What organism is most likely to be cultured from both the abscess and blood of an intravenous drug user?

The presence of Staphylococcus aureus as the organism most likely cultured from both an abscess and blood of an intravenous drug user reflects its common association with skin and soft tissue infections, as well as bloodstream infections, particularly in individuals with a history of drug use.

Intravenous drug users are prone to developing abscesses at injection sites due to non-sterile techniques used when injecting substances. Staphylococcus aureus is a skin commensal and is capable of causing significant infections when it enters through breaks in the skin. Its ability to cause both localized infections, like abscesses, and systemic infections, such as bacteremia, makes it a prime suspect in these clinical scenarios.

This organism can be particularly aggressive and is known to be associated with various complications, including endocarditis in intravenous drug users, which underscores its virulence and ability to spread from localized infections to the bloodstream.

Other organisms listed may be involved in infections but do not have the same level of association with both abscess formation and bacteremia in this specific population. For instance, Clostridium novyi is primarily associated with gas gangrene and not typically linked to abscesses in intravenous drug users, while Klebsiella pneumoniae is more