Environmental investigation of potentially pathogenicVibrio parahaemolyticusin the Seto-Inland Sea, Japan

Abstract

Seawater and organic material (live and/or dead matter deposited on any substratum submersed in seawater) were collected during the cool weather season from a coast of the Seto-Inland Sea, Japan, and analyzed to determine Vibrio parahaemolyticus densities and the occurrence of pathogenic strains, defined as those possessing tdh and/or trh genes by the polymerase chain reaction (PCR), using isolated DNA from enrichment culture of the samples. About 95% of the samples were positive for V. parahaemolyticus (with densities of 3 to >1400 cells per 100 ml water or 10 g organic samples) by the most-probable-number (MPN)-PCR technique with species-specific toxR primers, but only 40% were positive by the conventional MPN-culture technique (with densities ranging from 3 to 240 cells per 100 ml water or 10 g organics). Furthermore, the tdh and trh genes were positive in 55% and 20% of samples, respectively, by the MPN-PCR technique. No tdh and trh gene-positive strains were isolated by the conventional MPN-culture procedure. The difference in detection between the MPN-culture and the MPN-PCR techniques appeared to be significant and may be attributed to different detection sensitivities and other factors.

Pandemic Vibrio parahaemolyticus O3:K6 on the American continent

“…Vibrios cultured from environmental samples commonly lack the genes coding for proteins with associated pathogenic functions in humans and marine animals (e.g., tdh in V. parahaemolyticus ) (Deepanjali et al, 2005; Canizalez-Roman et al, 2011; Gutierrez West et al, 2013). However, few studies have reported the presence of the tdh and trh genes in V. parahaemolyticus strains of environmental origin; only 0–6% of the samples analyzed from the coasts of the U. S. (Kaysner et al, 1990; Depaola et al, 2000), Europe (Hervio-Heath et al, 2002), and Asia contained the tdh and/or trh genes (Vuddhakul et al, 2000; Wong et al, 2000; Alam et al, 2002). Most of the environmental strains are known to be KP-negative, and only 1–2% of the samples are KP-positive (Joseph et al, 1982; Nishibuchi and Kaper, 1995).…”

Distribution and dynamics of epidemic and pandemic Vibrio parahaemolyticus virulence factors

“…Although the gastroenteritis may be self-limited, the infection can cause septicemia that is life-threatening to those with a preexisting medical conditions (Su and Liu, 2007). In Japan, V. parahaemolyticus is responsible for 20–30% of all food poisoning cases (Alam et al, 2002) and is the common cause of seafood-borne illness in many Asian countries (Koralage et al, 2012; Yu et al, 2013). V. parahaemolyticus has also become the leading agent of human gastroenteritis associated with seafood consumption in the United States (Newton et al, 2012).…”

Genetic characterization of trh positive Vibrio spp. isolated from Norway

“…The frequency of tdh and/or trh expression among environmental V. parahaemolyticus isolates is typically <1%, but this may depend on location, sample source and detection method (Kaysner et al, 1990; Alam et al, 2002; Cook et al, 2002; Hervio-Heath et al, 2002; Martinez-Urtaza et al, 2008b). For example, between 49 and 78% of the sediment, water, or oyster samples from Willapa Bay (WA, U.S.) contained trh + V. parahaemolyticus (Kaysner et al, 1990).…”