An official website of the United States government.

Official websites use .gov
A .gov website belongs to an official government organization in the United States.

Secure .gov websites use HTTPS
A lock ( ) or https:// means you’ve safely connected to the .gov website. Share sensitive information only on official, secure websites.

Modeling the Viability and Survivability of Threat Agents in Food Matrices

Lindsay, James
USDA - Agricultural Research Service
Start date
End date
To develop computer models, including software enabling the user to predict the decay of Bacillus anthracis in food matrices. These mathematical models will allow the Biological Threat Characterization Center (BTCC) to predict the probable viability/stability of B. anthracis in various high risk food matrices provided the pertinent food conditions are known.
More information
Dr. Mark Tamplin at the USDA-ARS Eastern Regional Research Center, Wyndmoor, PA will perform the risk assessment modeling with data developed by the USDA-FSIS Eastern Laboratory and the USDA-FSIS Microbial Outbreaks and Special Projects Laboratory, located in Athens, GA. This task involves taking the FSIS data set, and using it to formulate viability/stability models that have useful predictive value. The problem encountered involves the assessment of the likelihood that a given agent (whose identity is known) will survive in/on a given food matrix, subject to defined environmental conditions (e.g., temperature). The data sets will be fit to straightforward mathematical expressions (decay curves), from which one can extrapolate or interpolate to obtain the desired information. In addition, we will carefully analyze the data sets to determine whether we can formulate an expression for a surface model (alternatively, a series of curves) for a given agent, that will account for all of the food-matrix-dependent data for that agent. One issue, not explicitly noted above, is whether the viability/stability of a given agent is independent of the local concentration of the agent. This is possibly unlikely because higher concentrations can promote the formation of multilayer films or aggregates, and cells/molecules in the interiors of such films/aggregates would be somewhat protected from the deleterious effects of an environmental stress. These models will be delivered to the sponsor in the form of a readily accessible computer program.
Funding Source
Agricultural Research Service
Project number
Accession number
Predictive Microbiology
Risk Assessment, Management, and Communication
Legislation and Regulations