A5057391414- Barrier Structure and Function Studies
- Salmonella and Campylobacter epidemiology
- Gut microbiota and health
- Clostridium difficile and Clostridium perfringens research
- Helicobacter pylori-related gastroenterology studies
- Vibrio bacteria research studies
- Gastrointestinal motility and disorders
- Viral gastroenteritis research and epidemiology
- Cancer Research and Treatments
- Trace Elements in Health
- Vitamin C and Antioxidants Research
- Ion Transport and Channel Regulation
- Veterinary medicine and infectious diseases
- Drug Transport and Resistance Mechanisms
- Oral microbiology and periodontitis research
- Bacterial biofilms and quorum sensing
- Yersinia bacterium, plague, ectoparasites research
- Gastroesophageal reflux and treatments
- Antibiotic Resistance in Bacteria
- Gastric Cancer Management and Outcomes
- Inflammatory Bowel Disease
- Curcumin's Biomedical Applications
- Escherichia coli research studies
- Aquaculture disease management and microbiota
- Viral Infections and Vectors
Charité - Universitätsmedizin Berlin
2014-2024
Freie Universität Berlin
2019-2024
Humboldt-Universität zu Berlin
2019-2024
Franklin University
2015
Ruhr University Bochum
2005-2012
Center for Rheumatology
2009
Significance The human gut microbiota is a complex community of microbes with enormous metabolic potential. Recognition the significance bacterial metabolites in mediating host interactions and impact perturbations this ecosystem on health has increased dramatically. Antibiotic therapy eliminates not only pathogens but also some commensal enteric microbiota, sometimes leading to inflammation diarrhea. Understanding how microbial imbalance actually causes disease challenging. This study...
Campylobacter jejuni secretes HtrA (high temperature requirement protein A), a serine protease that is involved in virulence. Here, we investigated the interaction of with host occludin, tight junction strand component. Immunofluorescence studies demonstrated infection polarized intestinal Caco-2 cells C. strain 81-176 resulted redistribution occludin away from junctions into cytoplasm, an effect was also observed human biopsies during acute campylobacteriosis. Occludin knockout were...
<h3>Objective</h3> α-Haemolysin (HlyA) influences host cell ionic homeostasis and causes concentration-dependent lysis. As a consequence, HlyA-producing <i>Escherichia coli</i> is capable of inducing 'focal leaks' in colon epithelia, through which bacteria antigens translocate. This study addressed the role HlyA as virulence factor pathogenesis colitis according to 'leaky gut' concept. <h3>Design</h3> To action colon, we performed oral administration HlyA-expressing <i>E coli</i>-536 its...
Campylobacter concisus infections of the gastrointestinal tract can be accompanied by diarrhea and inflammation, whereas colonization human oral cavity might have a commensal nature. We focus on pathophysiology C. effects different clinical fecal strains HT-29/B6 colon cells. Six eight were isolated. Mucus-producing epithelial monolayers infected with strains. Transepithelial electrical resistance (R(t)) tracer fluxes molecule size measured in Ussing chambers. Tight junction (TJ) protein...
Arcobacter butzleri causes watery diarrhea and bacteremia. Although, recently, more cases of have been caused by species, very little is known about its pathogenesis, the identification which aim this study.Human HT-29/B6 colonic epithelial monolayers were apically inoculated with A. butzleri. Transepithelial resistance macromolecule fluxes measured in Ussing chambers. Tight junction protein expression was analyzed Western blotting, subcellular distribution confocal laser-scanning...
Background. Aeromonads cause a variety of infections, including gastroenteritis, sepsis, and wound necrosis. Pathogenesis Aeromonas hydrophila its hemolysin has been characterized, but the mechanism epithelial barrier dysfunction is currently poorly understood. Methods. Human colon monolayers HT-29/B6 were apically inoculated with clinical isolates A. or secreted pore-forming toxin aerolysin. Epithelial resistance permeability for several markers determined in Ussing chambers, using 2-path...
Clostridium perfringens enterotoxin (CPE) causes food poisoning and antibiotic-associated diarrhea. It uses some claudin tight junction proteins (eg, claudin-4) as receptors to form Ca2+-permeable pores in the membrane, damaging epithelial cells small intestine colon. We demonstrate that only a subpopulation of colonic enterocytes which are characterized by apical dislocation claudins CPE-susceptible. CPE-mediated damage was enhanced if paracellular barrier impaired Ca2+ depletion,...
Background: The underlying pathophysiology of irritable bowel syndrome (IBS) is still unclear. Our aim was to investigate the pathophysiological mechanisms diarrhea, constipation, and antigen uptake in mixed-type IBS (IBS-M). Methods: Colonoscopic biopsies were obtained from IBS-M patients. Epithelial transport barrier function colonic mucosae characterized Ussing chambers using impedance spectroscopy. Mucosal permeability macromolecules measured. Western blotting for tight junction (TJ)...
