The extracellular fibrinogen-binding protein (Efb) from S. aureus binds divalently to fibrinogen and gives rise to a specific antibody response

Staphylococcus aureus is an important human and animal pathogen that causes a wide range of infections. These infections can be very serious and sometimes hard to get rid of, because of the many virulence factors the bacteria produce during infections. This project was a research of the extracellular fibrinogen-binding protein, Efb, which is a 15.9 kDa protein that has been shown to be an important virulence factor during S. aureus infections. The purpose with the project was to find out if the protein has more than one binding site to fibrinogen and if people produce antibodies against Efb. This was performed with methods such as affinity chromatography, ELISA, coagulation test and western blot. It was shown that Efb has two binding sites to fibrinogen. One is placed on the C-terminal part of Efb and the other on the N-terminal. It was also shown that the production of antibodies against Efb rises significantly in people during an ongoing infection