Treatment of diseases associated with antibiotic use

A compound having the formula (II): Formula ** ** for use in the treatment or prevention of a disease in a patient, caused by the presence of methicillin resistant Staphylococcus aureus (MRSA) wherein (a) disease is associated with the use of antibiotics or (b) the disease is associated with the use of chemotherapy or (c) the disease is associated with the use of antiviral therapy.