Investigators use light to kill microbial ‘vampires’
On July 24 Vanderbilt scientist Eric Skaar, Ph.D., MPH, summarized his group’s latest paper in a tweet: “If S. aureus is going to drink our blood like a vampire, let’s kill it with sunlight.”
“That thing has been retweeted so many times,” said Skaar, the Ernest W. Goodpasture Professor of Pathology in the Vanderbilt University School of Medicine. “It’s one of the most popular tweets I’ve ever put out about our research.”
No wonder. Staphylococcus aureus (staph) is the leading cause of hospital-acquired infections. Antibiotic-resistant strains of the bug, like MRSA, can kill.
Staph needs iron to grow. “It breaks open the blood cells and grabs the hemoglobin and pulls the iron out,” Skaar said. Other Gram-positive pathogens probably do the same thing. “But the S. aureus systems are by far the most well studied,” he said.
Now Skaar and his colleagues have found a new way to destroy these microbial vampires. Just as daylight strips Dracula of his power, they have shown that an enzyme-activating small molecule they developed, when combined with “photodynamic therapy,” can kill bacteria in mouse models of skin and soft tissue infections.