title: Evaluation of a novel chimeric B cell epitope-based vaccine against mastitis induced by either Streptococcus agalactiae or Staphylococcus aureus in mice.
abstract: To construct a universal vaccine against mastitis induced by either Streptococcus agalactiae or Staphylococcus aureus, the B cell epitopes of the surface immunogenic protein (Sip) from S. agalactiae and clumping factor A (ClfA) from S. aureus were analyzed and predicted. sip-clfA, a novel chimeric B cell epitope-based gene, was obtained by overlap PCR, and then the recombinant Sip-ClfA (rSip-ClfA) was expressed and purified. rSip-ClfA and inactivated S. agalactiae and S. aureus were formulated into different vaccines with mineral oil as the adjuvant and evaluated in mouse models. The rSip-ClfA vaccination induced immunoglobulin G (IgG) titers higher than those seen in groups immunized with inactivated bacteria. Furthermore, the response to rSip-ClfA immunization was characterized as having a dominant IgG1 subtype, whereas both bacterial immunizations produced similar levels of IgG1 and IgG2a. The antiserum capacities for opsonizing adhesion and phagocytosis were significantly greater in the rSip-ClfA immunization group than in the killed-bacterium immunization groups (P < 0.05). The immunized lactating mice were challenged with either S. agalactiae or S. aureus via the intramammary route. At 24 h postinfection, the numbers of bacteria recovered from the mammary glands in the rSip-ClfA group were >5-fold lower than those in both inactivated-bacterium groups (P < 0.01). Histopathological examination of the mammary glands showed that rSip-ClfA immunization provided better protection of mammary gland tissue integrity against both S. agalactiae and S. aureus challenges. Thus, the recombinant protein rSip-ClfA would be a promising vaccine candidate against mastitis induced by either S. agalactiae or S. aureus.
authors.affiliation: The State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan 430070, China.
authors.forename: Haiyang
authors.initials: H
authors.lastname: Xu
authors.forename: Changmin
authors.initials: C
authors.lastname: Hu
authors.forename: Rui
authors.initials: R
authors.lastname: Gong
authors.forename: Yingyu
authors.initials: Y
authors.lastname: Chen
authors.forename: Ningning
authors.initials: N
authors.lastname: Ren
authors.forename: Ganwen
authors.initials: G
authors.lastname: Xiao
authors.forename: Qian
authors.initials: Q
authors.lastname: Xie
authors.forename: Minmin
authors.initials: M
authors.lastname: Zhang
authors.forename: Qin
authors.initials: Q
authors.lastname: Liu
authors.forename: Aizhen
authors.initials: A
authors.lastname: Guo
authors.forename: Huanchun
authors.initials: H
authors.lastname: Chen
mesh_terms: D000276:Adjuvants, Immunologic / Q000008:administration & dosage; D000818:Animals; D000907:Antibodies, Bacterial / Q000097:blood; D058491:Bacterial Load; D001426:Bacterial Proteins / Q000235:genetics / Q000276:immunology; D002417:Cattle; D003030:Coagulase / Q000235:genetics / Q000276:immunology; D018985:Epitopes, B-Lymphocyte / Q000235:genetics / Q000276:immunology*; D005260:Female; D006651:Histocytochemistry; D007074:Immunoglobulin G / Q000097:blood; D008321:Mammary Glands, Animal / Q000382:microbiology; D008413:Mastitis / Q000276:immunology / Q000382:microbiology / Q000517:prevention & control*; D051379:Mice; D008807:Mice, Inbred BALB C; D008899:Mineral Oil / Q000008:administration & dosage; D009895:Opsonin Proteins / Q000097:blood; D010587:Phagocytosis; D011994:Recombinant Proteins / Q000235:genetics / Q000276:immunology; D013209:Staphylococcal Vaccines / Q000008:administration & dosage / Q000235:genetics / Q000276:immunology*; D013211:Staphylococcus aureus / Q000235:genetics / Q000276:immunology* / Q000302:isolation & purification; D013292:Streptococcus agalactiae / Q000235:genetics / Q000276:immunology* / Q000302:isolation & purification; D014614:Vaccines, Synthetic / Q000008:administration & dosage / Q000235:genetics / Q000276:immunology
chemical_list: D000276:Adjuvants, Immunologic; D000907:Antibodies, Bacterial; D001426:Bacterial Proteins; C515944:ClfA protein, Staphylococcus aureus; D003030:Coagulase; D018985:Epitopes, B-Lymphocyte; D007074:Immunoglobulin G; D009895:Opsonin Proteins; D011994:Recombinant Proteins; D013209:Staphylococcal Vaccines; D014614:Vaccines, Synthetic; D008899:Mineral Oil