A 20-year -old college athlete, Ms. G., had arthroscopic knee surgery. Over the next week she noticed mild swelling, increasing pain, and a small amount of redness at the incision site. Within three weeks the incision site had nearly completely healed, but the patient's knee remained swollen and painful.

In addition she was febrile (41.3°C) (pyrexia) and had developed vomiting (emesis) and diarrhea. She came to the emergency department for treatment. Examination revealed a sunburn like rash on her face, mild skin peeling above the eyes and red eyes and lips. Her blood pressure was 70/50 mm Hg and she had elevated white cells but reduced number of platelets. Ms. G. was admitted to the intensive care unit.

After investigating further you uncover the following facts. Last year Ms. G. was selected for the Olympic team. During that year she was also admitted to the psychiatric hospital because she threatened to kill herself. In addition there were 12 police reports because she threatened her boyfriend with bodily harm or death.

After the surgery you find out that throat, nasal, urine and blood cultures were negative for Streptococcus pyogenes and for Staphylococcus aureus. To stabilize her she received fluid and electrolytes as well as vasopressors and was treated with oxacillin.

1. Knowing these new facts is it possible that the disease is psychosomatic?

2. Why was oxacillin chosen?

3. What is the molecular mechanism of action by this antibiotic?

4. What is the molecular mechanism of resistance to this antibiotic?