Use of the surface proteins GapC and Mig of Streptococcus dysgalactiae as potential protective antigens against bovine mastitis.
Streptococcus dysgalactiae is a significant pathogen associated with bovine mastitis in lactating and nonlactating dairy cows, causing a severe inflammatory response of the mammary gland, which results in major economic losses to the dairy industry. Two proteins from S. dysgalactiae strain SDG8 were tested for their protective capacity against a homologous bacterial challenge in a dry cow model. The first was a bovine plasmin receptor protein (GapC), which shares 99.4% sequence identity to the plasmin-binding Plr protein of group A streptococci. The second protein product was Mig, a alpha2-M-, IgG-, and IgA-binding protein present on the cell surface of SDG8. We investigated the efficacy of immunization with purified recombinant forms of GapC and Mig by measuring the number of somatic cells and assessing the presence of the challenge strain in mammary secretions following challenge. In this model, we found that, although the number of quarters containing SDG8 was significantly reduced in the GapC- but not in the Mig-immunized animals, the somatic cell counts from teat secretions were significantly decreased in both the GapC and Mig vaccinates.
Bolton
Alexandra
A
Vaccine and Infectious Disease Organization, University of Saskatchewan, Saskatoon, Canada.
Song
Xin-Ming
XM
Willson
Philip
P
Fontaine
Michael C
MC
Potter
Andrew A
AA
Perez-Casal
Jose
J
D000818:Animals; D000942:Antigens, Bacterial / Q000235:genetics / Q000276:immunology* / Q000378:metabolism; D001425:Bacterial Outer Membrane Proteins / Q000235:genetics / Q000276:immunology*; D001426:Bacterial Proteins / Q000276:immunology* / Q000378:metabolism; D002417:Cattle; D002462:Cell Membrane / Q000378:metabolism*; D008414:Mastitis, Bovine / Q000382:microbiology / Q000517:prevention & control*; D022541:Streptococcal Vaccines / Q000008:administration & dosage* / Q000276:immunology; D013291:Streptococcus / Q000235:genetics / Q000276:immunology*; D014611:Vaccination; D014614:Vaccines, Synthetic / Q000235:genetics / Q000276:immunology; D000511:alpha-Macroglobulins / Q000378:metabolism
D000942:Antigens, Bacterial; D001425:Bacterial Outer Membrane Proteins; D001426:Bacterial Proteins; C469817:GapC protein, Streptococcus; D022541:Streptococcal Vaccines; D014614:Vaccines, Synthetic; D000511:alpha-Macroglobulins