Identification of immunoreactive extracellular proteins of Streptococcus agalactiae in bovine mastitis.
Streptococcus agalactiae is a common pathogen that causes bovine mastitis. The aims of this study were to evaluate the antibody response against S. agalactiae extracellular proteins in the whey and serum of naturally infected bovines and to identify possible immunodominant extracellular antigens. IgG1 antibodies against S. agalactiae extracellular proteins were elevated in the whey and serum of naturally infected bovines. In the whey, the levels of IgG1 specific for S. agalactiae extracellular proteins were similar in infected and noninfected milk quarters from the same cow, and the production of antibodies specific for S. agalactiae extracellular proteins was induced only by infection with this bacterium. The immunoreactivity of extracellular proteins with bovine whey was clearly different in infected versus control animals. Group B protective surface protein and 5'-nucleotidase family protein were 2 major immunoreactive proteins that were detected only in the whey of infected cows, suggesting that these proteins may be important in the pathogenesis of S. agalactiae-induced mastitis. This information could be used to diagnose S. agalactiae infection. In addition, these antigens may be useful as carrier proteins for serotype-specific polysaccharides in conjugate vaccines.
Trigo
Gabriela
G
Instituto de Ciências Biomédicas de Abel Salazar, Universidade do Porto, Porto, Portugal.
Ferreira
Paula
P
Ribeiro
Niza
N
Dinis
Márcia
M
Andrade
Elva Bonifácio
EB
Melo-Cristino
José
J
Ramirez
Mário
M
Tavares
Delfina
D
D015720:5'-Nucleotidase / Q000276:immunology*; D000818:Animals; D000907:Antibodies, Bacterial / Q000032:analysis / Q000097:blood; D000942:Antigens, Bacterial / Q000276:immunology*; D000954:Antigens, Surface / Q000276:immunology*; D001426:Bacterial Proteins / Q000276:immunology*; D002417:Cattle; D005260:Female; D007074:Immunoglobulin G / Q000032:analysis / Q000097:blood; D008414:Mastitis, Bovine / Q000276:immunology* / Q000382:microbiology; D013290:Streptococcal Infections / Q000276:immunology / Q000382:microbiology / Q000662:veterinary*; D013292:Streptococcus agalactiae / Q000235:genetics / Q000276:immunology* / Q000302:isolation & purification
D000907:Antibodies, Bacterial; D000942:Antigens, Bacterial; D000954:Antigens, Surface; D001426:Bacterial Proteins; D007074:Immunoglobulin G; C447143:group B protective surface protein, S agalactiae; D015720:5'-Nucleotidase