What is the most common organism responsible for osteomyelitis related to intravenous drug use?

Osteomyelitis associated with intravenous drug use is often due to the introduction of pathogens through non-sterile injection practices. The most common organism involved in these cases is Staphylococcus aureus. This bacterium is typically found on the skin and can easily enter the bloodstream when skin barriers are breached during injection.

While Pseudomonas aeruginosa can indeed be involved, especially in cases where there is contaminated equipment or in patients with certain risk factors, it is not the most common organism overall for osteomyelitis linked to IV drug use. In contrast, Staphylococcus aureus is not only highly prevalent but also known for its virulence and ability to form biofilms, which complicates treatment and contributes to persistent infection.

The pathophysiology underlying this condition highlights how Staphylococcus aureus can lead to bone infection. It can gain access to the bone via hematogenous spread, particularly following an injection that may carry the bacteria directly into the systemic circulation. This capability makes it a leading cause of osteomyelitis in this patient population.

In summary, the correct answer reflects the epidemiological association of Staphylococcus aureus with osteomyelitis related to intravenous drug use, emphasizing its role as a