DATE: January 31, 2017
TIME: 9:00AM PT, 12:00PM ET

Gautam Dantas - While the most acute effects of increasing antibiotic resistance in pathogens are observed in clinical settings, it is becoming increasingly clear that the evolution and transmission dynamics of resistance gene dissemination is an ecological problem. Indeed, steady use and abuse of antibiotics over the past century in food animals, humans, and the environment has provided substantial selective pressure for enrichment of resistance genotypes in each of their associated microbiomes. An over-reliance on culture-based methods, the standard in the study of clinical resistance, has vastly underestimated these reservoirs of resistance genes (or ‘resistomes’). To address this issue, we have recently developed high-throughput metagenomic functional selections, aided by next-generation sequencing, to characterize resistomes encoded by the microbiota of healthy human adults and children as well as diverse soils. By combining these analyses with 16S amplicon sequencing and deep shotgun sequencing, we model the impact of various anthropogenic perturbations on the transmission and evolutionary dynamics of microbial communities and their resistomes across time and habitats. Hundreds of resistance genes we identify from specific taxa in these different microbial communities are identical to resistance genes found in major human pathogens, indicating recent genetic exchange between these microbes. We also find thousands of functionally validated resistance genes which are genetically novel, but flanked by genes involved in horizontal gene transfer, including transposases and integrases. Together, these findings highlight the substantial antibiotic resistome encoded by microbes from diverse environments, which is available for exchange with pathogens, with the potential to severely exacerbate the problems with clinical resistance.

Shuiquan Tang - The rapid growth of Microbiomics and Metagenomics Studies has increased the demand for standard methods to improve the reproducibility and quality of the data being generated.   Therefore, there is a need for standard reference materials for the development, evaluation, calibration, and validation of complex microbiomics workflows encompassing sample collection, sample preparation, and analyses. To address these fundamental challenges, the scientists at Zymo Research have created reference materials for the development of the most accurate and unbiased workflows from sample collection to analyses. In this seminar, we will show how these reference materials improve the quality of data generated from Microbiomic studies.

Learning Objective 1: Attendees will learn about networks of exchanging antibiotics resistance across human commensal, environmental, and pathogenic bacteria.

Learning Objective 2: Attendees will learn how individual steps in their microbiomics workflow can be standardized to greatly improve the quality and reproducibility of the data generated.