Bacillus anthracis, the etiological agent of anthrax, is a well-established model organism. For B. anthracis and most other infectious diseases, knowledge regarding transmission and infection parameters in natural systems, in large part, comprises data gathered from closely controlled laboratory experiments. Fatal, natural anthrax infections transmit the bacterium through new host-pathogen contacts at carcass sites, which can occur years after death of the previous host. For the period between contact and death, all of our knowledge is based upon experimental data from domestic livestock and laboratory animals. Here we use a noninvasive method to explore the dynamics of anthrax infections, by evaluating the terminal diversity of B. anthracis in anthrax carcasses. We present an application of population genetics theory, specifically, coalescence modeling, to intrainfection populations of B. anthracis to derive estimates for the duration of the acute phase of the infection and effective population size converted to the number of colony-forming units establishing infection in wild plains zebra (Equus quagga). Founding populations are small, a few colony-forming units, and infections are rapid, lasting roughly between 1 d and 3 d in the wild. Our results closely reflect experimental data, showing that small founding populations progress acutely, killing the host within days. We believe this method is amendable to other bacterial diseases from wild, domestic, and human systems.

中文翻译：

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感染炭疽杆菌群体的合并模型可以估计野生群体中的感染参数。


炭疽芽孢杆菌是炭疽病的病原体，是一种成熟的模式生物。对于炭疽杆菌和大多数其他传染病，有关自然系统中传播和感染参数的知识在很大程度上包括从严格控制的实验室实验中收集的数据。致命的自然炭疽感染通过尸体部位的新宿主与病原体接触传播细菌，这可能发生在前一个宿主死亡数年后。对于从接触到死亡这段时间，我们所有的知识都是基于家畜和实验动物的实验数据。在这里，我们使用非侵入性方法，通过评估炭疽尸体中炭疽芽孢杆菌的终端多样性来探索炭疽感染的动态。我们提出了群体遗传学理论（特别是合并模型）对炭疽芽孢杆菌内感染群体的应用，以得出感染急性期持续时间的估计值以及有效群体大小转换为在炭疽杆菌中建立感染的菌落形成单位的数量。野生平原斑马（Equus quagga）。创始种群很小，只有几个菌落形成单位，感染速度很快，在野外大约持续 1 到 3 天。我们的结果密切反映了实验数据，表明小型创始种群迅速进展，在几天内杀死了宿主。我们相信这种方法适用于野生、家养和人类系统的其他细菌性疾病。