A substance being studied in the prevention of bacterial infections that occur in catheters (thin tubes that carry fluids into or out of the body). It is a combination of minocycline, an antibiotic that blocks the growth of bacteria, and EDTA, a substance that keeps blood clots from forming. M-EDTA removes metals that bacteria use to form biofilms (thin layers stuck to surfaces). Also called minocycline-EDTA.