Researchers at CalTech , The Washington University School of Medicine, and the University of Florida have successfully modeled the ‘Type Four Secretion’ system unique to legionella bacteria. Previously, other scientists have not been able to accurately model this mechanism as the bacteria are only about 40 nanometers in diameter. This process, referred to as the ‘Toxin Gun’ by some, is responsible for the bacteria’s noted resistance to some antibiotics. The ‘Toxin Gun’ secretes thousands of toxic molecules that infect and significantly weaken cells, overloading the body’s immune response. The ‘Toxin Gun’ also shoots out material that is coded with antibiotic resistance genes, thereby allowing more creating more bacteria that is now resistant to some forms of antibiotics. The researchers state that studying the structure of the system is the first step in developing drugs that can prevent this process from ever taking place. The head researcher, Dr. Debnath Ghosal, further stated that the results of this study and any future treatments developed because of the research can also be applied to other bacteria that share a similar secretion mechanism. The different types of bacteria that Ghosnal refers to are responsible for stomach cancer, whooping cough, and the extremely rare Q Fever.
More information about the team’s research can be found here.
Below is an animated model of the process, created by the research team.