A thermo-resistant and RNase-sensitive cargo from extracellular vesicles modifies the behaviour of enterobacteria.

Extracellular vesicles (EVs) recently emerged as important players in the pathophysiology of parasitic infections. While the protist parasite  can produce EVs, their role in giardiasis remains obscure. can disrupt gut microbiota biofilms and transform commensal bacteria into invasive pathobionts at sites devoid of colonizing trophozoites via unknown mechanisms.

Hypoxia-inducible factor-driven glycolytic adaptations in host-microbe interactions.

Mammalian cells utilize glucose as a primary carbon source to produce energy for most cellular functions. However, the bioenergetic homeostasis of cells can be perturbed by environmental alterations, such as changes in oxygen levels which can be associated with bacterial infection. Reduction in oxygen availability leads to a state of hypoxia, inducing numerous cellular responses that aim to combat this stress.

Co-regulation of biofilm formation and antimicrobial resistance in Acinetobacter baumannii: from mechanisms to therapeutic strategies.

In recent years, multidrug-resistant Acinetobacter baumannii has emerged globally as a major threat to the healthcare system. It is now listed by the World Health Organization as a priority one for the need of new therapeutic agents. A.

Campus node-based wastewater surveillance enables COVID-19 case localization and confirms lower SARS-CoV-2 burden relative to the surrounding community.

Wastewater-based surveillance (WBS) has been established as a powerful tool that can guide health policy at multiple levels of government. However, this approach has not been well assessed at more granular scales, including large work sites such as University campuses. Between August 2021 and April 2022, we explored the occurrence of SARS-CoV-2 RNA in wastewater using qPCR assays from multiple complimentary sewer catchments and residential buildings spanning the University of Calgary's campus and how this compared to levels from the municipal wastewater treatment plant servicing the campus.

Regulatory Functions of Hypoxia in Host-Parasite Interactions: A Focus on Enteric, Tissue, and Blood Protozoa.

Body tissues are subjected to various oxygenic gradients and fluctuations and hence can become transiently hypoxic. Hypoxia-inducible factor (HIF) is the master transcriptional regulator of the cellular hypoxic response and is capable of modulating cellular metabolism, immune responses, epithelial barrier integrity, and local microbiota. Recent reports have characterized the hypoxic response to various infections.

The role of mucin -glycans in microbiota dysbiosis, intestinal homeostasis, and host-pathogen interactions.

Mucin -linked glycans are important mediators of host-microbiota-pathogen interactions in the gastrointestinal tract. The major component of intestinal mucus, the MUC2 mucin, is densely glycosylated, with up to 80% of its weight-to-volume ratio represented by -linked glycans. Glycosylation of secretory gel-forming mucins has an enormous impact on intestinal barrier function, microbial metabolism, and mucus colonization by both pathogenic and commensal microbes.

Gut microbiota biofilms: From regulatory mechanisms to therapeutic targets.

Gut microbiota contain communities of viruses, bacteria, fungi, and Eukarya, and live as biofilms. In health, these biofilms adhere to the intestinal mucus surface without contacting the epithelium. Disruptions to the equilibrium between these biofilms and the host may create invasive pathobionts from these commensal communities and contribute to disease pathogenesis.

Protoporphyrin IX derived from dual-species anaerobic biofilms of and attenuates bovine neutrophil function.

Host immune cells and clinical interventions often fail to eradicate biofilm-mediated infections, resulting in chronic inflammation. The role of the biofilm three-dimensional structure in this tolerant phenotype has been studied extensively; however, the impact of small molecules released from biofilm-bacteria in modulating host immune function is less well understood. A model of mixed-species biofilms composed of and was developed to evaluate bovine neutrophil responses to bioactive molecules released from either biofilm or planktonic bacteria.

Giardia duodenalis cysteine proteases cleave proteinase-activated receptor-2 to regulate intestinal goblet cell mucin gene expression.

Giardia duodenalis cysteine proteases have been identified as key virulence factors and have been implicated in alterations to intestinal goblet cell activity and mucus production during Giardia infection. The present findings demonstrate a novel mechanism by which Giardia cysteine proteases modulate goblet cell activity via cleavage and activation of protease-activated receptor 2. Giardia duodenalis (assemblage A) increased MUC2 mucin gene expression in human colonic epithelial cells in a manner dependent upon both protease-activated receptor 2 activation and Giardia cysteine protease activity.

Knowledge Gaps in the Understanding of Antimicrobial Resistance in Canada.

Current limitations in the understanding and control of antimicrobial resistance (AMR) in Canada are described through a comprehensive review focusing on: (1) treatment optimization; (2) surveillance of antimicrobial use and AMR; and (3) prevention of transmission of AMR. Without addressing gaps in identified areas, sustained progress in AMR mitigation is unlikely. Expert opinions and perspectives contributed to prioritizing identified gaps.

Enteric Tuft Cells in Host-Parasite Interactions.

Enteric tuft cells are chemosensory epithelial cells gaining attention in the field of host-parasite interactions. Expressing a repertoire of chemosensing receptors and mediators, these cells have the potential to detect lumen-dwelling helminth and protozoan parasites and coordinate epithelial, immune, and neuronal cell defenses against them. This review highlights the versatility of enteric tuft cells and sub-types thereof, showcasing nuances of tuft cell responses to different parasites, with a focus on helminths reflecting the current state of the field.

