Analysis of Mechanisms of Interaction between Ciprofloxacin-Based Radiopharmaceutical Labeled with Technetium-99m and Cultured Staphylococcus aureus

Mechanisms of interaction between ciprofloxacin-based radiopharmaceutical labeled with technetium-99m and cultured Staphylococcus aureus were studied. The substance, reagent for radiopharmaceutical, and the radiopharmaceutical demonstrated similar bactericidal activity against the test bacterial cultures, which confi rmed specifi c antibacterial activity of technetium-99m-labeled ciprofloxacin. The technetium-99m-labeled antibiotic reversibly interacts with inactivated Staphylococcus aureus culture, which indicates the existence of an additional non-specific pathway for radiopharmaceutical accumulation in the bacterial inflammation focus. Our experiment ruled out the possibility of binding free technetium-99m at concentrations <5% (its concentration in the radiopharmaceutical) with Staphylococcus aureus.