Vibrio cholerae, which lives in association with plankton in brackish, temperate waters the world over, is the causative agent of endemic and epidemic cholera. Hallmarks of the disease include prodigious watery diarrhea resulting from the action of secreted cholera toxin (CT), and infrequent but deadly explosive epidemics. The strong link between explosive epidemics and human crowding accompanied with untreated drinking water suggests a very efficient mode of fecal-oral transmission. We have discovered a heightened state of transmissibility of stool V. cholerae (referred to simply as """"""""hyperinfectivity""""""""), which persists even after shedding into water reservoirs. Knowledge of the molecular basis for this phenotype, and a general characterization of this transmissible form of V. cholerae, would contribute to the design of vaccines to prevent cholera at the initial stage of infection.
Aim 1 of this proposal will use transcriptional profiling and proteomics to help define this transmissible form. Spotted DNA microarrays will be used to determine the transcriptome of stool V. cholerae incubated in pond water, and this will be compared to that of fresh stool V. cholerae to identify potential differences. The results will be validated by quantitatively assaying the steady state mRNA and protein levels from select genes. Microscopy and transcriptome data on stool V. cholerae predict a bacterial state of motility working in the absence of chemotactic signaling. This counterintuitive state is hypothesized to be responsible, at least in part, for the hyperinfective phenotype.
In Aim 2 of this proposal, quantitative immunodetection using paralog-specific antisera will be used to test for reduced expression of all three CheW linker proteins and all three CheR methytransferases in fresh and pond water-incubated stool V. cholerae, as is predicted by current transcriptome data. In addition, capillary tube chemotaxis assays will be performed directly on V. cholerae from these samples to substantiate this hypothesis.
Aim 2 will also test a second hypothesis, that ToxR regulated factors, which are essential for pathogenesis, are not playing a role in the hyperinfectious state. Finally, Aim 3 will use mutation and infectivity analyses to determine if other metabolic, physiologic or phenotypic properties of the bacteria contribute to the hyperinfective phenotype or, alternatively, to colonization of an environmental planktonic host, Anabaena variabilis. These studies will establish a basis for understanding the hyperinfective phenotype, and the properties in general, that are exhibited by fresh and pond water-incubated stool V. cholerae. In turn, this knowledge will enhance our understanding of transmission of this and perhaps other water-borne pathogens, it will aid in the development of new cholera vaccines that target the antigens of 'incoming' vibrios, and it may suggest new approaches for the prevention of the dissemination of this lethal organism.

Agency
National Institute of Health (NIH)
Institute
National Institute of Allergy and Infectious Diseases (NIAID)
Type
Research Project (R01)
Project #
5R01AI055058-04
Application #
7048469
Study Section
Special Emphasis Panel (ZRG1-BM-1 (02))
Program Officer
Hall, Robert H
Project Start
2003-05-15
Project End
2008-04-30
Budget Start
2006-05-01
Budget End
2007-04-30
Support Year
4
Fiscal Year
2006
Total Cost
$348,245
Indirect Cost
Name
Tufts University
Department
Biochemistry
Type
Schools of Medicine
DUNS #
039318308
City
Boston
State
MA
Country
United States
Zip Code
02111
Duncan, Miles C; Forbes, John C; Nguyen, Y et al. (2018) Vibrio cholerae motility exerts drag force to impede attack by the bacterial predator Bdellovibrio bacteriovorus. Nat Commun 9:4757
Molina-Quiroz, Roberto C; Silva-Valenzuela, Cecilia; Brewster, Jennifer et al. (2018) Cyclic AMP Regulates Bacterial Persistence through Repression of the Oxidative Stress Response and SOS-Dependent DNA Repair in Uropathogenic Escherichia coli. MBio 9:
Manneh-Roussel, Jainaba; Haycocks, James R J; Magán, Andrés et al. (2018) cAMP Receptor Protein Controls Vibrio cholerae Gene Expression in Response to Host Colonization. MBio 9:
Reyes-Robles, Tamara; Dillard, Rebecca S; Cairns, Lynne S et al. (2018) Vibrio cholerae outer membrane vesicles inhibit bacteriophage infection. J Bacteriol :
Shull, Lauren M; Camilli, Andrew (2018) Transposon Sequencing of Vibrio cholerae in the Infant Rabbit Model of Cholera. Methods Mol Biol 1839:103-116
Li, Peng; Kinch, Lisa N; Ray, Ann et al. (2017) Acute Hepatopancreatic Necrosis Disease-Causing Vibrio parahaemolyticus Strains Maintain an Antibacterial Type VI Secretion System with Versatile Effector Repertoires. Appl Environ Microbiol 83:
Yen, Minmin; Cairns, Lynne S; Camilli, Andrew (2017) A cocktail of three virulent bacteriophages prevents Vibrio cholerae infection in animal models. Nat Commun 8:14187
Wang, Zhu; Lazinski, David W; Camilli, Andrew (2017) Immunity Provided by an Outer Membrane Vesicle Cholera Vaccine Is Due to O-Antigen-Specific Antibodies Inhibiting Bacterial Motility. Infect Immun 85:
Silva-Valenzuela, Cecilia A; Lazinski, David W; Kahne, Shoshanna C et al. (2017) Growth arrest and a persister state enable resistance to osmotic shock and facilitate dissemination of Vibrio cholerae. ISME J 11:2718-2728
McDonough, EmilyKate; Kamp, Heather; Camilli, Andrew (2016) Vibrio cholerae phosphatases required for the utilization of nucleotides and extracellular DNA as phosphate sources. Mol Microbiol 99:453-69

Showing the most recent 10 out of 47 publications