Phage satellites are genetic elements that depend on helper phages for induction, packaging and transfer. To promote their lifestyles, they have evolved elegant and sophisticated strategies to inhibit phage reproduction, which will be reviewed here. We will principally focus on the convergent interference mechanisms used by phage-inducible chromosomal islands (PICIs), which are a family of satellite phages present in both Gram-positive and Gram-negative bacteria. While some PICI elements have been extensively studied for their roles in virulence and antibiotic resistance, recent studies have highlighted their relevance in controlling phage ecology and diversity. In many cases, these interference mechanisms are complemented by additional strategies that promote the preferential PICI packaging and dissemination of these elements in nature. Since the PICI-encoded mechanisms target conserved phage mechanisms, we propose here that the PICIs form part of the initial innate immune system that phages must overcome to infect their bacterial host.

中文翻译：

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超越 CRISPR-Cas 保护措施：PICI 编码的先天免疫系统保护细菌免受噬菌体捕食。

噬菌体卫星是依赖于辅助噬菌体进行诱导、包装和转移的遗传元件。为了促进他们的生活方式，他们已经进化出优雅而复杂的策略来抑制噬菌体繁殖，本文将对此进行综述。我们将主要关注噬菌体诱导染色体岛 (PICIs) 使用的会聚干扰机制，PICIs 是存在于革兰氏阳性和革兰氏阴性细菌中的卫星噬菌体家族。虽然一些 PCI 元素因其在毒力和抗生素抗性中的作用而被广泛研究，但最近的研究强调了它们在控制噬菌体生态学和多样性方面的相关性。在许多情况下，这些干扰机制得到了其他策略的补充，这些策略促进了这些元素在自然界中的优先 PCI 包装和传播。