Methicillin-resistant staphylococcus aureus is a strain of staphylococcus aureus which is genetically different from other S. aureus. This strain is resistant to some antibiotics like methicillin therefore they are tougher to treat than other strains of staphylococcus.
They can be transferred from one person to another by direct contact with the person or through indirect contact like contact with the person's belongings. So as Luis fails to perform hand hygiene after caring for Nicole and spread it to Theodore than it will come in direct contact because bacteria is transferred directly from Luis skin to other patient.
These are elements that are specific to the patient. While the family history can add to the patient's health, its not germane to a specific episode of treatment.
