APPLICATION OF A FLUORESCENT REDOX DYE FOR ENUMERATION OF METABOLICALLY ACTIVE BACTERIA ON ALBUMIN-COATED TITANIUM SURFACES

A bacterial staining method using fluorescent redox dye 5-cyano-2,3-di tolyl tetrazolium chloride (CTC) is described for quantifying actively respiring bacteria that adhere to commercially pure titanium surfaces coated with cross-linked albumin. This has not been possible to date using ordinary DNA stains such as propidium iodide (PI) or Hoechst, bo th of which produce a very bright background. With this technique, it was demonstrated that the cross-linked albumin inhibited the adherence of Staphylococcus aureus and Staph, epidermidis to the titanium surfa ce.