title: Colonization of Beef Cattle by Shiga Toxin-Producing Escherichia coli during the First Year of Life: A Cohort Study.
abstract: Each year Shiga toxin-producing Escherichia coli (STEC) are responsible for 2.8 million acute illnesses around the world and > 250,000 cases in the US. Lowering the prevalence of this pathogen in animal reservoirs has the potential to reduce STEC outbreaks in humans by controlling its entrance into the food chain. However, factors that modulate the colonization and persistence of STEC in beef cattle remain largely unidentified. This study evaluated if animal physiological factors such as age, breed, sex, and weight gain influenced the shedding of STEC in beef cattle. A cohort of beef calves (n = 260) from a multi-breed beef calf population was sampled every three months after birth to measure prevalence and concentration of STEC during the first year of life. Metagenomic analysis was also used to understand the association between the STEC colonization and the composition of gut microflora. This study identified that beef calves were more likely to shed STEC during the first 6 months and that STEC shedding decreased as the animal matured. Animal breed group, sex of the calf, and average weight gain were not significantly associated with STEC colonization. The metagenomic analysis revealed for the first time that STEC colonization was correlated with a lower diversity of gut microflora, which increases as the cattle matured. Given these findings, intervention strategies that segregate younger animals, more likely to be colonized by STEC from older animals that are ready to be harvested, could be investigated as a method to reduce zoonotic transmission of STEC from cattle to humans.
authors: Department of Animal Sciences, Institute of Food and Agricultural Sciences, University of Florida, Gainesville, Florida, United States of America.|Emerging Pathogens Institute, University of Florida, Gainesville, Florida, United States of America.
authors: Raies A
authors: RA
authors: Mir
authors: Emerging Pathogens Institute, University of Florida, Gainesville, Florida, United States of America.|Department of Environmental and Global Health, College of Public Health and Health Professions, University of Florida, Gainesville, FL, United States of America.
authors: Thomas A
authors: TA
authors: Weppelmann
authors: Department of Animal Sciences, Institute of Food and Agricultural Sciences, University of Florida, Gainesville, Florida, United States of America.
authors: Mauricio
authors: M
authors: Elzo
authors: Food Science and Human Nutrition Department, Institute of Food and Agricultural Sciences, University of Florida, Gainesville, Florida, United States of America.
authors: Soohyoun
authors: S
authors: Ahn
authors: Department of Animal Sciences, Institute of Food and Agricultural Sciences, University of Florida, Gainesville, Florida, United States of America.
authors: J Danny
authors: JD
authors: Driver
authors: Department of Animal Sciences, Institute of Food and Agricultural Sciences, University of Florida, Gainesville, Florida, United States of America.|Emerging Pathogens Institute, University of Florida, Gainesville, Florida, United States of America.
authors: KwangCheol Casey
authors: KC
authors: Jeong
mesh_terms: D000367:Age Factors; D000818:Animals; D057138:Bacterial Shedding; D001835:Body Weight; D002417:Cattle / Q000382:microbiology*; D002418:Cattle Diseases / Q000453:epidemiology / Q000382:microbiology*; D004269:DNA, Bacterial / Q000145:classification / Q000302:isolation & purification; D004927:Escherichia coli Infections / Q000453:epidemiology / Q000662:veterinary*; D005243:Feces / Q000382:microbiology; D005260:Female; D000069196:Gastrointestinal Microbiome / Q000235:genetics; D016015:Logistic Models; D008297:Male; D012737:Sex Factors; D054323:Shiga-Toxigenic Escherichia coli / Q000302:isolation & purification*
chemical_list: D004269:DNA, Bacterial