Yi Tian, Wang Yang, Shen Jianzhong, Wu Congming, Shen Yingbo
College of Veterinary Medicine, China Agricultural University, Beijing 100193, China.
Sheng Wu Gong Cheng Xue Bao. 2023 Jan 25;39(1):34-44. doi: 10.13345/j.cjb.220343.
Antimicrobial resistance has become a major public health issue of global concern. Conjugation is an important way for fast spreading drug-resistant plasmids, during which the type Ⅳ pili plays an important role. Type Ⅳ pili can adhere on the surfaces of host cell and other medium, facilitating formation of bacterial biofilms, bacterial aggregations and microcolonies, and is also a critical factor in liquid conjugation. PilV is an adhesin-type protein found on the tip of type Ⅳ pili encoded by plasmid R64, and can recognize the lipopolysaccharid (LPS) molecules that locate on bacterial membrane. The shufflon is a clustered inversion region that diversifies the PilV protein, which consequently affects the recipient recognition and conjugation frequency in liquid mating. The shufflon was firstly discovered on an IncI1 plasmid R64 and has been identified subsequently in plasmids IncI2, IncK and IncZ, as well as the pathogenicity island of . The shufflon consists of four segments including A, B, C, and D, and a specific recombination site named sfx. The shufflon is regulated by its downstream-located recombinase-encoding gene , and different rearrangements of the shufflon region in different plasmids were observed. Mobile colistin resistance gene , which has attracted substantial attentions recently, is mainly located in IncI2 plasmid. The shufflon may be one of the contributors to fast spread of . Herein, we reviewed the discovery, structure, function and prevalence of plasmid mediated shufflon, aiming to provide a theoretical basis on transmission mechanism and control strategy of drug-resistant plasmids.
抗菌耐药性已成为全球关注的重大公共卫生问题。接合作用是耐药质粒快速传播的重要途径，在此过程中Ⅳ型菌毛发挥着重要作用。Ⅳ型菌毛可黏附于宿主细胞表面及其他介质上，促进细菌生物膜、细菌聚集体和微菌落的形成，也是液体接合作用中的关键因素。PilV是一种黏附素型蛋白，位于质粒R64编码的Ⅳ型菌毛尖端，可识别位于细菌膜上的脂多糖（LPS）分子。改组基因簇是一个可使PilV蛋白多样化的成簇倒位区域，从而影响液体交配中的受体识别和接合频率。改组基因簇最初在IncI1质粒R64上被发现，随后在IncI2、IncK和IncZ质粒以及[具体病原体]的致病岛中也被鉴定出来。改组基因簇由包括A、B、C和D的四个区段以及一个名为sfx的特定重组位点组成。改组基因簇受其下游的重组酶编码基因调控，并且在不同质粒中观察到改组基因簇区域的不同重排。最近备受关注的可移动黏菌素耐药基因主要位于IncI2质粒中。改组基因簇可能是[可移动黏菌素耐药基因]快速传播的因素之一。在此，我们综述了质粒介导的改组基因簇的发现、结构、功能和流行情况，旨在为耐药质粒的传播机制和控制策略提供理论依据。
