795th Monthly Meeting – May 23, 2022 – Annual Student Chapter Meeting
Mechanisms of genetic change and the natural history of pathogenesis in Haemophilus influenzae
Joshua Chang Mell, Ph.D.
Assistant Professor of Microbiology & Immunology
Drexel University College of Medicine
The main goal of the Mell lab is to understand how mechanisms of inheritance affect genetic
variation, and conversely, how genetic variation affects mechanisms of inheritance (i.e., “the
genetics of genetics”). Our primary model system is the human bacterial pathogen Haemophilus
influenzae, an important agent of ear infections (otitis media) in children, as well as lung infections
associated with chronic respiratory conditions. H. influenzae, like many other pathogens, is
naturally competent, able to actively transport environmental DNA through its cell membranes
and incorporate homologous molecules into its chromosomes. This pathway, called “natural
transformation,” is a major mechanism of gene transfer across bacteria and has a profound effect
on genome evolution, including spreading antibiotic resistances and other virulence
determinants. Our current research seeks to answer three major questions using a combination
of microbiology, molecular genetics, and genomics/bioinformatics approaches:
- What factors control transformation frequency across the genome?
- Can natural transformation be exploited to map pathogenesis genes?
- How do bacterial genomes change during the course of chronic infections?
Student Talks (4:00pm to 5:00pm)
4:00-4:20pm: “Toll-Like Receptors Dictate Microglia Responses to Beta-Coronaviruses”
Elijah Davis, PhD Candidate in the Navas-Martin lab, Drexel University College of Medicine
4:20-4:40pm: “The role of bacterial amyloid curli in Salmonella-induced Reactive Arthritis”
Kaitlyn Grando, PhD Candidate in the Tükel lab, Temple University Lewis Katz School of Medicine
4:40-5:00pm: “The role of the Kingella kingae lipopolysaccharide in galactan surface anchoring”
Nina Montoya, PhD Candidate in the St. Geme lab, University of Pennsylvania Perelman School of Medicine
5:15 – 6:15pm Keynote Speaker
This lecture was recorded and can be viewed on the EPAASM YouTube channel, click here: View Lecture