title: The CodY regulator is essential for virulence in Streptococcus suis serotype 2.
abstract: The main role of CodY, a global regulatory protein in most low G + C gram-positive bacteria, is in transcriptional repression. To study the functions of CodY in Streptococcus suis serotype 2 (S. suis 2), a mutant codY clone named ∆codY was constructed to explore the phenotypic variation between ∆codY and the wild-type strain. The result showed that the codY mutation significantly inhibited cell growth, adherence and invasion ability of S. suis 2 to HEp-2 cells. The codY mutation led to decreased binding of the pathogen to the host cells, easier clearance by RAW264.7 macrophages and decreased growth ability in fresh blood of Cavia porcellus. The codY mutation also attenuated the virulence of S. suis 2 in BALB/c mice. Morphological analysis revealed that the codY mutation decreased the thickness of the capsule of S. suis 2 and changed the surface structures analylized by SDS-PAGE. Finally, the codY mutation altered the expressions of many virulence related genes, including sialic acid synthesis genes, leading to a decreased sialic acid content in capsule. Overall, mutation of codY modulated bacterial virulence by affecting the growth and colonization of S. suis 2, and at least via regulating sialic acid synthesis and capsule thickness.
authors.affiliation: State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan 430070, China.|Shanghai Laboratory Animal Research Center, Shanghai 201203, China.
authors.forename: Liping
authors.initials: L
authors.lastname: Feng
authors.affiliation: State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan 430070, China.
authors.forename: Jiawen
authors.initials: J
authors.lastname: Zhu
authors.affiliation: State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan 430070, China.
authors.forename: Haitao
authors.initials: H
authors.lastname: Chang
authors.affiliation: State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan 430070, China.
authors.forename: Xiaoping
authors.initials: X
authors.lastname: Gao
authors.affiliation: Shanghai Laboratory Animal Research Center, Shanghai 201203, China.
authors.forename: Cheng
authors.initials: C
authors.lastname: Gao
authors.affiliation: Shanghai Laboratory Animal Research Center, Shanghai 201203, China.
authors.forename: Xiaofeng
authors.initials: X
authors.lastname: Wei
authors.affiliation: Hubei key laboratory of Animal Embryo and Molecular Breeding, Institute of Animal Husbandry and Veterinary Sciences, Hubei Academy of Agricultural Sciences, Wuhan 430070, China.
authors.forename: Fangyan
authors.initials: F
authors.lastname: Yuan
authors.affiliation: State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan 430070, China.|Cooperative Innovation Center of Sustainable Pig Production, Wuhan 430070, China.
authors.forename: Weicheng
authors.initials: W
authors.lastname: Bei
mesh_terms: D000818:Animals; D001422:Bacterial Adhesion / Q000235:genetics; D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism*; D002460:Cell Line; D004195:Disease Models, Animal; D005260:Female; D015964:Gene Expression Regulation, Bacterial; D006461:Hemolysis; D008264:Macrophages / Q000382:microbiology / Q000502:physiology; D051379:Mice; D050296:Microbial Viability / Q000235:genetics / Q000276:immunology; D009154:Mutation; D010587:Phagocytosis / Q000235:genetics / Q000276:immunology; D012097:Repressor Proteins / Q000235:genetics / Q000378:metabolism*; D065288:Serogroup; D013290:Streptococcal Infections / Q000382:microbiology; D017011:Streptococcus suis / Q000145:classification / Q000302:isolation & purification / Q000472:pathogenicity / Q000502:physiology*; D013552:Swine; D014774:Virulence / Q000235:genetics
chemical_list: D001426:Bacterial Proteins; D012097:Repressor Proteins