The capsule of Staphy lococcus aureus clinical strains

Research Project

Project/Area Number	07670315
Research Category	Grant-in-Aid for Scientific Research (C)
Allocation Type	Single-year Grants
Section	一般
Research Field	Bacteriology (including Mycology)
Research Institution	Kyushu University
Principal Investigator	UMEDA Akiko Kyushu University, Medicine, Assistant Professor, 医学部, 講師 (30078604)
Project Period (FY)	1995 – 1996
Project Status	Completed (Fiscal Year 1996)
Budget Amount *help	¥500,000 (Direct Cost: ¥500,000) Fiscal Year 1996: ¥500,000 (Direct Cost: ¥500,000)
Keywords	Staphylococcus aureus / capsule / pathogenicity / 莱膜
Research Abstract	We purified a protein (protein associated with the capsular polysaccharide : PAC) from the capsular layr of clinically isolated encapsulated strains of Staphylococcus aureus. It was a glycoprotein of a molecular size of 200 kDa measured by SDS PAGE.The antiserum raised in a rabbit for PAC reacted not only with the protrein but also with the extracted capsular polysaccharide but not with the cell wall teichoic acid. Immunoelectron microscopic examination of the antiserum treated cell revealed that the antiserum reacted both with the cell wall surface of the encapsulated strain and with the cell wall surface digested with pepsin which removed the cell wall associated proteins almost completely. These results suggested that the sugar moiety of the glycoprotein could be a part of the capsular polysaccharide and the protein could be covalently associated with the capsular layr. The protein had the highly hydrophobic character and it gave the hydrophobic surface character to the encapsulated clinical strains of S.aureus. It can be assumed that the protein may have some roles for the colonization of the bacteria to the host cell surface.