BEGIN:VCALENDAR
VERSION:2.0
PRODID:icalendar-ruby
CALSCALE:GREGORIAN
X-WR-CALNAME:PhD Dissertation Defense: Taylor Nguyen
X-WR-TIMEZONE:Pacific Time (US & Canada)
BEGIN:VEVENT
DTSTAMP:20260521T083843Z
UID:tag:localist.com\,2008:EventInstance_48747218978248
DTSTART:20250207T220000Z
DTEND:20250207T230000Z
DESCRIPTION:Title: Engineering the microbiome: using bacteriophages to prob
 e the ecological dynamics of gut communities\n\nAbstract: As associations 
 between gut microbiome composition and various disease states are increasi
 ngly established\, efforts to engineer gut communities as therapeutic solu
 tions have accelerated. In addition to therapeutic clinical applications\,
  phages provide exciting opportunities in basic science research to probe 
 ecological dynamics in microbial communities. Antibiotics are typically us
 ed to remove targeted species\, but they can have long-lasting\, deleterio
 us\, and off-target effects. Here\, we harness the lytic activity of bacte
 riophages (hereafter\, phages)\, viruses that target and lyse to bacteria.
  We isolate novel bacteriophages to target and remove gut commensal Escher
 ichia fergusonii (Ef) from complex\, undefined stool-derived in vitro comm
 unities (SICs). We found that Ef growth is unaffected by the emergence of 
 resistance when treated with phage in monoculture\, but phage-resistant mu
 tants that emerge in a community setting exhibited a fitness disadvantage 
 that allowed other Proteobacteria to expand. Using a cocktail of phages\, 
 we successfully knocked out Ef from all of our complex\, undefined SICs. U
 sing these knockout communities\, we showed that Ef is responsible for the
  community colonization resistance against Salmonella invasion. To showcas
 e the power of phage-based species removal\, we co-cultured an Ef transpos
 on mutant library with the knockout communities to probe the genetic mecha
 nisms of Ef survival and growth in a community setting. We found that gene
 s related to outer membrane (OM) structure and assembly play key roles in 
 growth in community contexts. These OM-mutants are sensitized to toxic by-
 products produced by another community member\, highlighting the chemical 
 warfare-based ecological interactions within gut communities. In summary\,
  we establish that phage-based removal of a species enables the precise\, 
 controlled manipulation of community composition necessary for mechanistic
  study of ecological interactions within complex\, undefined microbial com
 munities.\n\nPlease contact Madelyn Bernstein for the Zoom link
LOCATION:AllenX 101X
SUMMARY:PhD Dissertation Defense: Taylor Nguyen
URL;VALUE=URI:https://events.stanford.edu/event/phd-dissertation-defense-ta
 ylor-nguyen
CATEGORIES:PhD Defense
END:VEVENT
END:VCALENDAR