Objective: To evaluate the application of real-time RT-PCR and semi-nested RT-PCR in the detection of norovirus in oysters and analyzing the genetic characteristics of the isolates. Methods: Real-time fluorescent RT-PCR and semi-nested RT-PCR were used to detect norovirus GⅠ/GⅡ in fresh oysters collected from the markets in Beijing from November 2014 to October 2015. The detection rate of the parallel test was also analyzed. In addition, the reliability of semi-nested RT-PCR was evaluated by agreement rate and consistency test (Kappa value). The positive products of norovirus GⅠ/GⅡ capsid protein region gene by semi-nested RT-PCR were sequenced. Software BioEdit 7.0.9.0 was used for sequence alignment, and software Mega 6.0 was used to construct the evolutionary tree. Results: In 72 samples, the detection rate of norovirus was 31.94% (23/72) by real-time RT-PCR, 38.89% (28/72) by semi-nested RT-PCR and 48.61% (35/72) by parallel test. The coincidence rate of the two methods was 73.61%, a moderate degree (Kappa value =0.43). A total of 13 norovirus strains were successfully sequenced, and 11 strains (7 GⅡ.17 strains, 2 GⅡ. 4 Sydney_ 2012 strains, 1 GⅡ. 1 strain and 1 GⅡ. 21 strain) were obtained from norovirus positive samples by two RT-PCR methods, two strains (1 GⅡ. 17 strain and 1 GⅡ. 3 strain) were obtained from real-time RT-PCR negative samples which were positive for norovirus by semi-nested RT-PCR. The similarity between these strains and reference strains from diarrhea patients, environmental sewage, and shellfish products were 84.4% - 100.0%. Conclusions: The parallel test of norovirus in oysters by two RT-PCR methods can improve the detection rate and detect more genotypes. Norovirus strains in oysters were highly homologous with reference strains from diarrheal patients, environmental sewage, and shellfish products. Therefore, surveillance, prevention and control for norovirus should be carried out in people who have frequent contacts with oysters and related environments.
Animals ; Beijing ; Humans ; Norovirus/genetics* ; Ostreidae ; RNA, Viral/genetics* ; Real-Time Polymerase Chain Reaction ; Reproducibility of Results ; Reverse Transcriptase Polymerase Chain Reaction

Animals ; Cadmium/toxicity* ; Dysbiosis/metabolism* ; Gastrointestinal Microbiome ; Glutamine/pharmacology* ; Methionine ; Mice ; Mice, Inbred C57BL ; Ostreidae ; Protein Hydrolysates ; Tyrosine

This study examined the microbiological quality of daycare center meals. Six menu items from five daycare centers in Daegu included uncooked processed foods (seasoned cucumber and lettuce salad), post-preparation after cooking processed foods (rolled omelet and seasoned soybean sprout), and cooking processed foods (panbroiled beef with oyster sauce and seasoned pork roast). Microbiological analyses were performed for the aerobic plate counts (APC), coliforms, and Escherichia coli. The analyses were conducted in July and November 2017. The mean APC and coliform count of seasoned cucumber decreased significantly from 4.71 log colony forming units (CFU)/g and 2.50 log CFU/g in July to 4.07 log CFU/g and 1.78 log CFU/g in November, respectively (P < 0.01 and P < 0.001). The APC of panbroiled beef with oyster sauce and seasoned pork roast were significantly lower in July (1.84 and 1.79 log CFU/g) than in November (2.41 and 2.28 log CFU/g) (P < 0.001). The coliform counts of panbroiled beef with oyster sauce and seasoned pork roast were significantly greater in November (2.11 and 1.62 log CFU/g) (P < 0.001). E. coli was not detected. Among the foods prepared using the three preparation processes, the post-preparation after cooking processed foods had the lowest microbial quality. The APC and coliform counts of cooking processed foods were satisfactory in July, with an acceptable rating for pan-broiled beef with oyster sauce in November. Time-temperature control and the prevention of cross-contamination are essential during meal production for food safety, regardless of the season.
Cooking ; Daegu ; Escherichia coli ; Food Safety ; Lettuce ; Meals ; Ostreidae ; Red Meat ; Seasons ; Soybeans ; Stem Cells

In patients with hepatocellular carcinoma (HCC) or liver cirrhosis (LC) accompanied by hepatitis E virus (HEV) infection, hepatic failure often leads to debility. Here, we report about a 63-year-old man with alcoholic LC who was referred to our hospital with jaundice and abdominal distension 10 days earlier. Abdominal computed tomography showed necrotic HCC accompanied by left lobe shrinkage without tumor progression. Laboratory and imaging findings revealed no acute infection focus. The patient reported no herbal medicine or alcohol consumption, and there was no evidence of acute viral hepatitis. One month later, HEV immunoglobulin M positivity was confirmed, and deterioration of liver function due to HEV infection was suspected. The patient often ate raw oysters and sashimi, as well as boar meat, which is a well-known risk food for HEV infection. His umbilical hernia deteriorated due to tense ascites and infection by skin abrasion. The patient progressed to hepatorenal syndrome and eventually died. Liver function preservation is important when treating HCC patients. Therefore, clinicians should pay more attention to the prevention of HEV and others causes of direct liver injury.
Alcohol Drinking ; Alcoholics ; Ascites ; Carcinoma, Hepatocellular ; Hepatitis E virus ; Hepatitis E ; Hepatitis ; Hepatorenal Syndrome ; Herbal Medicine ; Hernia, Umbilical ; Humans ; Immunoglobulin M ; Jaundice ; Liver ; Liver Cirrhosis ; Liver Failure ; Meat ; Middle Aged ; Ostreidae ; Skin ; Transcutaneous Electric Nerve Stimulation

