SUMMARY
Patricia (Trish) J. Simner, Ph.D., studies how antimicrobial‑resistant bacteria evolve, spread and cause disease, with a focus on gram‑negative organisms that produce beta-lactamases or more specifically, carbapenemases. Her research combines molecular epidemiology, microbial genomics and translational diagnostics to uncover the genetic and ecological forces shaping antimicrobial resistance. She develops and evaluates diagnostic methods — such as rapid phenotypic assays, metagenomic sequencing and whole‑genome sequencing — to detect resistant organisms and guide appropriate therapy.
Dr. Simner also explores host-pathogen interactions, environmental reservoirs and healthcare‑associated transmission pathways to better understand how resistant bacteria circulate in clinical and global settings. Through extensive interdisciplinary collaborations, she integrates genomics, clinical microbiology, engineering, data science and stewardship principles to generate evidence that informs patient management, surveillance strategies and global antimicrobial‑resistance interventions. Her work aims to accelerate effective treatment, reduce transmission and support the responsible use of antimicrobials across diverse healthcare environments.
Focus areas
- Molecular drivers of antimicrobial resistance. Dr. Simner investigates how gram‑negative bacteria acquire, maintain and transmit resistance determinants, including extended‑spectrum beta-lactamases, AmpC beta-lactamases and carbapenemases. Her work examines chromosomal mutations, plasmid mobility and gene amplification events that enable pathogens to withstand even last‑line therapies. She also studies how antibiotic exposure influences the gain, loss or expression of resistance genes in hospital settings and across global networks.
- Development of rapid and genomic diagnostics. Dr. Simner's research advances diagnostic tools capable of identifying pathogens and antimicrobial resistance markers directly from clinical specimens. She evaluates rapid phenotypic assays, molecular detection platforms and next‑generation sequencing workflows — including metagenomic and long‑read whole‑genome sequencing — to accelerate time to actionable results. She also leads comparative studies that validate these technologies for real‑world clinical and infection‑control use.
- Genomic epidemiology and transmission mapping. Dr. Simner applies whole‑genome sequencing and metagenomic approaches to trace the spread of resistant organisms within hospitals and across international sites. Her work uncovers environmental reservoirs, patient‑to‑patient transmission patterns and global dissemination routes that drive the emergence of high‑risk bacterial clones. These insights support more effective containment strategies and strengthen surveillance networks in both high‑ and low‑resource settings.
- Susceptibility testing to guide therapy. Dr. Simner develops and validates antimicrobial susceptibility testing methods that provide more accurate, clinically relevant results to guide patient care. Her studies support updated interpretive criteria, optimized testing algorithms and enhanced reporting practices. This helps healthcare professionals select the most effective treatments while reducing unnecessary escalation to broad-spectrum agents.
Significance to patient care
Dr. Simner helps healthcare professionals quickly identify which bacteria are causing an infection and which antibiotics are most likely to work. By improving tests that detect dangerous, drug‑resistant germs, her research shortens the time it takes to begin the right treatment. This helps reduce complications, supports faster recovery and prevents infections from spreading in hospitals. Her work also promotes smarter antibiotic use, which protects patients by slowing the rise of hard‑to‑treat bacteria. Overall, her research leads to quicker answers, safer care and better outcomes for people with serious infections.
Professional highlights
- Editor, Journal of Clinical Microbiology, 2020-present.
- National Institutes of Health:
- Vice chair, Antibacterial Resistance Leadership Group, Diagnostic Committee, 2020-present.
- Co‑investigator, Pneumonia Direct Pilot, Antibacterial Resistance Leadership Group, National Institute of Allergy and Infectious Diseases, 2024-2025.
- Principal investigator, EVI Grant for AI‑Enabled Antimicrobial Resistance Prediction, European Vaccine Initiative, 2023-2028.
- Centers for Disease Control and Prevention:
- Co‑investigator, Targeted Research to Advance Prevention of Healthcare‑Associated Infections and Antimicrobial Resistance, CDC Prevention Epicenters Program, 2021-2026.
- Principal investigator, CDC Global Action in Healthcare Network – Antimicrobial Resistance Module, 2021-2026.
- Elected fellow, American Academy of Microbiology, 2025.
- Meritorious Service Award, College of American Pathologists, 2024.
- Richard S. Schwalbe Award, Maryland Branch, American Society for Microbiology, 2024.
- Service Award, Clinical and Laboratory Standards Institute, 2023.