IMPACTS OF IRRIGATION WATER QUALITY PERSISTENCE AND TRANSMISSION OF E.COLI O157:H7 FROM SOIL TO PLANTS

I. The objective of this cooperative research project is to Investigate the population dynamics of Escherichia coli O157:H7 on plant roots grown under various irrigation water salinity regimes in the field and growth chamber. II. Investigate persistence of E. coli O157:H7 in soil, irrigation water, and rhizophere under different environmental conditions. III. Utilize fluorescence-activated cell sorter (FACS) technologies to determine genes that are specifically expressed by E. coli O157:H7 cells on plant surfaces. IV. Construct knock-out mutations in E. coli O157:H7 genes that are specifically expressed in the root and test their involvement in survival and interactions with indigenous microflora. V. Develop predictive models for E. coli O157:H7 persistence/survival in soil and on plants grown under field conditions.