Ryan Shields is a pharmacist-scientist interested in antimicrobial drug resistance in gram-negative bacteria and yeast. His research focuses on the use of molecular markers of resistance to predict patient responses to treatment; the use of pharmacokinetic-pharmacodynamic models to suppress and overcome antimicrobial resistance; antimicrobial susceptibility testing methods; elucidating new mechanisms of antimicrobial drug resistance, and the clinical impact of infections due to extensively-drug resistant pathogens. Using these approaches, Dr. Shields and colleagues have developed treatment paradigms for difficult-to-treat pathogens, including Candida glabrata, Acinetobacter baumannii, and carbapenem-resistant Klebsiella pneumoniae, leading to improved patient outcomes. Dr. Shields is also the Co-Director of the Antimicrobial Management Program at UPMC Presbyterian hospital.