Research Microbiologist

Environmental Microbial and Food Safety Lab 
USDA, ARS, BA, ANRI, EMFSL
10300 Baltimore Avenue
Building 173 Room 103, BARC-East
Beltsville, MD 20705
Phone 301.504.5760, Fax 301.504.6608
www.ars.usda.gov/ba/anri/emfsl/shelton

Education

• Ph.D. 1983, Michigan State University; E. Lansing, MI
• M.S. 1978, Michigan State University; E. Lansing, MI
• B.S. 1975, Florida State University; Tallahassee, FL (cum laude)
• 1971 Northern Illinois University; DeKalb, IL

Professional Experience

• 2004-current: Research Leader, Environmental Microbial Safety Laboratory USDA/Agricultural Research Service, Beltsville, MD, Elucidate sources and fate of human pathogens in manures, water, and produce. Develop methods for sensitive, quantitative detection of human pathogens in water and produce. CRADA with Creatv Microtech to develop integrated biosensor for detection of waterborne pathogens and toxins.
• 1994-1998: Adjunct Instructor, Dept. of Environmental Engineering Johns Hopkins University, Baltimore, MD, Taught graduate courses in Environmental Microbiology and Bioremediation.
• 1993-2000: Research Microbiologist, Environmental Chemistry Laboratory USDA/Agricultural Research Service, Beltsville, MD, Developed strategies to minimize pathogen and agrochemical transport to waters. Assessed impact of agronomic practices on fate/efficacy of nutrients and pesticides.
• 1985-1993: Research Microbiologist, Pesticide Degradation Laboratory USDA/Agricultural Research Service, Beltsville, MD, Developed and implemented biotechnologies for the disposal/remediation of pesticide wastes. Isolated pesticide-degrading microorganisms and elucidated metabolic pathways.
• 1983-1985: Post-doctoral Research Associate, Dept. of Soil and Environmental Sciences University of California, Riverside, CA, Isolated and characterized aerobic bacteria which biodegrade organic pollutants.
• 1978-83: Research Assistant, Dept. of Crop and Soil Sciences Michigan State University; E. Lansing, MI, Isolated a new and novel genus of anaerobic bacterium (Desulfomonile tiedje) which metabolizes chloro-aromatic compounds. Developed standard test method for anaerobic biodegradation.
• 1976-78: Research Assistant, Dept. of Botany and Plant Pathology Michigan State University; E. Lansing, MI, Determined effects of harvest duration on asparagus yield and vigor.

Statement of Research

Develops new methods for rapid, quantitative detection of human pathogens, elucidating environmental parameters controlling pathogen transport to surface and ground waters. Assesses pathogen dispersal and survival in water, soil, manure, and produce. Develops strategies to minimize transport and dissemination of pathogens from animal manures to potable waters and fresh produce.

A microbial ecologist with over 25 years experience in environmental microbiology, analytical chemistry, microbial transformations of organic pollutants, and fate/transport of agrochemicals and pathogens. Extensive experience working with pollutants (eg., pesticides, solvents, inorganic fertilizers, greenhouse gases) and pathogenic agents (eg., Cryptosporidium parvum, Escherichia coli O157) in a variety of environmental matrices including soils, air, manures, surface waters, and groundwater. Extensive experience in the design and implementation of laboratory, bench scale, greenhouse, field plot and watershed scale studies. Current research mission includes developing new methods for rapid, quantitative detection of human pathogens, elucidating environmental parameters controlling pathogen transport to surface and ground waters, and developing strategies to minimize transport of pathogens from animal manures to potable waters.

Collaborators

• Creatv MicroTech, Inc.; Cha-Mei Tang, Pete Amstutz, Peixuan Zhu,Shuhong Li
• Inova Fairfax Hospital; Choong Park
• Mitre Corp.; Elaine Mullen
• Anacostia Watershed Society; Masaya Maeda, James Connoly
• Quickpath Technologies, Inc.; Rick Spedden, Lynda Kiefer
• Spiralcat of Maryland; Carol Collins

Professional Affiliations

• American Society for Microbiology
• International Association for Food Protection