Category Archives: Vibrio

USA – New Oyster Rules Aim to Reduce Vibrio Cases

Coastal Review

Division of Marine Fisheries Director Steve Murphey implemented the new oyster harvest control measures through Proclamation SS-1-2020  and Proclamation SS-2-2020, both issued Monday.

The Division of Marine Fisheries announced that while the state’s public health record concerning shellfish-related illnesses is one of the best in the country, the number of Vibrio cases nationwide had increased in recent years. Vibrio are naturally occurring bacteria in coastal waters that can cause illness in humans if precautions are not taken during the warmer months of the year.

The new regulations also will bring the state into conformity with guidance from the National Shellfish Sanitation Program, which is the federal, state and industry cooperative program recognized by the U. S. Food and Drug Administration and the Interstate Shellfish Sanitation Conference for the sanitary control of shellfish produced and sold for human consumption.

The changes include the following new requirements to:

  • Shade oysters harvested between May 1 and Oct. 14. This involves providing shade over harvested oysters or covering the oysters with a light-colored tarp or other nontoxic material while they are stored on the vessel, floating container when the oysters are not submerged, or a vehicle (this is already required for the harvest of clams in the summer).
  • Resubmerge oysters exposed to the air for greater than five hours between May 1 and Oct. 14 (this might occur during air-drying or de-fouling with gear such as OysterGro). The oysters must remain submerged for at least 14-days to abate Vibrio levels that may have been elevated.
  • Clarify that when working in intertidal waters the term “start of harvest” begins when the oyster is first exposed by the receding tide.
  • Clarify the tagging procedures when oysters leave the lease for tumbling or culling.
  • Resubmerge oysters moved from one growing area to another for at least 21 days prior to harvest (Certified shellfish dealers with a wet storage permit are exempt). This may prevent the closure of multiple growing areas in the event of an illness outbreak.

Previously implemented regulations pertaining to recording the start of harvest on the harvest tag and delivering the oysters to a licensed dealer within a specified time remain in effect.

For more information, contact Shannon Jenkins, chief of the division’s Shellfish Sanitatio

RASFF Alert- Vibrio cholerae – Raw Soft Shelled Crab


RASFF – Vibrio cholerae (presence /25g) in raw soft shell crabs from Thailand in the Netherlands

USA – Cooked Butterfly Tail-On Whiteleg Shrimp (Sushi Ebi), Lot #2019.10.02 – Vibrio


CDC Vibrio

Image CDC

AFC Distribution Corp. (“AFC”) of Rancho Dominguez, California is voluntary recalling Cooked Butterfly Tail-On Whiteleg Shrimp (Sushi Ebi), Lot #2019.10.02, utilized in various prepared menu offerings with sell-by dates ranging from 02/19/2020 to 03/13/2020, because this ingredient may have a potential to be contaminated with Vibrio parahaemolyticusVibrio parahaemolyticus is an organism which can cause illnesses such as nausea, vomiting, diarrhea, fever and chills.

The recalled ingredient, Cooked Butterfly Tail-On Whiteleg Shrimp (Sushi Ebi), was distributed to designated retail AFC sushi counters, where it is further processed into prepared sushi items, within grocery stores, cafeterias, and corporate dining centers in the following states: AK, AL, AR, AZ, CA, CO, CT, FL, GA, IA, AD, IL, IN, KS, KY, LA, MA, MD, MI, MN, MO, MT, NC, ND, NE, NH, NM, NY, OH, OR, PA, SC, SD, TN, TX, UT, VA, WA, WV, WY.

To date there have been no confirmed illnesses.

While AFC has ceased using the recalled ingredient, we urge anyone who has any AFC product containing Cooked Butterfly Tail-On Whiteleg Shrimp to discard or return product to their point of purchase for a full refund.


Research -An in situ-Synthesized Gene Chip for the Detection of Food-Borne Pathogens on Fresh-Cut Cantaloupe and Lettuce


Fresh foods are vulnerable to foodborne pathogens which cause foodborne illness and endanger people’s life and safety. The rapid detection of foodborne pathogens is crucial for food safety surveillance. An in situ-synthesized gene chip for the detection of foodborne pathogens on fresh-cut fruits and vegetables was developed. The target genes were identified and screened by comparing the specific sequences of Salmonella Typhimurium, Vibrio parahemolyticusStaphylococcus aureusListeria monocytogenes, and Escherichia coli O157:H7 from the National Center for Biotechnology Information database. Tiling array probes were designed to target selected genes in an optimized hybridization system. A total of 141 specific probes were selected from 3,227 hybridization probes, comprising 26 L. monocytogenes, 24 S. aureus, 25 E. coli O157:H7, 20 Salmonella Typhimurium, and 46 V. parahemolyticus probes that are unique to this study. The optimized assay had strong amplification signals and high accuracy. The detection limit for the five target pathogens on fresh-cut cantaloupe and lettuce was approximately 3 log cfu/g without culturing and with a detection time of 24 h. The detection technology established in this study can rapidly detect and monitor the foodborne pathogens on fresh-cut fruits and vegetables throughout the logistical distribution chain, i.e., processing, cleaning, fresh-cutting, packaging, storage, transport, and sale, and represents a valuable technology that support the safety of fresh agricultural products.

