Mobile genetic elements have profoundly influenced the evolution of bacterial pathogens. Many determinants of virulence and antibiotic resistance are borne by mobile elements, such as plasmids and bacteriophages, which are capable of horizontal transmission. During the current grant cycle, we explored several fundamental questions regarding the molecular biology of two mobile genetic elements, CTXqj and SXT, which have profoundly influenced the pathogenicity and evolution ofthe cholera pathogen. Vibrio cholerae. Addressing these aims has yielded observations that suggest previously unrecognized mechanisms of bacteriophage gene regulation and new insights regarding the biology and evolution of Integrative Conjugative Elements (ICEs). Furthermore, knowledge gained from these studies proved to be critical for our studies of the origin of the V. cholerae strain that gave rise to the cholera outbreak in Haiti. During this grant cycle, we also expanded the scope of our work to include investigation of new aspects of V. cholerae biology and pathogenicity. In particular, we developed a new infant rabbit model of disease that closely resembles human cholera. We will exploit this model and new high throughput tools we have developed to address three new aims during the MERIT extension period: 1) Assess the spatial and temporal patterns of V. cholerae gene expression during infection;2) Identify and characterize the determinants of V. cholerae transmission;and 3) Characterize the innate immune response to V. cholerae intestinal colonization. Completion of these studies will provide the most comprehensive knowledge ofthe course of gene expression during infection for any bacterial pathogen. Additionally, it will enhance our understanding of the processes underlying V. cholerae pathogenicity and transmission. Finally, these studies should provide insight into the innate immune response within the intestinal tract, modulation of which has profound ramifications both for normal intestinal homeostasis and for disease. Collectively, these studies will yield valuable new knowledge for the creation of new antimicrobial agents and vaccines.

Public Health Relevance

threat from cholera, an acutely dehydrating diarrheal disease caused by Vibrio cholerae, is dramatically illustrated by the devesting cholera outbreak that began in Haiti in October 2010. The long-term aims of our studies - to understand the evolution, biology, and mechanisms of pathogenicity of V. cholerae - are promoting our ability to modulate disease in individuals and its spread within a community.

National Institute of Health (NIH)
National Institute of Allergy and Infectious Diseases (NIAID)
Method to Extend Research in Time (MERIT) Award (R37)
Project #
Application #
Study Section
Special Emphasis Panel (NSS)
Program Officer
Hall, Robert H
Project Start
Project End
Budget Start
Budget End
Support Year
Fiscal Year
Total Cost
Indirect Cost
Brigham and Women's Hospital
United States
Zip Code
Livny, Jonathan; Zhou, Xiaohui; Mandlik, Anjali et al. (2014) Comparative RNA-Seq based dissection of the regulatory networks and environmental stimuli underlying Vibrio parahaemolyticus gene expression during infection. Nucleic Acids Res 42:12212-23
Möll, Andrea; Dörr, Tobias; Alvarez, Laura et al. (2014) Cell separation in Vibrio cholerae is mediated by a single amidase whose action is modulated by two nonredundant activators. J Bacteriol 196:3937-48
Pritchard, Justin R; Chao, Michael C; Abel, Sören et al. (2014) ARTIST: high-resolution genome-wide assessment of fitness using transposon-insertion sequencing. PLoS Genet 10:e1004782
Okada, Ryu; Zhou, Xiaohui; Hiyoshi, Hirotaka et al. (2014) The Vibrio parahaemolyticus effector VopC mediates Cdc42-dependent invasion of cultured cells but is not required for pathogenicity in an animal model of infection. Cell Microbiol 16:938-47
Kota, Swathi; Charaka, Vijaya K; Ringgaard, Simon et al. (2014) PprA contributes to Deinococcus radiodurans resistance to nalidixic acid, genome maintenance after DNA damage and interacts with deinococcal topoisomerases. PLoS One 9:e85288
Espaillat, Akbar; Carrasco-López, César; Bernardo-García, Noelia et al. (2014) Structural basis for the broad specificity of a new family of amino-acid racemases. Acta Crystallogr D Biol Crystallogr 70:79-90
Taylor, Dawn L; Bina, X Renee; Slamti, Leyla et al. (2014) Reciprocal regulation of resistance-nodulation-division efflux systems and the Cpx two-component system in Vibrio cholerae. Infect Immun 82:2980-91
Dörr, Tobias; Möll, Andrea; Chao, Michael C et al. (2014) Differential requirement for PBP1a and PBP1b in in vivo and in vitro fitness of Vibrio cholerae. Infect Immun 82:2115-24
Munera, Diana; Ritchie, Jennifer M; Hatzios, Stavroula K et al. (2014) Autotransporters but not pAA are critical for rabbit colonization by Shiga toxin-producing Escherichia coli O104:H4. Nat Commun 5:3080
Millet, Yves A; Alvarez, David; Ringgaard, Simon et al. (2014) Insights into Vibrio cholerae intestinal colonization from monitoring fluorescently labeled bacteria. PLoS Pathog 10:e1004405

Showing the most recent 10 out of 53 publications