"All MRSAs" refers to different strains or types of methicillin-resistant Staphylococcus aureus (MRSA), which is a group of bacteria resistant to many antibiotics. The main types of MRSA are:
- HA-MRSA (Healthcare-associated or Hospital-acquired MRSA): Found mostly in hospitals, nursing homes, and other healthcare settings. These strains are associated with invasive procedures or devices like surgeries, IV tubing, or catheters.
- CA-MRSA (Community-associated MRSA): Occurs in healthy people outside healthcare settings, often causing skin infections. CA-MRSA strains are genetically distinct from HA-MRSA and tend to be more virulent.
- LA-MRSA (Livestock-associated MRSA): Found in animals such as pigs and can be transmitted to humans, especially in people working with livestock.
There are also various genetic lineages or clones of MRSA like ST239-MRSA-III (Brazilian clone), EMRSA strains common in the UK, USA300 common in the US community, and others that differ geographically and by resistance and virulence traits.
In summary, "all MRSAs" includes these three main acquisition settings (HA, CA, LA), each with multiple genetic strains that vary in resistance and virulence profiles.
