Title: In sickness and in health: using genomics and metagenomics to study the human gut microbiome before, during, and after traveler’s diarrhea
Presenter: Taylor Richter (Institute of Genome Science, University of Maryland, School of Medicine)
Description: Severity of diarrheal disease is dependent on the interactions between the pathogen, resident microbiome, and host factors (such as immune function). Here we investigate the interactions between enterotoxigenic E. coli (ETEC), a leading cause of diarrhea in the developing world, and the resident population of E. coli as well as the rest of the microbiome of six human hosts. Individual E. coli colonies and whole community DNA were isolated as part of an ETEC challenge study, from before, during, and after ETEC infection. Whole genome sequences obtained from the E. coli colonies were used in phylogenomic and comparative genomic analyses to investigate the diversity of the resident E. coli, as well as the dynamics of the challenge strain, H10407. ETEC failed to become the dominant E. coli clone in two of the six challenge subjects, each whom exhibited limited clinical presentation of diarrhea. The E. coli communities of the remaining four subjects became ETEC dominant during the challenge, but returned to their original, subject-specific populations following treatment with antibiotics, suggesting resiliency of the resident E. coli population following major ecological disruptions. Both 16S rRNA and complete metagenomic sequence analyses were performed to study the responses of the resident bacterial community to the pathogen challenge and antibiotics. Shannon diversity and species relative abundance measurements confirm that alterations to the microbial community are subject-specific, but are not directly correlated with disease severity. These studies provide valuable insight in to the impact of the ETEC challenge and antibiotic treatment on the gastrointestinal tract microbiome, as well as the composition and responses of microbial communities resistant and susceptible to perturbation.
Location: Smith Hall, room 359
Time: 3:30pm
Date: March 27th, 2018
