MSCRAMM adhesin proteins mediate the initial attachment of bacteria to host tissue, providing a critical step to establish infection.

Examples include protein A

Protein A

Protein A is a 40-60 kDa MSCRAMM surface protein originally found in the cell wall of the bacterium Staphylococcus aureus. It is encoded by the spa gene and its regulation is controlled by DNA topology, cellular osmolarity, and a two-component system called ArlS-ArlR. It has found use in...

, clumping factor A

Clumping factor A

Clumping factor A, or ClfA, is a virulence factor from Staphylococcus aureus that binds to fibrinogen.ClfA also has been shown to bind to complement regulator I protein....

 (ClfA), fibronectin binding protein A

Fibronectin binding protein A

Fibronectin binding protein A is a Staphylococcus aureus MSCRAMM cell surface-bound protein that binds to both fibronectin and fibrinogen....

 (FnbpA) from Staphylococcus aureus

Staphylococcus aureus

Staphylococcus aureus is a facultative anaerobic Gram-positive coccal bacterium. It is frequently found as part of the normal skin flora on the skin and nasal passages. It is estimated that 20% of the human population are long-term carriers of S. aureus. S. aureus is the most common species of...

, SdrG from Staphylococcus epidermidis

Staphylococcus epidermidis

Staphylococcus epidermidis is one of thirty-three known species belonging to the genus Staphylococcus. It is part of human skin flora, and consequently part of human flora. It can also be found in the mucous membranes and in animals. Due to contamination, it is probably the most common species...

, M protein

M protein

M protein may refer to:* M protein ', a virulence factor of the bacterium Streptococcus pyogenes* Another name for paraprotein, an abnormal protein in the urine or blood, often seen in multiple myeloma or MGUS...

 from Streptococcus pyogenes

Streptococcus pyogenes

Streptococcus pyogenes is a spherical, Gram-positive bacterium that is the cause of group A streptococcal infections. S. pyogenes displays streptococcal group A antigen on its cell wall. S...

, and protein G

Protein G

Protein G is an immunoglobulin-binding protein expressed in group C and G Streptococcal bacteria much like Protein A but with differing specificities. It is a 65-kDa and a 58 kDa cell surface protein that has found application in purifying antibodies through its binding to the Fc region...

 in other Streptococcus species. All of these MSCRAMMs bind to fibrinogen except protein A, that binds IgG, but also other targets for MSCRAMMs are known, such as fibronectin. Protein M binds to the Fc region of certain antibodies.

The MSCRAMMs have mainly been studied in Gram positive pathogens and are promising drug targets.

The monoclonal antibody tefibazumab

Tefibazumab

Tefibazumab is a humanized monoclonal antibody for the treatment of severe infections with Staphylococcus aureus. Possible indications include the treatment of S. aureus in patient with cystic fibrosis and of methicillin-resistant S. aureus.It was developed by Inhibitex....

 targets ClfA and has been tested in a phase II trial.