Cell Membrane Immunogens of a Biofilm-producing Staphylococcus aureus Isolate Adjuvanted with Bacterial Chromosomal DNA Are Protective in a Mouse Mastitis Model

Abstract

Biofilm-forming staphylococci have been implicated in persistent bovine udder infections. Prophylactic potential of Staphylococcus aureus biofilm phenotype-associated immunogens in mouse models of systemic, but not intramammary infections has been demonstrated. In the present study, the authors observed protection in a murine model of intramammary infection by two subcutaneous injections at four-week interval of biofilm-forming S. aureus cell membrane antigens mixed with homologous chromosomal DNA as adjuvant, when challenged after eight weeks by intramammary route with 10⁶ CFUs of biofilm-forming S. aureus. The immunoblot analysis indicated that five biofilm phenotype-associated polypeptides, 105, 90, 46, 36, and 33 kDa were more important than others as immunogens. These findings would be useful in selection of biofilm phenotype-associated S. aureus immunogen(s) for a candidate vaccine against bovine mastitis.

Keywords: Staphylococcus aureus, biofilms, cell membrane antigens, chromosomal DNA adjuvant, murine mastitis model