Catch the star! Spatial information activates the manual motor system

Previous research demonstrated a close bidirectional relationship between spatial attention and the manual motor system. However, it is unclear whether an explicit hand movement is necessary for this relationship to appear. A novel method with high temporal resolution – bimanual grip force registration – sheds light on this issue. Participants held two grip force sensors while being presented with lateralized stimuli (exogenous attentional shifts, Experiment 1), left- or right-pointing central arrows (endogenous attentional shifts, Experiment 2), or the words "left" or "right" (endogenous attentional shifts, Experiment 3). There was an early interaction between the presentation side or arrow direction and grip force: lateralized objects and central arrows led to an increase of the ipsilateral force and a decrease of the contralateral force. Surprisingly, words led to the opposite pattern: increased force in the contralateral hand and decreased force in the ipsilateral hand. The effect was stronger and appeared earlier for lateralized objects (60 ms after stimulus presentation) than for arrows (100 ms) or words (250 ms). Thus, processing visuospatial information automatically activates the manual motor system, but the timing and direction of this effect vary depending on the type of stimulus.

New Insights on the Early Interaction Between Typhoid and Non-typhoid Salmonella Serovars and the Host Cells

Salmonella enterica is a common source of food and water-borne infections, causing a wide range of clinical ailments in both human and animal hosts. Immunity to Salmonella involves an interplay between different immune responses, which are rapidly initiated to control bacterial burden. However, Salmonella has developed several strategies to evade and modulate the host immune responses. In this sense, the main knowledge about the pathogenicity of this bacterium has been obtained by the study of mouse models with non-typhoidal serovars. However, this knowledge is not representative of all the pathologies caused by non-typhoidal serovars in the human. Here we review the most important features of typhoidal and non-typhoidal serovars and the diseases they cause in the human host, describing the virulence mechanisms used by these pathogens that have been identified in different models of infection.

Child Development and Early Interaction: PERL Research Protocol, a Preventive Home Visiting Program, Randomized Controlled Trial in France

Background: Early childhood is a key period for reducing the social inequalities that affect health. Some parenting support and home visitation programs have proven to be effective in assisting parents during this period. France's Protection Maternelle et Infantile (maternal and child welfare) services (PMIs) are at the heart of this primary prevention and may adapt their intervention to improve parenting support. In this manuscript, we describe the protocol of the PERL study, an intervention based on a home visiting program.Method and design: The PERL study is a single-center, randomized, controlled interventional trial. The aim was to assess the impact of a preventive home visiting program on the development of young children and parent-baby interaction. Visits were made by PMI nurses to 64 randomly recruited families from the general population. All families who had a baby born after 37 weeks of pregnancy between September 2018 and December 2019, and who resided in the trial area were eligible. Participants were randomly allocated to the intervention group or the control group. The PMI nurses made 12 home visits in the first year, 6 in the second year, and 4 in the third and fourth years of the child's life. Primary and secondary outcomes were measured when the child was 4 and 24 months old. These measurements recorded (i) the child's developmental milestones, in particular, language and socio emotional skills, (ii) early interaction, maternal sensitivity, and attachment patterns, (iii) maternal psychopathology including depression.Discussion: This study aims to assess the impact of home visits, made by specifically-trained and supervised nurses, on the child's development and parent-child interactions. Such interventions are complementary to other preventive programs addressing the impact of social inequalities on perinatal health. Placing nurses' professional skills at the center of this project may prove an effective and cost-saving intervention compared to existing programs. The study proposes a prevention model that is in keeping with the principle of reducing social inequalities in health by providing support from the earliest age through public service.Clinical Trial Registration: The clinical trial number is NCT03506971, registered on April 24, 2018.

The Development of Giving in Forms of Object Exchange: Exploring the Roots of Communication and Morality in Early Interaction around Objects

Giving is an act of great social importance across cultures, with communicative as well as moral dimensions because it is linked to sharing and fairness. We critically evaluate various explanations for how this social process develops in infancy and take a process-relational approach, using naturalistic observations to illustrate forms of interaction involving the exchange of objects and possible developmental trajectories for the emergence of different forms of giving. Based on our data, we propose that the object becomes a pivot point for interaction, and through the process of such interaction the social actions of showing and giving emerge and take on diverse social meanings within the relations between infants and caregivers.

Ehrlichia ruminantium uses its transmembrane protein Ape to adhere to host bovine aortic endothelial cells

Ehrlichia ruminantium is an obligate intracellular bacterium, transmitted by ticks of the genus Amblyomma and responsible for heartwater, a disease of domestic and wild ruminants. High genetic diversity of E. ruminantium strains hampers the development of an effective vaccine against all strains present in the field. In order to develop strategies for the control of heartwater through both vaccine and alternative therapeutic approaches, it is important to first gain a better understanding of the early interaction of E. ruminantium and its host cell. Particularly, the mechanisms associated with bacterial adhesion remain to elucidate. Herein, we studied the role of E. ruminantium membrane protein ERGA_CDS_01230 (UniProt Q5FFA9), a probable iron transporter, in the adhesion process to host bovine aortic endothelial cells (BAEC). The recombinant version of the protein ERGA_CDS_01230, successfully produced in the Leishmania tarentolae system, is O-glycosylated. Following in vitro culture of E. ruminantium in BAEC, the expression of CDS ERGA_CDS_01230 peaks at the extracellular infectious elementary body stages. This result suggest the likely involvement of ERGA_CDS_01230, named hereafter Ape for Adhesion protein of Ehrlichia, in the early interaction of E. ruminantium with its host cells. We showed using flow cytometry and scanning electron microscopy that beads coated with recombinant ERGA_CDS_01230 (rApe) adheres to BAEC. In addition, we also abserved that rApe interacts with proteins of the cell lysate, membrane and organelle fractions. Additionally, enzymatic treatment degrading dermatan and chondroitin sulfates on the surface of BAEC is associated with a 50% reduction in the number of bacteria in the host cell after a development cycle, indicating that glycosaminoglycans seem to play a role in the adhesion of E. ruminantium to the host cell. Finally, Ape induces a humoral response in vaccinated animals. Globally, our work identifying the role of Ape in E. ruminantium adhesion to host cells makes it a gold vaccine candidate and represents a first step toward the understanding of the mechanisms of cell invasion by E. ruminantium.

