Spread and transmission of bacterial pathogens in experimental populations of the nematode Caenorhabditis elegans.
Spread and transmission of bacterial pathogens in experimental populations of the nematode Caenorhabditis elegans.
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DOI：
10.1128/aem.01037-14
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发表时间：
2014-09
影响因子：
4.4
通讯作者：
Restif O
中科院分区：
文献类型：
--
作者：
Diaz SA;Restif O
秀丽隐杆线虫常被用作研究细菌毒力和先天免疫的模式物种。近年来，已发现线虫对细菌感染的免疫应答的多种机制。然而，尽管越来越多的兴趣在生化和分子基础上的线虫细菌协会，许多问题仍然是关于他们的生态。虽然最近的研究表明，自由生活的线虫可以作为土壤中的机会致病菌的载体，蠕虫可能有助于这些细菌的持久性和传播的程度还没有量化。我们进行了一系列的实验，以测试是否殖民和传播之间的C。线虫可以使两种条件致病菌（沙门氏菌和铜绿假单胞菌）在大肠杆菌占据的琼脂平板上传播。我们监测了S.肠杆菌和铜绿假单胞菌从单个感染的线虫到它们的后代，并测量蠕虫内和平板上的细菌负荷。特别地，我们分析了影响细菌动态的三个因素：（i）细菌的初始来源，（ii）细菌种类，和（iii）宿主的摄食行为。结果表明，蠕虫通过脱落和传播增加了细菌的传播。此外，我们发现，尽管铜绿假单胞菌在蠕虫中的传播率相对较高，但其致病作用减少了蠕虫的总数。这项研究为了解线虫在环境中病原菌的流行病学和进化中的作用开辟了新的途径。
Caenorhabditis elegans is frequently used as a model species for the study of bacterial virulence and innate immunity. In recent years, diverse mechanisms contributing to the nematode's immune response to bacterial infection have been discovered. Yet despite growing interest in the biochemical and molecular basis of nematode-bacterium associations, many questions remain about their ecology. Although recent studies have demonstrated that free-living nematodes could act as vectors of opportunistic pathogens in soil, the extent to which worms may contribute to the persistence and spread of these bacteria has not been quantified. We conducted a series of experiments to test whether colonization of and transmission between C. elegans nematodes could enable two opportunistic pathogens (Salmonella enterica and Pseudomonas aeruginosa) to spread on agar plates occupied by Escherichia coli. We monitored the transmission of S. enterica and P. aeruginosa from single infected nematodes to their progeny and measured bacterial loads both within worms and on the plates. In particular, we analyzed three factors affecting the dynamics of bacteria: (i) initial source of the bacteria, (ii) bacterial species, and (iii) feeding behavior of the host. Results demonstrate that worms increased the spread of bacteria through shedding and transmission. Furthermore, we found that despite P. aeruginosa's relatively high transmission rate among worms, its pathogenic effects reduced the overall number of worms colonized. This study opens new avenues to understand the role of nematodes in the epidemiology and evolution of pathogenic bacteria in the environment.