Karatan Lab
Nick Walter
Ece Karatan
karatane@appstate.edu
Appalachian State University
Department of Biology
Rankin Science North
319 (Office), 303 (Lab)
828-262-6742
Effect of host-derived molecules on V. cholerae virulence gene expression
Vibrio cholerae, the causative agent of the disease cholera, is a pathogenic bacterium that colonizes the human gastrointestinal track. Upon successful colonization V. cholerae secretes an exotoxin called Cholera Toxin (CTX), which is responsible for the clinical symptoms of Cholera. CTX causes massive water secretion from the epithelial cells that line the intestine, which leads to perfuse diarrhea. Aside from CTX, another major player in V. cholerae pathogenicity is the Toxin-Coregulated Pilus (TCP). TCP is a type 4 pilus, which functions in cell-to-cell adhesion. This is the major factor that allows colonization of the intestinal epithelium in a host. TCP production and CTX secretion are factors in virulence that are under the control of complex regulatory networks, which are ultimately responsive to and modulated by environmental signals.
The goal of my biology honors research project has been to determine the effect of a class of small molecules that are produced by the host on V. cholerae virulence gene expression, in particular TCP and CTX production. I have shown that these molecules inhibit agglutination, a tell-tale sign of TCP production, at millimolar concentrations (Fig. 1). Currently, I am looking to see if they have a similar effect on CTX production as well. The outcome of this project has the potential to yield insight into the effect of the host intestinal environment
