Purification and characterization of staphylococcus aureus serotype 8 capsular polysaccharide : production of monoclonal antibodies specific for type 8 capsular polysaccharide /

Abstract

Infections caused by Staphylococcus aureus (S. aureus) remain the number one cause of hospital-acquired infections. Immunocompromised patients, who are most often the target of these infections, are unable to form antibodies against the carbohydrate molecules. Therefore, they would benefit from a passive administration of pre-formed antibodies. The goals of this study were: 1) to obtain a pure cell wall carbohydrate of type 8 S. aureus, 2) to develop ELISA techniques for detecting anti-capsular antibodies from mouse serum, and 3) to produce monoclonal antibodies against type 8 CP. Enzyme digested bacterial carbohydrate preparations were separated by DEAE-Sephacel chromatography. Analysis of the fractions demonstrated the presence of six peaks that absorbed at 21 3 nm. Two tested positive for reducing sugar. One was eliminated because of teichoic acid contamination. Purified capsular polysaccharide and fonnalintreated bacteria were used to develop ELISAs to test for monoclonal antibodies in sera. Monoclonal antibodies from mice immunized with S. aureus, type 8 failed to bind to type 8 capsular polysaccharide, but the experiments successfully detected cross-reactive binding to type 5 capsular polysaccharide.