An accessory is connected between a leg bag and a urinary catheter to prevent microorganisms migrating from the leg bag up through the catheter. The accessory has a sleeve, connectors to connect the sleeve to the leg bag and to the urinary catheter, a filter positioned within the sleeve that can be coated with an antimicrobial composition, and a valve to prevent fluid from moving from the leg bag to the catheter. The antimicrobial coated sleeve can be used with or with out the filter. The filter is made by compounding a polymeric resin powder with an antimicrobial composition.