Spatial and temporal features of the growth of a bacterial species colonizing the zebrafish gut.
Spatial and temporal features of the growth of a bacterial species colonizing the zebrafish gut.
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DOI：
10.1128/mbio.01751-14
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发表时间：
2014-12-16
期刊：
影响因子：
6.4
通讯作者：
Parthasarathy R
中科院分区：
文献类型：
--
作者：
Jemielita M;Taormina MJ;Burns AR;Hampton JS;Rolig AS;Guillemin K;Parthasarathy R
脊椎动物的肠道是微生物生态系统的所在地，这些生态系统在宿主的发育和健康中发挥着关键作用。对这些微生物群落的时空动态知之甚少，限制了我们对基本特性的理解，例如它们的生长，繁殖和持久性机制。为了解决这个问题，我们接种最初无菌斑马鱼幼虫与荧光标记的气单胞菌属物种，代表丰富的属在斑马鱼肠道。使用光片荧光显微镜来获得跨越肠道的三维图像，我们量化了整个细菌负荷，因为在几个小时内，建立的种群从数十个细胞增长到数万个细胞。这些数据首次测量了活脊椎动物肠道内微生物物种的生长动力学，并显示出与逻辑生长模型稳健拟合的动力学。有趣的是，细菌在整个肠道中的分布是不均匀的，细菌聚集体的生长速度比离散的个体要高得多。聚集体生长的形式表明簇集细菌的固有较高的分裂速率，而不是表面介导的聚集成簇。因此，肠道细菌相对于宿主和彼此的空间组织影响整体生长动力学，这表明空间表征将是宿主相关微生物群落组装预测模型的重要输入。我们的肠道是大量微生物的家园，它们影响健康和疾病的许多方面。虽然我们现在对肠道微生物群的组成有了很多了解，但我们对它们在人类或任何动物中的空间结构和时间动态知之甚少：微生物种群如何建立自己，生长，波动和持续。为了解决这个问题，我们利用了一种模式生物，斑马鱼，和一种新的光学成像技术，光片荧光显微镜，第一次可视化的殖民化的活的，脊椎动物肠道特定的细菌具有足够的分辨率，以量化的人口范围从几个人到数万个细菌细胞。我们的研究结果提供了前所未有的细菌生长动力学的措施，也显示了空间结构对细菌种群的影响，这只能通过直接成像来揭示。
The vertebrate intestine is home to microbial ecosystems that play key roles in host development and health. Little is known about the spatial and temporal dynamics of these microbial communities, limiting our understanding of fundamental properties, such as their mechanisms of growth, propagation, and persistence. To address this, we inoculated initially germ-free zebrafish larvae with fluorescently labeled strains of an Aeromonas species, representing an abundant genus in the zebrafish gut. Using light sheet fluorescence microscopy to obtain three-dimensional images spanning the gut, we quantified the entire bacterial load, as founding populations grew from tens to tens of thousands of cells over several hours. The data yield the first ever measurements of the growth kinetics of a microbial species inside a live vertebrate intestine and show dynamics that robustly fit a logistic growth model. Intriguingly, bacteria were nonuniformly distributed throughout the gut, and bacterial aggregates showed considerably higher growth rates than did discrete individuals. The form of aggregate growth indicates intrinsically higher division rates for clustered bacteria, rather than surface-mediated agglomeration onto clusters. Thus, the spatial organization of gut bacteria both relative to the host and to each other impacts overall growth kinetics, suggesting that spatial characterizations will be an important input to predictive models of host-associated microbial community assembly. Our intestines are home to vast numbers of microbes that influence many aspects of health and disease. Though we now know a great deal about the constituents of the gut microbiota, we understand very little about their spatial structure and temporal dynamics in humans or in any animal: how microbial populations establish themselves, grow, fluctuate, and persist. To address this, we made use of a model organism, the zebrafish, and a new optical imaging technique, light sheet fluorescence microscopy, to visualize for the first time the colonization of a live, vertebrate gut by specific bacteria with sufficient resolution to quantify the population over a range from a few individuals to tens of thousands of bacterial cells. Our results provide unprecedented measures of bacterial growth kinetics and also show the influence of spatial structure on bacterial populations, which can be revealed only by direct imaging.