The Occurrence of Vibrio vulnificus, V. parahaemolyticus and V. cholerae in the Indian River Lagoon, Florida, with Implications for Human Health

Summary: Vibrio bacteria are emerging pathogens responsible for 80,000 illnesses and 100 deaths in the United States each year. Infections are directly linked to the marine environment and are acquired by consuming contaminated seafood or exposing wounds during aquatic activities. Florida has the highest national incidence of vibriosis, with 20% of its cases reported from the Indian River Lagoon region, a popular recreation destination. This study utilized a combination of cultivation and molecular techniques to investigate the local distribution of V. vulnificus, V. parahaemolyticus and V. cholerae in this local waterway. The targeted species were found in an array of samples which may facilitate their transmission to humans. Overall, these bacteria were abundant in estuarine sediments (Vp: 2,439 CFU/g, Vv: 303 CFU/g, Vc: 176 CFU/g), on the sharp edges of oyster shells (Vp: 82 CFU/cm, Vv: 102 CFU/cm, Vc: 41 CFU/cm), and in the water column (Vp: 3.78 CFU/ml, Vv: 5.51 CFU/ml, Vc: 2.46 CFU/ml). Vibrio also pose a hazard to recreational anglers as they were recovered from fish (Vp: 61%, Vv: 55%, Vc: 30%), live bait shrimp (Vp: 80%, Vv: 37%, Vc: 0%) and hooks (Vp: 32%, Vv: 18%, Vc: 0%). Additionally, a molecular analysis of the V. vulnificus virulence revealed that the local population was dominated by disease-causing (vcgC) strains, which may explain why wound-related infections are common in this region. Vibrio occurrence varied both spatially and temporally due to their relationship with salinity and temperature. These bacteria exhibited a strong negative correlation with salinity, being particularly abundant near freshwater discharge locations. Due to Florida’s year-round warm climate, these species were found to be permanent members of the local microbial community. Seasonal peaks in abundance occurred between August and October, a period which corresponds with the warmest water temperatures as well as frequent rainfall. Predictive models were constructed based on
2016
Includes bibliography.
Degree granted: Dissertation (Ph.D.)--Florida Atlantic University, 2016.
Collection: FAU Electronic Theses and Dissertations Collection