T2SS are multi-protein complexes involved in the secretion of different virulence factors, particularly the assembly of hair-like appendages, called pili, on the bacterial surface. Type IV pili (T4P) are virulence factors that aid in the pathogenesis of uropathogenic Escherichia coli (UPEC). Two strains of UPEC, CFT073 and UTI89 were recently shown to contain gene clusters coding for T2SS and T4P. The purpose of this study is to determine whether or not these genes have a functional purpose in the virulence of these model strains. CFT073 and UTI89 were grown under varying conditions to determine if and when the T2SS genes were expressed. The bacterial membranes were then broken open, and the RNA was isolated and purified. Reverse transcription PCR was used to convert RNA into cDNA. A polymerase chain reaction with specific primers was used to amplify genes important to in the functioning of T2SS. The 16S gene, a common gene in all UPEC, was used as a reference. The PCR products were then run on a 1% agarose gel, to determine whether T2SS and T4P genes were expressed. Semi-quantitative analysis was used to measure the DNA band intensities of the gels. The intensities were used to examine the level of gene expression of the bacteria grown under different conditions. I found that the expression levels of T2SS and T4P genes varied depending on the gene and condition, but the fact that there was expression at all proved that these genes do have a functional purpose in UPEC.

Support and funding for this study was provided by the Simons Fellowship Program and the Center for Molecular Medicine.