title: Longitudinal follow-up of the persistence and dissemination of EHEC on cattle farms in Belgium.
abstract: A longitudinal survey was performed on three cattle herds known to be positive for, respectively, Enterohemorrhagic Eschericia coli (EHEC) O157, O26/O103, and O26 in a slaughterhouse study. This study aimed to investigate the persistence and dissemination of EHEC in beef cattle and beef cattle farms. At each farm, a cohort of 10 animals was sampled, seven times on farm B and eight times on farms A and C, at intervals of approximately 4-6 weeks. In addition, incoming cattle and environmental samples were also examined for the presence of EHEC at each sampling occasion. In 65 (18.8%) out of 345 samples, EHEC was detected, of which 41 were from cohort animals, four from incoming cattle and 20 from environmental samples (cats 3/23; dogs 2/7; feed 4/23, water 2/23, and dust 9/23). On two farms, non-EHEC strains harboring either vtx or eae genes were detected in 21 samples. EHEC was detected at least once in 23 of the cohort animals, with a maximum of four positive sampling occasions. Genetic typing by pulsed-field gel electrophoresis (PFGE) demonstrated that a same strain occurred for several months (up to 11 months) in two of three cattle farms. Among the environmental samples, dust harbored EHEC most frequently. In conclusion, transmission and dissemination of EHEC might have occurred not only in the bovine reservoir but also in the farm environment and in other farm animals.
authors.affiliation: Department of Veterinary Public Health and Food Safety, Laboratory of Hygiene and Technology, Faculty of Veterinary Medicine, Ghent University, Merelbeke, Belgium. Adelheid@as4.be
authors.forename: Maria-Adelheid
authors.initials: MA
authors.lastname: Joris
authors.forename: Karen
authors.initials: K
authors.lastname: Verstraete
authors.forename: Koen
authors.initials: K
authors.lastname: De Reu
authors.forename: Lieven
authors.initials: L
authors.lastname: De Zutter
mesh_terms: D000821:Animal Feed / Q000382:microbiology; D000818:Animals; D001530:Belgium; D002415:Cats / Q000382:microbiology; D002417:Cattle / Q000382:microbiology*; D002418:Cattle Diseases / Q000382:microbiology* / Q000635:transmission; D004285:Dogs / Q000382:microbiology; D004391:Dust / Q000032:analysis; D016521:Electrophoresis, Gel, Pulsed-Field; D054324:Enterohemorrhagic Escherichia coli / Q000145:classification / Q000235:genetics / Q000302:isolation & purification*; D004927:Escherichia coli Infections / Q000635:transmission / Q000662:veterinary*; D005243:Feces / Q000382:microbiology; D008137:Longitudinal Studies; D008297:Male
chemical_list: D004391:Dust