Yersinia murine toxin is not required for early-phase transmission of Yersinia pestis by Oropsylla montana (Siphonaptera: Ceratophyllidae) or Xenopsylla cheopis (Siphonaptera: Pulicidae)
Yersinia murine toxin is not required for early-phase transmission of Yersinia pestis by Oropsylla montana (Siphonaptera: Ceratophyllidae) or Xenopsylla cheopis (Siphonaptera: Pulicidae)
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DOI：
10.1099/mic.0.082123-0
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发表时间：
2014-11-01
期刊：
影响因子：
2.8
通讯作者：
Eisen, Rebecca J.
中科院分区：
文献类型：
--
作者：
Johnson, Tammi L.;Hinnebusch, B. Joseph;Eisen, Rebecca J.
鼠疫是由鼠疫耶尔森氏菌引起的，其特征是静止期被快速传播的动物流行病打断。经典的“阻塞跳蚤”范例，通过该范例，在感染后（p.i.）平均1-2周在跳蚤的腺胃中形成阻塞，迫使饥饿的跳蚤多次吸血，从而增加了传播的机会。最近，在动物流行病学中，早期传播（EPT）的重要性已被强调，它发生在堵塞形成之前。虽然跳蚤传播受阻的生理和分子机制已得到很好的表征，但EPT的病原体载体相互作用尚未阐明。在封闭的跳蚤模型中，耶尔森氏菌鼠毒素（Ymt）已被证明对促进跳蚤中肠的定殖很重要。EPT的一个可能机制是在摄食过程中跳蚤中肠的感染性物质回流。这种机制需要细菌在中肠中定居并存活至少短暂的时间，这一过程由Ymt介导。Y.在我们的研究中，使用了对人类有害的鼠疫菌Oropsylamontana（Siphonaptera：Ceratophyllidae）或印鼠客蚤Xenopsylamcheopis（Siphonaptera：Pulicidae）来验证这一假设。用Y.含有非功能性ymt的鼠疫杆菌，该ymt先前被证明不能定殖中肠，然后允许在感染后3天饲喂SKH-1小鼠。我们的研究结果表明，Ymt是不需要的EPT的跳蚤物种。
Plague, caused by Yersinia pestis, is characterized by quiescent periods punctuated by rapidly spreading epizootics. The classical 'blocked flea' paradigm, by which a blockage forms in the flea's proventriculus on average 1-2 weeks post-infection (p.i.), forces starving fleas to take multiple blood meals, thus increasing opportunities for transmission. Recently, the importance of early-phase transmission (EPT), which occurs prior to blockage formation, has been emphasized during epizootics. Whilst the physiological and molecular mechanisms of blocked flea transmission are well characterized, the pathogen vector interactions have not been elucidated for EPT. Within the blocked flea model, Yersinia murine toxin (Ymt) has been shown to be important for facilitating colonization of the midgut within the flea. One proposed mechanism of EPT is the regurgitation of infectious material from the flea midgut during feeding. Such a mechanism would require bacteria to colonize and survive for at least brief periods in the midgut, a process that is mediated by Ymt. Two key bridging vectors of Y. pestis to humans, Oropsylla montana (Siphonaptera: Ceratophyllidae) or Xenopsylla cheopis (Siphonaptera: Pulicidae), were used in our study to test this hypothesis. Fleas were infected with a mutant strain of Y. pestis containing a non-functional ymt that was shown previously to be incapable of colonizing the midgut and were then allowed to feed on SKH-1 mice 3 days p.i. Our results show that Ymt was not required for EPT by either flea species.