Intracellular passage triggers a molecular response in Brucella abortus that increases its infectiousness

Brucella abortus is a facultative extracellular-intracellular pathogen that encounters a diversity of environments within the host cell. We report that bacteria extracted from infected cells at late stages (48 h post-infection) of the intracellular life cycle significantly increase their ability to multiply in new target cells. This increase depends on early interaction with the cell surface since bacteria become more adherent and penetrate more efficiently as compared to in vitro grown bacteria. At this late stage of infection, the bacterium locates within an autophagosome-like compartment, facing starving and acidic conditions. At this point, the two-component system BvrR/BvrS becomes activated, and the expression of the transcriptional regulator VjbR and the type IV secretion system VirB increased. Using bafilomycin to inhibit BvrR/BvrS activation and specific inhibitors for VjbR and VirB we showed that the BvrR/BvrS and VjbR systems correlate with the increased interaction with new host cells while the VirB system does not. Bacteria released from infected cells under natural conditions displayed the same phenotype as intracellular bacteria. We propose a model in which the B. abortus BvrR/BvrS system senses the transition from its replicative niche at the endoplasmic reticulum to the autophagosome-like exit compartment. This activation leads to the expression of VirB participating in the release of the bacterium from the cells and an increase in VjbR expression that results in a more efficient interaction with new host cells.

Analysis of Pseudocercospora fijiensis genes upregulated during early interaction with Musa acuminata (var. Dwarf Cavendish)

Pseudocercospora fijiensis is a filamentous, hemi[B1] biotrophic fungus whose infection process in banana comprises biotrophic and necrotrophic phases; the biotrophic phase is the longer and less damaging of the two but is nonetheless a crucial stage of fungal establishment in the host. To discover the genes essential in this stage, we conducted an interaction experiment to isolate the transcriptome of the P. fijiensis and Musa acuminata interaction during the first 9 days of infection. Of more than 7000 P. fijiensis genes identified, the fifteen most highly expressed genes (RPKM>500) were analyzed. Specific non-canonical effector candidates were identified following in silico characterization which may be fundamental to pathogenicity. This report reveals essential details of a poorly-elucidated stage of the P. fijiensis-Musa sp. pathosystem.

Autoregulation dependent and independent mechanisms are responsible for the systemic control of nodule formation by the plant N demand

In legumes interacting with rhizobia the formation of symbiotic organs responsible for the acquisition of atmospheric nitrogen is depending of the plant nitrogen (N) demand. We discriminated between local and systemic impact of nitrogen on nodule formation using Medicago truncatula plants cultivated in split-root systems. We obtained evidence of the control of nodule formation by whole plant systemic N-satisfaction signaling but obtained little evidence of a local control by mineral nitrogen. We characterized the impact of systemic N signaling on the root transcriptome reprogramming associated to nodule formation. We identified, large genes clusters displaying common expression profiles in response to systemic N signaling enriched in particular fonctions required during these biological processes. We found evidence of a strong effect of SUNN in the control by systemic N signaling of many genes involved in the early interaction with rhizobium as well as organogenesis supporting a role of autoregulation pathway in systemic N signaling. However, we also found evidence that major SUNN independent systemic N signaling controls were maintained in the mutant. This study shed light on the unexpected high complexity of the control of nodule formation by systemic N signaling, that probably involves multiple pathways.

Pseudomonas putida Represses JA- and SA-Mediated Defense Pathways in Rice and Promotes an Alternative Defense Mechanism Possibly through ABA Signaling

The signaling pathways induced by Pseudomonas putida in rice plants at the early plant–rhizobacteria interaction stages, with and without inoculation of Xanthomonas oryzae pv. oryzae, were studied. In the absence of pathogen, P. putida reduced ethylene (ET) production, and promoted root and stem elongation. Interestingly, gene OsHDA702, which plays an important role in root formation, was found significantly up-regulated in the presence of the rhizobacterium. Although X. oryzae pv. oryzae inoculation enhanced ET production in rice plants, P. putida treatment repressed ET-, jasmonic acid (JA)- and salicylic acid (SA)-mediated defense pathways, and induced the biosynthesis of abscisic acid (ABA), and the overexpression of OsHDA705 and some pathogenesis-related proteins (PRs), which in turn increased the susceptibility of the rice plants against the pathogen. Collectively, this is the first work on the defense signaling induced by plant growth-promoting rhizobacteria in plants at the early interaction stages, and suggests that rhizobacteria stimulate an alternative defense mechanism in plants based on ABA accumulation and OsHDA705 signaling.