Heteroresistance is a form of phenotypic heterogeneity in a population, therefore we are interested in deciphering mechanisms that allow cells of the same population to exhibit different features. We seek to understand the mechanisms that generate antibiotic heteroresistance to different antibiotics, particularly cephalosporins, in Enterobacter and similar Gram-negative species isolated from human infections. We are also interested in pathways that support resistance, and mechanisms that generate heterogeneity in other types of phenotypes. Our long-term goal is to improve antibiotic development and treatment by providing insights into antibiotic resistance, heteroresistance, and fundamental bacterial biology.