胸膜肺炎放线杆菌 tadF 基因缺失株构建及生物学特性研究  

Construction and Biological Characterization of tadF Gene Deletion Strain of Actinobacillus pleuropneumoniae

作　　者：熊威振 冀笑明 任豆豆 梁萱 魏雨婷 崔国林 许金朋 XIONG Wei-zhen;JI Xiao-ming;REN Dou-dou;LIANG Xuan;WEI Yu-ting;CUI Guo-lin;XU Jin-peng(College of Life Science and Food Engineering,Hebei University of Engineering,Handan,Hebei,056038,China;Handan Animal Disease Prevention and Control Center,Handan,Hebei,056008,China)

机构地区：[1]河北工程大学生命科学与食品工程学院,河北邯郸056038 [2]邯郸市动物疫病预防控制中心,河北邯郸056008

出　　处：《动物医学进展》2025年第2期10-16,共7页Progress In Veterinary Medicine

基　　金：河北省自然科学基金项目(C2020402050);河北省教育厅科学研究项目(BJK2024031)。

摘　　要：为探究tadF基因对胸膜肺炎放线杆菌(App)生物学特性及毒力的影响,研究基于App血清1型4074株,通过两步单交换同源重组及正负向筛选,构建tadF基因缺失株,并测定亲本株和缺失株生长曲线、侧翼基因表达水平、生物被膜形成能力、细胞黏附入侵能力和对小鼠的致病力。结果显示,成功构建tadF基因缺失株4074ΔtadF,该基因缺失对App生物被膜形成能力和侧翼基因表达水平无显著影响,但缺失株增殖速度慢于亲本株,tadF基因缺失显著降低App对PAM细胞的黏附入侵能力(P<0.05),亲本株黏附入侵能力为缺失株的1.75倍;对小鼠致病力检测结果显示,缺失株对小鼠的LD 50是亲本株的2.5倍,表明tadF基因缺失株对小鼠致病力下降。说明胸膜肺炎放线杆菌tadF基因缺失导致App增殖变慢,并降低其对细胞黏附入侵能力和对小鼠的毒力,为App黏附素作用机制研究提供参考。The tadF gene deletion strain of Actinobacillus pleuropneumoniae was constructed based on the parent strain of serotype 1 4074 by two-step single transconjugation and double homologous recombinations.The biological characteristics and virulence of tadF deletion strain were investigated by testing the growth curves,the expression level of flanking genes,the ability of biofilm formation,the ability of cellular adhesion and invasion,and the LD 50 in mice compared to the parent strain.The tadF deletion strain 4074Δ tadF was successfully constructed.The deletion of tadF caused no significant effect on the biofilm formation ability and flanking gene expression level of A.pleuropneumoniae .However,the tadF deletion strain showed a reduced growth rate.The loss of tadF reduced significantly the strain adhesion and invasion ability to PAM ( P <0.05),with the parent strain 1.75-fold to the deletion strain.The tadF deletion strain exhibited attenuated virulence of A.pleuropneumoniae in the mouse model,with the 2.5-fold LD 50 than that of the parent strain.In conclusion,the deletion of tadF gene in A.pleuropneumoniae resulted in reduced growth rate and the ability in the adhesion and invasion to PAMs,and attenuated virulence to mice.This study provides a reference for the mechanism of the adhesin function in A.pleuropneumoniae .

关 键 词：胸膜肺炎放线杆菌 tadF基因 黏附素 缺失株 生物学特性 

分 类 号：S852.61[农业科学—基础兽医学]