Recent research has identified a protein that helps bacteria break away from implanted medical devices, such as catheters, and spread throughout the body. The finding provides insight into how bacterial communities called biofilms cause disease and suggests a potential target for treatment of certain hospital-acquired infections.
Biofilms made up of Staphylococcus epidermidis and S. aureus (“staph”) bacteria are major causes of infection in hospitals. They are difficult to treat and often resistant to antibiotics.
To determine how bacteria from biofilms detach and spread, an NIAID research team studied a protein released by S. epidermidis known as PSM-beta. They targeted PSM-beta because its structure hinted that it might disrupt cellular interactions that help bacteria stick together in a biofilm. Their research identified roles for PSM-beta in helping biofilms develop their characteristic sponge-like organization and in facilitating the detachment and spread of bacterial cell clusters.
In mice with implanted catheters, the researchers observed normal S. epidermidis bacteria spreading to organs and body fluids, but a mutant strain lacking PSM-beta barely migrated. In an attempt to stop the bacteria from spreading, the team treated the mice with antibodies against PSM-beta. The antibodies prevented bacteria from spreading to organs and strongly inhibited spread to the lymph nodes. These findings suggest that interfering with biofilm detachment mechanisms could prevent the spread of biofilm-associated infections in the body.
Wang R, Khan BA, Cheung GY, Bach TH, Jameson-Lee M, Kong KF, Queck SY, Otto M. Staphylococcus epidermidis surfactant peptides promote biofilm maturation and dissemination of biofilm-associated infection in mice. J Clin Invest. 2011 Jan 4;121(1):238-48.
Last Updated January 08, 2013