鲍曼不动杆菌CRISPR相关蛋白Csy1对耐药性和毒力的影响  

The effect of CRISPR-associated protein Csy1 on drug resistance and virulence of Acinetobacter baumannii

作　　者：李梦影 孙晓利 王宇航[1] 杨洁 郑文浩 何香玲 季诗雨 焦红梅[1] 郭停停 李国才[1] LI Mengying;SUN Xiaoli;WANG Yuhang;YANG Jie;ZHENG Wenhao;HE Xiangling;JI Shiyu;JIAO Hongmei;GUO Tingting;LI Guocai(Jiangsu Key Laboratory of Non-Coding RNA/Jiangsu Co-Innovation Center for Prevention and Control of Important Animal Infectious Diseases Zoonoses/College of Medicine,Yangzhou University,Yangzhou 225009,China)

机构地区：[1]扬州大学医学院/江苏省非编码RNA重点实验室/江苏省动物重要疫病与人兽共患病防控协同创新中心,江苏扬州225009

出　　处：《扬州大学学报（农业与生命科学版）》2021年第1期35-40,共6页Journal of Yangzhou University：Agricultural and Life Science Edition

基　　金：国家自然科学基金资助项目(82073611、82002186、81471906)。

摘　　要：采用RecAb同源重组系统,将携带I-Fb亚型CRISPR-Cas系统的鲍曼不动杆菌临床分离株AB43的csy1基因敲除,观察野生株(AB43)和缺失株(AB43Δcsy1)的耐药性、生物膜形成以及小鼠致死率等生物学性状变化,并通过转录组测序分析两者间的差异表达基因。与野生株相比,csy1的缺失显著提高突变株的耐药水平和体外形成生物膜的能力,且AB43Δcsy1感染组小鼠的存活率与AB43感染组相比显著降低,提示其毒力有所提高。RNA-seq分析结果显示,csy1的缺失能影响细菌与抗生素耐药性、毒力以及代谢相关基因的表达,推测是引起AB43Δcsy1表型变化的主要原因。结果提示Csy1蛋白可通过调节自身基因表达抑制鲍曼不动杆菌的耐药性、生物膜形成及致病性。这说明创造有利于维持CRISPR-Cas系统的环境,保证CRISPR-Cas系统阳性菌株处于进化优势地位,使鲍曼不动杆菌保持低毒力和抗生素敏感状态。The csy1 gene of Acinetobacter baumannii clinical isolate AB43, carrying the I-Fb subtype CRISPR-Cas system, was knocked out using RecAb homologous recombination system. Then the phenotypic changes such as drug resistance, biofilm formation, and survival rate of mice infected with the wild-type strain(AB43) and the deletion mutant(AB43Δcsy1) were detected. Further, the differentially expressed genes were analyzed by transcriptome sequencing(RNA-seq). Compared with AB43, the deletion of csy1 significantly increased the resistance level and biofilm formation ability of AB43Δcsy1 in vitro. Moreover, the survival rate of mice in the AB43Δcsy1 infection group was significantly lower than the AB43 infection group, suggesting that the virulence of the mutant strain had increased. RNA-seq analysis results showed that csy1 affected the expression of a series of genes related to antibiotic resistance, virulence and metabolic processes, which supposed to be the main reason for the phenotypic changes of AB43Δcsy1. The above results indicated that Csy1 can inhibit the drug resistance, biofilm formation and pathogenicity of A.baumannii by regulating its own gene expression. Therefore, creating an environment conducive to maintaining the CRISPR-Cas system and ensuring that the positive strains of the CRISPR-Cas system in an evolutionary dominant position can enable A.baumannii to maintain a low virulence and antibiotic sensitivity.

关 键 词：鲍曼不动杆菌 CRISPR-Cas系统 Csy1蛋白 耐药性 毒力 

分 类 号：Q936[生物学—微生物学]