How Flesh-Eating Bacteria Attack the Body’s Immune System

“Flesh-eating” bacteria are able to survive and spread in the body by degrading a key immune defense molecule, according to researchers at the University of California, San Diego, School of Medicine and Skaggs School of Pharmacy and Pharmaceutical Sciences. The finding, which could aid in development of new treatments for serious infections in human patients, will be reported in the August 14 issue of the journal Cell Host & Microbe.

Led by senior author Victor Nizet, MD, UC San Diego professor of pediatrics and pharmacy and an infectious diseases physician at Rady Children’s Hospital, San Diego, the researchers showed that a protease known as SpyCEP (Strep. pyogenes cell envelope protease) – produced in large amounts by the most dangerous strains of strep – inactivates an immune system molecule that controls the body’s white blood cells ability to fight bacteria. Without signals from this molecule, white blood cells become slower and weaker, and infections can spread out of control.

“These findings may suggest a new approach to treating serious strep infections by supporting our body’s natural defense system,” said Nizet.