Infectious blood source alters early foregut infection and regurgitative transmission of Yersinia pestis by rodent fleas.
Infectious blood source alters early foregut infection and regurgitative transmission of Yersinia pestis by rodent fleas.
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DOI：
10.1371/journal.ppat.1006859
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发表时间：
2018-01
期刊：
影响因子：
6.7
通讯作者：
Hinnebusch BJ
中科院分区：
文献类型：
--
作者：
Bland DM;Jarrett CO;Bosio CF;Hinnebusch BJ
蚤可通过早期传播（EPT）和生物膜依赖传播（BDT）两种途径传播鼠疫耶尔森菌。不同种类的跳蚤传播效率不同，不同研究的结果并不总是一致的。一个复杂的变量是用于感染性血餐的啮齿动物血液的种类。为了深入了解EPT的作用机制和宿主血液对其的影响，我们给跳蚤喂了小鼠、大鼠、豚鼠和沙鼠的血；感染后1 ~ 3 d评估感染部位、消化道感染特点及鼠疫菌的传播力。令人惊讶的是，10-28%的两种啮齿动物跳蚤在喂食无菌大鼠或豚鼠血液后的24小时内将一部分受感染的血粉反流到食道。我们将这种现象称为感染后食管反流（PIER）。相比之下，在喂食无菌小鼠或沙鼠血液的啮齿动物跳蚤中很少观察到PIER。PIER与充满前脑室的鼠疫菌、红细胞间质和氧合血红蛋白晶体的密集混合聚集体的积累有关。在下一次喂食时，有PIER的跳蚤出现部分阻塞的可能性是没有PIER的跳蚤的3-25倍，新鲜血液保留在食道内。在喂食具有细菌血症的大鼠血液3天后，蒙大拿口蝗感染组比使用小鼠血液感染组传播更多的CFU，并且这种增强的传播依赖于生物膜。我们的数据支持一个模型，其中EPT是由鼠疫杆菌从部分阻塞的跳蚤前肠反流引起的，并且EPT和BDT有时可以暂时重叠。大鼠和Sciurids的血红蛋白的相对不溶性以及它们的血液消化较慢似乎促进了反流传播，这可能是这些啮齿动物在鼠疫生态学中特别突出的原因之一。鼠疫耶尔森氏菌是鼠疫的细菌病原体，它是由以携带这种疾病的啮齿动物的血液为食的跳蚤传播的。比较跳蚤在感染后传播鼠疫的效率的研究得出的结论并不一致，这可能是因为使用了各种啮齿动物的血液来源。为了调查这一点，我们用四种不同类型的啮齿动物血液感染了三种不同的跳蚤，并比较了三天后它们的传播情况。当使用大鼠或豚鼠的血液进行感染时，两种有效传播的啮齿动物跳蚤倾向于将细菌和血液反流到它们的食道，而当使用小鼠或沙鼠的血液时则不然。这种反流现象似乎与不同啮齿类动物血红蛋白分子的溶解度有关。相比之下，猫蚤是一种低效的传递者，它们从未将受感染的血液反流到食道中。使用引起反流的大鼠血液感染的啮齿动物跳蚤比那些以受感染的老鼠血液为食的跳蚤传播了更多的鼠疫杆菌。这些发现提高了我们对跳蚤如何在感染后很快传播鼠疫杆菌的理解，并提出了某些啮齿动物在鼠疫生态中比其他啮齿动物更突出的原因。
Fleas can transmit Yersinia pestis by two mechanisms, early-phase transmission (EPT) and biofilm-dependent transmission (BDT). Transmission efficiency varies among flea species and the results from different studies have not always been consistent. One complicating variable is the species of rodent blood used for the infectious blood meal. To gain insight into the mechanism of EPT and the effect that host blood has on it, fleas were fed bacteremic mouse, rat, guinea pig, or gerbil blood; and the location and characteristics of the infection in the digestive tract and transmissibility of Y. pestis were assessed 1 to 3 days after infection. Surprisingly, 10–28% of two rodent flea species fed bacteremic rat or guinea pig blood refluxed a portion of the infected blood meal into the esophagus within 24 h of feeding. We term this phenomenon post-infection esophageal reflux (PIER). In contrast, PIER was rarely observed in rodent fleas fed bacteremic mouse or gerbil blood. PIER correlated with the accumulation of a dense mixed aggregate of Y. pestis, red blood cell stroma, and oxyhemoglobin crystals that filled the proventriculus. At their next feeding, fleas with PIER were 3–25 times more likely to appear partially blocked, with fresh blood retained within the esophagus, than were fleas without PIER. Three days after feeding on bacteremic rat blood, groups of Oropsylla montana transmitted significantly more CFU than did groups infected using mouse blood, and this enhanced transmission was biofilm-dependent. Our data support a model in which EPT results from regurgitation of Y. pestis from a partially obstructed flea foregut and that EPT and BDT can sometimes temporally overlap. The relative insolubility of the hemoglobin of rats and Sciurids and the slower digestion of their blood appears to promote regurgitative transmission, which may be one reason why these rodents are particularly prominent in plague ecology. Yersinia pestis, the bacterial agent of plague, is transmitted by fleas that feed on blood from rodents that carry this disease. The conclusions from studies comparing how efficiently fleas transmit plague after becoming infected have been inconsistent, possibly because a variety of rodent blood sources have been used. To investigate this, we infected three different flea species with Y. pestis using four different types of rodent blood and compared how well they could transmit three days later. The two rodent flea species that transmitted efficiently tended to reflux bacteria and blood into their esophagus when rat or guinea pig blood was used for the infections, but not when mouse or gerbil blood was used. This reflux phenomenon appears to be related to the solubility of the hemoglobin molecule of different rodent species. In contrast, cat fleas, inefficient transmitters, never refluxed their infected blood meal into the esophagus. Rodent fleas that were infected using reflux-inducing rat blood transmitted more Y. pestis than those that fed on infected mouse blood. These findings improve our understanding of how fleas transmit Y. pestis soon after becoming infected and suggest a reason why certain rodents figure more prominently in plague ecology than others.
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影响因子：
--
作者：
BURROUGHS, AL
通讯作者：
BURROUGHS, AL
影响因子：
2.8
作者：
Johnson, Tammi L.;Hinnebusch, B. Joseph;Eisen, Rebecca J.
通讯作者：
Eisen, Rebecca J.
影响因子：
2.1
作者：
Boegler, Karen A.;Graham, Christine B.;Eisen, Rebecca J.
通讯作者：
Eisen, Rebecca J.
早期传播在耶尔森氏菌的传播中的作用。
影响因子：
2.1
作者：
Eisen RJ;Dennis DT;Gage KL
通讯作者：
Gage KL
影响因子：
3.1
作者：
DONNENBERG, MS;KAPER, JB
通讯作者：
KAPER, JB