Publications by authors named "Katja Brunner"

Antibiotic treatments have detrimental effects on the microbiome and lead to antibiotic resistance. To develop a phage therapy against a diverse range of clinically relevant Escherichia coli, we screened a library of 162 wild-type (WT) phages, identifying eight phages with broad coverage of E. coli, complementary binding to bacterial surface receptors, and the capability to stably carry inserted cargo.

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Strategies employed by pathogenic enteric bacteria, such as Shigella, to subvert the host adaptive immunity are not well defined. Impairment of T lymphocyte chemotaxis by blockage of polarised edge formation has been reported upon Shigella infection. However, the functional impact of Shigella on T lymphocytes remains to be determined.

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Over the past 10 years, the "Pathogénie Microbienne Moléculaire" unit of Professor Philippe Sansonetti has studied the molecular cross talk between the intestinal microbiota and the gut epithelium, aiming to better understand how this mutualistic symbiosis delineates homoeostasis and, when perturbed, prompts pathology. To do so, the unit has manipulated both bacterial and epithelial cells, and used cutting-edge technology. More recently, the lab has turned its focus also on studying the intestinal crypt and more specifically the intestinal stem cell for their role in epithelial regeneration and long-term epithelium renewal.

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The enteropathogen, , is highly virulent and remarkably adjusted to the intestinal environment of its almost exclusive human host. Key for pathogenicity is the injection of virulence effectors into the host cell its type three secretion system (T3SS), initiating disease onset and progression by the vast diversity of the secreted T3SS effectors and their respective cellular targets. The multifaceted modulation of host signaling pathways exerted by T3SS effectors, which include the subversion of host innate immune defenses and the promotion of intracellular bacterial survival and dissemination, have been extensively reviewed in the recent past.

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The pathogenicity of , increasingly found in the human gastrointestinal (GI) tract, is unclear. Some studies indicate that its role in GI conditions has been underestimated, whereas others suggest that the organism has a commensal-like phenotype. For the enteropathogen , the lipooligosaccharide (LOS) is a main driver of virulence.

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Article Synopsis
  • Direct interactions between bacterial glycans and host cell glycans play a crucial role in the attachment of pathogenic bacteria, such as the Gram-negative bacterium responsible for acute rectocolitis, to epithelial cells.
  • Researchers discovered that nonactivated CD4 T lymphocytes can be made susceptible to the bacteria by introducing sialylated glycosphingolipids, making them behave like activated T cells and allowing them to bind to the bacteria.
  • This binding is essential for the bacteria to inject effects into the host cells, with the process relying on the polymerization of actin, highlighting the importance of glycan interactions in bacterial pathogenesis and host specificity.
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Background: The effect that traditional and modern DNA extraction methods have on applications to study the role of gut microbiota in health and disease is a topic of current interest. Genomic DNA was extracted from three faecal samples and one probiotic capsule using three popular methods; chaotropic (CHAO) method, phenol/chloroform (PHEC) extraction, proprietary kit (QIAG). The performance of each of these methods on DNA yield and quality, microbiota composition using quantitative PCR, deep sequencing of the 16S rRNA gene, and sequencing analysis pipeline was evaluated.

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Campylobacter jejuni is a commensal bacterium in the intestines of animals and birds and a major cause of food-borne gastroenteritis in humans worldwide. Here we show that exposure to pancreatic amylase leads to secretion of an α-dextran by C. jejuni and that a secreted protease, Cj0511, is required.

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