Daniel Nelson

Professor

Nelson Group

Contact

Email: nelsond@umd.edu

Call: (240) 314-6249

Education

  • Postdoctoral Research, Bacterial Pathogenesis, Rockefeller University, 1999-2004
  • Ph.D., Biochemistry and Molecular Biology, University of Georgia, Athens, 1999
  • M.B.A., Zicklin School of Business, City University of New York, 2003
  • B.S., Biology, University of California, Irvine, 1993

Profile

Dr. Nelson is an internationally recognized researcher in the field of antimicrobial discovery. The alarming increase of multidrug-resistant bacteria, the emergence of new pathogens, and the desire to reduce/eliminate antimicrobial use in agriculture products have prompted new antimicrobial discovery initiatives. Researchers seek to identify and develop alternative antimicrobial therapeutics that are not susceptible to traditional antibiotic resistance mechanisms. The Nelson lab harnesses peptidoglycan hydrolase enzymes, called endolysins, from bacteriophage and applies them to bacterial pathogens. These enzymes act rapidly on contact to degrade the bacterial cell wall of both animal and human pathogens, resulting in death of the bacterial cell.

CURRENT RESEARCH

Electron microscopy of a pneumococcal cell undergoing endolysin-mediated lysis. The cell wall has been degraded and the extruding membrane is osmotically ruptured.

The Nelson lab works with endolysins effective against several human pathogens, including methicillin-resistant Staphylococcus aureus (i.e. MRSA), Clostridium difficile, Streptococcus pyogenes, and Bacillus anthracis (anthrax). The lab is also studying endolysins effective against critical animal pathogens, including  Streptococcus equi (equine strangles disease), Streptococcus suis (meningitis and other infections in pigs), Streptococcus uberis (bovine mastitis), and Staphylococcus aureus (bovine mastitis). 

Dr. Nelson brings together the unique ability to cross disciplines and effectively incorporate cell biology, microbiology, and structural biology with bioengineering approaches to advance endolysin research and discovery. Employing rational methods (computational design or chimeragenesis) and random methods (directed evolution), his group is generating endolysins with more desirable attributes, such as higher activity, an expanded host range, a more favorable thermostability profile, or the ability to enter human cells to kill intracellular pathogens. It is anticipated that these bioengineering approaches will result in development of the next generation endolysins with enhanced properties.

Most recently, the Nelson lab is developing a platform technology, termed InstaVax, which exploits the ability of endolysin binding domains to target an “ImmunoBridge”, an antigen against which most people have circulating antibodies, to the surface of bacteria. The endolysin domains will redirect the pre-existing immunity against the ImmunoBridge towards the invading pathogen, leading to clearance of infection. 

     

Publications
2022
Immunogenicity of Endolysin PlyC.
Controlled Proteolysis of an Essential Virulence Determinant Dictates Infectivity of Lyme Disease Pathogens.
Structure of Escherichia coli O157:H7 bacteriophage CBA120 tailspike protein 4 baseplate anchor and tailspike assembly domains (TSP4-N).
2021
DNA Dye Sytox Green in Detection of Bacteriolytic Activity: High Speed, Precision and Sensitivity Demonstrated With Endolysins.
Computational models in the service of X-ray and cryo-electron microscopy structure determination.
Molecular basis for recognition of the Group A Carbohydrate backbone by the PlyC streptococcal bacteriophage endolysin.
High avidity drives the interaction between the streptococcal C1 phage endolysin, PlyC, with the cell surface carbohydrates of Group A Streptococcus.
Application of bacteriophage-derived endolysins to combat streptococcal disease: current state and perspectives.
2020
Characterization of the Bacteriophage-Derived Endolysins PlySs2 and PlySs9 with In Vitro Lytic Activity against Bovine Mastitis Streptococcus uberis.
Structure and function of bacteriophage CBA120 ORF211 (TSP2), the determinant of phage specificity towards E. coli O157:H7.
2019
Linker Editing of Pneumococcal Lysin ClyJ Conveys Improved Bactericidal Activity.
Characterization of LysBC17, a Lytic Endopeptidase from Bacillus cereus.
Contributions of Net Charge on the PlyC Endolysin CHAP Domain.
Structure and tailspike glycosidase machinery of ORF212 from E. coli O157:H7 phage CBA120 (TSP3).
ClyJ Is a Novel Pneumococcal Chimeric Lysin with a Cysteine- and Histidine-Dependent Amidohydrolase/Peptidase Catalytic Domain.
2018
Safety Studies of Pneumococcal Endolysins Cpl-1 and Pal.
Discovery and Biochemical Characterization of PlyP56, PlyN74, and PlyTB40-Bacillus Specific Endolysins.
Borrelia burgdorferi surface-located Lmp1 protein processed into region-specific polypeptides that are critical for microbial persistence.
Short communication: Recombinant bacteriophage endolysin PlyC is nontoxic and does not alter blood neutrophil oxidative response in lactating dairy cows.
2017
Complete Genome Sequence of Klebsiella pneumoniae Phages SopranoGao, MezzoGao, and AltoGao.