Koagulaasinegatiivsed

Koagulaasinegatiivsed refers to a group of bacteria that do not produce the enzyme coagulase. This enzyme is a virulence factor primarily associated with Staphylococcus aureus, enabling it to clot plasma. The absence of coagulase is a key characteristic used in the laboratory to differentiate S. aureus from other staphylococcal species, which are collectively known as coagulase-negative staphylococci (CoNS).

Coagulase-negative staphylococci are a diverse group, with Staphylococcus epidermidis and Staphylococcus saprophyticus being among the most clinically significant species. While often considered commensals or normal flora of the skin and mucous membranes, CoNS can also cause infections, particularly in immunocompromised individuals or those with indwelling medical devices like catheters or prosthetic implants. Their ability to form biofilms is a major factor in device-related infections, making them difficult to eradicate.

Common infections caused by CoNS include skin and soft tissue infections, urinary tract infections (especially in sexually active women for S. saprophyticus), and bloodstream infections, often related to intravenous access. The treatment of CoNS infections can be challenging due to increasing antimicrobial resistance. Identification of the specific species and susceptibility testing are crucial for effective management.