane (OM) containing GPLs in its inner leaflet and primarily lipopolysaccharides in its outer leaflet. In E.

Anti-diarrheal drug loperamide induces dysbiosis in zebrafish microbiota via bacterial inhibition.

Background: Perturbations of animal-associated microbiomes from chemical stress can affect host physiology and health. While dysbiosis induced by antibiotic treatments and disease is well known, chemical, nonantibiotic drugs have recently been shown to induce changes in microbiome composition, warranting further exploration. Loperamide is an opioid-receptor agonist widely prescribed for treating acute diarrhea in humans.

Gnotobiotic rainbow trout (Oncorhynchus mykiss) model reveals endogenous bacteria that protect against Flavobacterium columnare infection.

The health and environmental risks associated with antibiotic use in aquaculture have promoted bacterial probiotics as an alternative approach to control fish infections in vulnerable larval and juvenile stages. However, evidence-based identification of probiotics is often hindered by the complexity of bacteria-host interactions and host variability in microbiologically uncontrolled conditions. While these difficulties can be partially resolved using gnotobiotic models harboring no or reduced microbiota, most host-microbe interaction studies are carried out in animal models with little relevance for fish farming.

Mining zebrafish microbiota reveals key community-level resistance against fish pathogen infection.

The long-known resistance to pathogens provided by host-associated microbiota fostered the notion that adding protective bacteria could prevent or attenuate infection. However, the identification of endogenous or exogenous bacteria conferring such protection is often hindered by the complexity of host microbial communities. Here, we used zebrafish and the fish pathogen Flavobacterium columnare as a model system to study the determinants of microbiota-associated colonization resistance.

YeeJ is an inverse autotransporter from Escherichia coli that binds to peptidoglycan and promotes biofilm formation.

Escherichia coli is a commensal or pathogenic bacterium that can survive in diverse environments. Adhesion to surfaces is essential for E. coli colonization, and thus it is important to understand the molecular mechanisms that promote this process in different niches.

Biological and chemical strategies for exploring inter- and intra-kingdom communication mediated via bacterial volatile signals.

Airborne chemical signals emitted by bacteria influence the behavior of other bacteria and plants. We present an overview of in vitro methods for evaluating bacterial and plant responses to bacterial volatile compounds (BVCs). Three types of equipment have been used to physically separate the bacterial test strains from either other bacterial strains or plants (in our laboratory we use either Arabidopsis or tobacco plant seedlings): a Petri dish containing two compartments (BI Petri dish); two Petri dishes connected with tubing; and a microtiter-based assay.

Biofilm microenvironment induces a widespread adaptive amino-acid fermentation pathway conferring strong fitness advantage in Escherichia coli.

Bacterial metabolism has been studied primarily in liquid cultures, and exploration of other natural growth conditions may reveal new aspects of bacterial biology. Here, we investigate metabolic changes occurring when Escherichia coli grows as surface-attached biofilms, a common but still poorly characterized bacterial lifestyle. We show that E.

Airborne Bacterial Interactions: Functions Out of Thin Air?

Bacteria produce and release a large diversity of small molecules including organic and inorganic volatile compounds, hereafter referred to as bacterial volatile compounds (BVCs). Whereas BVCs were often only considered as wasted metabolic by-product sometimes perceived by animal olfactory systems, it is increasingly clear that they can also mediate cross-kingdom interactions with fungi, plants and animals. Recently, in vitro studies also reported the impact of BVCs on bacterial biology through modulation of antibiotic resistance, biofilm formation and virulence.

Role of bacterial volatile compounds in bacterial biology.

Bacterial interactions with neighboring microorganisms via production of small metabolites enable bacteria to respond and adapt to environmental changes. The study of intercellular interactions primarily focused on soluble metabolites, but bacteria also produce and release into their headspace a wide variety of volatile secondary metabolites, the ecological roles of which have generally been overlooked. However, bacterial volatile compounds are known to contribute to interkingdom interactions (plant, fungi and nematodes), and recent studies also identified their at-a-distance influence on bacterial behavior.

Aerial exposure to the bacterial volatile compound trimethylamine modifies antibiotic resistance of physically separated bacteria by raising culture medium pH.

Unlabelled: Bacteria release a wide diversity of small bioactive molecules that often correspond to secondary metabolites. Among them, volatile molecules produced under various growth conditions were shown to mediate cross-kingdom interactions with plants, nematodes, and fungi. Although the role of volatile compounds in bacterial biology is not well understood, recent reports indicated that they could play a role in airborne interactions between bacteria and influence antibiotic resistance, biofilm formation, and virulence.

Induction of the Cpx envelope stress pathway contributes to Escherichia coli tolerance to antimicrobial peptides.

Antimicrobial peptides produced by multicellular organisms as part of their innate system of defense against microorganisms are currently considered potential alternatives to conventional antibiotics in case of infection by multiresistant bacteria. However, while the mode of action of antimicrobial peptides is relatively well described, resistance mechanisms potentially induced or selected by these peptides are still poorly understood. In this work, we studied the mechanisms of action and resistance potentially induced by ApoEdpL-W, a new antimicrobial peptide derived from human apolipoprotein E.

Characterization of a Mycobacterium smegmatis uvrA mutant impaired in dormancy induced by hypoxia and low carbon concentration.

Background: The aerobic fast-growing Mycobacterium smegmatis, like its slow-growing pathogenic counterpart Mycobacterium tuberculosis, has the ability to adapt to microaerobiosis by shifting from growth to a non-proliferating or dormant state. The molecular mechanism of dormancy is not fully understood and various hypotheses have been formulated to explain it. In this work, we open new insight in the knowledge of M.