Background: Hantaviruses are zoonotic agents that cause hemorrhagic fevers and thought to be transmitted humans by exposure aerosolized excreta of infected rodents. Puumala virus (PUUV) is the predominant endemic hantavirus in Europe. A large proportion PUUV-infected patients suffer from gastrointestinal symptoms unclear origin. In this study we demonstrate PUUV infection can occur via alimentary tract. Methods: We investigated susceptibility human small intestinal epithelium for analyzed...
Campylobacter jejuni (C. jejuni) is the most common cause of foodborne gastroenteritis worldwide. The bacteria induce diarrhea and inflammation by invading intestinal epithelium. Curcumin a natural polyphenol from turmeric rhizome Curcuma longa, medical plant, commonly used in curry powder. aim this study was investigation protective effects curcumin against immune-induced epithelial barrier dysfunction C. infection. indirect jejuni-induced defects its protection were analyzed co-cultures...
The human pathogen Helicobacter pylori has infected more than half of the world's population. Nevertheless, first step infection, acute colonization gastric mucus, is poorly understood. For successful colonization, H. must retain active motility in lumen until it reaches safety mucus layer. To identify factors determining we inserted bacteria into stomach anesthetized Mongolian gerbils. We adjusted juice to defined pH values between 2.0 and 6.0 by using an autotitrator. Despite fact that...
Key points Interleukin‐13 (IL‐13) causes intestinal epithelial barrier dysfunction, and is implicated in the pathogenesis of Th2‐driven inflammation (e.g. ulcerative colitis). However, it unclear whether sodium channel (ENaC) – main limiting factor for absorption distal colon also influenced by IL‐13 if so, what mechanism(s). We demonstrate an cell model as well mouse that reduced ENaC activity. show impairs ENaC‐dependent transport activating JAK1/2–STAT6 signalling pathway. These results...
Campylobacter jejuni is a bacterial human pathogen causing gastroenteritis and sequelae like irritable bowel syndrome. Epidemiologists count the campylobacteriosis by C. as most common foodborne zoonosis diarrheal disease worldwide. Based on bioinformatics predictions for potential protective compounds in campylobacteriosis, question was raised whether plant-based polyphenol resveratrol sufficient to attenuate intestinal epithelial damage induced jejuni. We investigated this performing...
Background: Campylobacter jejuni (C. jejuni) is one of the most common causes bacterial gastroenteritis worldwide. One sequela this infection development post-infectious irritable bowel syndrome (PI-IBS). It has been suggested that a dysfunctional intestinal barrier may promote IBS development. We aimed to test hypothesis against background leaky gut concept for low-grade inflammation in PI-IBS. Methods: identified patients with persistent PI-IBS symptoms after C. infection. During...
Abstract Zinc homoeostasis exerts protective effects in inflammatory intestinal diseases and zinc supplementation has been successfully used for treating infectious diarrhoea. This study aimed at a characterisation of on focal leak induction by α-haemolysin (HlyA)-producing Escherichia coli (E. coli) as mechanism colitis. We conducted vivo experiments oral challenge gnotobiotic mice colonised with HlyA-expressing E. -536. Mice were either fed defined normal or high diet to analyse...
Human Campylobacter infections are progressively rising and of high socioeconomic impact. In the present preclinical intervention study we investigated anti-pathogenic, immuno-modulatory intestinal epithelial barrier preserving properties vitamin D applying an acute campylobacteriosis model. Therefore, secondary abiotic IL-10-/- mice were perorally treated with synthetic 25-OH-cholecalciferol starting four days before peroral jejuni infection. Whereas application did not affect...
Campylobacter jejuni is a widespread zoonotic pathogen and the leading bacterial cause of foodborne gastroenteritis in humans. Previous infection studies showed disruption intercellular contacts, induction epithelial apoptosis, immune activation, all three contributing to intestinal barrier dysfunction diarrhea. The present study aims determine impact subepithelial cells on during underlying pathological mechanisms. Infection was performed co-culture confluent monolayers human colon cell...
The risk of Helicobacter pylori infection is highest in childhood, but the colonization process stomach mucosa poorly understood. We used anesthetized Mongolian gerbils to study initial stages H. colonization. Prandial and postprandial gastric conditions characteristic humans different ages were simulated. fraction bacteria that reached deep mucus layer varied strongly with modelled conditions. Colonization success was weak fast reacidification typical adults. efficiency entry also low a...
Klebsiella oxytoca causes antibiotic-associated hemorrhagic colitis and diarrhea. This was attributed largely to its secreted cytotoxins tilivalline tilimycin, inductors of epithelial apoptosis. To study whether exerts further barrier effects, T84 monolayers were challenged with bacterial supernatants derived from tilivalline/tilimycin-producing AHC6 or isogeneic tilivalline/tilimycin-deficient strain Mut-89. Both preparations decreased transepithelial resistance, enhanced fluorescein...