Exploring potential threats of antibiotic resistance in Vibrio. spp isolated from oysters on Georgia’s coast

Georgia’s coastal region is looking to expand the existing oyster mariculture industry, but safety of this is unknown. To determine safety of this expansion, concentrations of 3 species of Vibrio bacteria were monitored over a calendar year near Sapelo Island and Brunswick, GA; antibiotic tests were done to assess antibiotic resistance patterns from bacteria found at these sites. Vibrio spp. are commonly found in shellfish, including oysters. V. alginolyticus, V. parahaemolyticus, and V. vulnificus can cause illnesses if the oysters consumed contain a high enough concentration of bacteria. V. vulnificus can cause life-threatening necrotizing fasciitis, while V. parahaemolyticus is the leading cause of seafood-borne illness worldwide. V. alginolyticus can cause mild wound infections, but is more threatening to oysters, causing high mortality amongst populations. These infections are treated using antibiotics, but antibiotic resistance patterns existing amongst the bacteria pose an increased risk to consumers. V. parahaemolyticus samples were further tested against 8 different antibiotics to investigate antibiotic resistance patterns; this species was chosen as it was the most concentrated during the collection period. Isolation of V. parahaemolyticus was done using CHROMagar^TM, and antibiotic resistance tests were performed using Liofilchem® antibiotic concentration strips. Minimum Inhibitory Concentration (MIC) values were recorded and compared to international resistance standards. Results show that there are approximately equal amounts of Vibrio spp. found in all sites. V. parahaemolyticus has shown resistance to at least one antibiotic. This work can be used to create a warning to consumers about true safety of oyster consumption.