• Journal of Microbiology
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• v.42 no.2
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• pp.74-79
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• 2004

Ingestion of shellfish-associated Vibrio parahaemolyticus is the primary cause of potentially severe gas-troenteritis in many countries. However, only Kanagawa phenomenon (hemolysin) positive (KP$\^$+/) strains of V. parahaemolyticus are isolated from patients, whereas >99％ of strains isolated from the environment do not produce this hemolysin (i.e. are KP$\^$-/). The reasons for these differences are not known. Following a temperature downshift, Vibrio parahaemolyticus enters the viable but noncultur-able (VBNC) state wherein cells maintain viability but cannot be cultured on routine microbiological media. We speculated that KP$\^$+/ and KP$\^$-/ strains may respond differently to the temperature and salinity conditions of seawater by entering into this state which might account for the low numbers of cul-turable KP$\^$+/ strains isolated from estuarine waters. The response of eleven KP$\^$+/ and KP$\^$-/ strains of V. parahaemolyticus following exposure to a nutrient and temperature downshift in different salinities, similar to conditions encountered in their environment, was examined. The strains included those from which the KP$\^$+/ genes had been selectively removed or added. Our results indicated that the ability to produce hemolysin did not affect entrance into the VBNC state. Further, VBNC cells of both biotypes could be restored to the culturable state following an overnight temperature upshift.

• Fisheries and Aquatic Sciences
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• v.25 no.8
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• pp.429-440
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• 2022

This study assessed the effects of oxygen and ozone nanobubbles on gill morphology, weight gain, and mortality of Pacific white shrimp (Penaeus vannamei), as well as the level of Vibrio parahaemolyticus and water quality of shrimp culture tanks under lab conditions. Two experiments were carried out with oxygen macrobubble, ozone macrobubble, oxygen nanobubble, ozone nanobubble, and control treatments (air-stone macrobubble). Experiments were done in triplicate in 100 L tanks with 15‰ saline water, and 20 shrimp per tank. Tanks in Experiment 1 were not inoculated with bacteria; tanks in Experiment 2 were inoculated with V. parahaemolyticus at a concentration of 10⁶ CFU/mL. The results revealed that short treatments with ozone nanobubbles had minimal impact on shrimp gills, mortality, and growth rates, reduced V. parahaemolyticus concentration in water compared to the other groups, and improve water quality. These laboratory results indicate that ozone nanobubble treatment may be useful for controlling V. parahaemolyticus. More work is needed to find the best protocol to apply the technology on a commercial scale.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.47 no.5
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• pp.508-515
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• 2014

The contamination status of Vibrio parahaemolyticus in commercially valuable shellfish from the south and west coasts of Korea and the antimicrobial resistance patterns of isolated V. parahaemolyticus were investigated from July through October, 2011. The range of V. parahaemolyticus concentrations in oysters Crassostrea gigas and short neck clams Venerupis philippinarum was <30~290 MPN/100 g and <30~46,000 MPN/100 g, respectively, and greater than 10,000 MPN/100 g of V. parahaemolyticus was detected from 7 of 40 short neck clams. During the survey period, 436 strains of V. parahaemolyticus were isolated (129 from oysters and 307 from short-neck clams) and the antimicrobial resistance patterns of all of the isolates were examined. Antimicrobial resistance against at least one antibiotic was seen in 79.8% of the oyster isolates (103 strains) and 63.8% of the short neck clam isolates (196 strains). The antimicrobial resistance patterns were relatively simple because the antimicrobial resistance of the isolates was simply due to resistance to ampicillin. Only one oyster isolate and three short neck clam isolates showed multiple antibiotic resistance, i.e., resistance against more than four antibiotics.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.49 no.4
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• pp.460-466
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• 2016

