Which blood product is most susceptible to gram-positive infections?

Platelets are indeed the blood product most susceptible to gram-positive infections. This susceptibility arises primarily due to the storage conditions and the nature of platelet preparation. Platelets are typically stored at room temperature, which creates an environment conducive to bacterial growth, particularly for gram-positive bacteria like Staphylococcus and Streptococcus species.

Additionally, platelets are often pooled from multiple donors, increasing the risk of contamination if even one donor has a colonization of these bacteria. Unlike red blood cells and fresh frozen plasma, which are stored under conditions that inhibit bacterial growth – red blood cells at 4 degrees Celsius and fresh frozen plasma at -18 degrees Celsius – the room temperature storage of platelets makes them a higher risk for bacterial contamination.

Cryoprecipitate, while also a blood product, is stored differently and at lower temperatures, which minimizes the risk of bacterial growth compared to platelets. Thus, the characteristics of platelet storage and preparation put them at a greater risk of being involved in gram-positive infections, making them the correct answer in this context.