title: Immunocytochemical studies of Salmonella Typhimurium invasion of porcine jejunal epithelial cells.
abstract: Although infection of pigs with Salmonella Typhimurium represents a serious problem, most studies on Salmonella infection have been carried out in other species. The purpose of the current study was to examine the route(s) of entry of Salmonella Typhimurium in pigs, using a jejunal loop model. The infection process was followed over 240 min using single to triple immunocytochemical detection of Salmonella and intestinal cell markers. Salmonella invasion was observed in both cytokeratin-18-positive and -negative cylindrical absorptive cells within 5-10 min. Subepithelial invasion of ordinary villi was consistently less marked than invasion of the subepithelial layer of Peyer's patches. Our results show that several epithelial cell types were invaded by Salmonella, and that Peyer's patches represent the main portal of entry in early Salmonella infection. Additionally, infection was associated with alterations in the keratin and F-actin cytoskeleton of intestinal epithelial cells, probably reflecting toxin-mediated actions. Such changes were confined to the proximal region of the jejunum, demonstrating a regional heterogeneity of intestinal epithelial cell responses to Salmonella infection.
authors.affiliation: Department of Anatomy and Physiology1 and Department of Veterinary Microbiology2, The Royal Veterinary and Agricultural University, Gronnegaardsvej 7, DK-1870 Frederiksberg C, Denmark.
authors.forename: Kirsten
authors.initials: K
authors.lastname: Schauser
authors.affiliation: Department of Anatomy and Physiology1 and Department of Veterinary Microbiology2, The Royal Veterinary and Agricultural University, Gronnegaardsvej 7, DK-1870 Frederiksberg C, Denmark.
authors.forename: John Elmerdahl
authors.initials: JE
authors.lastname: Olsen
authors.affiliation: Department of Anatomy and Physiology1 and Department of Veterinary Microbiology2, The Royal Veterinary and Agricultural University, Gronnegaardsvej 7, DK-1870 Frederiksberg C, Denmark.
authors.forename: Lars-Inge
authors.initials: LI
authors.lastname: Larsson
mesh_terms: D000199:Actins / Q000032:analysis; D000818:Animals; D003599:Cytoskeleton / Q000737:chemistry / Q000473:pathology; D004847:Epithelial Cells / Q000737:chemistry / Q000382:microbiology / Q000473:pathology; D007150:Immunohistochemistry; D007413:Intestinal Mucosa / Q000737:chemistry / Q000382:microbiology* / Q000473:pathology; D007583:Jejunum / Q000737:chemistry / Q000382:microbiology* / Q000473:pathology; D007633:Keratins / Q000032:analysis; D010581:Peyer's Patches / Q000473:pathology; D012481:Salmonella Infections, Animal / Q000378:metabolism / Q000382:microbiology* / Q000473:pathology; D012486:Salmonella typhimurium / Q000472:pathogenicity*; D013194:Staining and Labeling; D013552:Swine
chemical_list: D000199:Actins; D007633:Keratins