91制片厂

The Hall lab focuses on defeating persistent bacterial infections through:

• In silico design of novel anti-stringent response mechanisms targeting virulence factors and toxins
• Biofilm-disrupting agents to restore antibiotic efficacy
• Non-thermal plasma (NTP) as an antimicrobial tool, investigating bacterial tolerance to its reactive species and optimizing clinical applications
• Computational modeling paired with in vitro validation to develop impactful bacterial therapeutics
• Molecular diagnostics for rapid, precise infection detection

The lab’s interdisciplinary approach—spanning chemistry, microbiology, and biotechnology—aims to revolutionize treatments and diagnostics, from NTP’s potential in wound care to next-generation diagnostic tools.

Current Lab Members

• Michiko Thwe, PhD Candidate – Biomedical Engineering, 91制片厂 (Co-advisor: Dr. Garth Ehrlich)
• Felicity Tso, MS (Completed), PhD Candidate – Microbiology & Immunology, 91制片厂 (Co-advisor: Dr. Garth Ehrlich)

Former Lab Members

• Karan Bamb, MS (Completed) – Molecular and Cell Biology and Genetics, 91制片厂 (Co-advisor: Dr. Josh Mell)
  Thesis: Multidrug Tolerance and the Stringent Response in Diverse Clinical Isolates of Haemophilus influenzae
• Lauren Walsh, MS Candidate (Completed) – Microbiology & Immunology, 91制片厂 (Co-advisor: Dr. Vandana Miller)
  Thesis: Investigating Stringent Response-Mediated Tolerance to Non-thermal Plasma in Escherichia coli

Interested in joining the Hall lab or collaborating? Let’s connect!

Innovative Strategies for Combatting Chronic Biofilm Infections

• The Challenge: Chronic biofilms shield bacteria from antibiotics, increasing resistance up to 1,000-fold. The stringent response, driven by alarmones like (p)ppGpp via RelA and RSH homologs, creates persister cells that sustain infections.
• Our Approach: We design small molecule inhibitors to disrupt biofilm formation and the stringent response using:
  • Computational modeling to identify targets and design compounds
  • Organic synthesis to create inhibitors
  • In vivo and in vitro assays to validate biofilm degradation and antibiotic re-sensitization
  • Quantification of (p)ppGpp levels to assess inhibitor efficacy in disrupting the stringent response
• Impact: Disrupting bacterial defenses enhances antibiotic effectiveness, offering new solutions for chronic infections.

Investigating Bacterial Tolerance to Non-Thermal Plasma

• The Challenge: Non-thermal plasma (NTP) kills bacteria using reactive oxygen and nitrogen species (RONS) and UV radiation, but sub-lethal doses trigger stress responses (e.g., antioxidant enzymes, SOS DNA repair), enabling tolerance and potential antibiotic cross-resistance.
• Our Approach: We study bacterial NTP tolerance by:
  • Analyzing molecular stress response mechanisms
  • Testing survival under controlled plasma conditions
  • Identifying pathways to enhance NTP efficacy
• Impact: Optimizing NTP prevents tolerance, advancing plasma-based therapies for clinical use.

Developing Antimicrobial Materials

• The Challenge: Microbes on surfaces pose infection risks, and conventional materials often lack broad, safe antimicrobial efficacy.
• Our Approach: We create innovative antimicrobial materials by:
  • Designing compounds and coatings with potent microbe-killing properties
  • Applying them to practical surfaces
  • Evaluating effectiveness against diverse pathogens in lab tests
• Impact: These materials enhance safety in public and clinical settings by preventing infections.

Advancing Microbiology Diagnostics: Sepsis and Sequencing

• The Challenge: Slow, imprecise diagnostics for sepsis and bloodstream infections (BSIs) delay species-specific identification, hindering timely treatment.
• Our Approach: We develop advanced molecular diagnostic tools to:
  • Rapidly detect and identify bacteria, fungi, and parasites in blood samples
  • Compare performance against traditional diagnostics in clinical settings
  • Improve speed and accuracy for better patient outcomes
• Impact: Faster, precise diagnostics transform sepsis care, enabling tailored therapies that save lives.

Patents

• Hall, D.C., Jr., Ji, H., Ehrlich, G.D. (2025). Methods of Treating, Ameliorating, and/or Preventing Bacterial Infection, or Methods of Reducing Adverse Effects Caused by Bacteria. U.S. Patent Application 18/884,251, filed March 20, 2025.
• Ji, H., Ehrlich, G.D., Hall, D.C., Jr., Król, J.E., Cahill, J.P. (2023). RelA Inhibitors for Biofilm Disruption. U.S. Patent 11,666,555, issued June 6, 2023.

Drexel Magazine (2023)

Selected Publications

鈥淪urfactant-Impregnated MOF-Coated Fabric for Antimicrobial Applications鈥�
Schwenk, G. R.; Glass, A. M.; Ji, H.-F.; Ehrlich, G. D.; Navas-Martin, S.; Kr贸l, J. E.; Hall, D. C., Jr.
ACS Applied Bio Materials. 2023 January; 6 (1), 238

鈥淏acterial Biofilm Growth on 3D-Printed Materials鈥�
Hall Jr. D. C., Palmer P., Ji H., Ehrlich G, Kr贸l J
Frontiers in Microbiology. May 2021 12:646303

鈥淭he Development of a Pipeline for the Identification and Validation of Small-Molecule RelA Inhibitors for Use as Anti-Biofilm Drugs鈥�
Hall Jr. D. C., Kr贸l J, Cahill J, Ji H, Ehrlich G
Microorganisms. 2020 August 28; 8(9):1310

鈥淎 search for medications to treat COVID-19 via in silico molecular docking models of the SARS-CoV-2 spike glycoprotein and 3CL protease鈥�
Hall Jr. D. C., Ji H
Travel Medicine and Infectious Disease. 2020 May; 35:101646

Invited Talks

鈥淪tringent Response Inhibitors: A Pathway to Novel Antibiofilm Agents鈥�
Keynote Lecture, ILADS International, Munich, Germany (April 2024)

鈥淥utsmarting Pathogens: Navigating the Frontier of Drug Discovery with Stringent Response Inhibitors鈥�
805th EPAASM Branch Meeting, Philadelphia, Pa. (September 2023)

鈥淩ational Development of Anti-Biofilm Drugs鈥�
Shirtliff Biofilm Symposium, UMD, College Park, Md. (March 2023)