Carrie Rosenberger's research focuses on Salmonella, the bacteria responsible for an estimated 16 million cases of typhoid fever worldwide each year. Research has shown that Salmonella typhimurium, a strain of the bacteria, causes widespread disease by penetrating the inner membrane of the intestinal wall and residing in macrophages (immune cells that normally help destroy bacteria). Rosenberger is investigating how Salmonella typhimurium avoids destruction by altering macrophage genes. To study the complex interactions between cells and the bacteria, she is using gene arrays, technology that enables simultaneous measurement of how hundreds of macrophage genes change during infection. Rosenberger hopes the research will increase understanding of how Salmonella causes disease and helps in the design of more effective treatments. She also hopes to broaden knowledge of how cells and pathogens (disease-producing organisms) interact.