Genetic Diversity and Evolutionary Research Progress of the <i>poxtA</i> Gene in <i>Enterococcus</i>

肠球菌作为重要的条件致病菌，其多重耐药性(MDR)特别是对利奈唑胺的耐药性日益严峻，对临床治疗构成重大挑战。poxtA基因作为ABC-F家族核糖体保护蛋白的编码基因，可介导肠球菌对恶唑烷酮类、氯霉素类和四环素类药物的耐药性。本文介绍了poxtA基因的发现、功能和基因环境的多样性，并系统总结了该基因在全球范围内的分布与流行特征。poxtA基因多位于质粒中，与插入元件IS1216E密切相关，且常与optrA、cfr、fexB等耐药基因共携带。poxtA基因广泛分布于人类、动物和环境来源的肠球菌中，其中屎肠球菌和粪肠球菌为主要携带菌种，属于克隆复合群17 (CC17)的菌株在临床环境中占据主导地位。需要注意的是，兽用抗生素的滥用加速了poxtA的进化与传播。需加强耐药基因的跨宿主传播监测，优化抗生素使用策略，以避免利奈唑胺耐药基因的流行。Enterococcus, as a critical opportunistic pathogen, poses escalating challenges in clinical treatment due to the rising prevalence of multidrug resistance (MDR), particularly linezolid resistance. The poxtA gene, encoding an ABC-F family protein, mediates resistance to oxazolidinones, phenicols, and tetracyclines. This article reviews the discovery, functional role, and genetic environment diversity of the poxtA gene, while systematically summarizing its global distribution and epidemiological characteristics. The poxtA gene is predominantly located on plasmids, closely associated with the insertion element IS1216E, and frequently co-carried with resistance genes such as optrA, cfr, and fexB. It is widely distributed in Enterococcus strains of human, animal, and environmental origins, with E. faecium and E. faecalis serving as primary carriers. Strains belonging to clonal complex 17 (CC17) dominate clinical settings. Notably, the misuse of veterinary antibiotics has accelerated the evolution and dissemination of poxtA. Enhanced monitoring of cross-host transmission of resistance genes and optimized antibiotic stewardship are imperative to curb the spread of linezolid resistance determinants.