University Lille, CNRS, INSERM, CHU Lille, Institut Pasteur de Lille, U1019-UMR9017-CIIL-Centre d'Infection et d'Immunité de Lille, Lille, France.
University Lille, CNRS, INSERM, CHU Lille, Institut Pasteur de Lille, US41-UMS2014 - PLBS, Lille, France.
Appl Environ Microbiol. 2023 Apr 26;89(4):e0209122. doi: 10.1128/aem.02091-22. Epub 2023 Mar 20.
Yersinia pestis (the agent of flea-borne plague) must obstruct the flea's proventriculus to maintain transmission to a mammalian host. To this end, Y. pestis must consolidate a mass that entrapped Y. pestis within the proventriculus very early after its ingestion. We developed a semiautomated fluorescent image analysis method and used it to monitor and compare colonization of the flea proventriculus by a fully competent flea-blocking Y. pestis strain, a partially competent strain, and a noncompetent strain. Our data suggested that flea blockage results primarily from the replication of Y. pestis trapped in the anterior half of the proventriculus. However, consolidation of the bacteria-entrapping mass and colonization of the entire proventricular lumen increased the likelihood of flea blockage. The data also showed that consolidation of the bacterial mass is not a prerequisite for colonization of the proventriculus but allowed Y. pestis to maintain itself in a large flea population for an extended period of time. Taken as the whole, the data suggest that a strategy targeting bacterial mass consolidation could significantly reduce the likelihood of Y. pestis being transmitted by fleas (due to gut blockage), but also the possibility of using fleas as a long-term reservoir. Yersinia pestis (the causative agent of plague) is one of the deadliest bacterial pathogens. It circulates primarily among rodent populations and their fleas. Better knowledge of the mechanisms leading to the flea-borne transmission of Y. pestis is likely to generate strategies for controlling or even eradicating this bacillus. It is known that Y. pestis obstructs the flea's foregut so that the insect starves, frantically bites its mammalian host, and regurgitates Y. pestis at the bite site. Here, we developed a semiautomated fluorescent image analysis method and used it to document and compare foregut colonization and disease progression in fleas infected with a fully competent flea-blocking Y. pestis strain, a partially competent strain, and a noncompetent strain. Overall, our data provided new insights into Y. pestis' obstruction of the proventriculus for transmission but also the ecology of plague.
鼠疫耶尔森菌（跳蚤传播鼠疫的病原体）必须阻塞跳蚤的前胃才能将疾病传播给哺乳动物宿主。为此，鼠疫耶尔森菌必须在摄入后尽早形成一个团块，将鼠疫耶尔森菌困在前胃中。我们开发了一种半自动荧光图像分析方法，并使用该方法监测和比较了完全有能力阻止跳蚤传播的鼠疫耶尔森菌菌株、部分有能力的菌株和无能力的菌株对跳蚤前胃的定植。我们的数据表明，跳蚤阻塞主要是由于被困在前胃前半部分的鼠疫耶尔森菌的复制。然而，细菌包埋团块的凝结和整个前胃腔的定植增加了跳蚤阻塞的可能性。数据还表明，细菌团块的凝结不是前胃定植的前提条件，但允许鼠疫耶尔森菌在大量跳蚤种群中维持自身很长一段时间。总的来说，数据表明，针对细菌团块凝结的策略可以显著降低鼠疫耶尔森菌通过跳蚤传播的可能性（由于肠道阻塞），但也降低了使用跳蚤作为长期储存库的可能性。鼠疫耶尔森菌（鼠疫的病原体）是最致命的细菌病原体之一。它主要在啮齿动物种群及其跳蚤中循环。更好地了解导致鼠疫耶尔森菌通过跳蚤传播的机制可能会产生控制甚至根除这种杆菌的策略。已知鼠疫耶尔森菌阻塞了跳蚤的前肠，使昆虫饥饿，疯狂地叮咬其哺乳动物宿主，并在前肠叮咬部位吐出鼠疫耶尔森菌。在这里，我们开发了一种半自动荧光图像分析方法，并使用该方法记录和比较了完全有能力阻止跳蚤传播的鼠疫耶尔森菌菌株、部分有能力的菌株和无能力的菌株感染跳蚤后的前肠定植和疾病进展。总的来说，我们的数据为鼠疫耶尔森菌阻塞前胃以进行传播提供了新的见解，但也为鼠疫的生态学提供了新的见解。
