Stephen Melville

Associate Professor - Biological Sciences

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Synopsis:

Dr. Melville uses molecular techniques to identify how the bacterial pathogen Clostridium perfringens moves through tissues in the body, is able to overwhelm the immune system, and prevent itself from being killed.

Description:

Clostridium perfringens is a soil-borne bacterial pathogen that is the third most common cause of food poisoning in the U.S. It can also invade muscle tissue through an open wound, after which it is 100 percent fatal if the infected tissue is not removed from the body. In 2006, Dr. Melville discovered that C. Perfringens has type IV pili (TFP) and uses them to move in a gliding fashion. Since then, he and his laboratory team have continued to research the underlying mechanisms for explaining how TFP functions in order to cause disease, and the molecular mechanisms used to assemble the pili themselves. Dr. Melville uses a series of genetic, biochemical and biophysical approaches to answer these questions. Because the bacteria can move so fast through infected tissue (3 inches per hour), a better understanding of their motility is crucial for the development of better treatment strategies, beyond tissue removal and large doses of antibiotics.

C. perfringens can also evade being killed by host phagocytic cells by secreting toxins that disrupt the membrances of these phagocytes. The bacteria can then escape the killing compartment (phagosome) or actually kill the phagocytes themselves. Dr. Melville is interested in how these factors influence the onset and spread of a C. perfringens infection.