title: (p)ppGpp synthetases regulate the pathogenesis of zoonotic Streptococcus suis.
abstract: (p)ppGpp-mediated stringent response is one of the main adaption mechanism in bacteria, and the ability to adapt to environment is linked to the pathogenesis of bacterial pathogens. In the zoonotic pathogen Streptococcus suis, there are two (p)ppGpp synthetases, RelA and RelQ. To investigate the regulatory functions of (p)ppGpp/(p)ppGpp synthetases on the pathogenesis of S. suis, the phenotypes of the [(p)ppGpp(0)] mutant ΔrelAΔrelQ and its parental strain were compared. Light and electron microscopy observation showed that the mutant strain had a longer chain-length than its parental strain. Disruption of relA and relQ led to decreased adhesive and invasive ability to HEp-2 cells, and increased sensitivity to the blood killing and phagocytosis. Mouse infection experiments showed that the mutant strain was attenuated and easier to be cleaned up in vivo. Quantitative reverse transcription PCR (qRT-PCR) analysis indicated that the expressions of virulence related genes involving in morphology and virulence were down-regulated in the mutant strain. Our study demonstrated that the (p)ppGpp synthetases or (p)ppGpp can regulate the pathogenesis of this important zoonotic pathogen.
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; Hubei Key Laboratory of Animal Embryo and Molecular Breeding, Institute of Animal and Veterinary Science, Hubei Academy of Agricultural Sciences, Wuhan 430064, China.
authors.forename: Tengfei
authors.initials: T
authors.lastname: Zhang
authors.affiliation: State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan 430070, China.
authors.forename: Zhipeng
authors.initials: Z
authors.lastname: Su
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: Lu
authors.initials: L
authors.lastname: Li
authors.affiliation: State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan 430070, China.
authors.forename: Dong
authors.initials: D
authors.lastname: Wang
authors.affiliation: State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan 430070, China.
authors.forename: Ran
authors.initials: R
authors.lastname: Xiao
authors.affiliation: State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan 430070, China.
authors.forename: Muye
authors.initials: M
authors.lastname: Teng
authors.affiliation: State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan 430070, China.
authors.forename: Meifang
authors.initials: M
authors.lastname: Tan
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. Electronic address: rzhou@mail.hzau.edu.cn.
authors.forename: Rui
authors.initials: R
authors.lastname: Zhou
mesh_terms: D000818:Animals; D001422:Bacterial Adhesion; D001770:Blood Bactericidal Activity; D002460:Cell Line; D004195:Disease Models, Animal; D004705:Endocytosis; D004847:Epithelial Cells / Q000382:microbiology; D017353:Gene Deletion; D020869:Gene Expression Profiling; D015964:Gene Expression Regulation, Bacterial; D006801:Humans; D008025:Ligases / Q000235:genetics / Q000378:metabolism*; D051379:Mice; D050296:Microbial Viability; D008853:Microscopy; D010587:Phagocytosis; D060888:Real-Time Polymerase Chain Reaction; D013290:Streptococcal Infections / Q000276:immunology / Q000382:microbiology / Q000473:pathology; D017011:Streptococcus suis / Q000166:cytology / Q000235:genetics* / Q000472:pathogenicity*; D014774:Virulence; D037521:Virulence Factors / Q000032:analysis / Q000235:genetics
chemical_list: D037521:Virulence Factors; D008025:Ligases; C028812:guanosine 3',5'-polyphosphate synthetases
keywords: (p)ppGpp synthetases; Pathogenesis; Streptococcus suis; Stringent response