肺炎克雷伯菌和鲍曼不动杆菌Ⅵ型分泌系统研究进展

Advances in Klebsiella pneumoniae and Acinetobacter baumannii type Ⅵ secretion systems

鲍曼不动杆菌(Acinetobacter baumannii,Aba)和肺炎克雷伯菌(Klebsiella pneumoniae,Kpn)等条件致病性革兰氏阴性菌导致的院内感染,给医疗卫生管理和人类生命健康带来极大挑战。多重耐药菌株的播散及细菌毒力的增加亟需新的治疗策略应对。Ⅵ型分泌系统(typeⅥsecretion system,T6SS)是多种革兰氏阴性菌编码的一种保守"分泌装置",能够以接触依赖的方式将效应蛋白注射到其他原核或真核细胞中,实现抗菌和抗宿主功能,与细菌的环境适应性、竞争力及宿主内定植能力密切相关。T6SS基因簇由核心基因、效应基因以及相关基因组成,其编码的T6SS效应蛋白存在高度多样性,在病原菌感染过程中发挥着重要作用。本文旨在对鲍曼不动杆菌和肺炎克雷伯菌T6SS介导的细菌间竞争、宿主内定植、接合质粒相互作用以及T6SS表达调控等方面的研究进展进行综述,为未来研究T6SS相关抗菌活性、毒力和耐药等提供理论基础。

Nosocomial infections caused by gram-negative opportunistic pathogens,including Acinetobacter baumannii(A.baumannii)and Klebsiella pneumoniae(K.pneumoniae),pose a great challenge to health care management and human health.New treatment strategies are urgently needed to tackle with the spread of multi-drug resistant strains and the increase in bacterial virulence.TypeⅥsecretion system(T6SS),a conservative secretory apparatus encoded in a variety of gram-negative bacteria,can inject effectors into other prokaryotic or eukaryotic cells in a contact-dependent manner to achieve antibacterial and anti-host properties.It is closely related to the environmental adaptability,competitiveness and colonization ability of bacteria in hosts.The T6SS gene cluster is composed of core genes,effector genes and associated genes,and the effectors encoded by it are highly diverse and play an important role in pathogen infection.This review summarized the advances in A.baumannii and K.pneumoniae T6SS in terms of competition,host colonization,interaction between conjugative plasmids and expression regulation,aiming to provide reference for future study on T6SS-related antimicrobial activity,virulence and resistance.