title: Association between animal age and the prevalence of Shiga toxin-producing Escherichia coli in a cohort of beef cattle.
abstract: Even with advancements in pre- and post-harvest food safety, Shiga toxin-producing Escherichia coli (STEC) still present challenges to human health. Since cattle are the primary reservoir for STEC, lowering the prevalence of this pathogen in farm animals may reduce STEC outbreaks in humans. However, because many of the factors that modulate the colonization and persistence of STEC in cattle remain unknown, reducing STEC in this host is challenging. In this study, we evaluated a cohort of beef cattle one to eleven years of age to determine the effect of animal age on the prevalence of STEC. During the first year of sample collection, heifers had significantly lower STEC prevalence than cows (37.5% vs. 70%). In the second year of sample collection, STEC prevalence peaked in cows that were two years of age and tended to decrease as animals became older. In addition, by studying a subset of the animals in both years, we observed an increase in STEC prevalence from 40.6% to 53.1% in heifers, whereas cows had a net decrease in STEC prevalence from 71.4% to 61.9%. The results from this study indicate that animal age is a significant factor that influences the prevalence of STEC in cattle. These findings have implications for the development of on-farm mitigation strategies by targeting animals with the highest risk of shedding; it could be possible to reduce pathogen transmission among cattle and prevent zoonotic or foodborne transmission to humans.
authors.affiliation: Department of Animal Sciences, Institute of Food and Agricultural Sciences, University of Florida, Gainesville, FL 32611, United States; Emerging Pathogens Institute, University of Florida, Gainesville, FL 32611, United States.
authors.forename: Raies A
authors.initials: RA
authors.lastname: Mir
authors.affiliation: Emerging Pathogens Institute, University of Florida, Gainesville, FL 32611, United States; Department of Environmental and Global Health, College of Public Health and Health Professions, University of Florida, Gainesville, FL 32611, United States.
authors.forename: Thomas A
authors.initials: TA
authors.lastname: Weppelmann
authors.affiliation: Department of Animal Sciences, Institute of Food and Agricultural Sciences, University of Florida, Gainesville, FL 32611, United States; Emerging Pathogens Institute, University of Florida, Gainesville, FL 32611, United States.
authors.forename: Minyoung
authors.initials: M
authors.lastname: Kang
authors.affiliation: Department of Animal Sciences, Institute of Food and Agricultural Sciences, University of Florida, Gainesville, FL 32611, United States; Emerging Pathogens Institute, University of Florida, Gainesville, FL 32611, United States.
authors.forename: Todd M
authors.initials: TM
authors.lastname: Bliss
authors.affiliation: North Florida Research and Education Center, Institute of Food and Agricultural Sciences, University of Florida, Marianna, FL 32446, United States.
authors.forename: Nicolas
authors.initials: N
authors.lastname: DiLorenzo
authors.affiliation: North Florida Research and Education Center, Institute of Food and Agricultural Sciences, University of Florida, Marianna, FL 32446, United States.
authors.forename: G Cliff
authors.initials: GC
authors.lastname: Lamb
authors.affiliation: Food Science and Human Nutrition Department, Institute of Food and Agricultural Sciences, University of Florida, Gainesville, FL 32611, United States.
authors.forename: Soohyoun
authors.initials: S
authors.lastname: Ahn
authors.affiliation: Department of Animal Sciences, Institute of Food and Agricultural Sciences, University of Florida, Gainesville, FL 32611, United States; Emerging Pathogens Institute, University of Florida, Gainesville, FL 32611, United States. Electronic address: kcjeong@ufl.edu.
authors.forename: Kwang Cheol
authors.initials: KC
authors.lastname: Jeong
mesh_terms: D000375:Aging; D000818:Animals; D002417:Cattle; D002418:Cattle Diseases / Q000382:microbiology*; D004196:Disease Outbreaks; D004927:Escherichia coli Infections / Q000382:microbiology / Q000662:veterinary*; D005260:Female; D006801:Humans; D015995:Prevalence; D054323:Shiga-Toxigenic Escherichia coli / Q000302:isolation & purification*
keywords: Animal factors; Pre-harvest food safety; Prevalence, Age; STEC