The scope and type of property rights recognized over the effectiveness of antibiotics have a direct effect on how those claiming ownership engage in the exploitation and stewardship of this scarce resource. We examine the different property claims and rights the four major interest groups are asserting on antibiotics: (i) the inventors, (ii) those demanding that the resource be treated like any other transferable commodity, (iii) those advocating usage restrictions based on good stewardship principles and (iv) those considering the resource (...) as common heritage of humankind. (shrink)