The Center for Alternatives to Animal Testing is an academic center affiliated with the Division of Toxicological Sciences in the Department of Environmental Health Sciences of the Johns Hopkins University Bloomberg School of Public Health.

 

Johns Hopkins School of Public Health

Research Grants 1997-1998

In Vitro Assay to Assess S. aureus Enterotoxin A Activity in Food

Linda Rassoly, PhD
Johns Hopkins University School of Public Health, Baltimore, Maryland

S. aureus enterotoxin A is one of the leading causes of food poisoning in North America with as little as 100 ng of SEA producing the symptoms. The most commonly used assay to measure SEA is an ELISA. The drawbacks of the ELISA assay are occurences of false positive results and inability to measure the activity of the toxin. The only test that measures the activity of SEA is an animal assay using kittens or monkeys. This test involves intravenous injection or reeding of monkeys or kittens with contaminated samples. The drawbacks of this animal assay are: low reliability, lack of quantitation, high cost, low sensitivity and requirement for animals and suitable animal facitilities.

that causes T cell proliferation, we are suggesting an alternative and far more sensitive method for SEA activity measurement. It does not require the use of animals and will specifically detect biologically active SEA (but not heat denatured SEA).

The purpose of this research proposal is to replace current animal assay for detection of S. aureus enterotoxin A (SEA) activity with a more sensitive non-radioactive in vitro cell proliferation assay. The specific goals are the isolation of SEA-reactive T cell clones; developing an in vitro proliferation assay using the T cell clones to measure SEA levels; testing suitability of a non-radioactive assay to replace the radioactive 3H-based proliferation assay in quantitation of SEA activity in food samples; and adjusting the assay to measure SEA activity in foods.