Studies on Staphylococcus

Immunoserological relationship between antigenic fractions extracted from Staphylococcus aureus and anti-Staphy. aureus rabbit serum were carried out by sensitized-blood cell haemagglutination reaction and anaphylactic contracting reaction of the isolated guinea pig's ileum passively sensitized with anti-Staphy. aureus rabbit serum. The results obtained were as follows: Antigenic fractions were obtained from Staphy. aureus (A-11) and Staphy. epidermidis (B-12) by the modified method of Verway. By chemical analysis Fraction-A-1 and A-2 was nucleoprotein, Fraction B was protein, Fraction C was polysaccharide and Fraction R was crude nucleoprotein. Coagulase was also prepared by Blobel's method. Tannic acid red cell haemaggulutination reaction was most sensitive when nucleoprotein was used as the sensitized antigen, next crude extraction, purified coagulase, protein and polysaccharide. Cross reactions were also observed with nucleoprotein, polysaccharide and protein derived from Staphy. epidermidis.Remarkable anaphylactic reaction of the isolated intestine of the guinea pig passively sensitized with anti-Staphy. aureus rabbit serum was observed by adding crude extract, protein-fraction or nucleoprotein fraction, but not a reaction was observed with polysaccharide or purified coagulase. However, intestinal anaphylactic reaction was also observed with crude extract and protein-fraction of Staphy. epidermidis. These facts suggest that common antigenicity exists in protein fraction of Staphy.aureus and Staphy. epidermidis.