From 2011 to 2013, we conducted a full sanitary survey of pollution sources in proximity to a designated shellfish growing area in Korea, and their impact on the sea area therein. From this area, 836 ...seawater samples and 93 oyster samples were examined to evaluate their bacteriological quality. There were 483 potential pollution sources in the drainage area of the Jaranman-Saryangdo area, including 38 sources discharging water. It demonstrates that while many pollution sources have been identified, no significant impact occurred within the designated shellfish growing area. Variations in fecal coliform (FC) levels in seawater were closely related to rainfall. The FC levels of seawater and oysters from the designated area met the regulation limits set by various countries. Our study indicates that the oysters produced in this area are apparently safe for raw consumption based on their bacterial quality.
•Sanitary survey for inland pollution sources, seawater, and oysters were conducted.•No significant pollution impact occurred within the shellfish growing area.•Fecal contamination of seawater was closely related to rainfall.•The water quality of the shellfish growing area met the regulation limits.•The oysters produced from this area are apparently safe for raw consumption.
The antimicrobial resistance patterns to 15 antimicrobial agents of Vibrio parahaemolyticus and Vibrio alginolyticus isolated from farmed fishes, including olive flounder (Paralichthys olivaceus), ...black rockfish (Sebastes schlegeli), red sea bream (Pagrus major), and sea bass (Lateolabrax japonicus), were investigated from 2005 through 2007. A total of 218 V. parahaemolyticus isolates and 153 V. alginolyticus isolates were obtained from the 180 fish samples collected from fish farms located along the southern coast of Korea. We found that 65.1% of V. parahaemolyticus and 85.6% of V. alginolyticus isolates showed antimicrobial resistance against more than one antimicrobial agent. The prevalence of resistance in V. parahaemolyticus isolates to ampicillin was highest (57.8%), followed by resistance to rifampin (11.9%), streptomycin (8.7%), and trimethoprim (6.4%). V. alginolyticus isolates were also most resistant to ampicillin (75.2%), followed by tetracycline (15.0%), trimethoprim (12.4%), and rifampin (9.8%). The prevalence of multiresistance to four or more antimicrobials was higher in V. alginolyticus (11.1%) than in V. parahaemolyticus (5%). Antimicrobial resistance rates per isolate of V. parahaemolyticus and V. alginolyticus possessing virulence genes were not different from those of the rest of the isolates.
An investigation was conducted into the clinical symptoms and causative agent associated with a whelk poisoning incident that occurred in March 2005 in Korea. The whelk consumed in the poisoning ...incident was identified as Neptunea intersculpta. All of the 17 patients suffered from eyeball pain, headache, dizziness, abdominal pain, and nausea but no diarrhea. The causative agent was identified as tetramine, based on results from liquid chromatography-tandem mass spectrometry. Based on the tetramine concentration in the leftover whelk meat and the amount of meat consumed, the amount of tetramine ingested by the patients was estimated to be >or = 10 mg. This is the first report of the identification of tetramine as the causative agent in whelk poisoning in Korea. The anatomical distribution of tetramine in fresh and boiled N. intersculpta was examined. The toxin concentration in the meat was higher in specimens boiled in the shell than in fresh specimens collected on the same date. In meat boiled separately after removing the shell, the salivary gland, and the midgut gland, the tetramine concentration was much lower than that in fresh specimens or those boiled in the shell. This result suggests that boiling the meat after removing the salivary gland is a suitable way to prevent tetramine poisoning.
From 2009 to 2013, 80 oyster and 16 seawater samples were collected from the southern coast of Korea, including designated shellfish growing areas for export. The concentrations and bioaccumulation ...of heavy metals were determined, and a potential risk assessment was conducted to evaluate their hazards towards human consumption. The cadmium (Cd) concentration in oysters was the highest of three hazardous metals, including Cd, lead (Pb), and mercury (Hg), however, below the standards set by various countries. The metal bioaccumulation ratio in oysters was relatively high for zinc and Cd but low for Hg, Pb, arsenic, and chromium. The estimated dietary intakes of all heavy metals for oysters accounted for 0.02 %–17.75 % of provisional tolerable daily intake. The hazard index for all samples was far <1.0, which indicates that the oysters do not pose an appreciable hazard to humans for the metal pollutants of study.
