Comparison of two selective and differential media for the isolation of Vibrio vulnificus from the environment

Introduction Vibrio vulnificus is an opportunistic human pathogen that naturally inhabits estuarine and coastal waters worldwide. This gram-negative bacterium is ubiquitous in these environments and has been isolated from water, sediments, fish, and shellfish such as bivalve mollusks. V. vulnificus is a medically important pathogen due to its ability to cause fulminant and potentially fatal systemic infection when ingested via raw or undercooked shellfish. In addition, this water-borne pathogen can cause severe wound infections often resulting in necrotizing fasciitis. Considering the medical relevance of this pathogen, it is important to be able to isolate and identify this organism from the environment even when occurring at very low numbers. Our lab has previously developed and modified a selective and differential medium, CPC+, which is efficient at isolating V. vulnificus from the environment without the need for enrichment (Warner and Oliver, 2007). Recently, another medium, CHROMagar Vibrio (here denoted CaV) has come into use as a means for isolating vibrios from the environment. The goal of our study was to compare the efficacy of CPC+ and CaV in isolating V. vulnificus, and to highlight the benefits and downfalls of each one.