Isolation, Characterization, and Antibiotic Susceptibility Testing of Halophilic Bacteria from the Grand Saline Salt Marsh

Halophilic bacteria have the ability to survive in hypersaline environments and are of interest because of the unique mechanisms they utilize to survive in high salt concentrations. However, environmental halophiles have not been well characterized in the past, especially regarding antibiotic susceptibility testing. A few recent studies have been conducted that indicate the presence of antibiotic resistance genes in bacteria that have been around since before the widespread use of antibiotics (Martinez 2012; Dennis 2014). By examining the antibiotics susceptibility of halophilic bacteria isolated from the Grand Saline Salt Marsh, this could give further clues as to how the purpose of antibiotic resistance genes found in nature have changed over time. For this project, three wet soil samples were collected at different sites around the salt marsh. Isolates were assessed with 16s rRNA gene sequencing, biochemical testing, and optimum salt tolerance determination in order to identify the isolates. Antibiotics susceptibility testing of the isolates was performed using the Kirby-Bauer method.