magazine story to find out more.
expression of green fluorescent protein by Salmonella are two ARS
collaborators with the University of Maryland, Eastern Shoregrad student
Kalpana Dulal (left) and microbiologist Dwayne Boucaud. Click the image for
more information about it.
Models Predict Poultry Pathogen Behavior
By Jim Core
June 7, 2005
Computer models that more accurately predict the growth of food
pathogens are being developed by the Agricultural Research Service (ARS) and are available online. These models
make better predictions about food safety because they gauge how pathogens are
affected by competition from other food microbes.
ARS food technologist
P. Oscar, at the ARS
Food Safety Research Laboratory in Princess Anne, Md., models the growth
and survival of Salmonella and Campylobacter on chicken. The lab,
based at the University of Maryland Eastern
Shore campus, is affiliated with the ARS Eastern Regional Research Center
in Wyndmoor, Pa.
Oscar's research is part of a growing field, known as predictive
microbiology, that estimates the behavior of foodborne pathogens in response to
environmental conditions encountered in food production and processing
Previously, models were often developed by studying pathogens in broth
with no other microbes present. Researchers thought this would allow them to
accurately predict pathogen behavior in food. But this is not always the case
because these models don't consider the role competing microorganisms have in
ARS researchers will produce more realistic models using a system to
rate the performance of current models. Oscar recently developed an "acceptable
prediction zone" method for evaluating existing models. The method establishes
criteria for verifying and validating models, classifying them to show which
are best, and then pinpointing changes to improve the models.
According to Oscar, most current broth models predict much higher
pathogen numbers than would be present in real food with microbial competition.
Posting poultry pathogen models, as well as other food safety models,
on the ERRC's Pathogen
Modeling Program Website should accelerate the use of models by food
industries and other professionals in the field of predictive microbiology.
more about this research in the June issue of Agricultural Research
magazine, available online at:
ARS is the U.S. Department of
Agriculture's chief scientific research agency.