A Vibrio T6SS-Mediated Lethality in an Aquatic Animal Model

ABSTRACT Bacteria belonging to the genus Vibrio include many known and emerging pathogens. Horizontal gene transfer of pathogenicity islands is a major contributor to the emergence of new pathogenic Vibrio strains. Here, we use the brine shrimp Artemia salina as a model and show that the marine bacterium Vibrio proteolyticus uses a horizontally shared type VI secretion system, T6SS3, to intoxicate a eukaryotic host. Two T6SS3 effectors, which were previously shown to induce inflammasome-mediated pyroptotic cell death in mammalian phagocytic cells, contribute to this toxicity. Furthermore, we find a novel T6SS3 effector that also contributes to the lethality mediated by this system against Artemia salina. Therefore, our results reveal a T6SS that is shared among diverse vibrios and mediates host lethality, indicating that it can lead to the emergence of new pathogenic strains. IMPORTANCE The rise in sea surface temperature has been linked to the spread of bacteria belonging to the genus Vibrio and the human illnesses associated with them. Since vibrios often share virulence traits horizontally, a better understanding of their virulence potential and determinants can prepare us for new emerging pathogens. In this work, we showed that a toxin delivery system found in various vibrios mediates lethality in an aquatic animal. Taken together with previous reports showing that the same system induces inflammasome-mediated cell death in mammalian phagocytic cells, our findings suggest that this delivery system and its associated toxins may contribute to the emergence of pathogenic strains

Learner Engagement: A Review of Approaches in the Psychology of Education and Art Education

This article critically examines the concept of ‘engagement’ as it has emerged within two distinct bodies of literature in the fields of art education and the psychology of education. In order to grapple with the heterogeneous nature of this literature, a meta‐narrative review was conducted whereby recurring narratives from various sub‐fields including special educational needs, gallery education and human development, were systematically identified and analysed in order to clarify the diversity of ways in which the concept of engagement is used within different research traditions. Areas of overlap between the ways in which the concept is understood and treated within these various texts were examined, as well as a consideration of the potential for any tensions to arise between them. It will be argued that the gap between the manner in which learner engagement is conceived and employed within these disciplines is not as wide as one might presume and that rather than these being incongruous with one another, in many respects, the approaches adopted within each discipline are complementary. It will be suggested that with further disciplinary exchange, especially with respect to the role of educational artefacts and social signals arising during the learning process, wider scope arises for advancing our understanding of learner engagement