中文摘要：本研究证实，胞外多糖-粘多糖的过量产生，使得裂解病毒能在阻碍它们复制的细菌菌群中存活。一系列在串联转移培养中，粘液型大肠杆菌MG1655菌群，可以可抗对耐受具有不同受体、需要独立突变才能产生表面耐药性的裂解噬菌体抗性的，粘液型大肠杆菌菌群MG1655来说，需要独立的表面抗性突变能够以可以维持这些噬菌体而几乎不影响它们的总密度。通过数学模型分析，提出以下假设：噬菌体可以在黏液细胞占主导的菌群中存活，这主要由于归因于从耐药的黏液状态到易感的非黏液状态的高转变率。通过对种群动态、单细胞实验以及基因组分析进行测试，结果与假设一致。本文还讨论了这些黏液型大肠杆菌普遍耐药的原因、大肠杆菌黏液型菌群中负责从黏液状态到敏感状态的的高转变率的遗传及分子机制。
外文摘要：We present evidence that phage resistance resulting from overproduction of exopolysaccharides, mucoidy, provides a general answer to the longstanding question of how lytic viruses are maintained in populations dominated by bacteria upon which they cannot replicate. In serial transfer culture, populations of mucoid Escherichia coli MG1655 that are resistant to lytic phages with different receptors, and thereby requiring independent mutations for surface resistance, are capable of maintaining these phages with little effect on their total density. Based on the results of our analysis of a mathematical model, we postulate that the maintenance of phage in populations dominated by mucoid cells can be attributed primarily to high rates of transition from the resistant mucoid states to susceptible non-mucoid states. Our tests with both population dynamic and single cell experiments as well as genomic analysis are consistent with this hypothesis. We discuss reasons for the generalized resistance of these mucoid E. coli, and the genetic and molecular mechanisms responsible for the high rate of transition from mucoid to sensitive states responsible for the maintenance of lytic phage in mucoid populations of E. coli.
外文关键词：mucoidy；E. coli；bacteriophage；phage therapy；bacterial ecology；phage ecology
作者：Chaudhry, W；Lee, E；Worthy, A；Weiss, Z；Grabowicz, M；Vega, N；Levin, B
作者单位：Emory Univ
期刊名称：FEMS MICROBIOLOGY ECOLOGY
期刊影响因子：3.675
出版年份：2020
出版刊次：10
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