Purpose: There has been a recent, rapid increase in prevalence of Methicillin-resistant Staphylococcus aureus (MRSA) among patients with Cystic Fibrosis (22% across US CF centers in 2009). Some epidemiologic studies suggest possible worse outcomes, a recent analyses showing this with chronic but not intermittent MRSA. Given the chronic difficult to treat lung infections in CF it is unclear how the onset of MRSA should be approached. This randomized, controlled, interventional study seeks to determine if an early eradication protocol is effective for eradication of MRSA and will provide an opportunity to obtain data regarding early clinical impact of new isolation of MRSA.