proposed. Small molecules being investigated for their ability to inhibit virulence factors and virulence factor expression include alkaloids, flavonoids, and peptides. Experimental studies are done to characterize specific bacterial pathogens and to identify their specific virulence factors. Scientists are trying to better understand these virulence factors through identification and analysis to better understand the infectious process in hopes that new diagnostic techniques, specific antimicrobial compounds, and effective vaccines or toxoids may be eventually produced to treat and prevent infection. There are three general experimental ways for the virulence factors to be identified: biochemically, immunologically, and genetically. For the most part, the genetic approach is the most extensive way in identifying the bacterial virulence factors. Bacterial DNA can be altered from pathogenic to non-pathogenic, random mutations may be introduced to their genome, specific genes encoding for membrane or secretory products may be identified and mutated, and genes that regulate virulence genes maybe identified. Experiments involving Yersinia pseudotuberculosis have been used to change the virulence phenotype of non-pathogenic bacteria to pathogenic. Because of horizontal gene transfer, it is possible to transfer the a clone of the DNA from Yersinia to a non-pathogenic E. coli and have them express the pathogenic virulence factor. Transposon, a DNA element inserted at random, mutagenesis of bacteria DNA is also a highly used experimental technique done by scientists. These transposons carry a marker that can be identified within the DNA. When placed at random, the transposon may be placed next to a virulence factor or placed in the middle of a virulence factor gene, which stops the expression of the virulence factor. By doing so, scientists can make a library of the genes using these markers and easily find the genes that cause the virulence factor. See also Resistance-Nodulation-Cell Division Superfamily (RND) Filamentation References