Show simple item record

dc.contributor.advisorAthanasiadou, Spiridoula
dc.contributor.advisorSparks, Nick
dc.contributor.authorRussell, Katherine Margaret
dc.date.accessioned2017-11-16T13:45:46Z
dc.date.available2017-11-16T13:45:46Z
dc.date.issued2016-07-02
dc.identifier.urihttp://hdl.handle.net/1842/25514
dc.description.abstractClostridium perfringens is the aetiological agent of Necrotic enteritis (NE); a disease that impacts on the health and welfare of broilers. This disease is a large cost to the industry and presents as lesions in the small intestine hindering productivity. Antibiotics are commonly used to treat NE but as pressure increases to limit their use further information about disease onset and broiler responses to the bacteria and it’s virulence factors during infection is required to implement new preventative measures and treatments. NetB is a secreted toxin from C. perfringens which has an important role in NE onset. Using an in situ intestinal loop model we have been able to characterise: I) temporal broiler responses to NetB positive bacterial culture supernatant (Chapter 2), ii) early host responses to different isolates possessing NetB (virulent) or not (avirulent) in the presence or absence of bacterial cells (Chapter 3) and iii) the responses of two commercial broiler breeds (Chapter 4) four hours post exposure. Samples collected from these experiments have been used for histology, mRNA expression and immunohistology. We have shown differences in mRNA expression in the duodenum of broilers after exposure to C. perfringens cells as well as the culture supernatant from the isolates used after four hours. The presence of bacteria cells resulted in up-regulation of pro-inflammatory cytokine, IFN-γ, mRNA, whereas it resulted in down-regulation of B-LA, mRNA a gene involved in presentation of pathogens to immune cells. IL-6 mRNA expression was also reduced in the presence of virulent isolates. This could indicate a possible evasion strategy for C. perfringens in broilers. Immunohistochemical analysis indicated that slower growing broilers have increased numbers of immune cells (macrophages and γδ T cells) in their duodenum compared with faster growing broilers, although this did not appear to have an effect on mRNA expression levels of pro-inflammatory cytokines, 4h post antigen infusion. Overall we detect greater changes when bacteria are included with culture supernatant and have highlighted possible mechanisms for C. perfringens to avoid the broiler immune system. Induction of NE in the literature requires pre-disposing factors, including co-infection with other intestinal pathogens and dietary manipulation of the host. The final experiment trialled protocols administering a virulent isolate of C. perfringens in-feed and via gavage along with an increased protein source to induce NE (Chapter 5). These models were not considered to be consistent for further investigation of NE in the future.en
dc.contributor.sponsorBiotechnology and Biological Sciences Research Council (BBSRC)en
dc.language.isoenen
dc.publisherThe University of Edinburghen
dc.relation.hasversionS. Athanasiadou, KM Russell, P Kaiser, T Kanellos, STG Burgess, MA Mitchell, RE Clutton, SW Naylor, MR Hutchings, NH Sparks. Genome-wide transcriptomic analysis identifies pathways affected by the infusion of Clostridium perfringens culture supernatant in the duodenum of broilers in situ. The Journal of Animal Science. 93:6,p3152-3163en
dc.subjectbroileren
dc.subjectC. perfringensen
dc.subjectqPCRen
dc.subjectIHCen
dc.subjectimmunohistochemistryen
dc.subjecthistologyen
dc.titleIntestinal responses to Clostridium perfringens in broilersen
dc.typeThesis or Dissertationen
dc.type.qualificationlevelDoctoralen
dc.type.qualificationnamePhD Doctor of Philosophyen


Files in this item

This item appears in the following Collection(s)

Show simple item record