COURSES TAUGHT

BMS 212 - Introductory Microbiology
BMS 213 - Microbiology Lab
BMS 412 - Medical Bacteriology
BMS 413 - Medical Bacteriology Lab

BMS 422 - Bacterial Physiology

BMS 423 - Bacterial Physiology Lab

EDUCATION

Ph.D. (Genetics) University of Iowa, 2003
M.S. Department of Poultry Science, University of Arkansas, 1997
B.S. (Microbiology), Idaho State University, Pocatello, Idaho, 1994

RESEARCH INTERESTS

My research has revolved around understanding the pathogenic mechanisms of Salmonella and Escherichia coli.   Currently, I am focused on two areas of interest.  My first project involves looking for additional genes necessary for Salmonella pathogenesis.  Studies have shown that the genes involved in Salmonella pathogenesis are often found in specific areas known as pathogenicity islands. Salmonella Pathogenicity Island 1 (SPI-1) contain numerous genes involved in the formation of the type III secretion system and other secreted effector proteins.  Activation of this island allows for bacterial invasion of intestinal cells. A second critical island (SPI-2) is required for survival within macrophage after invasion.  Due to the number of genes required for these processes, I have focused on the regulatory genes that control activation and repression of these islands in response to environmental signals. In the course of these studies I identified a repressor known as hilE, which represses the activation of SPI-1.  Studies of the sequences around hilE suggest that this repressor falls in a 40 kb region of the chromosome that has all of the hallmarks of a pathogenicity island, yet very little is known about the function of the genes around hilE.  Since its identification, we have created ten different polar mutations in open reading frames within this potential pathogenicity island.  Work has commenced trying to analyze the effects these mutations have on Salmonella virulence by utilizing gene reporter, cell invasion, macrophage survival, bacterial adherence, and cell motility assays under various inducing and noninducing environmental conditions.  Any effects on Salmonella invasion could then be further characterized by identifying how each of the mutations leads to changes in Salmonella invasion in response to an environmental signal.

My second project is looking for genes important for Escherichia coli biofilm formation under conditions that mirror its natural environment.  Previous work has identified many genes needed for the activation and formation of a biofilm when the bacteria are grown under aerobic conditions.  As E. coli is commonly found in the anaerobic conditions of the colon we are trying to identify regulator genes that are responsible for increasing or decreasing biofilm formation in response to oxygen.  We have developed a biofilm assay to screen for biofilm formation that can be used under aerobic, microaerophilic and anaerobic conditions.  Transposon mutagenesis allows the creation of random mutations within the chromosome that can then be characterized via the biofilm assay.  This is an ongoing project which will hopefully find a variety of different regulators and will teach students a variety of microbiological and molecular techniques.