Research
Overview
Gram-positive pathogens like Streptococci are the leading causes of human infections. These bacteria can cause diverse array of diseases such as pneumonia, meningitis, endocarditis, necrotizing faciitis to name a few. During the last two decades, gram-positive bacteria are becoming increasingly resistant to the available drugs, a very serious concern. These bacteria express a wide range of virulence factors that enable them to establish infections. Most of these virulence factors are either secreted or cell-wall associated. Several proteases play an important role in the expression, processing and maturation of these virulence factors. One of the main focuses of our laboratory is to study how various surface proteases affect virulence factor expression in streptococci. We are also studying how these proteases affect biofilm formation by various streptococci such as S. mutans.
A second project of the laboratory is to study the regulation of virulence gene expression in streptococci such as S. pyogenes and S. mutans. Expression of virulence factors is under complex regulatory networks and is not fully understood in streptococci. Our laboratory is interested in the mechanisms by which these bacteria regulate its virulence repertoire in response to host signals encountered during infection. Specifically, we have focused our studies on the molecular mechanisms of two-component signal transduction pathways that regulate a wide range of virulence genes in various streptococci. Our long term goal is to increase overall knowledge of gram-positive bacterial pathogenesis and to develop new treatment strategies.
Recently our lab started research on Acinectobacter baumannii, an emerging nosocomial pathogen involved in a variety of infections ranging from minor soft-tissue infections to more severe infections such as ventilator-associated pneumonia and bacteremia. A. baumannii has the ability to acquire an antibiotic resistance cassette from the environment and this trait has allowed the organism to persist in healthcare settings and also has the remarkable ability to survive prolonged periods under highly desiccated conditions on dry surfaces, a phenomenon that is not commonly found with other Gram-negative pathogens. The primary goals of the lab are to study the mechanisms of desiccation tolerance, develop genetic tools to study virulence and discover novel anti-infectives.