Circulating tumor cells (CTCs) are identified in transit within the blood stream of cancer patients and have been proven to be a main cause of metastatic disease. Current approaches for the ...size-based isolation of CTCs have encountered technical challenges as some of the CTCs have a size similar to that of leukocytes and therefore CTCs are often lost in the process. Here, we propose a novel strategy where most of the CTCs are coated by a large number of microbeads to amplify their size to enable complete discrimination from leukocytes. In addition, all of the microbead labeling processes are carried out in a continuous manner to prevent any loss of CTCs during the isolation process. Thus, a microfluidic mixer was employed to facilitate the efficient and selective labeling of CTCs from peripheral blood samples. By generating secondary vortex flows called Taylor–Gortler vortices perpendicular to the main flow direction in our microfluidic device, CTCs were continuously and successfully coated with anti-epithelial cell adhesion molecule-conjugated beads. After the continuous labeling, the enlarged CTCs were perfectly trapped in a micro-filter whereas all of the leukocytes escaped.
Lipophilic toxin profiles associated with diarrhetic shellfish poisoning in Korean bivalves were investigated by liquid chromatography-mass spectrometry (LC-MS). Okadaic acid (OA), dinophysistoxins ...(DTX), pectenotoxins (PTX) and yessotoxin (YTX) in bivalves were quantified by LC-MS. Thirty-eight bivalve samples were collected from five different areas on the south coast of Korea during January to June 2006. Dinophysistoxin-1 (DTX1) and OA were found in some samples of both mussel Mytilus edulis and oyster Crassostrea gigas. The levels of DTX1 and OA found in the hepatopancreas of the samples were 0.04-0.23 μg/g and 0.03-0.08 μg/g, respectively. Dinophysistoxin-3 was found in the hepatopancreas of the short-necked clam Ruditapes philippinarum at a concentration of 0.06 μg/g. PTX and YTX were not detected from all of the samples examined. This is the first report of the unambiguous identification of OA and its derivatives, by LC-MS, in Korean bivalves.
Samples of seven species of cephalopods and crustaceans were collected from major fish markets on the Korean coast and analyzed for mercury (Hg) using a direct Hg analyzer and for the metals cadmium ...(Cd), lead (Pb), chromium, silver, nickel, copper, and zinc using inductively coupled plasma mass spectrometry. The distributions of heavy metals in muscles, internal organs, and whole tissues were determined, and a risk assessment was conducted to provide information concerning consumer safety. The heavy metals accumulated to higher levels (P < 0.05) in internal organs than in muscles for all species. The mean concentrations of Cd, which had the highest concentrations of the three hazardous metals (Cd, Pb, and Hg), in all internal organs (except those of blue crab) exceeded the regulatory limits set by Korea and the European Union. The Cd concentrations in all whole tissues of squid and octopus (relatively large cephalopods), red snow crab, and snow crab exceeded the European Union limits. The estimated dietary intake of Cd, Pb, and Hg for each part of all species accounted for 1.73 to 130.57%, 0.03 to 0.39%, and 0.93 to 1.67%, respectively, of the provisional tolerable daily intake adopted by the Joint Food and Agriculture Organization and World Health Organization Expert Committee on Food Additives; the highest values were found in internal organs. The hazard index (HI) is recognized as a reasonable parameter for assessing the risk of heavy metal consumption associated with contaminated food. Because of the high HI (>1.0) of the internal organs of cephalopods and the maximum HI for whole tissue of 0.424, consumers eating internal organs or whole tissues of cephalopods could be at risk of high heavy metal exposure. Therefore, the internal organs of relatively large cephalopods and crabs (except blue crab) are unfit for consumption. However, consumption of flesh after removing internal organs is a suitable approach for decreasing exposure to harmful metals.
