An introduction to antibiotic-free techniques to eliminate Staphylococcus aureus from blood

Abstract

Here, we describe the implementation of three techniques for capturing and killing Staphylococcus aureus in blood in vitro inside a medical tube. The first technique involves capturing and removing pathogens using antibodies that are coated, via a simple chemical process, on the inner walls of a modified medical tube (tube capturing technique). In the second technique, a photosensitizer-antibody conjugate adheres to the pathogens while in circulation. When blood flows through the same kind of tube, the conjugate is activated by near-infrared (NIR) light to kill pathogens (photodynamic therapy technique). For the third technique, pathogens are exposed to light in the ultraviolet (UV) range while circulating through a similar tube (UV technique), which kills the pathogens. We spiked blood with S. aureus, starting with about 107 CFU/mL and ending at 108 CFU/mL after 5 hours. While the spiked bacteria rapidly grew in nutrition-rich whole blood, each of the three techniques were able to independently remove between 61% and 84% more S. aureus in the experimental blood sample compared to the controls groups. When combined, these techniques demonstrated a removal rate between 87% and 92%.