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United States Department of Agriculture

Agricultural Research Service


item Arnold, Judy
item Boston, Whitney
item Stern, Norman
item Salley-guydon, Judith

Submitted to: The Louis Stokes-South Carolina Alliance Science & Engineering Conference
Publication Type: Abstract Only
Publication Acceptance Date: 7/8/2005
Publication Date: 7/23/2005
Citation: Arnold, J.W., Boston, W., Stern, N.J., Salley-Guydon, J. 2005. The assessment of bacteriocin activity against diverse strains of listeria. The Louis Stokes-South Carolina Alliance Science & Engineering Conference. p. 11

Interpretive Summary:

Technical Abstract: Food-borne infections are a major issue in public health. Because these infections are so prominent, new and effective means to kill the most common food pathogens are constantly sought. Bacteriocins are proteins that kill or inhibit the growth of other bacteria, and may be used as an alternative to chlorine and other chemicals. Bacteriocin 760 is produced by Streptococcus cricetus, a bacterium isolated from chicken intestinal flora. The activity of the bacteriocin against the common food pathogens Salmonella cholerasuis, Escherichia coli, and Staphylococcus aureus was compared with the activity against Listeria monocytogenes and other Listeria species. Each of six Listeria strains was grown separately on brain heart infusion broth and spread on agar plates. Three trials of bacteriocin tests with two replicates were performed on each pathogen using a petri dish separated into six sections labeled with six different concentrations ranging from 0.1 l/ml to 1mg/ml of bacteriocin 760. The bacterial culture (100 ÿl) was spread on the plate and allowed to air dry. After drying, the corresponding section was inoculated with 10µl of that bacteriocin concentration and air dried. After the bacteriocin drops dried, the plates were incubated at 37ºC for 24 hours. When the 24 hours elapsed, the zones of inhibition were measured. To measure the amount of bacteria that was tested, aerobic plate counts were performed. The bacteriocin tests show that the bacteriocins were effective against all the bacteria tested. The growth of Listeria strains was inhibited by concentrations from 12.5 g/ml to 1mg/ml of bacteriocin 760.

Last Modified: 07/25/2017
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