Coagulase-negative staphylococci include the microorganisms staphylococcus epidermidis, staphylococcus saprophyticus, and staphylococcus hominis. Both are gram-positive, catalase-positive, urease-positive cocci bacteria that are arranged in clusters. They are both components of normal body flora.
S. epidermidis is found on the skin but has an ability to form adherent biofilms on devices which are resistant to phagocytosis and can contaminate blood cultures. S. saprophyticus is found in the female reproductive tract and the perineum; and is the second-most common cause of uncomplicated UTI in young women (most common is E. coli). These bacteria cause opportunistic infections of medical devices, urinary tract infections, and wound infections.
The treatment for coagulase-negative staphylococci depends on the organism. Sensitivity testing assists with determining appropriate antibiotics. S. epidermidis is often methicillin-resistant. Catheter or device-related infections are typically treated with vancomycin and removal of the device. Sulfamethoxazole/Trimethoprim and tetracyclines are often sensitive. S. epidermidis and S. saprophyticus can be differentiated using the antibiotic drug Novobiocin; S. epidermidis is Novobiocin-sensitive while S. saprophyticus is Novobiocin-resistant