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United States Department of Agriculture

Agricultural Research Service

Research Project: MANAGEMENT OF TEMPERATE PASTURES AND SILVOPASTURES FOR SMALL FARM LIVESTOCK PRODUCTION Title: Effects of the ergot alkaloids dihydroergotamine, ergonovine, and ergotamine on growth of Escherichia coli O157:H7 in vitro

Authors
item Looper, Michael
item Edrington, Thomas
item Moubarak, A - UNIVERSITY OF AR
item Callaway, Todd
item Rosenkrans Jr, C - UNIVERSITY OF AR

Submitted to: Foodborne Pathogens and Disease
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: May 1, 2008
Publication Date: August 26, 2008
Citation: Looper, M.L., Edrington, T.S., Moubarak, A.S., Callaway, T.R., Rosenkrans Jr, C.F. 2008. Effects of the ergot alkaloids dihydroergotamine, ergonovine, and ergotamine on growth of Escherichia coli O157:H7 in vitro. Foodborne Pathogens and Disease. 5(5):25-30.

Interpretive Summary: Escherichia coli O157:H7 is one of the most common agents of foodborne illness in humans. How ergot alkaloids in endophyte-infected tall fescue affect growth of E. coli O157:H7 is unknown. ARS scientists from Booneville, AR, and College Station, TX, and personnel from the University of Arkansas conducted a series of experiments to evaluate the effects of ergot alkaloids on E. coli O157:H7 in both pure and mixed ruminal culture. Ergot alkaloids reduced E. coli O157:H7 in vitro. Ruminal and intestinal populations of E. coli O157:H7 may be influenced in livestock consuming endophyte-infected tall fescue, and these alterations could be due to the presence of ergot alkaloids in fescue plants. This information is of interest to livestock producers, extension personnel, and agricultural professionals who advise producers on livestock and food safety management practices.

Technical Abstract: A series of experiments were conducted to evaluate the effects of ergot alkaloids (dihydroergotamine, ergonovine, and ergotamine) on E. coli O157:H7 in both pure and mixed ruminal fluid culture. Alkaloids were added to solutions of E. coli O157:H7 strains 933 (pure and ruminal cultures) and 6058 (ruminal culture only), and growth rates and colony forming units (CFU) of E. coli O157:H7 were measured. A combination of all three alkaloids at either 2 or 500 µM decreased (P < 0.001) the growth rate of E. coli O157:H7 in pure culture compared to the individual alkaloids. Dihydroergotamine tended (P = 0.07) to reduce growth rate of E. coli O157:H7 in pure culture compared with ergonovine or ergotamine alone. Increased concentrations of dihydroergotamine and ergotamine decreased (P < 0.003) growth rate of E. coli O157:H7 but increasing concentrations of ergonovine did not influence (P > 0.10) E. coli O157:H7 growth rate. Similar to results in pure culture, a combination of all three alkaloids, independent of concentration, decreased (P < 0.001) the CFUs of E. coli O157:H7 strain 6058 in mixed ruminal culture compared to the individual ergot alkaloids. Dihydroergotamine decreased (P = 0.04) CFUs of E. coli O157:H7 strain 6058 when compared to ergonovine but CFUs was similar (P > 0.10) between dihydroergotamine and ergotamine. Ergot alkaloids commonly found in endophyte-infected tall fescue plants reduced E. coli O157:H7 in vitro. Ruminal and(or) intestinal populations of E. coli O157:H7 may be influenced in livestock consuming endophyte-infected tall fescue, and these alterations could be due to the presence of ergot alkaloids in fescue plants.

Last Modified: 11/28/2014