Streptococcus uberis whole-cell antigens (S. uberis antigens)

Streptococcus uberis is a Gram-positive, environmental pathogen that serves as a leading cause of clinical and subclinical mastitis in dairy cattle worldwide (Leigh, 1999). The whole-cell antigens of S. uberis encompass the entire suite of molecular components—including surface proteins like adhesion proteins (Sua), capsule polysaccharides, and lipoteichoic acids—presented by the inactivated bacterium (Ward et al., 2009). These antigens are primarily targeted in the development of bacterin vaccines, which aim to elicit a robust humoral immune response to prevent bacterial colonization and invasion of the mammary gland (Collado et al., 2018). Upon administration, the host immune system recognizes these diverse epitopes, stimulating the production of antibodies that facilitate opsonization and subsequent clearance by neutrophils (Schukken et al., 2011). This immunological approach is intended to reduce the severity of clinical mastitis and lower the somatic cell count in milk, thereby improving animal welfare and dairy productivity. However, the significant genetic diversity among S. uberis strains remains a major hurdle, as whole-cell antigens from one strain may not provide universal protection against all environmental variants (Leigh, 1999).

Other names

Streptococcus uberis bacterinS. uberis inactivated whole cellsStreptococcus uberis surface antigens

Induction of active immunity through the presentation of multiple bacterial epitopes to the host immune system, leading to the production of specific antibodies (IgG1 and IgG2) that enhance opsonization and phagocytic killing of the bacteria by mammary gland neutrophils (Collado et al., 2018; Schukken et al., 2011).