Theses and Dissertations


Qian Gu

Issuing Body

Mississippi State University


Silva, Juan L.

Committee Member

Kim, Tae Jo

Committee Member

Ma, Din-Pow

Committee Member

Schilling, M. Wes

Date of Degree


Document Type

Graduate Thesis - Open Access


Food Science and Technology

Degree Name

Master of Science (M.S.)


College of Agriculture and Life Sciences


Department of Food Science, Nutrition and Health Promotion


Escherichia coli O157:H7 detection in food is conducted mainly by DNA/PCR, immunoassay or conventional methods. However, all the methods require multiple incubation steps. Antibiotic and isolation agars were found as the main factors that lead to false-positive results. An improved rapid detection method was developed by decreasing detection time and enhancing easiness of detection without the need for any analytical instrumentation. A combination of selective ingredients and temperature was utilized to allow the growth of Escherichia coli O157:H7 in the detection. The detection method minimized the effects of the main false positive bacteria, Pseudomonas spp. and Enterobacter spp. The sensitivity, specificity and accuracy of the 24h detection method in foodstuffs were 96.2%, 99.6% and 97.0%, respectively when the original inoculation was 10-100cfu/g in food. This method can be utilized to detect Escherichia coli O157:H7 in foodstuffs more rapidly, economically and conveniently when compared to the methods that are currently used.