Peroxisomal cholesterol metabolism regulates yap-signaling, which maintains intestinal epithelial barrier function and is altered in Crohn's disease.

Intestinal epithelial cells line the luminal surface to establish the intestinal barrier, where the cells play essential roles in the digestion of food, absorption of nutrients and water, protection from microbial infections, and maintaining symbiotic interactions with the commensal microbial populations. Maintaining and coordinating all these functions requires tight regulatory signaling, which is essential for intestinal homeostasis and organismal health. Dysfunction of intestinal epithelial cells, indeed, is linked to gastrointestinal disorders such as irritable bowel syndrome, inflammatory bowel disease, and gluten-related enteropathies.

Peroxisome deficiency underlies failures in hepatic immune cell development and antigen presentation in a severe Zellweger disease model.

Peroxisome biogenesis disorders (PBDs) represent a group of metabolic conditions that cause severe developmental defects. Peroxisomes are essential metabolic organelles, present in virtually every eukaryotic cell and mediating key processes in immunometabolism. To date, the full spectrum of PBDs remains to be identified, and the impact PBDs have on immune function is unexplored.

The diverse roles of C-type lectin-like receptors in immunity.

Our understanding of the C-type lectin-like receptors (CTLRs) and their functions in immunity have continued to expand from their initial roles in pathogen recognition. There are now clear examples of CTLRs acting as scavenger receptors, sensors of cell death and cell transformation, and regulators of immune responses and homeostasis. This range of function reflects an extensive diversity in the expression and signaling activity between individual CTLR members of otherwise highly conserved families.

Towards early detection of neurodegenerative diseases: A gut feeling.

The gastrointestinal tract communicates with the nervous system through a bidirectional network of signaling pathways called the gut-brain axis, which consists of multiple connections, including the enteric nervous system, the vagus nerve, the immune system, endocrine signals, the microbiota, and its metabolites. Alteration of communications in the gut-brain axis is emerging as an overlooked cause of neuroinflammation. Neuroinflammation is a common feature of the pathogenic mechanisms involved in various neurodegenerative diseases (NDs) that are incurable and debilitating conditions resulting in progressive degeneration and death of neurons, such as in Alzheimer and Parkinson diseases.

Characterizing the Pain Experience of Children With Acute Gastroenteritis Based on Identified Pathogens.

Objectives: Pain is common with acute gastroenteritis (AGE) yet little is known about the severity associated with specific enteropathogens. We sought to explore the correlation of pain severity with specific enteropathogens in children with AGE.

Methods: Participants were prospectively recruited by the Alberta Provincial Pediatric EnTeric Infection TEam at 2 pediatric emergency departments (EDs) (December 2014-August 2018).

Comparative Evaluation of Luminex xTAG Gastrointestinal Pathogen Panel and Direct-From-Stool Real-Time PCR for Detection of Toxin in Stool Samples from a Pediatric Population.

Detection of toxins in patients with gastroenteritis has increasingly been accomplished through the use of enteric multiplex syndromic panels. Comparisons of the performance of these panels to both direct-from-stool (DFS) and culture-enriched stools followed by polymerase chain reaction (PCR) methods in pediatric populations are limited. Here, we compare the performance of the Luminex xTAG Gastrointestinal Pathogen Panel (GPP) to our DFS in-house real-time PCR (DFS RT-PCR) assay for the detection of toxin gene, , using 2641 stool specimens collected from children enrolled in the Alberta Provincial Pediatric EnTeric Infection Team (APPETITE) study in Alberta, Canada.

Clr-f expression regulates kidney immune and metabolic homeostasis.

The C-type lectin-related protein, Clr-f, encoded by Clec2h in the mouse NK gene complex (NKC), is a member of a family of immune regulatory lectins that guide immune responses at distinct tissues of the body. Clr-f is highly expressed in the kidney; however, its activity in this organ is unknown. To assess the requirement for Clr-f in kidney health and function, we generated a Clr-f-deficient mouse (Clr-f) by targeted deletions in the Clec2h gene.

Modulation of the cell membrane lipid milieu by peroxisomal β-oxidation induces Rho1 signaling to trigger inflammatory responses.

Phagocytosis, signal transduction, and inflammatory responses require changes in lipid metabolism. Peroxisomes have key roles in fatty acid homeostasis and in regulating immune function. We find that Drosophila macrophages lacking peroxisomes have perturbed lipid profiles, which reduce host survival after infection.

Molecular Detection of Non-O157 Shiga Toxin-Producing (STEC) Directly from Stool Using Multiplex qPCR Assays.

Non-O157 Shiga toxin-producing (STEC) can cause outbreaks that have great economic and health impact. Since the implementation of STEC screening in Alberta in 2018, it is also essential to have a molecular serotyping method with faster turnaround time for cluster identification and surveillance purposes. This study sought to perform molecular serotyping of the top six non-O157 (O26, O45, O103, O111, O121 and O145) STEC serotypes directly from stools and enrichment broths compared to conventional methods on isolates.

Hematochezia in children with acute diarrhea seeking emergency department care - a prospective cohort study.

Objectives: Although the passage of blood in stools in children represents a medical emergency, children seeking emergency department (ED) care remain poorly characterized. Our primary objective was to compare clinical characteristics and etiologic pathogens in children with acute diarrhea with and without caregiver-reported hematochezia. Secondary objectives were to characterize interventions and resource utilization.

