Novel detection method for Mycobacterium avium subsp. paratuberculosis using surface-enhanced Raman scattering based immunoassays

ANYL 325

Betsy Jean Yakes, byakes@iastate.edu, Departments of Chemistry and Chemical and Biological Engineering, Iowa State University, Ames Laboratory-USDOE, and Institute for Combinatorial Discovery, Ames, IA 50011, Robert J. Lipert, blipert@porter1.ameslab.gov, Institute of Combinatorial Chemistry, Ames Laboratory-USDOE, Iowa State University, Ames, IA 50011, John P. Bannantine, Bacterial Diseases of Livestock Research Unit, USDA/ARS/National Animal Disease Center, Ames, IA 50010, and Marc D. Porter, mporter@porter1.ameslab.gov, Department of Chemistry and of Chemical and Biological Engineering, Institute for Combinatorial Discovery, Ames Laboratory-USDOE, Iowa State University, 42 Spedding Hall, Ames, IA 50011.
Mycobacterium avium subsp. paratuberculosis (MAP), the causative agent of Johne's disease in cattle, imparts a loss of over $200 million to the U.S. dairy industry each year. One of the major obstacles in controlling the spread of this highly prevalent disease is the facile detection of the bacteria at low, subclinical levels. This paper introduces innovations that overcome both obstacles by using a sandwich immunosorbent assay, which is based on immunogold nanoparticle labels and surface-enhanced Raman scattering. By using monoclonal antibodies that are highly specific for a MAP surface protein, this labeling strategy yields large Raman signals that translate to a detection limit of ~500 bacteria/mL. This presentation will detail this assay, present evidence for shedding of the surface protein, and demonstrate its performance in complex sample matrices.
 

Analytical Approaches: Sensors
1:30 PM-4:20 PM, Thursday, 14 September 2006 Moscone Center -- Room 123, Oral

Division of Analytical Chemistry

The 232nd ACS National Meeting, San Francisco, CA, September 10-14, 2006