Diversity of domestic and imported assemblages of Giardia in Norway and multi-locus sequence typing of domestic assemblage A isolates.

Giardia duodenalis is a gastrointestinal parasite and one of the most frequently reported parasitic infections associated with contaminated water. This study investigated the diversity of domestic and imported Giardia assemblages in Norway, with a focus on the genetic characterization of domestic assemblage A isolates using multi-locus sequence typing (MLST) targeting six genome markers. We analysed 340 human, and 40 animal faecal samples collected between February 2022 and January 2024 from six medical microbiology laboratories and one veterinary diagnostic center across four Norwegian health regions.

Evaluating train drivers' performance to inform the development of automatic train operation.

Understanding train driver performance can provide valuable insights for the development of automatic train operation systems. This study investigates the visual perception of train drivers under different conditions using driving simulator experiments. The 43 participating train drivers were instructed to drive the train and react to stationary objects on the tracks of varying size and contrast to the background.

Culturing of Giardia lamblia under microaerobic conditions can impact metronidazole susceptibility by inducing increased expression of antioxidant enzymes.

The microaerophilic/anaerobic protist Giardia lamblia is a world-wide occurring parasite of the human small intestine. It causes giardiasis which manifests as diarrhoea accompanied by other sequelae. Giardiasis is most commonly treated with either the 5-nitroimidazole metronidazole or the benzimidazole albendazole.

Selective activity of Tabebuia avellanedae against Giardia duodenalis infecting organoid-derived human gastrointestinal epithelia.

Giardia duodenalis is a widespread intestinal protozoan that affects mammals, including humans. Symptoms can range from being subclinical to causing severe abdominal pain and diarrhoea. Giardiasis often requires repeated treatment with synthetic drugs like metronidazole.

Comparative genomics of reveals the emergence of an outbreak-associated population in Europe and its spread to the United States.

The zoonotic parasite is a global cause of gastrointestinal disease in humans and ruminants. Sequence analysis of the highly polymorphic gene enabled the classification of isolates into multiple groups (e.g.

The domed architecture of Giardias ventral disc is necessary for attachment and host pathogenesis.

After ingestion of dormant cysts, the widespread protozoan parasite Giardia lamblia colonizes the host gastrointestinal tract via direct and reversible attachment using a novel microtubule organelle, the ventral disc. Extracellular attachment to the host allows the parasite to resist peristaltic flow, facilitates colonization and is proposed to cause damage to the microvilli of host enterocytes as well as disrupt host barrier integrity. The 9 um in diameter ventral disc is defined by a highly complex architecture of unique protein complexes scaffolded onto a spiral microtubule (MT) array of one hundred parallel, uniformly spaced MT polymers that bend approximately one and a quarter turns to form a domed structure.

Oncogenic signaling is coupled to colorectal cancer cell differentiation state.

Colorectal cancer progression is intrinsically linked to stepwise deregulation of the intestinal differentiation trajectory. In this process, sequential mutations of APC, KRAS, TP53, and SMAD4 enable oncogenic signaling and establish the hallmarks of cancer. Here, we use mass cytometry of isogenic human colon organoids and patient-derived cancer organoids to capture oncogenic signaling, cell phenotypes, and differentiation states in a high-dimensional single-cell map.

Highly contiguous genomes of human clinical isolates of reveal assemblage- and sub-assemblage-specific presence-absence variation in protein-coding genes.

(syn. ) is a widespread gastrointestinal protozoan parasite with debated taxonomic status. Currently, eight distinct genetic sub-groups, termed assemblages A-H, are defined based on a few genetic markers.

Culture of Piglet Intestinal 3D Organoids from Cryopreserved Epithelial Crypts and Establishment of Cell Monolayers.

Intestinal organoids are increasingly being used to study the gut epithelium for digestive disease modeling, or to investigate interactions with drugs, nutrients, metabolites, pathogens, and the microbiota. Methods to culture intestinal organoids are now available for multiple species, including pigs, which is a species of major interest both as a farm animal and as a translational model for humans, for example, to study zoonotic diseases. Here, we give an in-depth description of a procedure used to culture pig intestinal 3D organoids from frozen epithelial crypts.

Detection and Molecular Characterization of and spp. Circulating in Wild Small Mammals from Portugal.

spp. and spp. are important diarrhea-causing protozoan parasites worldwide that exhibit broad host ranges.

Genetic diversity in the metronidazole metabolism genes nitroreductases and pyruvate ferredoxin oxidoreductases in susceptible and refractory clinical samples of Giardia lamblia.

The effectiveness of metronidazole against the tetraploid intestinal parasite Giardia lamblia is dependent on its activation/inactivation within the cytoplasm. There are several activating enzymes, including pyruvate ferredoxin reductase (PFOR) and nitroreductase (NR) 1 which metabolize metronidazole into toxic forms, while NR2 on the other hand inactivates it. Metronidazole treatment failures have been increasing rapidly over the last decade, indicating genetic resistance mechanisms.

Extensive testing of a multi-locus sequence typing scheme for Giardia duodenalis assemblage A confirms its good discriminatory power.

Background: The flagellated parasite Giardia duodenalis is a major and global cause of diarrhoeal disease. Eight genetically very distinct groups, known as assemblages A to H, have been recognized in the G. duodenalis species complex, two of which (assemblages A and B) infect humans and other mammalian hosts.

Human duodenal organoid-derived monolayers serve as a suitable barrier model for duodenal tissue.

