Project Number: 8042-32420-005-07
Start Date: Jan 23, 2009
End Date: Sep 30, 2013
Fimbriae, hair-like structures produced by many species of bacteria, vary in the composition of the fimbrial shaft and protein adhesins found on the tips. Bacterial adhesins selectively bind to tissue-specific glycans. For example, pathogens such as Salmonella and E. coli expressing Type I fimbriae attach to tissues/micelles coated with mannose. There are about twenty-two known fimbrial types. However, reproducibility and predictability of attachment is uncertain. Little is known about how the environment influences fimbrial production. Furthermore, Type I fimbriae are distributed among many bacterial species and there can be variations in the shaft fimbrin protein while the tip adhesin protein remains the same. We have selected a model strain, uropathogenic Escherichia coli (UPEC), to which we will obtain monoclonal antibodies produced against the target fimbriae. Immunoassay studies elucidating fimbrial expression as a function of environmental parameters will be conducted with methods developed for the Signalyte spectrofluorimeter(Creativ MicroTech) and imaged by Epifluorescent and Atomic Force Microscopy (NIST). Environmental parameters to be investigated include: pH (including shifts in pH), redox, temperature, culture age, nutrient ratios (carbon:nitrogen: phosphorus), nutrient composition, ionic strength, and cell chemical signaling effects. After establishing environmental conditions that reliably produce fimbrial expression, attachment studies to lipid-filled glycoprotein micelles provided by MITRE will be performed to establish optimal binding kinetics and survival. Target fimbriae will also be screened against available glycan microarrays.