【摘要】 四环素类抗生素广泛应用于临床、动物养殖及农业等领域，但其长期滥用导致耐药基因快速增殖，耐药菌株呈多宿主分布。替加环素作为第三代四环素类药物，是治疗多重耐药革兰氏阴性菌感染的关键药物，而tet(X)家族耐药基因介导的酶促灭活机制严重削弱了其临床价值。目前已鉴定出tet(X1)至tet(X57)等50余种变体，且耐药谱持续扩展。tet(X)家族的部分变体通过氨基酸突变优化蛋白结构，使细菌对替加环素的耐药性增强；并可通过插入序列及多种不相容性质粒等可移动遗传元件跨物种传播；常与其他耐药基因形成多重耐药基因簇；tet(X)家族阳性菌株已广泛分布于畜禽、野生动物、环境、食品及人类临床样本，呈现全球扩散趋势，形成“动物-环境-人类”的传播链条。本文从tet(X)家族的作用机制、分子分类、遗传背景及全球分布特征进行综述，为制定耐药防控策略提供理论依据。更多还原

【Abstract】 Tetracycline antibiotics are widely used in clinical, animal husbandry,and agriculture fields,but their long-term abuse leads to rapid proliferation of resistance genes and multi-host distribution of resistant strains. Tigecycline,as a third-generation tetracycline drug,is a key drug for treating multidrug-resistant Gram negative bacterial infections. However,the enzymatic inactivation mechanism mediated by tet(X) family resistance genes severely weakens its clinical value. At present,more than 50 variants including tet(X1) to tet(X57) have been identified,and the resistance spectrum continues to expand. Partial variants of the tet(X) family optimize protein structure through amino acid mutations,enhancing bacterial resistance to tigecycline;And it can be spread across species through the insertion of sequences and various incompatible plasmids and other mobile genetic elements;it often forms multiple resistance gene clusters with other resistance genes;the tet(X) family positive strain has been widely distributed in livestock,wildlife,environment,food,and human clinical samples,showing a global spread trend and forming a transmission chain of “animal-environment-human”. This article reviews the mechanism of action,molecular classification, genetic background,and global distribution characteristics of the tet(X) family,providing a theoretical basis for formulating drug resistance prevention and control strategies.更多还原