staphylococci --> Staphylococcus
(Science: bacteria) genus of nonmotile gram-positive bacteria that are found in clusters and that produce important exotoxins. Staphylococcus aureus (Staphylococcus pyogenes) is pyogenic, an opportunistic pathogen and responsible for a range of infections including severe sepsis, pneumonia, endocarditis and soft tissue infections. It has protein A on the surface of the cell wall. Coagulase production correlates with virulence: hyaluronidase, lipase and staphylokinase are released in addition to the toxins.