Methicillin-Resistant Staphylococcus aureus- Pharmacist
Staphylococcus aureus is a leading cause of infection in both the community and hospital settings. A highly virulent and hardy pathogen, it is notable for its ability to cause a wide variety of infections, ranging from simple skin and soft tissue infections (SSTIs) to life-threatening infections such as osteomyelitis and sepsis. Staphylococcus aureus is broadly subdivided into methicillin-sensitive Staphylococcus aureus (MSSA) and methicillin-resistant Staphylococcus aureus (MRSA). A common misconception among both clinicians and the general public is that MRSA causes more severe infections than MSSA. In reality, both organisms cause the same general types of infections, including life-threatening infections. However, from a drug therapy perspective, MRSA manifests a higher degree of antimicrobial resistance than MSSA, making treatment a challenge in both the outpatient and inpatient settings. For many years, MRSA was considered a nosocomial pathogen, primarily encountered in large, tertiary healthcare institutions. However, over the last 2 decades, there has been a dramatic increase in the incidence of MRSA infections in community and outpatient settings. Infections originating in these settings are commonly called community-associated methicillin-resistant Staphylococcus aureus (CA-MRSA) infections; those originating in the hospital or other healthcare settings (eg, skilled nursing facilities) are generally termed healthcare-associated methicillin-resistant Staphylococcus aureus (HA-MRSA) infections. This issue will review important concepts related to MRSA infections, with a focus on CA-MRSA. Important management strategies, including new antibiotics used in the treatment of MRSA, will be highlighted. With the increasing incidence of CA-MRSA infections, as well as a global increase in antimicrobial resistance in this pathogen, community providers play an important role in educating both patients and other providers about appropriate treatment options.