For almost 20 years I have been studying antimicrobial resistance in bacteria. These studies have included analyses of spatial distributions of resistant microbes and resistance genes, mathematical models of resistance development and spread, quantitative risk assessments related to the use of specific antibiotics and the subsequent augmentation of resistance, molecular analyses of resistance genes and their spread, and public health analyses estimating the excess burden of illness caused by these resistant microbes.
I actively investigate the ecology of foodborne pathogens such as Salmonella and Campylobacter in agricultural environments. The goal of these projects is to develop interventions on the farm and in the processing plant that reduce the risk to humans of being exposed to these pathogens.
In addition to studying the ecological factors affecting antimicrobial resistant pathogens and foodborne pathogens, I have studied other bacterial and viral pathogens. These studies have focused on the spread of these pathogens at the interface of humans, animals and the environment and on the assessment of interventions for minimizing the risk of transmission among these populations.