Usually, duodenal barriers are investigated using intestinal cell lines like Caco-2, which in contrast to native tissue are limited in cell-type representation. Organoids can consist of all intestinal cell types and are supposed to better reflect the in vivo situation. Growing three-dimensionally, with the apical side facing the lumen, application of typical physiological techniques to analyze the barrier is difficult.

From 3D to 2D: Harmonization of Protocols for Two-dimensional Cultures on Cell Culture Inserts of Intestinal Organoids from Various Species.

In the expanding field of intestinal organoid research, various protocols for three- and two-dimensional organoid-derived cell cultures exist. Two-dimensional organoid-derived monolayers are used to overcome some limitations of three-dimensional organoid cultures. They are increasingly used also in infection research, to study physiological processes and tissue barrier functions, where easy experimental access of pathogens to the luminal and/or basolateral cell surface is required.

Dissection of Barrier Dysfunction in Organoid-Derived Human Intestinal Epithelia Induced by Giardia duodenalis.

Background & Aims: The protozoa Giardia duodenalis is a major cause of gastrointestinal illness worldwide, but underlying pathophysiological mechanisms remain obscure, partly due to the absence of adequate cellular models. We aimed at overcoming these limitations and recapitulating the authentic series of pathogenic events in the primary human duodenal tissue by using the human organoid system.

Methods: We established a compartmentalized cellular transwell system with electrophysiological and barrier properties akin to duodenal mucosa and dissected the events leading to G.

NF-κB determines Paneth versus goblet cell fate decision in the small intestine.

Although the role of the transcription factor NF-κB in intestinal inflammation and tumor formation has been investigated extensively, a physiological function of NF-κB in sustaining intestinal epithelial homeostasis beyond inflammation has not been demonstrated. Using NF-κB reporter mice, we detected strong NF-κB activity in Paneth cells, in '+4/+5' secretory progenitors and in scattered Lgr5+ crypt base columnar stem cells of small intestinal (SI) crypts. To examine NF-κB functions in SI epithelial self-renewal, mice or SI crypt organoids ('mini-guts') with ubiquitously suppressed NF-κB activity were used.

Real-Time PCR for Molecular Detection of Zoonotic and Non-Zoonotic spp. in Wild Rodents.

Giardiasis in humans is a gastrointestinal disease transmitted by the potentially zoonotic genotypes (assemblages) A and B. Small wild rodents such as mice and voles are discussed as potential reservoirs for but are predominantly populated by the two rodent species and . Currently, the detection of zoonotic and non-zoonotic species and genotypes in these animals relies on cumbersome PCR and sequencing approaches of genetic marker genes.

Suitability of current typing procedures to identify epidemiologically linked human Giardia duodenalis isolates.

Background: Giardia duodenalis is a leading cause of gastroenteritis worldwide. Humans are mainly infected by two different subtypes, i.e.

Harmonization of Protocols for Multi-Species Organoid Platforms to Study the Intestinal Biology of and Other Protozoan Infections.

The small intestinal epithelium is the primary route of infection for many protozoan parasites. Understanding the mechanisms of infection, however, has been hindered due to the lack of appropriate models that recapitulate the complexity of the intestinal epithelium. Here, we describe an platform using stem cell-derived intestinal organoids established for four species that are important hosts of Apicomplexa and other protozoa in a zoonotic context: human, mouse, pig and chicken.

Genetic Diversity of the Flavohemoprotein Gene of : Evidence for High Allelic Heterozygosity and Copy Number Variation.

Purpose: The flavohemoprotein (gFlHb) in plays an important role in managing nitrosative and oxidative stress, and potentially also in virulence and nitroimidazole drug tolerance. The aim of this study was to analyze the genetic diversity of in assemblages A and B clinical isolates.

Methods: genes from 20 cultured clinical isolates were subjected to PCR amplification and cloning, followed by Sanger sequencing.

RORγt Treg to Th17 ratios correlate with susceptibility to Giardia infection.

Infections with Giardia are among the most common causes of food and water-borne diarrheal disease worldwide. Here, we investigated Th17, Treg and IgA responses, and alterations in gut microbiota in two mouse lines with varying susceptibility to Giardia muris infection. Infected BALB/c mice shed significantly more cysts compared with C57BL/6 mice.

Genetic variation in metronidazole metabolism and oxidative stress pathways in clinical assemblage A and B isolates.

Treatment-refractory cases have increased rapidly within the last decade. No markers of resistance nor a standardized susceptibility test have been established yet, but several enzymes and their pathways have been associated with metronidazole (MTZ) resistant . Very limited data are available regarding genetic variation in these pathways.

Giardia intestinalis cystatin is a potent inhibitor of papain, parasite cysteine proteases and, to a lesser extent, human cathepsin B.

Cystatins are important regulators of papain-like cysteine proteases. In the protozoan parasite Giardia intestinalis, papain-like cysteine proteases play an essential role in the parasite's biology and pathogenicity. Here, we characterized a cysteine protease inhibitor of G.

From Entry to Early Dissemination- Initial Encounter With Its Host.

is a zoonotic intracellular parasite, able to infect any warm-blooded animal via ingestion of infective stages, either contained in tissue cysts or oocysts released into the environment. While immune responses during infection are well-studied, there is still limited knowledge about the very early infection events in the gut tissue after infection via the oral route. Here we briefly discuss differences in host-specific responses following infection with oocyst-derived sporozoites vs.