Date of Award


Document Type

Restricted Thesis

Terms of Use

© 2016 Shaina Lu. All rights reserved. Access to this work is restricted to users within the Swarthmore College network and may only be used for non-commercial, educational, and research purposes. Sharing with users outside of the Swarthmore College network is expressly prohibited. For all other uses, including reproduction and distribution, please contact the copyright holder.

Degree Name

Bachelor of Arts


Biology Department

First Advisor

Amy Cheng Vollmer


Vibrio parahaemolyticus is a foodborne bacterial pathogen that is the leading global cause of seafood-associated gastroenteritis. V. parahaemolyticus infection of humans and other mammals requires type III secretion system 2 (T3SS2), which is encoded on a pathogenicity island (VPal-7). These secretion systems translocate effector proteins from the bacterial to the host cell cytosol. T3SS2 expression is induced in response to bile, and this induction is dependent on two transcription factors, VtrA and VtrB. Here we seek to elucidate additional putative regulators of the T3SS2 expression pathway through the use of a genome-wide transposon-insertion screen and comparative genomics of several clinical and environmental isolates of V. parahaemolyticus. We reveal an expansive genetic network controlling T3SS2 with many putative regulators to biologically validate.