Bacterial plasmids are extrachromosomal genetic elements that often carry antimicrobial resistance (AMR) genes and genes encoding increased virulence and can be transmissible among bacteria by conjugation. One key group of plasmids is the incompatibility group I1 (IncI1) plasmids, which have been isolated from multiple Enterobacteriaceae of food animal origin and clinically ill human patients. The IncI group of plasmids were initially characterized due to their sensitivity to the filamentous bacteriophage If1. Two prototypical IncI1 plasmids, R64 and pColIb-P9, have been extensively studied, and the plasmids consist of unique regions associated with plasmid replication, plasmid stability/maintenance, transfer machinery apparatus, single-stranded DNA transfer, and antimicrobial resistance. IncI1 plasmids are somewhat unique in that they encode two types of sex pili, a thick, rigid pilus necessary for mating and a thin, flexible pilus that helps stabilize bacteria for plasmid transfer in liquid environments. A key public health concern with IncI1 plasmids is their ability to carry antimicrobial resistance genes, including those associated with critically important antimicrobials used to treat severe cases of enteric infections, including the third-generation cephalosporins. Because of the potential importance of these plasmids, this review focuses on the distribution of the plasmids, their phenotypic characteristics associated with antimicrobial resistance and virulence, and their replication, maintenance, and transfer.

中文翻译：

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不相容组 I1 (IncI1) 质粒：它们的遗传学、生物学和公共卫生相关性

细菌质粒是染色体外遗传元件，通常携带抗菌素耐药性 (AMR) 基因和编码增加毒力的基因，并且可以通过结合在细菌之间传播。一组关键的质粒是不相容组 I1 (IncI1) 质粒，它已从多种肠杆菌科细菌中分离出来。食用动物来源和临床患病的人类患者。由于对丝状噬菌体 If1 的敏感性，最初对 IncI 组质粒进行了表征。两个原型 IncI1 质粒 R64 和 pColIb-P9 已被广泛研究，这些质粒由与质粒复制、质粒稳定性/维持、转移机械装置、单链 DNA 转移和抗菌素耐药性相关的独特区域组成。IncI1 质粒有些独特之处在于它们编码两种类型的性菌毛，一种是交配所必需的厚而硬的菌毛，另一种是有助于稳定细菌以在液体环境中转移质粒的薄而柔韧的菌毛。IncI1质粒的一个关键公共卫生问题是它们携带抗菌素耐药基因的能力，包括那些与用于治疗严重肠道感染病例的极其重要的抗菌药物相关的药物，包括第三代头孢菌素。由于这些质粒的潜在重要性，本综述重点关注质粒的分布、它们与抗菌素耐药性和毒力相关的表型特征，以及它们的复制、维持和转移。