Pathogen-Epithelium Interactions and Inflammatory Responses in Salmonella Dublin Infections through Bovine Ileal Monolayer Models Derived from Adult Organoids

Abstract Salmonella enterica serovar Dublin (S. Dublin) is an important enteric pathogen affecting cattle and poses increasing public health risks. Understanding the pathophysiology and host-pathogen interactions of S. Dublin infection is critical for developing effective control strategies, yet studies are hindered by the lack of physiologically relevant in vitro models. This study aimed to generate a robust bovine monolayer derived from adult ileal organoids, validate its feasibility as an in vitro infection model with S. Dublin, and evaluate the epithelial response to infection. A stable, confluent monolayer with a functional epithelial barrier was established under optimized culture conditions. The model's applicability for studying S. Dublin infection was confirmed by documenting intracellular bacterial invasion and replication and the resultant impacts on epithelial integrity, showing significant disruption of the monolayer, and a specific inflammatory response, providing insights into the pathogen-epithelium interactions. The study underscores the utility of organoid-derived monolayers in advancing our understanding of enteric infections in livestock and highlights implications for therapeutic strategy development and preventive measures, with potential applications extending to both veterinary and human medicine. The established bovine ileal monolayer offers a novel and physiologically relevant in vitro platform for investigating enteric pathogen-host interactions, particularly for pathogens like S. Dublin.