Eisen Rebecca J, Vetter Sara M, Holmes Jennifer L, Bearden Scott W, Montenieri John A, Gage Kenneth L
Bacterial Diseases Branch, Division of Vector Borne Infectious Diseases, National Center for Zoonotic, Enteric and Vector-Borne Diseases, Centers for Disease Control and Prevention, P.O. Box 2087, Fort Collins, CO 80522, USA.
J Med Entomol. 2008 Sep;45(5):933-8. doi: 10.1603/0022-2585(2008)45[933:sohbap]2.0.co;2.
Yersinia pestis, the etiological agent of plague, is transmitted by multiple flea species. Previous studies have reported wide variability in transmission efficiency among competent vectors. However, it is unclear to what extent such variation is explained by methodological differences among studies. To optimize an artificial feeding system where fleas are infected with controlled numbers of Y. pestis under standardized laboratory conditions that could be used to systematically compare vector efficiency, we sought to test the effect of host bloodmeal source on (1) the flea's ability to remain infected with Y. pestis and (2) bacterial loads in fleas. Here, we demonstrate that both prevalence of infection with a virulent strain of Y. pestis (CO96-3188) and bacterial loads in rock squirrel fleas (Oropsylla montana) are affected by host-associated blood factors. The generality of this observation was confirmed by repeating the study using the rat flea (Xenopsylla cheopis) and a commonly used avirulent laboratory strain of Y. pestis (A1122). Implications of the results for rate of spread of Y. pestis in naturally infected host populations are discussed.
鼠疫耶尔森菌是鼠疫的病原体，可通过多种跳蚤传播。以往的研究报告称，在适合传播的媒介中，传播效率存在很大差异。然而，尚不清楚这种差异在多大程度上是由研究方法的不同所导致的。为了优化一种人工喂食系统，即在标准化实验室条件下让跳蚤感染数量可控的鼠疫耶尔森菌，以便能够系统地比较媒介效率，我们试图测试宿主血源对（1）跳蚤保持感染鼠疫耶尔森菌的能力以及（2）跳蚤体内细菌载量的影响。在此，我们证明了感染强毒株鼠疫耶尔森菌（CO96 - 3188）的流行率以及岩松鼠跳蚤（山蚤）体内的细菌载量均受宿主相关血液因子的影响。通过使用印鼠客蚤以及常用的无毒力实验室菌株鼠疫耶尔森菌（A1122）重复该研究，证实了这一观察结果的普遍性。本文还讨论了这些结果对鼠疫耶尔森菌在自然感染宿主种群中传播速度的影响。