High-fat diet increases the severity of Giardia infection in association with low-grade inflammation and gut microbiota dysbiosis.

Exogenous factors that may influence the pathophysiology of Giardia infection remain incompletely understood. We have investigated the role of dietary fat in the pathogenesis of Giardia infection. Male 3 to 4-week-old C57BL/6 mice were fed either a low fat (LF) or a high fat (HF) diet for 12 days and challenged with G.

Cooperation between host immunity and the gut bacteria is essential for helminth-evoked suppression of colitis.

Background: Studies on the inhibition of inflammation by infection with helminth parasites have, until recently, overlooked a key determinant of health: the gut microbiota. Infection with helminths evokes changes in the composition of their host's microbiota: one outcome of which is an altered metabolome (e.g.

Effects of Hydrogen Sulfide on the Microbiome: From Toxicity to Therapy.

Hydrogen sulfide (HS), an important regulator of physiology and health, helps resolve inflammation and promotes tissue repair in the gastrointestinal tract. Gut microbiota live as a multispecies biofilm in close interaction with the upper mucus layer lining the epithelium. The relative abundance, spatial organization, and function of these microorganisms affect a broad range of health outcomes.

spp. and the Gut Microbiota: Dangerous Liaisons.

Alteration of the intestinal microbiome by enteropathogens is commonly associated with gastrointestinal diseases and disorders and has far-reaching consequences for overall health. Significant advances have been made in understanding the role of microbial dysbiosis during intestinal infections, including infection with the protozoan parasite , one of the most prevalent gut protozoa. Altered species composition and diversity, functional changes in the commensal microbiota, and changes to intestinal bacterial biofilm structure have all been demonstrated during the course of infection and have been implicated in pathogenesis.

Gastrointestinal biofilms in health and disease.

Microorganisms colonize various ecological niches in the human habitat, as they do in nature. Predominant forms of multicellular communities called biofilms colonize human tissue surfaces. The gastrointestinal tract is home to a profusion of microorganisms with intertwined, but not identical, lifestyles: as isolated planktonic cells, as biofilms and in biofilm-dispersed form.

Increased Mucosal Thrombin is Associated with Crohn's Disease and Causes Inflammatory Damage through Protease-activated Receptors Activation.

Background And Aims: Thrombin levels in the colon of Crohn's disease patients have recently been found to be elevated 100-fold compared with healthy controls. Our aim was to determine whether and how dysregulated thrombin activity could contribute to local tissue malfunctions associated with Crohn's disease.

Methods: Thrombin activity was studied in tissues from Crohn's disease patients and healthy controls.

Update on Giardia: Highlights from the seventh International Giardia and Cryptosporidium Conference.

Although Giardia duodenalis is recognized as one of the leading causes of parasitic human diarrhea in the world, knowledge of the mechanisms of infection is limited, as the pathophysiological consequences of infection remain incompletely elucidated. Similarly, the reason for and consequences of the very specific genome-organization in this parasite with 2 active nuclei is only partially known. Consistent with its tradition, the 7th International Giardia and Cryptosporidium Conference (IGCC 2019) was held from June 23 to 26, 2019, at the Faculty of Medicine and Pharmacy of the University of Rouen-Normandie, France, to discuss current research perspectives in the field.

Giardia spp. promote the production of antimicrobial peptides and attenuate disease severity induced by attaching and effacing enteropathogens via the induction of the NLRP3 inflammasome.

Polymicrobial infections of the gastro-intestinal tract are common in areas with poor sanitation. Disease outcome is the result of complex interactions between the host and pathogens. Such interactions lie at the core of future management strategies of enteric diseases.

Infection control in ERCP using a duodenoscope with a disposable cap (ICECAP): rationale for and design of a randomized controlled trial.

Background: Endoscopic retrograde cholangio-pancreatography (ERCP) is commonly performed in the management of pancreatic and biliary disease. Duodenoscopes are specialized endoscopes used to perform ERCP, and inherent to their design, a high rate of persistent bacterial contamination exists even after automated reprocessing and disinfection. Consequently, in recent years, ERCP has been associated with infection transmission, leading to several fatal patient outbreaks.

Pathogenesis and post-infectious complications in giardiasis.

Giardia is an important cause of diarrhoea, and results in post-infectious and extra-intestinal complications. This chapter presents a state-of-the art of our understanding of how this parasite may cause such abnormalities, which appear to develop at least in part in Assemblage-dependent manner. Findings from prospective longitudinal cohort studies indicate that Giardia is one of the four most prevalent enteropathogens in early life, and represents a risk factor for stunting at 2 years of age.

Enhanced Analgesic Effects and Gastrointestinal Safety of a Novel, Hydrogen Sulfide-Releasing Anti-Inflammatory Drug (ATB-352): A Role for Endogenous Cannabinoids.

The covalent linking of nonsteroidal anti-inflammatory drugs to a hydrogen sulfide (HS)-releasing moiety has been shown to dramatically reduce gastrointestinal (GI) damage and bleeding, as well as increase anti-inflammatory and analgesic potency. We have tested the hypothesis that an HS-releasing derivative of ketoprofen (ATB-352) would exhibit enhanced efficacy without significant GI damage in a mouse model of allodynia/hyperalgesia. ATB-352 was significantly more potent and effective as an analgesic than ketoprofen and did not elicit GI damage.