Bacterial Strategies of Implant Colonization and Resistance

Staphylococcus aureus remains a frequent cause of infections in both the community and the hospital. This pathogen accounts for about 13% of all nosocomial blood infections, and is the second most common cause of these infections. S. aureus has been implicated in a multitude of diseases, ranging from minor wound infections to more serious diseases, including endocarditis, pneumonia, osteomyelitis, and septic shock. Worldwide, the increasing resistance of S. aureus to various antibiotics complicates treatment of infections due to this microorganism. In contrast, coagulase-negative staphylococci (CoNS), such as Staphylococcus epidermidis, have long been dismissed as culture contaminants since they are commonly seen among the normal flora of human skin and mucous membranes. Bacteraemia caused by CoNS is rarely life-threatening, especially, if treated promptly and adequately. However, frank sepsis syndrome and fatal outcome may occur, especially in immunocompromised patients and/or if one of the more virulent species, such as Staphylococcus lugdunensis, is involved.