Thesis (Ph. D.)--University of Bergen, 1986. / Includes seven publications by Vasstrand and others.

Thesis (Ph. D.)--University of Bergen, 1986. / Includes seven publications by Vasstrand and others.

Thesis (M.S.)--University of Michigan, 2001. / Includes bibliographical references.

Thesis (M.S.)--University of Michigan, 1982.

Thesis (M.S.)--University of Michigan, 1982.

Thesis (Ph. D.)--State University of New York at Buffalo, 1999. / eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references.

Thesis (Ph. D.)--State University of New York at Buffalo, 1999. / eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references.

Inflammatory Bowel Disease (IBD) is an umbrella term used to describe a group of chronic, relapsing/remitting disorders of the gastrointestinal tract (GIT). While the precise aetiology of IBD is unknown, it is believed to be a result of the interaction of genetics, the immune system and the enteric microbiota. Thus, the search for potentially pathogenic microbial residents of the GIT is a current research focus. Fusobacterium nucleatum (Fn) is a member of the normal human microflora, including the GIT and has a well-characterized role in periodontitis in the oral setting. We have determined that Fn can be frequently recovered from human intestinal biopsies and furthermore, there is a positive correlation between recovery of Fn and the IBD status of the host. Fn strains from IBD patients were more invasive in vitro than strains from healthy controls and also demonstrated the ability to survive and proliferate inside host cells. Furthermore, while Fn strains from both IBD patients and healthy controls were able to induce expression of the pro-inflammatory cytokine IL-8 in vitro, in comparison to strains from controls, Fn strains from IBD patients resulted in decreased levels of IL-8 protein outside the host cells, suggesting that these strains may utilize sophisticated tactics to promote their survival. Thus, differences in virulence determinants among strains may be key to understanding a potential role for Fn in IBD. Characterization of virulence mechanisms utilized by Fn isolates from IBD patients could define a potentially important aspect of microbe/host interactions in this devastating disease, and indicate future therapeutic targets. / Canadian Institutes of Health Research, Canadian Digestive Health Foundation, Crohn's and Colitis Foundation of Canada

Thèse (M.Sc.)--Université Laval, 2002. / Bibliogr.: f. 80-98. Publ. aussi en version électronique.

Fusobacterium necrophorum är en gramnegativ anaerob bakterie som grupperas i ss. necrophorum och ss. funduliforme. Fusobacterium necrophorum ss. funduliforme har på senare tid misstänkts kunna spela en roll vid vanligare svalginfektioner såsom halsfluss. Syftet med detta arbete var att sätta upp och bepröva en metod för realtids-PCR (Polymerase Chain Reaction) enligt Taqman för att detektera ss funduliforme. Vi undersökte även hur förvaringstiden i transportmedium (Amies kol, Copan) och odlingsmedium (Fastidious Agar Broth) påverkar överlevnaden för F. necrophorum ss. funduliforme och resultatet från realtids-PCR. Bakteriesuspension av varierande koncentration applicerades på provtagningspinnar som direkt inkuberades i medium, varefter en pinne av vardera koncentration utodlades och DNA extraherades för varje dag försöket pågick. En serie 10-spädningar av extraherat DNA från ss funduliforme ,med en lägsta koncentration av 10 DNA-molekyler per µL, användes som standard och positiv kontroll för PCR. Fusobacterium necrophorum ss funduliforme kunde detekteras med realtids-PCR från alla prov under alla dagar försöket pågick, medan odlingarna visade bäst resultat om provet såddes ut inom ett dygn från provtagningen. Realtids-PCR kan därför detektera förekomsten av ss funduliforme efter längre förvaring och bör användas för exempelvis transporterade prover, medan traditionell utodling med fördel kan användas för diagnostering av ss fundulforme då PCR inte ger information om antibiotikaresistens hos isolatet. / Fusobacterium necrophorum are Gram-stain negative, anaerobic, bacteria that are grouped into subspecies necrophorum and funduliforme. Fusobacterium necrophorum ss. funduliforme has recently been suspected to play a role in common throat infections such as tonsillitis. The purpose of this work was to set up and test a method for real-time PCR (Polymerase Chain Reaction) according to Taqman with the purpose of detecting ss. funduliforme. We also examined how the storage time within transport medium (Amies charcoal, Copan) and culture medium (FAB-broth) affects the survival of the bacterium and the sensitivity of the culture and PCR methods. Bacterial suspensions of different concentrations were applied to pharyngeal sampling swabs and then directly incubated in transport medium. For each day the experiment lasted, a set of swabs of each concentration were cultured, DNA extracted, and real-time PCR performed. DNA extracted from ss. funduliforme was used as standards for the real-time PCR, with a minimum concentration of 10 DNA molecules per μL. Subspecies funduliforme could be detected from all days with real-time PCR while the cultures showed the best results if the sample was cultured within one day of collection. Real-time PCR can detect the presence of ss. funduliforme after prolonged storage and can therefore show accurate results for transported samples. Traditional culturing on growth medium is still a valuable and reliable method, provided that the samples are cultured within 24 hours. Culture may also be needed i.e. since PCR gives no information of the antibiotic resistance of the isolate.