Show simple item record

dc.contributor.advisorBiswas, Debabrataen_US
dc.contributor.authorPeng, Mengfeien_US
dc.date.accessioned2018-07-17T06:16:41Z
dc.date.available2018-07-17T06:16:41Z
dc.date.issued2018en_US
dc.identifierhttps://doi.org/10.13016/M21834574
dc.identifier.urihttp://hdl.handle.net/1903/20989
dc.description.abstractFoodborne enteric diseases cause millions of illness and thousands of deaths annually in the United States. Major enteric bacterial pathogens include Salmonella, enterohemorrhagic Escherichia coli O157:H7 (EHEC), Campylobacter, Listeria, Shigella, Vibrio, and Yersinia which account for more than 90% cases of culture-confirmed infections. Among these causative agents, Salmonella enterica is responsible for the highest rate of hospitalization and EHEC has the lowest infectious dose. Their pathogenesis involves numerous virulent factors whereas their colonization and invasion on host gut intestine mainly depend on the type III secretion system. The prevention of foodborne enteric diseases is of great concern to public health professionals, farmers, and food producers. Due to the increased public health concern about antibiotic-resistance dissemination, alternative strategies such as pro-commensal approach by applying probiotics, prebiotics, and combination of both (synbiotics) are of interests for prevention and therapy of foodborne enteric diseases. In this study, we both in vitro and in vivo evaluated the preventive capabilities of Lactobacillus against enteric pathogenic bacterial colonization and infection. Functional food cocoa and peanut containing prebiotic-like ingredients selectively promoted the growth of beneficial bacteria and stimulated the production of bio-active metabolites especially conjugated linoleic acids in Lactobacillus. We also detected the synergistic effects of Lactobacillus and cocoa/peanut on competitive exclusion of S. Typhimurium and EHEC, alteration on physicochemical properties, disruption of host-pathogen interactions, and down-regulation on virulence gene expressions. Furthermore, with homologous recombination, we overexpressed myosin cross-reactive antigen gene encoding linoleate isomerase in L. casei and improved the efficiency in their linoleic acids production as well as the gut intestinal adherence and colonization. By applying genetically engineered LC-CLA, S. Typhimurium and EHEC were much effectively controlled and restricted from all aspects in vitro mentioned before. Additionally, the in vivo pre-administration of LC-CLA reduced S. Typhimurium gut intestinal colonization/infection in a significant level and induced anti-inflammatory effects, which benefitted the overall mice gut health. Our findings established a baseline upon which self-promoting probiotic independent from prebiotic in prevention or treatment against enteric diseases can be explored.en_US
dc.language.isoenen_US
dc.titleSTIMULATION OF GROWTH AND METABOLITES PRODUCTION OF LACTOBACILLUS IN CONTROL OF ENTERIC BACTERIAL PATHOGEN INFECTION AND IMPROVING GUT HEALTHen_US
dc.typeDissertationen_US
dc.contributor.publisherDigital Repository at the University of Marylanden_US
dc.contributor.publisherUniversity of Maryland (College Park, Md.)en_US
dc.contributor.departmentMolecular and Cell Biologyen_US
dc.subject.pqcontrolledMicrobiologyen_US
dc.subject.pqcontrolledAnimal sciencesen_US
dc.subject.pqcontrolledFood scienceen_US
dc.subject.pquncontrolledEnteric bacterial pathogenen_US
dc.subject.pquncontrolledFunctional fooden_US
dc.subject.pquncontrolledGut microbiotaen_US
dc.subject.pquncontrolledPrebioticen_US
dc.subject.pquncontrolledProbioticen_US
dc.subject.pquncontrolledSynbioticen_US


Files in this item

Thumbnail

This item appears in the following Collection(s)

Show simple item record