Submitted to: Book Chapter
Publication Type: Book / Chapter
Publication Acceptance Date: January 13, 2011
Publication Date: August 1, 2011
Citation: Edrington, T.S., Nisbet, D.J. 2011. Melatonin and food safety: Investigating a possible role in the seasonality of the bacterial pathogen Escherichia coli 0157:H7 in cattle. In: Watson, R.R., editor. Melatonin in the Promotion of Health. Boca Raton, FL: CRC Press. p. 211-218. Interpretive Summary: Cattle are naturally infected with E. coli O157:H7, a bacteria that causes food sickness in humans. This bacteria is more common in cattle in the summer months than in the winter, but no one knows the reason for this seasonality. We hypothesize that day-length, and hormones that respond to day-length, are the underlying explanation for the seasonality of this pathogen. Research conducted by our laboratory provides support for our hypothesis and implicates gastrointestinal melatonin as a key factor. Understanding the biology of E. coli O157:H7 will enable the design of effective strategies to control this bacteria.
Technical Abstract: The seasonality of E. coli O157:H7 prevalence in feedlot cattle in the United States has been well documented but poorly understood. Our hypothesis, that this phenomenon is related to hormonal changes within the animal in response to changing day-length, is supported by the data from numerous studies conducted by our laboratory. Our data suggests that melatonin, and in particular gastrointestinal melatonin, is likely involved in the seasonal population dynamics of E. coli O157:H7 in cattle, and that further research in this area is warranted. Understanding the seasonality of this pathogen could potentially lead to pre-harvest intervention strategies to reduce E. coli O157:H7 in cattle and subsequently infections in humans when they are most prevalent.