A Characterization of Potentially Pathogenic Vibrio vulnificus Isolates Found in the New Hampshire Great Bay Estuary

Sarah E. Sanders, Stephen Jones, Loren Launen Department of Biology, Keene State College; Department of Natural Resources and Environmental Science,

University of New Hampshire

Introduction

Use whole genomic sequencing to categorize isolates into biotypes by genomic analysis.

Create phylogenies between GBE isolates and other Vibrio vulnificus bacteria, including known pathogens.

Determine if the rising numbers of GBE isolates are due to increased numbers of diverse Vibrio vulnificus or to expansion of a particular biotype.

Research Goals

A pathogen is any microorganism that causes disease. Staphylococcus aureus and Mycobacterium tuberculosis are examples of pathogenic bacteria. Determining bacterial pathogenicity is accomplished by characterizing aspects of bacterial structure as potential virulence factors. For instance, many pathogenic bacteria produce phenotypic capsules in order to protect themselves from the host’s immune system.

Method

Acknowledgements

Return to lab to test ideas

Design experiments to assess phenotype

Comparative genomics

Sequence gDNA and assemble chromosomes

Isolate gDNA from strains

Isolate Vibrio vulnificus from oysters (UNH)

Explore human or environmental interaction as potential drivers for biotype selection in the Great Bay Estuary.

Design experiments that link bacterial phenotype to genotype to assess potential bacterial pathogenicity.

Vibrio vulnificus is a prevalent bacterium found in both seawater and brackish areas of the United States, such as the Great Bay Estuary (GBE) of New Hampshire. Infections by Vibrio vulnificus are caused by wound exposure to seawater or by consumption of raw seafood such as oysters. Symptoms range from abdominal pain and vomiting to more severe effects such as septicemia, wound necrosis and gastroenteritis. Infections are especially deadly toward persons who have immunocompromised conditions or who suffer from liver cirrhosis due to alcohol toxicity. Interestingly, although the number of Vibrio vulnificus bacteria has risen markedly in recent years in the GBE, there have been no known infections.

In our lab, we hope to characterize Vibrio vulnificus isolates from the GBE at the genetic and phenotypic levels in order to better determine their potential pathogenicity and understand why their levels are rising.

Future Directions

Research students handling Vibrio vulnificus bacteria using biosafety

level 2 procedures

Wound necrosis caused bya Vibrio vulnificus infection

(Photo by Bayou Woman)

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Number of Vibrio vulnificus Isolated From the Great Bay Estuary in Years Sampled

Capsule showing structural support in bacteria

Support for this project is provided through the NH EPSCoR Program via the National Science Foundation’s Research Infrastructure Improvement Award # IIA-1330641. Support for student research salaries was provided in part by the IDeA Program, NIH Grant No. P20GM103506 (National Institute of General Medical Sciences). We thank Chantale Lacroix and Katie Featherston for technical support, Will Wroebel for photography support, Dana Gibson for poster support, Marianne O’Brien, Emma Wilson, and Brooke Miller, as well as the Keene State Office of Sponsored Projects and the School of Science and Social Science for administrative support.