Winners of "My Research in 180 Seconds"

Dr. Marco Alsina and Taylor Brown won 1st place and Audience Choice in the "My Research in 180 Seconds" competition. Check out their topics and transcripts below!

"Living on the Edge: Probing the Identity of Metals in Consumer Products"
Dr. Marco Alsina
1st place winner

Introduction and Motivation 
We use healthcare products routinely, or better put we release these products into the environment daily. Global sales of consumer health care products amount to over 280 billion (!) US dollars yearly, with products ranging from soap, toothpaste, shampoo, to cosmetics and sunscreens.

A significant fraction of these products contain metals such as Zn, Cu, and Sn. Although the effectiveness of using metals is well documented by clinical assays, there is much less information about their stability inside the product, or their toxicity once released into the environment. Metal toxicity is intimately linked to chemical identity, so in order to answer these questions we must be able to probe such metals. But how do we do that? Well we can use X-ray absorption spectroscopy, or XAS for short.

X-ray absorption spectroscopy

Well, matter contains atoms, and atoms contain electrons. By introducing energy via X-rays, can literally light electrons up to go beyond the edge of atomic confinement.

Further, the outgoing electron creates waves that are reflected by neighbor atoms, in analogy to a pebble being thrown at a pond. Such reflections depend on the nature of the surrounding neighbors, so a metal that is bound with carbonates produce a different signal than a metal bound to sulfates or phosphates, for instance.

Therefore, by measuring the XAS spectrum of known reference compounds we can interpret the signal of unknown samples, and determine the most likely environment for the metal. Further, we can use computational models to gain detailed insights into the structure of such compounds, including their energy required to reshape them.

This information is relevant for (i) product manufacturers, who seek to maximize the efficacy of their formulations; and for (ii) regulatory agencies, who seek consumer and environmental safety. In addition, understanding the mechanisms that govern the fate of these products holds the key for the development of recovery technologies that sustain circular green-economies, much needed in today’s world. But even in the face of great technological achievement, real change must come from within ourselves. In the words of Viktor Frankl:

“We must never forget that we may also find meaning in life even when confronted with a hopeless situation, when facing a fate that cannot be changed. For what then matters is to bear witness to the uniquely human potential at its best, which is to transform a personal tragedy into a triumph, to turn one’s predicament into a human achievement. When we are no longer able to change a situation we are challenged to change ourselves”.

Thank you for listening.

"Mobile Antibiotic Resistance Genes in the Indoor Microbiome"
Taylor Brown
Audience Choice winner

In indoor environments, bacteria face selective pressure to carry antibiotic resistant genes (ARGs) from antimicrobial substances used in furniture, building materials, and personal care products. Humans rely on antibiotics to clear bacterial infections, so understanding the way in which these genes are transferred, i.e., on mobile genetic elements, is critical. To investigate this phenomenon, dust samples were collected from over 100 collection sites in over 40 different athletic facilities. DNA from these samples was sequenced to assemble a metagenomic database, which was analyzed to locate ARGs in mobile genetic elements. In parallel, bacteria were cultured from these samples and exposed to antibiotics to screen for resistance phenotypes, and plasmid DNA was extracted from resistant species. From the metagenomics data, the ARG gidB was found only on plasmids, a common method of horizontal gene transfer. This gene codes for resistance to streptomycin, an antibiotic used to treat tuberculosis. Seven strains of streptomycin-resistant bacteria were identified from the culture isolates. To confirm the presence of gidB on plasmids in resistant bacteria, PCR primers were developed by dividing known sequences of gidB genes into categories based on their phylogenetic tree. This gene evolves quickly, so creating more than one specific primer was necessary. Optimization is ongoing to uniquely amplify this gene. Once gidB is identified in plasmid DNA, future experimentation will determine if this gene can be passed to other species of bacteria through conjugation. These results will direct future recommendations for antibiotic development and indoor environment design.