In the initial ideate phase, our team set out to find a problem plaguing local, nationwide, and worldwide communities that we could solve using synthetic biology. We started at the local level, researching various medicinal and environmental issues in the state of Florida, and seeing if similar trends applied at a national level. Our interest was initially piqued by a study conducted on dolphin species in the Indian River Lagoon that provided evidence of an increase in antibiotic resistance in the water over a 12-year period. Upon further research, we saw similar findings from California and Washington all the way to China and Australia. We decided to develop a solution to this problem due to its strong impact in our local community, as well as its ability to be generalized throughout the world.
As we delved deeper into the project, we found a critical problem. We contacted dozens of employees from the Florida Department of Environmental Protection (FDEP) for information about antibiotic testing in Florida’s waterways and wastewater treatment plants but found no direct studies or established protocols in place. Many responses were unaware of testing for antibiotics in Florida’s waters. Treatment plant managers and owners corroborated this finding.
South Shores WWTP near the Indian River Lagoon that a team member visited to speak with Mike Kelley
One of our members went on a socially distanced visit to a private treatment plant located near the Indian River Lagoon to discuss the lack of antibiotic testing with owner Mike Kelley. He informed us that the FDEP does not test influent or effluent samples for antibiotic concentrations. Mr. Kelley also told us that treatment plants do not have any infrastructure in place to degrade or remove antibiotics and antibiotic resistance genes during the treatment process, leaving them completely unregulated.
OUR SOLUTION
Our solution to the growing antibiotic resistance problem is called Sewage Purification Limiting Antibiotic Spread in Habitats, or SPLASH. SPLASH is an engineered E. coli cell that contains a constitutive promoter to allow constant production of transcripts of the ereB gene. These transcripts are translated to the erythromycin esterase type II protein, which will hydrolyze erythromycin molecules. The E. coli cell will also contain a toxin/antitoxin kill switch. This system works because the cell will always produce transcripts of the gene that is toxic to the cell, but it will only produce the antitoxin in the presence of methane, which is known to be found in wastewater treatment plants. In low concentration of methane, the cell stops producing the antitoxin which allows the toxin to kill the host cell and renders the plasmid useless when it is used by another bacteria
