Modeling On-Farm Escherichia coli O157:H7 Population Dynamics
Modeling On-Farm Escherichia coli O157:H7 Population Dynamics
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DOI：
10.1089/fpd.2008.0235
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发表时间：
2009-05-01
影响因子：
2.8
通讯作者：
Groehn, Y. T.
中科院分区：
文献类型：
--
作者：
Ayscue, P.;Lanzas, C.;Groehn, Y. T.
大肠杆菌O157：H7是一种潜在的致命食源性病原体，可能是人类感染饲养场牛的宿主。为了更有效地确定干预策略的目标，我们的目标是(1)评估不同饲养场生境在大肠杆菌O157：H7繁殖中的作用，以及(2)提供一个框架，以检查动物和周围环境对观察到的病原体动态的相对贡献。为了实现这些目标，我们开发了一个基于生态集合种群框架的数学模型来跟踪宿主内外的细菌种群动态。我们使用E.ColiO157：H7微生物学和流行病学文献描述了E.ColiO157：H7在围栏水平的栖息地，并解释了模型中水槽、饲养场、牛宿主和围栏地板中的E.ColiO157：H7种群过程。模拟结果表明，O157：H7能够维持饲养场中的活菌群，而不会在牛的胃肠道中净生长，这表明O157：H7可能并不总是作为专性寄生虫。水槽和受污染的围栏地板似乎是推动大肠杆菌O157：H7种群动态的特别有影响力的来源，因此将成为干预措施的主要环境目标，以有效减少围栏水平的大肠杆菌O157：H7负荷。
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.