From 2013 through 2015, we investigated the contamination status and antimicrobial resistance patterns of pathogenic Vibrio parahaemolyticus in commercially valuable seawater and shellfish (Oyster Crassostrea gigas, short-neck clam Venerupis philippinarum, ark shell Scapharca broughtonii and mussel Mytilus galloprovinciallis) from the southern coast of Korea. The detection rate of V. parahaemolyticus was highest in short-neck clams (23.7%), followed by ark shells (19.2%), oysters (15.9%), mussels (13.6%), and seawater (8.6%). The following percentages of PCR assays of shellfish were positive for the thermostable direct hemolysin-related hemolysin gene (trh) : oysters (12.8%), short-neck clams(11.8%), and ark shells (3.4%). Similar assays for the thermostable direct hemolysin gene (tdh) resulted in positive results for short-neck clams (5.9%) and ark shells (3.4%). Antimicrobial resistance was present in 100% of 8 tdh (+) and 2 trh (+) V. parahaemolyticus isolates challenged with ampicillin. However, all pathogenic V. parahaemolyticus were sensitive to 14 other antibiotics. To ensure the safety of shellfish consumption, the continuous monitoring of the prevalence and distribution of virulence factors of V. parahaemolyticus in shellfish farms is needed.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.50 no.6
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• pp.662-668
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• 2017

This study investigated the antimicrobial resistance patterns of Escherichia coli and Vibrio parahaemolyticus isolated from oysters Crassostrea gigas, short-necked clams Ruditapes philippinarum and corb shells Cyclina sinensis from the West Coast of Korea from June through November 2013. The antimicrobial susceptibility patterns of the isolated strains of E. coli and V. parahaemolyticus to 12 antimicrobial agents used in Korea for clinical or veterinary therapy were analyzed. Antimicrobial resistance to at least one antibiotic was seen in 52.0% of the E. coli isolates (156 strains) and 44.3% of the V. parahaemolyticus isolates (194 strains). The resistance of the E. coli (34.0%) and V. parahaemolyticus (41.8%) isolates to ampicillin was highest. Multiple antimicrobial resistance against at least three antimicrobials was seen in 9.0% of the E. coli isolates and 1.0% of the V. parahaemolyticus isolates.

• Journal of the Korean Society of Food Science and Nutrition
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• v.32 no.8
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• pp.1351-1356
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• 2003

Antibacterial activities of Chinese cabbage kimchi juice were determined against Staphylococcus aureus ATCC 6538p, Salmonella enteritidis ATCC 13076, Vibrio parahaemolyticus ATCC 17802 and Enterobater cloacae ATCC 13047. It was found out that 2% content of Chinese cabbage kimchi juice reduced the colony numbers of Salmonella enteritidis ATCC 13076, Enterobater cloacae ATCC 13047, Staphylococcus aureus ATCC 6538p and Vibrio parahemolyticus ATCC 17802 by 63%, 72%, 76% and 90%, respectively. 6% content of Chinese cabbage kimchi Juice completly inactivated Vibrio parahaemolyticus. But at the same content (6%) of Chinese cabbage kimchi juice, colony number of Salmonella enteritidis ATCC 13076 Enterobater cloacae ATCC 13047 and Staphylococcus aureus ATCC 6538p were reduced to 11%, 10% & 9%, respectively.10% Chinese cabbage kimchi juice had 100% inhibitory effect on all test bacteria. Therefore, Chinese cabbage kimchi has effective antibacterial activities against Staphylococcus aureus ATCC 6538p, Salmonella enteritidis ATCC 13076 Vibrio parahaemolyticus ATCC 17802 and Enterobacter cloacae ATCC 13047.

• Fisheries and Aquatic Sciences
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• v.25 no.9
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• pp.463-472
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• 2022

In this study, a microbial risk assessment was performed for the bacteria Vibrio parahaemolyticus, which causes a foodborne illness following the consumption of Jeotgal, a fermented seafood in South Korea. The assessment comprised of six stages: product, market, home, consumption, dose-response, and risk. The initial contamination level (IC) was calculated based on the prevalence of V. parahaemolyticus in 90 Jeotgal samples. The kinetic behavior of V. parahaemolyticus was described using predictive models. The data on transportation conditions from manufacturer to market and home were collected through personal communication and from previous studies. Data for the Jeotgal consumption status were obtained, and an appropriate probability distribution was established. The simulation models responding to the scenario were analyzed using the @RISK program. The IC of V. parahaemolyticus was estimated using beta distribution [Beta (1, 91)]. The cell counts during transportation were estimated using Weibull and polynomial models [δ = 1 / (0.0718 - 0.0097 × T + 0.0005 × T²)], while the probability distributions for time and temperature were estimated using Pert, Weibull, Uniform, and LogLogistic distributions. Daily average consumption amounts were assessed using the Pareto distribution [0.60284,1.32,Risk Truncate(0,155)]. The results indicated that the risk of V. parahaemolyticus infection through Jeotgal consumption is low in South Korea.

