Dr. Maddox has had an interest in mechanisms of bacterial virulence and pathogenesis. Her doctoral research examined the regulation of expression of K88 (F4) adhesin responsible for enterotoxigenic E. coli infections of neonatal swine. At the U. of Missouri (1989-1993), Penn State University (1993-2000) and at U. of Illinois (2000-present), her research focused on pathogen detection, virulence characteristics of Salmonella, E. coli, gastointestinal disease of livestock and and food safety. She has served for 4 years on the National Advisory Committee on Microbiological Criteria for Foods contributing expertise in preharvest food safety. Collaboration with animal scientists has lead to studies of non-antibiotic means to control enteritis of swine. Other research efforts examine the control of virulence in Streptococcus equi subsp. equi, and using site directed mutagenesis, we have developed attenuated modified live vaccine candidates. And recently, our lab has also been studying the significance of Staphylococcus pseudintermedius and other Staphylococus species causing canine pyoderma.