title: Mac Protein is not an Essential Virulence Factor for the Virulent Reference Strain Streptococcus suis P1/7.
abstract: Streptococcus suis is a major pathogen of pigs and also an important zoonotic agent for humans. A S. suis protein containing Mac-1 domain (designated Mac) is a protective antigen, exclusively cleaves porcine IgM, and contributes to complement evasion with the presence of high titers of specific porcine anti-S. suis IgM, but its role in S. suis virulence has not been investigated in natural healthy host without specific IgM. In this study, a mac deletion mutant was constructed by homologous recombination in S. suis serotype 2 virulent reference strain P1/7. Deletion of mac did not significantly influence phagocytosis or intracellular survival within murine macrophages RAW264.7, or the oxidative-burst induction of RAW264.7 and murine neutrophils. Furthermore, the mutant is as virulent as the wild-type strain in pig, mouse, and zebrafish infection models. Our data suggest that Mac is not essential for S. suis virulence in strain P1/7 in natural healthy host without specific IgM, and the immunogenicity of Mac does not appear to correlate with its significance for virulence.
authors.affiliation: College of Veterinary Medicine, Nanjing Agricultural University, No.1 Weigang Road, Nanjing, 210095, China.|Key Lab of Animal Bacteriology, Ministry of Agriculture, Nanjing, 210095, China.|OIE Reference Laboratory for Swine Streptococcosis, Nanjing, 210095, China.
authors.forename: Genhui
authors.initials: G
authors.lastname: Xiao
authors.affiliation: College of Veterinary Medicine, Nanjing Agricultural University, No.1 Weigang Road, Nanjing, 210095, China.|Key Lab of Animal Bacteriology, Ministry of Agriculture, Nanjing, 210095, China.|OIE Reference Laboratory for Swine Streptococcosis, Nanjing, 210095, China.
authors.forename: Zongfu
authors.initials: Z
authors.lastname: Wu
authors.affiliation: College of Veterinary Medicine, Nanjing Agricultural University, No.1 Weigang Road, Nanjing, 210095, China.|Key Lab of Animal Bacteriology, Ministry of Agriculture, Nanjing, 210095, China.|OIE Reference Laboratory for Swine Streptococcosis, Nanjing, 210095, China.
authors.forename: Shouming
authors.initials: S
authors.lastname: Zhang
authors.affiliation: College of Veterinary Medicine, Nanjing Agricultural University, No.1 Weigang Road, Nanjing, 210095, China.|Key Lab of Animal Bacteriology, Ministry of Agriculture, Nanjing, 210095, China.|OIE Reference Laboratory for Swine Streptococcosis, Nanjing, 210095, China.
authors.forename: Huanyu
authors.initials: H
authors.lastname: Tang
authors.affiliation: College of Veterinary Medicine, Nanjing Agricultural University, No.1 Weigang Road, Nanjing, 210095, China.|Key Lab of Animal Bacteriology, Ministry of Agriculture, Nanjing, 210095, China.|OIE Reference Laboratory for Swine Streptococcosis, Nanjing, 210095, China.
authors.forename: Fengqiu
authors.initials: F
authors.lastname: Wang
authors.affiliation: College of Veterinary Medicine, Nanjing Agricultural University, No.1 Weigang Road, Nanjing, 210095, China. lucp@njau.edu.cn.|Key Lab of Animal Bacteriology, Ministry of Agriculture, Nanjing, 210095, China. lucp@njau.edu.cn.|OIE Reference Laboratory for Swine Streptococcosis, Nanjing, 210095, China. lucp@njau.edu.cn.
authors.forename: Chengping
authors.initials: C
authors.lastname: Lu
mesh_terms: D000818:Animals; D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism*; D005260:Female; D007075:Immunoglobulin M / Q000276:immunology; D008264:Macrophages / Q000276:immunology / Q000382:microbiology; D051379:Mice; D008807:Mice, Inbred BALB C; D010587:Phagocytosis; D000067996:RAW 264.7 Cells; D013290:Streptococcal Infections / Q000276:immunology / Q000382:microbiology / Q000662:veterinary*; D017011:Streptococcus suis / Q000235:genetics / Q000378:metabolism / Q000472:pathogenicity*; D013552:Swine; D013553:Swine Diseases / Q000276:immunology / Q000382:microbiology*; D014774:Virulence; D037521:Virulence Factors / Q000235:genetics / Q000378:metabolism*; D015027:Zebrafish
chemical_list: D001426:Bacterial Proteins; D007075:Immunoglobulin M; D037521:Virulence Factors