致病性葡萄球菌cfr基因介导的多重耐药机制研究进展

Mechanism of cfr gene-mediated multiple drug resistance in pathogenic Staphylococcus

摘要:

葡萄球菌是临床常见致病菌及食源性致病菌，可在食品原料加工、包装及运输过程中污染食品，引起人体多种严重感染，其耐药性的不断增强对公共卫生安全产生了重大的威胁。葡萄球菌中cfr (chloramphenicol-florfenicol resistance)基因编码的甲基转移酶，可引起细菌核糖体RNA的甲基化，从而阻碍或减弱多种化学结构不同的抗生素与肽基转移酶活性中心(peptidyl transferase center，PTC)的结合，导致葡萄球菌多重耐药表型的出现。噁唑烷酮类药物−利奈唑胺是继万古霉素后治疗耐药革兰氏阳性菌所致感染的最后一道防线，cfr基因的出现大大加速了利奈唑胺耐药性的传播。cfr基因广泛分布于多种致病性葡萄球菌中，cfr基因与各类型可转移元件(质粒、转座子和整合相关元件等)密切关联的遗传环境是其广泛传播的结构基础。在cfr基因水平传播的过程中，食源性致病葡萄球菌作为中间者扮演着重要的角色。本文就近年来国内外对致病性葡萄球菌中cfr基因的分布状况、耐药机制、遗传环境、传播机制等进行综述，以期为防控致病性葡萄球菌的传播提供参考，以遏制多重耐药菌的进一步传播。

Abstract:

The foodborne pathogenic Staphylococcus is common in clinical settings. It contaminates food during the raw material processing, packaging, and transportation, thus causing a variety of serious human infections. However, the drug resistance of this species has been on the rise, posing a huge threat to public health. The methyltransferase encoded by the cfr (chloramphenicol-florfenicol resistance) gene in Staphylococcus can cause methylation of bacterial ribosomal RNA, thus blocking or weakening the binding between multiple antibiotics with different chemical structures and peptidyl transferase center (PTC). This explains the development of multiple drug resistance in this species. Linezolid, an oxazolidone, is regarded as the last line of defense after vancomycin in the treatment of infections caused by drug-resistant Gram-positive bacteria. cfr gene accelerates the spread of linezolid resistance. This gene is ubiquitous in a variety of pathogenic Staphylococcus bacteria and the close relationship of the gene with various mobile elements (plasmids, transposons, integration-related elements, etc.) is the structural basis for its wide spread. In the horizontal transfer of cfr gene, foodborne pathogenic Staphylococcus plays an important role as an intermediary. This study reviews the distribution, resistance mechanism, genetic environment, and transfer mechanism of cfr gene in pathogenic Staphylococcus, which is expected provide a reference for prevention and control of the spread of pathogenic Staphylococcus and the control of further spread of multidrug resistant bacteria.