In her research, Sarah D'Orazio, associate professor in the University of Kentucky Department of Microbiology, Immunology and Molecular Genetics, investigates why some people get sicker than others after ingesting the foodborne bacterial pathogen Listeria monocytogenes. Using a mouse model, her research team observed that a subset of mice most susceptible to the dangerous bacteria share one common trait: they are all female. With supplemental funding from the National Institutes of Health (NIH), D'Orazio has the resources to explore why Listeria infection affects females more severely than their male counterparts. Part of an effort to promote sex-based research, the NIH is investing $10 million in clinical and preclinical trials that consider sex, or gender, a fundamental variable in scientific results. D'Orazio was one of 82 researchers in the nation to receive an award to expand her studies to look specifically at the immune response to Listeria in both male and female mice. "It was an interesting observation, but we really didn't have the funds to investigate that question," D'Orazio said of comparing male and female immune responses. Launched in 2013, the supplemental grants from the NIH Office of Research on Women's Health are awarded to research studies that will contribute to a body of sex-based knowledge to inform future studies. The awards enable researchers to expand their studies to investigate sex-based differences by adding elements of gender comparison and data analysis. According to the NIH, an overreliance on male subjects in preclinical trials can obscure key findings related to sex differences that are later used in human studies. This year, the grants were awarded to projects spanning many scientific areas, including basic immunology, cardiovascular physiology and behavioral health. "This funding strategy demonstrates our commitment to moving the needle toward better health for all Americans, while helping grow our knowledge base for both sexes and building research infrastructure to aid future studies,” said Dr. Janine Austin Clayton, NIH associate director for women’s health research. “The scientists receiving these awards have approached their research questions with fresh thinking, and are looking for innovation and discovery through a new lens.” Prior to receiving the supplemental funding, D'Orazio's Listeria research was funded by an R01 grant from the NIH. Listeriosis is one of the most deadly foodborne infections in America. A 2011 outbreak in Colorado involving contaminated cantaloupes affected 147 people in 28 states, and resulted in 33 deaths. Since then, the USDA has recalled an average of 40 to 50 food products per year due to contamination with Listeria monocytogenes. From the start of the project, D'Orazio's research team factored sex as a possible variable in the mice's immune response to Listeria infection. D'Orazio is looking at how the rapid production of a pro-inflammatory cytokine in some mice helps to trigger clearance of the bacteria. With the additional funding, she and her research team will investigate whether this immune response differs in susceptible females compared to the more resistant male mice. MEDIA CONTACT: Elizabeth Adams,