Former President Bill Clinton announced yesterday that his foundation had negotiated deals with five major medical companies to steeply discount the price of two crucial diagnostic tests for H.I.V./AIDS in Africa and the Caribbean. [The 5 companies: Roche Molecular Diagnostics (part of Roche); Bayer Diagnostics (part of Bayer Group); Beckman Coulter; bioMérieux; Becton, Dickinson & Company (BD)]