BEGIN:VCALENDAR VERSION:2.0 PRODID:-//132.216.98.100//NONSGML kigkonsult.se iCalcreator 2.20.4// BEGIN:VEVENT UID:20251109T013655EST-3261h3asip@132.216.98.100 DTSTAMP:20251109T063655Z DESCRIPTION:Members of the Department of Food Science\, and all 海角精品黑料 Grad Students\, Postdocs\, and Academic Staff are invited to attend the Fall 2 025聽Food Science and Agricultural Chemistry聽Graduate Seminar.\n\nPresentat ion schedule\n\n\n \n \n Time\n Ph.D. Research Proposal Presenter\n \n \n \n \n \n 1 0:05 AM\n \n \n Unnikrishnan Kannan (George lab)\n \n \n \n \n Differential effect s of foodborne nanoplastics in inflammatory bowel disease (IBD) and non-IB D conditions聽\n\n Global plastic production continues to rise\, and persist ent polymers gradually break down into microplastics and nanoplastics (NPs ) that contaminate food and are subsequently ingested. However\, it remain s unclear how gastrointestinal (GI) transformation influences the bioactiv ity of these particles and whether this contributes to the progression of intestinal diseases. This study聽hypothesizes that foodborne NPs exacerbate inflammation and compromise intestinal barrier function in individuals pr edisposed to inflammatory bowel disease (IBD). To evaluate this\, we will develop a comprehensive library of food contact NPs and characterize to es tablish their surface chemistry. GI transformation will be simulated using the standardized INFOGEST protocol\, and pristine particles will be compa red with digesta-conditioned counterparts in-vitro epithelial barrier mode ls to quantify uptake pathways and cellular response. Interactions between NPs and the gut microbiome will be studied through in-vitro colonic ferme ntation to identify the taxonomic\n alterations and release of plastic addi tives to the gut. Findings will be extended to human intestinal organoids derived from non-IBD and IBD donors to assess tissue-level outcomes includ ing tight junction disruption\, retention\, and inflammation within an adv erse outcome. This integrative approach aims to clarify how physicochemica l transformation shapes epithelial stress\, barrier integrity\, and microb iome composition\, thereby contributing to IBD pathogenesis. Further\, the se studies are expected to identify molecular and cellular mechanisms unde rpinning health risks of NPs and guide mitigation strategies to protect vu lnerable populations\, including recommendations for safer food contact ma terials and reductions in dietary exposure.\n \n \n \n \n 10:30 AM\n \n \n Pierre- Luc Longchamps (Lu lab)\n \n \n \n \n Induction of聽Campylobacter jejuni聽persist er cells\n\n Campylobacter jejuni is the most common cause of bacterial gas troenteritis in Canada\, with its main sources being undercooked poultry\, raw milk and contaminated water. C. jejuni is sensitive to various enviro nmental stresses\, making its recovery challenging despite the frequency o f clinical cases. It is hypothesized that C. jejuni utilizes dormancy stat es such as the persister and VBNC state to tolerate environmental stresses and recover in favorable conditions. The persister state is a transient\, non-growing phenotypic state with increased tolerance to various stresses \, particularly antibiotic stress. Persisters may appear stochastically\, but it has been found that various stresses\, such oxidative stress\, UV s tress\, starvation and others can increase the persister fraction in a pop ulation. While persisters cannot be directly observed or counted in a popu lation\, time-killing curves with antibiotics can be utilized to estimate the number of persisters. The slope of the biphasic killing curve produced during these assays is used to estimate the initial persister count. The first two chapters will explore how various stresses encountered in the fo od supply chain (real food matrices and simulated food processing environm ents) can affect the persister population in C. jejuni cultures. In the fi nal chapters\, modern technologies including microfluidics and various -om ics tools (Raman spectroscopy\, RNA sequencing\, mass spectrometry\, etc.\ ,) will be utilized to identify key mechanisms in the dormancy continuum o f C. jejuni. Various mechanisms such as toxin-antitoxin systems\, SOS resp onse\, stringent response and (p)ppGpp will be tested to determine how the y affect the formation of C. jejuni聽 persister cells\;\n \n \n \n \n 11:00 AM\n \n \n Joana L贸pez Gachuzo (Lu lab)\n \n \n \n \n Inactivation of聽Campylobacter je juni聽persisters in the agro-ecosystem using metal oxide nanoparticles\n\n C ampylobacter jejuni is a foodborne pathogen primarily found in the intesti ne of animals\, with poultry serving as the main reservoir. It spreads thr ough cross-contamination in slaughterhouses and the consumption of underco oked meat. Common symptoms of campylobacteriosis include diarrhea\, vomiti ng\, and abdominal cramps\, but in severe cases\, the infection can affect the nervous system and lead to Guillain-Barr茅 syndrome. Due to its high p revalence in chicken meat\, C. jejuni poses a significant health risk in b oth developed and developing countries. Controlling this pathogen remains challenging because of its ability to survive harsh environments at high c oncentrations. Part of the reason for this is that C. jejuni can enter a d ormant state\, forming聽persister cells that evade detection by conventiona l culture methods due to their reduced metabolic activity under environmen tal stress\, such as antimicrobial exposure. Although these cells do not g row under unfavorable conditions\, they can resume replication once condit ions improve\,\n complicating efforts to eradicate the pathogen. Given thes e challenges\, the objective of my thesis is to inactivate C. jejuni persi sters\, incorporating metal oxide nanoparticles\, which generate reactive oxygen species (ROS)\, and damage cellular components by inducing stress. \n \n \n \n\n DTSTART:20251030T140000Z DTEND:20251030T153000Z LOCATION:4-045\, Raymond Building\, CA\, QC\, St Anne de Bellevue\, H9X 3V9 \, 21111 Lakeshore Road SUMMARY:Fall 2025 FDSC Graduate Seminar URL:/foodscience/channels/event/fall-2025-fdsc-graduat e-seminar-368610 END:VEVENT END:VCALENDAR