Molluscan shellfish (gastropods and bivalves) were collected from major fish markets on the Korean coast and analyzed for mercury by direct Hg analyzer and for other metals, such as cadmium, lead, ...chromium, silver, nickel, copper and zinc, using inductively coupled plasma mass spectrometry. Distribution of heavy metals in muscles, internal organs and whole tissues were determined and a potential risk assessment was conducted to evaluate their hazard for human consumption. Heavy metals were accumulated significantly higher (P < 0.05) in internal organs than in muscles for all species. The mean Cd level, which had the highest level of three hazardous metals (Cd, Pb, and Hg) in all internal-organ samples were above the regulatory limit of Korea and the mean level in whole tissue samples of the selected gastropod species, bay scallop and comb pen shell, exceeded the limit (except in a few cases). The sum of the estimated dietary intake of Cd, Pb and Hg for each part of all tested species accounted for 1.59-16.94, 0.02-0.36, and 0.07-0.16% respectively, of the provisional tolerable daily intake adopted by the Joint FAO/WHO Expert Committee on Food Additives. The hazard index for each part of gastropods and bivalves was below 1.0, however, the maximum HI for internal organs of all analysed species was quite high (0.71). These results suggest that consumption of flesh after removing the internal organs of some molluscan shellfish (all gastropod species, bay scallop and comb pen shell) is a suitable way for reducing Cd exposure.
From 2011 to 2013, we conducted a full sanitary survey of pollution sources in proximity to a shellfish growing area in the Hansan-Geojeman region in Korea, which includes a designated shellfish ...growing area. In the sea area, 1152 seawater and 209 oyster samples were collected and examined to evaluate their bacteriological quality. There were 758 potential pollution sources in the drainage area, including 40 sources discharging water in 2013. Fecal coliform (FC) concentrations and impact radii of discharges ranged from 1.8 to 700,000 MPN/100 mL and from 3 to 600 m, respectively; however, the pollutants did not reach the designated area. This demonstrates that the dilution of waste was sufficient such that no significant impact occurred within the designated shellfish growing area. The variation in the FC levels of seawater was closely related to season and rainfall. The FC levels of seawater and oysters from the designated area met the regulation limits set by various countries. No pathogens were found in any oysters. The results of the survey indicate that the oysters produced in this area are apparently safe for raw consumption based on their bacterial quality.
A new analytical method for erythromycin in fish by liquid chromatography/tandem mass spectrometry Park, M.J. (Quality Management Division, National Fisheries Peoducts Quality Inspection Service, Goyang, Republic of Korea); Park, M.S. (East Sea Fisheries Research Institute, National Fisheries Research and Development Institute, Gangneung, Republic of Korea); Lee, T.S. (Aquaculture Environment Research Center, National Fisheries Research and Development Institute, Tongyeong, Republic of Korea) ...
Food science and biotechnology,
06/2008, Letnik:
17, Številka:
3
Journal Article
Recenzirano
Erythromycin has been used to treat Streptococosis, Edwardsiellosis, Vibriosis, Bacterial enteritis in the cultured fish. In this study, a rapid and effective erythromycin analysis method with new ...sample treatment protocol and liquid chromatography/tandem mass spectrometry (LC/MS/MS) system for fish products was developed. For the erythromycin extraction from fish muscle, the solvent mixture composed of 0.2% meta-phosphoric acid and methanol (6:4) showed good recovery rate, and the optimum extraction solvent volume was 20 mL. Erythromycin detection using LC/MS/MS were carried out under electrospray ionization (ESI) positive condition and erythromycin mass value 576.2 and 157.9. And the detection limit of the established method was 0.005 mg/kg in fish products. The recovery rate of the developed method applied to the fish species were as following, olive flounder, 87.6±5.0%; black rockfish, 87.2±6.4%; eel, 85.2±4.8%; and rainbow trout, 86.0±6.2%. In the established method in this study, the correlation of coefficient values (R²) of erythromycin calibration curve (n=11) was 0.9998.
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