Prevention and Control of<i>Escherichia Coli</i>O157:H7

Besser, Thomas E.; LeJeune, Jeff; Rice, Dan; Hancock, Dale D.

doi:10.1002/9780470752616.ch18

Cited by 3 publications

(3 citation statements)

References 63 publications

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“…This has strong agreement with our deterministic and stochastic analyses that suggest most feedlots would support average cattle shedding at less than 100 CFU=g. Briefly, the E. coli O157:H7 predicted per gram of substrate in each compartment is also within the reported range of CFU in these media (Lynn et al, 1998;LeJeune et al, 2001aLeJeune et al, , 2001bJiang et al, 2002;Besser et al, 2003;Berry and Miller 2005;Amalaradjou et al, 2006), as would be expected given the logistic constraints imposed within each patch of the model.…”

Section: Interpretation and Assessmentmentioning

confidence: 54%

“…3) indicated that growth rates in feed could significantly impact the population dynamics of E. coli O157:H7 across the pen at high values. However, the values needed to affect dynamics in other patches are likely biologically infeasible; the exponential growth rate in feed has been reported as high as 2.5 per day (Lynn et al, 1998), but later attempts to replicate reproduction observed in the earlier study were unsuccessful (Besser et al, 2003). Thus, we defined a more modest growth rate in line with these observations as the baseline and conclude interventions targeted to reduce growth in feed will likely have little impact to the system's load of E. coli O157:H7.…”

Section: Interpretation and Assessmentmentioning

confidence: 95%

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Modeling On-FarmEscherichia coliO157:H7 Population Dynamics

Ayscue

Lanzas

Ivanek

et al. 2009

Foodborne Pathogens and Disease

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Escherichia coli O157:H7 is a potentially fatal foodborne pathogen with a putative reservoir for human infection in feedlot cattle. In order to more effectively identify targets for intervention strategies, we aimed to (1) assess the role of various feedlot habitats in E. coli O157:H7 propagation and (2) provide a framework for examining the relative contributions of animals and the surrounding environment to observed pathogen dynamics. To meet these goals we developed a mathematical model based on an ecological metapopulation framework to track bacterial population dynamics inside and outside the host. We used E. coli O157:H7 microbiological and epidemiological literature to characterize E. coli O157:H7 habitats at the pen level and account for E. coli O157:H7 population processes in water troughs, feedbunks, cattle hosts, and pen floors in the model. Simulations indicated that E. coli O157:H7 was capable of maintaining viable populations in the feedlot without net growth in the cattle gastrointestinal tract, suggesting E. coli O157:H7 may not always act as an obligate parasite. Water troughs and contaminated pen floors appeared to be particularly influential sources driving E. coli O157:H7 population dynamics and thus would serve as prime environmental targets for interventions to effectively reduce the E. coli O157:H7 load at the pen level.

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Section: Interpretation and Assessmentmentioning

confidence: 54%

Section: Interpretation and Assessmentmentioning

confidence: 95%

Modeling On-FarmEscherichia coliO157:H7 Population Dynamics

Ayscue

Lanzas

Ivanek

et al. 2009

Foodborne Pathogens and Disease

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“…There are several approaches to on‐farm control that theoretically could be used to reduce faecal shedding of E. coli O157:H7 in cattle. These strategies include reduced exposure through modification of management practices and interventions to increase animal resistance (Besser et al., 2003; Loneragan and Brashears, 2005). Strategies to increase animal resistance include the use of probiotics, vaccines, antibiotics, sodium chlorate, bacteriophages and other feed additives.…”

Section: Introductionmentioning

confidence: 99%

Pre‐harvest Interventions to Reduce the Shedding ofE. coliO157 in the Faeces of Weaned Domestic Ruminants: A Systematic Review

Sargeant

Amezcua

Rajić

et al. 2007

Zoonoses and Public Health

140

123

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Summary Our objective was to use formal systematic review methods to evaluate the efficacy of interventions to reduce faecal shedding of Escherichia coli O157 in post‐weaned ruminants by increasing animal resistance. The methodology consisted of an extensive search to identify all potentially relevant research, screening of titles and abstracts for relevance to the research question, quality assessment of relevant research, extraction of data from research of sufficient quality, and qualitative summarization of results. The interventions evaluated included probiotics, vaccination, antimicrobials, sodium chlorate, bacteriophages and other feed additives. There was evidence of efficacy for the probiotic combination Lactobacillus acidophilus NP51 (NPC 747) and Propionibacterium freudenreichii and for sodium chlorate in feed or water. The effectiveness of vaccination varied among studies and among vaccine protocols and there was no consistent evidence to suggest that antibiotic use was associated with a decrease in faecal shedding of E. coli O157, or that current industry uses of antimicrobials were associated with increased faecal shedding. There were an insufficient number of studies available to address the effectiveness of bacteriophages and several other feed additives. In general, few of the primary studies evaluated the interventions under commercial housing conditions with a natural disease challenge, there were inconsistencies in the results among study designs and in some cases among studies within study designs, and a relatively large proportion of publications were excluded based on quality assessment criteria. Few studies reported on associations between the proposed intervention and production parameters, such as average daily gain and feed: gain ratio. While the results suggest that some interventions may be efficacious, there are knowledge gaps in our understanding of the efficacy of pre‐harvest interventions to increase animal resistance to E. coli O157 that require further targeted research.

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