Gymnophalloides seoi (Digenea: Gymnophallidae) is a human intestinal trematode contracted by eating raw oysters (Crassostrea gigas) in the Republic of Korea (=Korea). It has been known to be highly endemic in Aphae Island, Shinan-gun, Jeollanam-do (Province). However, recent epidemiological status of G. seoi has not been reported since the 1990s. In this study, we investigated the prevalence of G. seoi metacercariae in natural and cultured oysters collected from 3 islands and 2 coastal areas in western parts of Korea. The oysters were examined using the artificial digestion method followed by stereomicroscopy. The overall positive rate of G. seoi metacercariae in natural oysters was 66.0% (99/150), and the oysters collected from Yubu Island showed the highest infection rate (74.0%). However, the metacercarial density per oyster was relatively low (1.5–2.4 per oyster). By contrast, no metacercaria was found in cultured oysters purchased from 2 coastal areas in Chungcheongnam-do. Thus, we could confirm that natural oysters produced from 3 western coastal islands are infected with G. seoi metacercariae, whereas cultured oysters purchased from 2 coastal areas were free from infection.
Chungcheongnam-do ; Digestion ; Eating ; Humans ; Islands ; Jeollanam-do ; Korea ; Metacercariae ; Methods ; Ostreidae ; Prevalence ; Republic of Korea

A survey was performed to know the recent infection status of digenetic trematode metacercariae in clams and oysters from 4 sites in western coastal regions of the Republic of Korea (=Korea). Four species of clams (Mactra veneriformis, Ruditapes philippinarum, Cyclina sinensis, and Saxidomus purpuratus) were collected from Taean-gun, Chungcheongnam-do (Province), Buan-gun (County) and Gochang-gun, Jeollabuk-do, and oysters, Crassostrea gigas, from Shinan-gun, Jeollanam-do were transferred to our laboratory on ice and examined by the artificial digestion method. The metacercariae of Himasthla alincia were detected in 3 species of clams, M. veneriformis, R. philippinarum, and C. sinensis from the 3 surveyed areas. The positive rate and the mean density per clam infected were 98.9% (30.8 metacercariae) in M. veneriformis, 60.0% (5.0) in R. philippinarum, and 96.0% (28.4) in C. sinensis. The positive rate (mean density) of Acanthoparyphium tyosenense metacercariae in M. veneriformis was 50.0% (2.1) from Taean-gun and 70.0% (2.8) from Gochang-gun. The metacercariae of Parvatrema spp. were detected in M. veneriformis and R. philippinarum from Taean-gun and Gochang-gun; the positive rate (mean density) was 63.3% (4,123) and 50.0% (19) in M. veneriformis, and 6.7% (126) and 100% (238) in R. philippinarum from the 2 regions, respectively. The metacercariae of Gymnophalloides seoi were detected in all 30 oysters from Shinan-gun, and their average density per oyster was 646. From the above results, it has been confirmed that more than 3 species of metacercariae are prevalent in clams from the western coastal regions, and G. seoi metacercariae are still prevalent in oysters from Shinan-gun, Jeollanam-do, Korea
Bivalvia* ; Chungcheongnam-do ; Crassostrea ; Digestion ; Ice ; Jeollabuk-do ; Jeollanam-do ; Korea ; Metacercariae* ; Methods ; Ostreidae* ; Prevalence* ; Republic of Korea* ; Trematoda

Eosinophilic gastroenteritis is a rare disease in which the symptoms are associated with eosinophilic infiltration in various layers of the gastrointestinal tract. A 56-year-old man complained of severe abdominal pain after eating yellow tail fish and oyster. There was no peripheral blood eosinophilia in the initial laboratory test. Abdominal computed tomography demonstrated circumferential wall thickening and dilatation of small intestine with ascites. An emergency laparotomy accompanied by segmental resection of the ileum and end-to-end anastomosis was performed. Histologically, there was a dense infiltration of eosinophils throughout the entire layers of ileal wall, through which this case could be diagnosed as eosinophilic enteritis. We did not prescribe systemic glucocorticosteroid, but asked him to avoid fish and oyster. He did not complain of recurrent gastrointestinal symptoms anymore after discharge. This is the case of eosinophilic gastroenteritis with intestinal obstruction requiring emergency surgery, which was developed or aggravated after ingestion of yellow tail fish and oyster that were suspected to be culprit foods. In patients with eosinophilic gastroenteritis, foods which are related to this abnormal condition should be identified and avoided to control this disease and prevent from aggravation or flare-up.
Abdominal Pain ; Ascites ; Dilatation ; Eating ; Emergencies ; Enteritis ; Eosinophilia ; Eosinophils* ; Food Hypersensitivity ; Gastroenteritis* ; Gastrointestinal Tract ; Humans ; Ileum ; Intestinal Obstruction* ; Intestine, Small ; Laparotomy ; Middle Aged ; Ostreidae* ; Rare Diseases ; Tail*

