Synchronization of E. coli O157 shedding in a grass-fed beef herd: a longitudinal study

Geraldine A C Lammers, Craig S McConnel, David Jordan, Michelle S Ayton, Stephen Morris, Edward Ian Patterson, Michael P Ward, Jane Heller

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10 Citations (Scopus)


This study aims to describe in detail the temporal dynamics of E. coli O157 shedding and risk factors for shedding in a grass-fed beef herd. During a 9-month period, 23 beef cows were sampled twice a week (58 sampling points) and E. coli O157 was enumerated from faecal samples. Isolates were screened by PCR for presence of rfbE, stx 1 and stx 2 . The prevalence per sampling day ranged from 0 to 57 . This study demonstrates that many members of the herd were concurrently shedding E. coli O157. Occurrence of rainfall (P <0.01), feeding silage (P <0.01) and lactating (P <0.01) were found to be predictors of shedding. Moving cattle to a new paddock had a negative effect on shedding. This approach, based on short-interval sampling, confirms the known variability of shedding within a herd and highlights that high shedding events are rare.
Original languageEnglish
Pages (from-to)3244 - 3255
Number of pages12
JournalEpidemiology and Infection
Issue number15
Publication statusPublished - 2015

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