Search

Bacterial coaggregation is a highly specific type of cell-cell interaction, well-documented among oral bacteria, and involves specific characteristics of the cell surface of the coaggregating strains. However, the understanding of the mechanisms promoting coaggregation in aquatic systems remains limited. This gap is critical to address, given the broad implications of coaggregation for multispecies biofilm formation, water quality, the performance of engineered systems, and diverse biotechnological applications. Therefore, this study aims to comprehensively characterize the cell surface of the coaggregating strain Delftia acidovorans 005P, isolated from drinking water, alongside a non-coaggregating strain, D. acidovorans 009P. By analyzing two strains of the same species, we aim to identify the factors contributing to the coaggregation ability of strain 005P. To achieve this, we employed a combination of physicochemical characterization, Fourier-transform infrared spectroscopy (FTIR), and advancing imaging techniques [transmission electron microscopy and cryo-electron tomography (cryo-ET)]. The coaggregating strain (005P) exhibited higher surface hydrophobicity, negative surface charge, and cell surface and co-adhesion energies than the non-coaggregating strain (009P). The chemical characterization of bacterial surfaces through FTIR revealed subtle differences, particularly in spectral regions linked to carbohydrates and phosphodiesters/amide III of proteins (860-930 cm -1 and 1212-1240 cm -1 , respectively). Cryo-ET highlighted significant differences in pili structures between the strains, such as variations in length, frequency, and arrangement. The pili in the 005P strain, identified as pili-like adhesins, serve as key mediators of coaggregation. By integrating physicochemical analyses and high-resolution imaging techniques, this study conclusively links the coaggregation ability of D. acidovorans 005P to its unique pili characteristics, emphasizing their crucial role in microbial coaggregation in aquatic environments., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Authors. Published by Elsevier B.V. All rights reserved.)

Modern poriferans are classified into four classes-Calcarea, Demospongiae, Hexactinellida and Homoscleromorpha-the recognition of which in fossil specimens almost exclusively relies on spicule morphology and arrangement. Early fossil representatives of the phylum Porifera are morphologically diverse, and many of them problematically display characteristics that are incompatible with the classification scheme developed for modern taxa. Critically, hexactine spicules-a diagnostic feature of hexactinellids among modern taxa-are found in various Cambrian and Ordovician taxa that cannot be accommodated within the hexactinellid body plan. Here we describe a new poriferan from the Drumian Marjum Formation of Utah, Polygoniella turrelli gen. et sp. nov., which exhibits a unique combination of complex anatomical features for a Cambrian form, including a syconoid-like organization, a thick body wall, and a multi-layered hexactin-based skeleton. The hexactinellid-like body wall architecture of this new species supports a Cambrian origin of the hexactinellid body plan and provides valuable insights into character evolution in early glass sponges., Competing Interests: We declare we have no competing interests., (© 2024 The Author(s).)

Experiencing trauma in childhood is a global public health issue linked to worse physical and mental health outcomes, including Post-Traumatic Stress Disorder (PTSD). Self-concept is a transdiagnostic concept linked to various psychopathologies and understanding its unique relationship to trauma is important. This meta-analysis aimed to understand the size of the effect between trauma and maltreatment and self-concept in children and adolescents. The current meta-analysis searched PubMed, PILOTS, PsycINFO, and Web of Science databases. Inclusion criteria involved studies with defined trauma exposure, valid measures of self-concept, and participants' mean age under 18 years old. One-hundred-and-thirty-four studies were included in the meta-analysis (N = 255,334). A random-effects meta-analysis was performed. A small negative relationship was observed between trauma exposure and self-concept (r = - 0.20, 95% CI - 0.22, - 0.18). This relationship was significantly moderated by some variables (type and nature of trauma exposure) but not others (participant gender, type of self-concept measure, quality of studies, country economic status). A small relationship between trauma exposure and negative self-concept in children and adolescents was detected, with repeated trauma exposure and type of trauma exposure moderating this relationship. This provides important directions for clinical practice around providing support for those exposed or most vulnerable to experiencing trauma., (© 2024. The Author(s).)