• Journal of the East Asian Society of Dietary Life
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• v.20 no.6
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• pp.881-887
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• 2010

This study was conducted to investigate the antibacterial activities of medicinal plant extracts. The results were as follows. Crude water and methanolic extracts of Sanguisorba officinalis Linne, Coptis chinensis Makino, and Portulaca oleracea Linne, among 31 kinds of medicinal plants, had strong antibacterial activities against S. aureus and V. parahaemolyticus, with the methanolic extract more effective than the water extract. The methnolic and water extracts of S. officinalis Linne had strong antibacterial activities against S. aureus and V. parahaemolyticus. Antibacterial activity against S. aureus and V. parahaemolyticus was observed with extracts of S. officinalis Linne at dilutions of 5 and 10%, respectively. The EtOAc, BuOH, and $H_2O$ fractions of the extract of S. officinalis Linne had antibacterial activities against S. aureus and V. parahaemolyticus. Specifically, the fractions had antibacterial activity against S. aureus at dilutions of 5, 2, and 1%, respectively. Regarding V. parahaemolyticus, the EtOAc, $H_2O$, and BuOH fractions had antibacterial activities at dilutions of 5, 2, and 1%, respectively.

• Journal of Food Hygiene and Safety
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• v.38 no.4
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• pp.246-254
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• 2023

V. parahaemolyticus causes waterborne and foodborne disease such as acute diarrhea. In this study, V. parahaemolyticus isolates from seawater, fish tanks, and distributed fishery products in Jeju were investigated for potential toxin or species-specific genes (tdh, trh, tlh, and toxR) using RT-PCR and their genetic characteristics were analyzed using Pulsed-field gel electrophoresis (PFGE). Overall, V. parahaemolyticus of 90 strains (36.7%), including 33 strains from seawater, 8 strains from fish tanks, and 50 strains from fishery products, were isolated from 245 samples. All V. parahaemolyticus strains did not detect the tdh gene, whereas all strains detected tlh or toxR genes. In addition, trh genes were detected in 3 strains from seawater and 1 strain from fishery products. Monthly quantitative testing of seawater revealed that V. parahaemolyticus was positively correlated with water temperature. The 90 strains of V. parahemolyticus obtained in this study showed by gene homology between types, ranging from 64.0-97.3%. Among these, thirteen types showed 100% homology between genes. These results indicate that continuous monitoring is needed to facilitate food poisoning epidemiological investigations because some isolated V. parahaemolyticus strains harbored toxin genes and V. parahaemolyticus strains isolated from seawater, fish tanks, and distributed fishery products showed genetic similarity.

• The Journal of the Korean Society for Microbiology
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• v.22 no.1
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• pp.61-70
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• 1987

Authors have isolated phages of V. parahaemolyticus from shellfish and investigated some of their characteristics. The results obtained were as follows: Twenty-three phage strains(9.2%) out of 250 specimens were isolated. Plaques of phages were small, clear or turbid and $0.5{\sim}1.5mm$ in diameter. The electron micrographs of K3 phages showed two morphology; one was a hexagonal head about 105nm with a tail about 12nm, the other was a hexagonnal head about 60nm with a tail about 25nm. The host ranges of pahges were limited to V. parahaemolyticus strains and there appeared to be no relationship between the K serotypes of V. parahaemolyticus strains and the host ranges of the phage isolates. The adsorption rate of phages were more than 80% for $10{\sim}15$ minutes, the inactivation rate at $60^{\circ}C$ was more than 99% for $40{\sim}45$ minutes. The pH stability range was between 6.0 and 8.0. The inactivation rate of phages by UV irradiation was more than 99% for $45{\sim}75$ seconds.