Identification of Streptococcus agalactiae and other Streptococcus species associated with bovine mastitis and the reactivity of a bovine anti-galactosyl antibody with their surface carbohydrates

Abstract

Fifteen isolates of Streptococcus species including six reference strains of S. agalactiae were obtained and their surface carbohydrates were examined for their galactosyl linkage properties using an anti-alpha galactosyl antibody purified from calf serum. Cattle produce anti-alpha-galactosyl antibodies naturally, possibly in response to microbial carbohydrates. The purpose of this thesis is to analyze the galactosyl linkages on the surface structures of Streptococcus strains by using these anti-galactosyl antibodies. The galactosyl linkages were studied through dot immunoblot assays with the natural bovine antibody and with two lectins, RCA₁₂₀ and Isolectin B₄, both with known galactosyl binding properties. Serological, morphological and biochemical tests were performed on the 15 isolates to examine any possible relationship associated with reactivity of the antibody. Because of lectin-like reactivity, the anti-alpha-galactosyl antibody could prove to be a diagnostic tool to kelp characterize strains of Streptococcus.