Various foods can induce anaphylaxis. However, mushrooms-induced anaphylaxis has not been reported in Korea. We report a patient with past anaphylactic episode caused by mushroom ingestion, confirmed by the skin test and specific IgE antibody to mushrooms. A 17-year-old girl with asthma was referred to our department due to itchy throat, dyspnea, and urticaria within 10 minutes after ingestion of a soup containing Oyster mushrooms. She presented an itching throat after ingestion of cooked mushrooms 3 years before the visit. She had an elevated serum IgE level (205 kU/L) and was sensitized to house dust mites. Skin prick tests with mushroom extracts showed a strong positive on Oyster and King Oyster mushrooms as well as Pyogo mushroom. The specific IgE antibody to each mushroom measured by enzyme-linked immunosorbent assay showed significant positive results to Oyster and Pyogo mushroom extracts, but was negative on King Oyster mushroom. We educated her to avoid eating Oyster and Pyogo mushrooms for preventing recurrence, whereas we couldn't perform oral challenge tests.
Adolescent ; Agaricales* ; Anaphylaxis* ; Asthma ; Dyspnea ; Eating* ; Enzyme-Linked Immunosorbent Assay ; Female ; Humans ; Immunoglobulin E ; Korea ; Ostreidae ; Pharynx ; Pleurotus ; Pruritus ; Pyroglyphidae ; Recurrence ; Skin ; Skin Tests ; Urticaria

This study was performed to investigate the sedative-hypnotic activity of gamma-aminobutyric acid (GABA)-enriched fermented marine organisms (FMO), including sea tangle (FST) and oyster (FO) by Lactobacillus brevis BJ20 (L. brevis BJ20). FST and FO were tested for their binding activity of the GABA(A)-benzodiazepine and 5-HT(2C) receptors, which are well-known molecular targets for sleep aids. We also measured the sleep latency and sleep duration during pentobarbital-induced sleep in mice after oral administration of FST and FO. In GABA(A) and 5-HT(2C) receptor binding assays, FST displayed an effective concentration-dependent binding affinity to GABA(A) receptor, similar to the binding affinity to 5-HT(2C) receptor. FO exhibited higher affinity to 5-HT(2C) receptor, compared with the GABA(A) receptor. The oral administration of FST and FO produced a dose-dependent decrease in sleep latency and increase in sleep duration in pentobarbital-induced hypnosis. The data demonstrate that FST and FO possess sedative-hypnotic activity possibly by modulating GABA(A) and 5-HT(2C) receptors. We propose that FST and FO might be effective agents for treatment of insomnia.
Administration, Oral ; Animals ; Aquatic Organisms* ; gamma-Aminobutyric Acid ; Hypnosis ; Lactobacillus brevis ; Mice ; Ostreidae ; Receptor, Serotonin, 5-HT2C ; Receptors, GABA-A ; Sleep Initiation and Maintenance Disorders

The study was conducted to compare the effects of different agro-wastes on the growth, yield, and nutritional composition of oyster mushrooms Pleurotus ostreatus (PO) and Pleurotus cystidiosus (PC). Seven substrate formulas including sawdust (SD), corncob (CC), sugarcane bagasse (SB) alone and in combination of 80 : 20, 50 : 50 ratio between SD and CC, SD and SB were investigated. The results indicated that different substrate formulas gave a significant difference in total colonization period, characteristics of fruiting bodies, yield, biological efficiency (BE), nutritional composition and mineral contents of two oyster mushrooms PO and PC. The results showed that increasing CC and SB reduced C/N ratio, and enhanced some mineral contents (Ca, P, and Mg) of substrate formulas. The increased amount of CC and SB of substrate formulas enhanced protein, ash, mineral contents (Ca, K, Mg, Mn, and Zn) of fruiting bodies of both mushrooms. Substrates with 100% CC and 100% SB were the most suitable substrate formulas for cultivation of oyster mushrooms PO and PC in which they gave the highest values of cap diameter, stipe thickness, mushroom weight, yield, BE, protein, fiber, ash, mineral content (Ca, K, and Mg) and short stipe length. However, substrate formula 100% CC gave the slowest time for the first harvest of both mushrooms PO and PC (46.02 days and 64.24 days, respectively). It is also found that the C/N ratio of substrate formulas has close correlation with total colonization period, mushroom weight, yield, BE and protein content of mushroom PO and PC.
Agaricales ; Colon ; Fruit ; Ostreidae* ; Pleurotus* ; Saccharum