Research – Researchers find spread of bacteria in seafood likely impacted by trade

Food Safety News

A Centers for Disease Control and Prevention study has found that international trade of shellfish might be involved in the dispersal of Vibrio parahaemolyticus populations into the United States and Spain. The study found that severe weather, such as El Niño conditions in Peru, provide ideal conditions for the proliferation of Vibrio parahaemolyticus, Vibrio alginolyticus and Vibrio vulnificus.

The CDC reports that compared to other major foodborne illnesses, Vibrio parahaemolyticus infections have been steadily increasing. Vibrio parahaemolyticus is the leading cause of seafood-related bacterial infections globally. The CDC estimates that the average annual incidence of all Vibrio infections increased 54 percent during 2006–2017. Vibrio parahaemolyticus is believed to be responsible for about 35,000 human infections each year in the United States and has been the leading cause of foodborne infections in China since the 1990s.

The transition of V. parahaemolyticus disease from a regional to a global pathogen is connected to the emergence of isolates with epidemic potential.

Research – Occurrence and Abundance of Pathogenic Vibrio Species in Raw Oysters at Retail Seafood Markets in Northwestern Mexico

Journal of Food Protection


Seafood has frequently been associated with foodborne illness because pathogens are easily introduced during seafood cultivation, handling, and processing. Vibrio parahaemolyticus and Vibrio cholerae are human pathogens that cause gastroenteritis and cholera, respectively, and Vibrio vulnificus can cause fatal wound infections and septicemia. However, information about the occurrence of these pathogens in oysters from the Pacific coast of Mexico is limited to V. parahaemolyticus. In the present study, we evaluated the presence and abundance of these three Vibrio species in 68 raw oysters (Crassostrea corteziensis) obtained from retail seafood markets in Sinaloa, Mexico. The most probable number (MPN)–PCR assay was used for amplification of the tlh (thermolabile hemolysin), ompW (outer membrane protein), and vvhA (hemolytic cytolysin) genes that are specific to V. parahaemolyticus, V. cholerae, and V. vulnificus, respectively. All oyster samples were positive for at least one Vibrio species. V. parahaemolyticus, V. cholerae, and V. vulnificus prevalences were 77.9, 8.8, and 32.3% overall, respectively, and most species were present in all sample periods with increased prevalence in period 3. The tdh (thermostable direct hemolysin) gene was detected in 30.1%, trh (TDH-related hemolysin) was detected in 3.7%, and tdh/trh was detected in 7.5% of the total tlh-positive samples (53 of 68), whereas the pandemic serotype O3:K6 (orf8 positive) was detected in only 1 sample (1.8%). The total prevalence of tdh and/or trh was 41.5%. In none of the samples positive for V. cholerae were the cholera toxin (ctxA) and cholix (chxA) toxigenic genes or the rfb gene encoding the O1 and O139 antigens amplified, suggesting the presence of non-O1 non-O139 V. cholerae strains. Our results clearly indicated a high prevalence of pathogenic Vibrio species in raw oysters from retail seafood markets in Mexico. Consumption of these raw oysters carries the potential risk of foodborne illness, which can be limited by cooking.

  • V. parahaemolyticus, V. cholerae, and V. vulnificus were prevalent in raw oysters from Mexico.

  • The tdh and trh genes and the pandemic O3:K6 serotype were detected in raw oysters.

  • The ctxA and chxA genes, and O1/O139 serotypes were absent from V. cholerae–positive samples.

  • The consumption of raw oysters represents a health risk for Vibrio infections.

Research – Oxidative Disinfectants Activate Different Responses in Vibrio parahaemolyticus

Journal of Food Protection


Vibrio parahaemolyticus is a prevalent seafoodborne enteropathogen that has become a global concern since the spread of its pandemic strain in 1996. This study investigates the responses of this pathogen to the oxidative disinfectants hydrogen peroxide, chlorine dioxide, and peracetic acid. Expression of the regulator genes oxyR and rpoS, determined by reverse transcription PCR, in V. parahaemolyticus wild-type, oxyR mutant, and rpoS mutant strains exhibited similar patterns in response to the tested oxidative disinfectants. The transcription of the rpoS gene was markedly enhanced in the oxyR mutant strain in the exponential phase. The expression of catalase KatE1 was tracked by using a LacZ fusion reporter in these strains. The experimental results revealed that KatE1 was a significant scavenger of hydrogen peroxide and peracetic acid in V. parahaemolyticus, and RpoS may partially compensate for the regulatory role of OxyR in the oxyR mutant strain. In contrast to its responses to hydrogen peroxide and paracetic acid, KatE1 was not the primary scavenger of chlorine dioxide in these V. parahaemolyticus strains. This study shows that these disinfectants activated a basic oxidative response in this pathogen with different features.