Probing Prokaryotic Social Behaviors with Bacterial "Lobster Traps"
Probing Prokaryotic Social Behaviors with Bacterial "Lobster Traps"
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DOI：
10.1128/mbio.00202-10
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发表时间：
2010-09-01
期刊：
影响因子：
6.4
通讯作者：
Shear, Jason B.
中科院分区：
文献类型：
--
作者：
Connell, Jodi L.;Wessel, Aimee K.;Shear, Jason B.
细菌是社会有机体，当成群存在时表现出不同的行为/表型。这些行为包括构建耐抗生素固着生物膜群落以及与小信号分子通信（群体感应[QS]）的能力。我们对生物膜和 QS 的理解主要源于对含有大量细胞（通常超过 10(8) 个细菌）的细菌群落的体外研究；然而，在自然界中，细菌通常存在于由少得多的细胞组成的密集簇（聚集体）中。事实上，含有 10(1) 至 10(5) 个细胞的细菌簇对于许多细菌病原体的传播非常重要。在这里，我们描述了一种进行机制研究的通用策略，以探究高密度细菌簇中控制抗生素耐药性和 QS 介导的毒力因子产生的分子过程。该策略涉及将单个细菌封闭在三维皮升级微腔（称为细菌“龙虾陷阱”）内，该微腔由可渗透营养物、废物和其他生物活性小分子的壁限定。在这些陷阱中，细菌通常分裂成极其密集（10（12）细胞/毫升）的克隆群体，其最终群体大小与在自然存在的细菌簇中观察到的相似。使用这些陷阱，我们提供了强有力的证据，证明在低细胞数/高密度细菌簇内，QS 不仅受到细菌密度的调节，而且还受到周围介质的群体大小和流速的调节。我们还证明，抗生素耐药性随着细胞密度的增加而发展，只有大约 150 种限制性细菌表现出与生物膜细菌类似的抗生素耐药性表型。总之，这些发现为低细胞数/高密度细菌群体的临床相关表型提供了重要见解。 重要性 原核生物是能够协调群体行为的社会生物，包括构建抗生素抗性生物膜和与小信号分子（群体感应 [QS]）通信的能力。尽管人们在了解生物膜形成和 QS 方面付出了巨大努力，但很少有研究在高密度/低细胞数量群体中检验这些过程。此类研究具有临床意义，因为许多感染是由小细菌群引发的。
Bacteria are social organisms that display distinct behaviors/phenotypes when present in groups. These behaviors include the abilities to construct antibiotic-resistant sessile biofilm communities and to communicate with small signaling molecules (quorum sensing [QS]). Our understanding of biofilms and QS arises primarily from in vitro studies of bacterial communities containing large numbers of cells, often greater than 10(8) bacteria; however, in nature, bacteria often reside in dense clusters (aggregates) consisting of significantly fewer cells. Indeed, bacterial clusters containing 10(1) to 10(5) cells are important for transmission of many bacterial pathogens. Here, we describe a versatile strategy for conducting mechanistic studies to interrogate the molecular processes controlling antibiotic resistance and QS-mediated virulence factor production in high-density bacterial clusters. This strategy involves enclosing a single bacterium within three-dimensional picoliter-scale microcavities (referred to as bacterial "lobster traps") defined by walls that are permeable to nutrients, waste products, and other bioactive small molecules. Within these traps, bacteria divide normally into extremely dense (10(12) cells/ml) clonal populations with final population sizes similar to that observed in naturally occurring bacterial clusters. Using these traps, we provide strong evidence that within low-cell-number/high-density bacterial clusters, QS is modulated not only by bacterial density but also by population size and flow rate of the surrounding medium. We also demonstrate that antibiotic resistance develops as cell density increases, with as few as similar to 150 confined bacteria exhibiting an antibiotic-resistant phenotype similar to biofilm bacteria. Together, these findings provide key insights into clinically relevant phenotypes in low-cell-number/high-density bacterial populations.IMPORTANCE Prokaryotes are social organisms capable of coordinated group behaviors, including the abilities to construct antibiotic-resistant biofilms and to communicate with small signaling molecules (quorum sensing [QS]). While there has been significant effort devoted to understanding biofilm formation and QS, few studies have examined these processes in high-density/low-cell-number populations. Such studies have clinical significance, as many infections are initiated by small bacterial populations (