title: Identification and characterisation a surface-associated arginine peptidase in Streptococcus suis serotype 2.
abstract: Streptococcus suis is an important zoonotic pathogen worldwide and is responsible for disease in swine and humans. In the present study, we identified and characterised a surface-associated peptidase (abpb, amylase-binding protein B) in Streptococcus suis serotype 2 (S. suis 2) that has high hydrolytic activity towards H-Arg-pNa, with maximum activity at pH 7.0. Stimulation of RAW 264.7 macrophages with purified recombinant abpb protein triggered the release of pro-inflammatory cytokines. An abpb-deficient mutant ΔAbpb was constructed by homologous recombination to determine the role of abpb in S. suis 2. The mutant ΔAbpb showed decreased adherence to Hep-2 cells and attenuated virulence in a mouse model compared to the wild type strains. The results of the infection showed impaired bacterial growth in vivo and poor colonisation of the organs. In a protection assay, the recombinant abpb provided excellent protection against a lethal challenge of S. suis 2. Together, these findings suggest that abpb contributes to the pathogenicity of S. suis 2 and may be another target for S. suis prevention and control.
authors.affiliation: Unit of Animal Infectious Disease, National State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan 430070, China; College of Animal Science and Veterinary Medicine, Huazhong Agricultural University, Wuhan 430070, China.
authors.forename: Kaisong
authors.initials: K
authors.lastname: Huang
authors.affiliation: Unit of Animal Infectious Disease, National State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan 430070, China; College of Animal Science and Veterinary Medicine, Huazhong Agricultural University, Wuhan 430070, China.
authors.forename: Zengzhi
authors.initials: Z
authors.lastname: Yuan
authors.affiliation: Unit of Animal Infectious Disease, National State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan 430070, China; College of Animal Science and Veterinary Medicine, Huazhong Agricultural University, Wuhan 430070, China.
authors.forename: Jingtao
authors.initials: J
authors.lastname: Li
authors.affiliation: Unit of Animal Infectious Disease, National State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan 430070, China; College of Animal Science and Veterinary Medicine, Huazhong Agricultural University, Wuhan 430070, China.
authors.forename: Qiang
authors.initials: Q
authors.lastname: Zhang
authors.affiliation: Unit of Animal Infectious Disease, National State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan 430070, China; College of Animal Science and Veterinary Medicine, Huazhong Agricultural University, Wuhan 430070, China.
authors.forename: Zhongmin
authors.initials: Z
authors.lastname: Xu
authors.affiliation: Unit of Animal Infectious Disease, National State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan 430070, China; College of Animal Science and Veterinary Medicine, Huazhong Agricultural University, Wuhan 430070, China.
authors.forename: Shuxian
authors.initials: S
authors.lastname: Yan
authors.affiliation: Unit of Animal Infectious Disease, National State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan 430070, China; College of Animal Science and Veterinary Medicine, Huazhong Agricultural University, Wuhan 430070, China.
authors.forename: Anding
authors.initials: A
authors.lastname: Zhang
authors.affiliation: Unit of Animal Infectious Disease, National State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan 430070, China; College of Animal Science and Veterinary Medicine, Huazhong Agricultural University, Wuhan 430070, China. Electronic address: jml8328@126.com.
authors.forename: Meilin
authors.initials: M
authors.lastname: Jin
mesh_terms: D000818:Animals; D002473:Cell Wall / Q000201:enzymology*; D016207:Cytokines / Q000378:metabolism; D010450:Endopeptidases / Q000235:genetics* / Q000302:isolation & purification / Q000378:metabolism*; D004789:Enzyme Activation; D005260:Female; D023061:Gene Order; D056426:Genetic Loci; D005822:Genetic Vectors / Q000235:genetics; D018836:Inflammation Mediators / Q000378:metabolism; D051379:Mice; D009154:Mutation; D011994:Recombinant Proteins; D065288:Serogroup; D013290:Streptococcal Infections / Q000276:immunology / Q000378:metabolism / Q000382:microbiology; D017011:Streptococcus suis / Q000145:classification / Q000235:genetics* / Q000276:immunology / Q000378:metabolism*
chemical_list: D016207:Cytokines; D018836:Inflammation Mediators; D011994:Recombinant Proteins; D010450:Endopeptidases; C034735:arginine protease
keywords: Antigen; Arginine peptidase; Pathogenicity; Streptococcus suis; Streptococcus suis serotype 2