The present invention relates to methods and compositions for reducing sialidase activity and inhibiting bacterial proliferation of one or more bacteria in a platelet product preparation from one or more donors. In general, the method includes contacting the platelet product preparation with an amount of a sialidase inhibitor, to thereby obtain a sialidase inhibitor-treated platelet product preparation. Sialidase activity is reduced and the proliferation of one or more bacteria is inhibited, as compared to a platelet product preparation not subjected to the sialidase inhibitor treatment.