Identification of Shiga-Toxin-Producing Shigella Infections in Travel and Non-Travel Related Cases in Alberta, Canada.

It has long been accepted that Shiga toxin (Stx) only exists in serotype 1. However, in recent decades, the presence of Shiga toxin genes () in other spp. have been reported.

The Drosophila melanogaster as Genetic Model System to Dissect the Mechanisms of Disease that Lead to Neurodegeneration in Adrenoleukodystrophy.

Drosophila melanogaster is the most successful genetic model organism to study different human disease with a recent increased popularity to study neurological disorders. Drosophila melanogaster has a complex yet well-defined brain with defined anatomical regions with specific functions. The neuronal network in the adult brain has a structural organization highly similar to human neurons, but in a brain that is much more amenable for complex analyses.

Direct Clostridioides difficile ribotyping from stool using capillary electrophoresis.

Clostridioides difficile(C. difficile) genotyping is essential for surveillance of emerging strains, transmissions, and outbreak investigations, but culture is lengthy and may not be routinely performed, which necessitates culture-independent genotyping methods. We aimed to develop a direct from stool C.

Association of Ct Values from Real-Time PCR with Culture in Microbiological Clearance Samples for Shiga Toxin-Producing (STEC).

Shiga toxin-producing (STEC) are associated with acute gastroenteritis worldwide, which induces a high economic burden on both healthcare and individuals. Culture-independent diagnostic tests (CIDT) in frontline microbiology laboratories have been implemented in Alberta since 2019. The objectives of this study were to determine the association between gene detection and culture positivity over time using STEC microbiological clearance samples and also to establish the frequency of specimen submission.

A Central Role for Ly49 Receptors in NK Cell Memory.

In the past decade, the study of NK cells was transformed by the discovery of three ways these "innate" immune cells display adaptive immune behavior, including the ability to form long-lasting, Ag-specific memories of a wide variety of immunogens. In this review, we examine these types of NK cell memory, highlighting their unique features and underlying similarities. We explore those similarities in depth, focusing on the role that Ly49 receptors play in various types of NK cell memory.

Epidemiology of Shiga Toxin-Producing O157 in the Province of Alberta, Canada, 2009-2016.

Shiga toxin-producing (STEC) infections are the product of the interaction between bacteria, phages, animals, humans, and the environment. In the late 1980s, Alberta had one of the highest incidences of STEC infections in North America. Herein, we revisit and contextualize the epidemiology of STEC O157 human infections in Alberta for the period 2009-2016.

Comparative Evaluation of Enteric Bacterial Culture and a Molecular Multiplex Syndromic Panel in Children with Acute Gastroenteritis.

Although enteric multianalyte syndromic panels are increasingly employed, direct comparisons with traditional methods and the inclusion of host phenotype correlations are limited. Luminex xTAG gastrointestinal pathogen panel (GPP) and culture results are highly concordant. However, phenotypic and microbiological confirmatory testing raises concerns regarding the accuracy of the GPP, especially for spp.

Pigment Visibility on Rectal Swabs Used To Detect Enteropathogens: a Prospective Cohort Study.

Data are lacking regarding the impact of visible pigment on rectal swab diagnostic accuracy. We describe the test characteristics of rectal swabs with and without pigment in children with gastroenteritis. Between December 2014 and September 2017, children (age, <18 years) with ≥3 episodes of vomiting and/or diarrhea in a 24-h period and symptoms for <7 days were enrolled through two pediatric emergency departments and from a province-wide nursing telephone advice line in Alberta, Canada.

General detection of Shiga toxin 2 and subtyping of Shiga toxin 1 and 2 in Escherichia coli using qPCR.

Shiga toxin-producing E. coli (STEC) is a gastrointestinal pathogen and has been recognized as one of the serious problems in public health. Shiga toxin genes (stx) can be grouped into different types according to their differences in sequence and biological activities.

Diagnostic Interpretation Guidance for Pediatric Enteric Pathogens: A Modified Delphi Consensus Process.

Background: We sought to develop diagnostic test guidance definitions for pediatric enteric infections to facilitate the interpretation of positive test results in the era of multianalyte molecular diagnostic test platforms.

Methods: We employed a systematic, two-phase, modified Delphi consensus process consisting of three web-based surveys and an expert panel face-to-face meeting. In phase 1, we surveyed an advisory panel of North American experts to select pathogens requiring diagnostic test guidance definition development.

Identification of Enteric Viruses in Oral Swabs from Children with Acute Gastroenteritis.

Stool is the diagnostic specimen of choice to identify enteropathogens in pediatric gastroenteritis. However, stool collection is challenging and its diagnostic characteristics in patients with isolated vomiting are unknown. Therefore, we evaluated if oral swabs are a suitable alternative specimen to stools.

High genetic variability of norovirus leads to diagnostic test challenges.

Background: It is important to understand the diagnostic accuracy of multiplex panels such as the Luminex xTAG Gastrointestinal Pathogen Panel (GPP) as they are increasingly employed for routine diagnostics worldwide. Recent evaluations in our laboratory identified lower detection rates of norovirus genogroup II (NoV GII) using GPP compared to our laboratory-developed RT-qPCR, Gastroenteritis Virus Panel (GVP).

Objectives: To characterize the cases of discordant NoV GII results between GPP and GVP and determine the sensitivity of the two assays for specific NoV GII genotypes.