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United States Department of Agriculture

Agricultural Research Service

Research Project: GLYCOPROTEIN MICELLES FOR PATHOGEN COLLECTION AND STABILIZATION
2012 Annual Report


1a.Objectives (from AD-416):
The objective of this agreement is to establish the proof-of-concept that floating glycoprotein film-coated micelles can be used to capture pathogens from aqueous matrices and stabilize them during transport and storage. Initial research conducted at The MITRE Corporation (MITRE) was patented and licensed to Quickpath Bioscience.


1b.Approach (from AD-416):
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 pedictability 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 Corporation will be performed to establish optimal binding kinetics and survival. Target fimbriae will also be screened against available glycan microarrays.


3.Progress Report:

Studies are being conducted to identify the predominant fimbriae/pili expressed by specific pathogens in order to identify suitable glycans for capture. Fimbriae play a crucial role in attachment of bacteria to biotic (plant) and abiotic surfaces and formation of biofilms. An understanding of these processes is critical to understanding survival and to developing intervention strategies to prevent contamination of fresh produce.


Last Modified: 10/24/2014
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