Emergence of a New Vibrio parahaemolyticus Serotype in Raw Oysters

Abstract

This is the first reported outbreak of V parahaemolyticus serotype O3:K6 infection in the United States. The emergence of a virulent serotype and elevated seawater temperatures and salinity levels may have contributed to this large multistate outbreak of V parahaemolyticus. Bacteriologic monitoring at harvest sites did not prevent this outbreak, suggesting that current policy and regulations regarding the safety of raw oysters require reevaluation. Consumers and physicians should understand that raw or undercooked oysters can cause illness even if harvested from monitored beds. In patients who develop acute gastroenteritis within 4 days of consuming raw or undercooked oysters, a stool specimen should be tested for Vibrio species using specific media. JAMA. 2000;284:1541-1545.

Biosynthesis of the Osmoprotectant Ectoine, but Not Glycine Betaine, Is Critical for Survival of Osmotically Stressed Vibrio parahaemolyticus Cells

“…Vibrio parahaemolyticus is of significant medical importance, as it is the leading cause of seafood-associated bacterial gastroenteritis worldwide (20)(21)(22)(23). Generally, the bacterium infects the host through the gastrointestinal tract, where it encounters stress conditions such as low pH, bile salts, antimicrobial peptides, and low salinity as well as challenges from the host immune system.…”

Vibrio parahaemolyticusO3:K6 Epidemic Diarrhea, Chile, 2005

“…parahaemolyticus ( 3 , 4 ). Stool samples of 60 patients with acute diarrhea were analyzed by standard procedures ( 5 , 6 ). Serotyping confirmed that all V .…”

“…Serotyping confirmed that all V . parahaemolyticus isolates were O3:K6 ( 5 , 6 ), did not produce urease, and showed the Kanagawa phenomenon (virulence-associated hemolysis) ( 5 8 ). PCR analysis indicated that the genome of these isolates contained tdh , tlh , and toxRS /new open reading frame 8 DNA sequences and lacked trh sequences ( 1 , 7 ), which are consistent with molecular characteristics of the pandemic clone O3:K6 ( 1 , 5 – 8 ).…”

“…parahaemolyticus O3:K6 to affect many susceptible persons if preventive measures are not taken and enforced quickly ( 6 – 9 ). Temperature and salinity have been reported as factors that influence concentrations of V .…”

“…parahaemolyticus O3:K6 pandemic clone may have also been facilitated by expansion of international trade because bacteria could have been transported to Chile by ballast water from the Northern Hemisphere ( 1 , 4 , 6 ). As in previous outbreaks, shellfish responsible for this epidemic were harvested near international shipping lanes ( 1 , 3 , 4 , 6 ). The appearance of V .…”