Event Title

Protozoa Associated with Romaine Lettuce

Location

CSU Ballroom

Start Date

20-4-2015 10:00 AM

End Date

20-4-2015 11:30 AM

Student's Major

Biological Sciences

Student's College

Science, Engineering and Technology

Mentor's Name

Dorothy Wrigley

Mentor's Email Address

dorothy.wrigley@mnsu.edu

Mentor's Department

Biological Sciences

Mentor's College

Science, Engineering and Technology

Description

Green leafy produce, like lettuce, is subjected to minimal treatment post harvesting and has recently been linked with several outbreaks of food borne disease. Given the proximity of lettuce with protozoa and bacteria, it is possible that the protozoa may play a role in pathogen survival on lettuce, especially for those pathogens that can adapt to living inside protozoan cells. This project is examining the incidence of protozoa on grocery store lettuce and the potential association of Escherichia coli with the found protozoa. Romaine lettuce was mixed with either distilled water or phosphate buffered saline, then the liquid was cultured at 25C with oatmeal flakes for protozoal food. After 7 days most cultures had protozoa which appear to be ciliates but they were all low concentration of protozoa. Subculture of the protozoa for testing with E. coli has been difficult and I am currently trying to increase the concentrations of protozoa for further testing. These methods will be presented. Initial testing of a soil ciliate with E. coli showed very little internalization of the E. coli by the ciliate. Another observation was that protozoa are more difficult to find on grocery store Romaine during the winter months.

This document is currently not available here.

Share

COinS
 
Apr 20th, 10:00 AM Apr 20th, 11:30 AM

Protozoa Associated with Romaine Lettuce

CSU Ballroom

Green leafy produce, like lettuce, is subjected to minimal treatment post harvesting and has recently been linked with several outbreaks of food borne disease. Given the proximity of lettuce with protozoa and bacteria, it is possible that the protozoa may play a role in pathogen survival on lettuce, especially for those pathogens that can adapt to living inside protozoan cells. This project is examining the incidence of protozoa on grocery store lettuce and the potential association of Escherichia coli with the found protozoa. Romaine lettuce was mixed with either distilled water or phosphate buffered saline, then the liquid was cultured at 25C with oatmeal flakes for protozoal food. After 7 days most cultures had protozoa which appear to be ciliates but they were all low concentration of protozoa. Subculture of the protozoa for testing with E. coli has been difficult and I am currently trying to increase the concentrations of protozoa for further testing. These methods will be presented. Initial testing of a soil ciliate with E. coli showed very little internalization of the E. coli by the ciliate. Another observation was that protozoa are more difficult to find on grocery store Romaine during the winter months.

Recommended Citation

Son, Hee. "Protozoa Associated with Romaine Lettuce." Undergraduate Research Symposium, Mankato, MN, April 20, 2015.
http://cornerstone.lib.mnsu.edu/urs/2015/poster_session_A/13