猪链球菌SSU0468基因缺失株的构建及其对菌株形态和抗氧化能力的影响  

Construction of SSU0468 deletion strain and its effect on strain morphology and antioxidant capacity in Streptococcus suis

作　　者：董子璇 孙俊杰 代兴杨 赵文斌 王晓明 王丽平[1] DONG Zixuan;SUN Junjie;DAI Xingyang;ZHAO Wenbin;WANG Xiaoming;WANG Liping(College of Veterinary Medicine,Nanjing Agricultural University,Nanjing 210095,China)

机构地区：[1]南京农业大学动物医学院,江苏南京210095

出　　处：《畜牧与兽医》2025年第3期111-117,共7页Animal Husbandry & Veterinary Medicine

基　　金：国家自然科学基金项目(32072915)。

摘　　要：旨在初步探究猪链球菌mutT-like家族基因SSU0468的功能。采用无痕缺失方法构建猪链球菌P1/7的SSU0468基因缺失株,通过测定菌株的菌体形态、菌落溶血环大小、药物敏感性、生长速率,以及利福平突变频率和H2O2处理下的细菌存活率,比较野生株P1/7和缺失株ΔSSU0468的基本生物学特性差异。结果:经PCR和测序验证,SSU0468基因被成功敲除;与野生型菌株相比,SSU0468缺失后对菌株的溶血活性、药物敏感性无影响,但会使菌株生长变慢,并使菌体链长增加,发生丝状化;SSU0468缺失后还会导致菌株在对数期末期的突变频率显著下降(P<0.01),并且缺失株用不同浓度的H2O2处理后的存活率显著低于野生株(P<0.01)。试验结果提示SSU0468基因与猪链球菌形态以及生长相关,并可增强菌株的抗氧化能力。研究结果为揭示猪链球菌mutT-like家族的基因功能奠定基础。This study was to preliminarily investigate the functions of the mutT-like gene SSU0468 in Streptococcus suis.The SSU0468 gene deletion strain of Streptococcus suis P1/7 was constructed using the markerless genetic manipulation method.The basic biological characteristics of the mutant strainΔSSU0468 and the wild strain P1/7 were compared by determining their bacterial morphology,colony haemolysis ring size,antimicrobial agent sensitivity,growth rates,rifampicin mutation frequency,and the survival rates of the bacteria under H2O2 treatment.The results were that SSU0468 gene was successfully knocked out proved by PCR and sequencing.Compared with the wild-type strain,the deletion of SSU0468 had no effect on the haemolytic activity and drug sensitivity of the strain.However,it decreased the growth rate of the strain,but increased its chain length and resulted in a filamentous morphology.In addition,the deletion of SSU0468 resulted in a significant decrease in the mutation frequency of the strain at the end of the logarithmic phase(P<0.01),and the survival rate of the deletion strain was significantly lower than that of the wild strain following the treatment with H2O2(P<0.01).The present results suggested that the SSU0468 gene was associated with the morphology and growth of Streptococcus suis and enhanced the antioxidant capacity of the strain.This finding would facilitate our initial understanding of the function of the mutT-like family in Streptococcus suis.

关 键 词：猪链球菌 mutT-like基因 菌体形态 突变 存活率 

分 类 号：S859[农业科学—临床兽医学]