title: Infection of porcine colon explants with "Brachyspira hampsonii" leads to increased epithelial necrosis and catarrhal exudate.
abstract: Mucohemorrhagic diarrhea in pigs caused by Brachyspira spp. has a global distribution, and an economic impact on affected farms due to poor performance of animals. Demonstrations that "Brachyspira hampsonii" is pathogenic have been achieved using in vivo animal models, but a critical knowledge gap exists regarding the pathogenic mechanisms employed by Brachyspira. Here, we used in vitro organ culture of porcine colon to investigate interactions between "B. hampsonii" and explants during the first 12 h of contact. Explants were either inoculated with "B. hampsonii" or sterile culture broth. Responses to infection were evaluated by optical microscopy and quantitative PCR. Significantly greater numbers of necrotic crypt cells and thicker catarrhal exudate were observed on infected explants compared to controls. Spirochaetes were observed in the mucus layer, in contact with necrotic exfoliated cells, in crypts and the lamina propria. Statistical differences were observed in mRNA levels between inoculated and control explants for IL-1α, TNF-α and ZO-1 using a Bayesian analysis, but not observed using the ΔΔCq method. These results provide a demonstration of a porcine colon explant model for investigating interactions of Brachyspira with its host and show that initial effects on the host are observed within the first 12 h of contact.
authors.affiliation: Department of Veterinary Microbiology, Western College of Veterinary Medicine, University of Saskatchewan, Saskatoon, Saskatchewan, SK S7N 5B4, Canada.|Department of Farm Animal Health, Faculty of Veterinary Medicine, Utrecht University, Utrecht, 3584 CL, The Netherlands.
authors.forename: Matheus O
authors.initials: MO
authors.lastname: Costa
authors.affiliation: Department of Veterinary Microbiology, Western College of Veterinary Medicine, University of Saskatchewan, Saskatoon, Saskatchewan, SK S7N 5B4, Canada.
authors.forename: Champika
authors.initials: C
authors.lastname: Fernando
authors.affiliation: Department of Large Animal Clinical Sciences, Western College of Veterinary Medicine, University of Saskatchewan, Saskatoon, Saskatchewan, SK S7N 5B4, Canada.
authors.forename: Roman
authors.initials: R
authors.lastname: Nosach
authors.affiliation: Department of Large Animal Clinical Sciences, Western College of Veterinary Medicine, University of Saskatchewan, Saskatoon, Saskatchewan, SK S7N 5B4, Canada.
authors.forename: John C S
authors.initials: JCS
authors.lastname: Harding
authors.affiliation: Department of Veterinary Microbiology, Western College of Veterinary Medicine, University of Saskatchewan, Saskatoon, Saskatchewan, SK S7N 5B4, Canada.
authors.forename: Janet E
authors.initials: JE
authors.lastname: Hill
mesh_terms: D000818:Animals; D015415:Biomarkers; D001706:Biopsy; D017400:Brachyspira / Q000502:physiology*; D003092:Colitis / Q000662:veterinary*; D016207:Cytokines / Q000378:metabolism; D005122:Exudates and Transudates; D016905:Gram-Negative Bacterial Infections / Q000662:veterinary*; D018836:Inflammation Mediators / Q000378:metabolism; D007413:Intestinal Mucosa / Q000378:metabolism / Q000382:microbiology* / Q000473:pathology*; D008297:Male; D009336:Necrosis; D013552:Swine; D013553:Swine Diseases / Q000378:metabolism / Q000382:microbiology* / Q000473:pathology*
chemical_list: D015415:Biomarkers; D016207:Cytokines; D018836:Inflammation Mediators
keywords: Brachyspira; IVOC; mucohemorrhagic colitis; organ explant; swine