The vital role of CovS in the establishment of Streptococcus equi subsp.zooepidemicus virulence

作     者：XU Bin MA Zhe ZHOU Hong LIN Hui-xing FAN Hong-jie XU Bin;MA Zhe;ZHOU Hong;LIN Hui-xing;FAN Hong-jie

作者机构：MOE Joint International Research Laboratory of Animal Health and Food SafetyCollege of Veterinary MedicineNanjing Agricultural UniversityNanjing 210095P.R.China Key Laboratory of Veterinary Biological Engineering and Technology of Ministry of Agriculture and Rural AffairsNational Research Center of Veterinary Biologicals Engineering and TechnologyInstitute of Veterinary MedicineJiangsu Academy of Agricultural SciencesNanjing 210014P.R.China Jiangsu Co-innovation Center for the Prevention and Control of Important Animal Infectious Diseases and ZoonosesYangzhou UniversityYangzhou 225009P.R.China 

出 版 物：《Journal of Integrative Agriculture》 (农业科学学报（英文版）)

年 卷 期：2023年第22卷第2期

页      面：568-584页

核心收录：

学科分类：090601[农学-基础兽医学] 09[农学] 0906[农学-兽医学] 0901[农学-作物学] 

基　　金：supported by the National Key Research and Development Program of China(2021YFD1800400) the National Natural Science Foundation of China(31872480) the Jiangsu Agriculture Science and Technology Innovation Fund,China(CX(19)2020) the Priority Academic Program Development of Jiangsu Higher Education Institutions,China(PAPD)。 

主　　题：Streptococcus equi subsp.zooepidemicus covS natural variation virulence regulation 

摘      要：Streptococcus equi subsp.zooepidemicus(SEZ)is an important zoonotic agent.Here,a virulence-attenuated strain M35246 derived from natural variation of wild-type SEZ ATCC35246 was found.M35246 showed a deletion of 25contiguous genes as well as a loss-of-function mutation in covS.Subsequently,a 25-gene-deleted strain(ΔPI),a covS-mutant strain(Mcov S),and relevant complementary strains were constructed and investigated.M35246 and Mcov S were significantly less encapsulated and exhibited poorer anti-phagocytic capacity compared to wild-type SEZ.McovS was significantly more sensitive toβ-lactams,aminoglycosides,macrolides,and lincosamides than wild-type SEZ.M35246,McovS,andΔPI exhibited an increase in median lethal dose(LD_(50))in mice by 10~5,10~5,and 5 times when compared to wild-type SEZ,respectively.Neither M35246 nor McovS were isolated from mice 48 h after being challenged with approximately 2000 times the LD_(50)of wild-type SEZ.Transcriptome analysis showed that 668 significantly differentially expressed genes existed between McovS and wild-type SEZ.Numerous virulence factor-encoding genes and anabolicrelated genes in McovS that were involved in anti-phagocytosis,capsule formation,pathogenicity,and antibiotic resistance were downregulated significantly relative to the wild-type strain.This study revealed that the CovS plays a vital role in the establishment of SEZ virulence.