MicroRNAs (miRNAs) act as regulators of gene expression by binding to the 3’ untranslated region (UTR) of target genes. They perform important biological functions in the various species. Among many miRNAs, miR-21-3p is known to serve vital functions in development and apoptosis in olive flounder. Using genomic and bioinformatic tools, evolutionary conservation of miR-21-3p was examined in various species, and expression pattern was analyzed in olive flounder. Conserved sequences (5’-CAGUCG-3’) in numerous species were detected through the stem-loop structure of miR-21-3p. Thus, we analyzed target genes of miR-21-3p. Among them, 3’ UTR region of PPIL2 gene indicated the highest binding affinity with miR-21-3p based on the minimum free energy value. The PPIL2 gene showed high expression levels in testis tissue of the olive flounder, whereas miR-21-3p showed rather ubiquitous expression patterns except in testis tissue, indicating that miR-21-3p seems to control the PPIL2 gene expression in a complementary repression manner in various tissues of olive flounder. Taken together, this current study contributes to infer the target gene candidates for the miR-21-3p using bioinformatics tools. Furthermore, our data offers important information on the relationship between miR-21-3p and target gene for further functional study.
Apoptosis ; Computational Biology ; Conserved Sequence ; Flounder* ; Gene Expression ; MicroRNAs ; Olea* ; Repression, Psychology ; Testis ; Untranslated Regions

To express Pleurocidin in Escherichia coli and to enhance the secretory efficiency of the fusion protein, the gene encoding Pleurocidin was ligated with Cherry DNA sequence via blunt-end ligation. Then this fusion gene was cloned into pET22b (+) vector and the recombinant plasmid was transformed into E. coli BL21 (DE3). Lactose was used to induce expression of fusion protein. The recombinant plasmid pET22b (+) -CP was successfully constructed and high-level expression of fusion protein was induced with lactose. Statistics showed that addition of glycine after 16 h of induction significantly enhanced the secretory efficiency of the fusion protein. After hydrolysis of the fusion protein by diluted hydrochloric acid and some further purification steps, r-Pleurocidin was obtained with antibacterial activity against E. coli DH5α and Bacillus subtilis BS168. In conclusion, the fusion protein was expressed in E. coli and biologically active r-Pleurocidin was obtained after hydrochloric acid cleavage and purification.
Animals ; Cloning, Molecular ; Escherichia coli ; metabolism ; Fish Proteins ; biosynthesis ; Flounder ; Recombinant Fusion Proteins ; biosynthesis

Since Kudoa septempuntata was identified as a causative agent of food poisoning associated with raw olive flounder Paralichthys olivaceus, interest and concern regarding the parasite have increased. However, there have been no investigations or reports of other Kudoa species infecting the fish (except for K. paralichthys, which infects the brain) in Korea. We found cysts filled with myxospores of Kudoa species in muscles of cultured olive flounder specimens and identified these to the species level. Mature spores were quadrate, measuring 8.7±0.5 μm in length, 9.2±0.4 μm in thickness, and 12.9±0.6 μm in width. The spores containing 4 polar capsules had a length of 2.1±0.2 μm and a width of 1.8±0.3 μm. The partial 18S and 28S rDNA of isolates showed 99–100% similarities with K. ogawai. Using these morphological and molecular analyses, the species was identified as K. ogawai. This study is the first report of K. ogawai infection in cultured olive flounder in Korea.
Capsules ; DNA, Ribosomal ; Flounder ; Foodborne Diseases ; Korea ; Muscles ; Olea ; Parasites ; Spores

The antibacterial activities of the essential oil of Eucalyptus globulus (EOEG) was determined against 7 fish pathogenic bacteria (Edwardsiella tarda, Streptococcus iniae, S. parauberis, Lactococcus garviae, Vibrio harveyi, V. ichthyoenteri and Photobacterium damselae) obtained from farmed olive flounder. The inhibitory activity was evaluated by three methods: Disc diffusion method, minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC). According to the disc diffusion test, as the concentration of EOEG (5-40 µg) rises, the inhibitory zone increases in size. Compared with amoxicillin, tetracycline and chloramphenicol, EOEG showed similar antibacterial activity. The MIC of EOEG ranged from 7.8 to 125 mg/mL and MBC values ranged from 62 to 250 mg/mL. These results show that EOEG has antimicrobial activity against all seven bacteria, but there was no marked difference between each genus. From these results, it is suggested that EOEG can be used as an antimicrobial agent against fish bacterial diseases in the fish industry.
Agriculture ; Amoxicillin ; Bacteria* ; Chloramphenicol ; Diffusion ; Eucalyptus* ; Flounder ; Lactococcus ; Methods ; Microbial Sensitivity Tests ; Olea ; Photobacterium ; Streptococcus ; Tetracycline ; Vibrio

Sinuolinea capsularis Davis, 1917 is myxosporean that infect the urinary system of the host fish. Insufficient morphological and molecular data of S. capsularis exits, and it is therefore difficult to make an accurate identification of the parasite. We tried a series of morphological and molecular analysis to identify an myxosporean isolated from urinary bladder of cultured olive flounder, Paralichthys olivaceus, from Jeju island in the Republic of Korea. Some of them were observed under a light microscope and SEM, and remain samples were used molecular and phylogenetic analysis. Mature spores were subspherical, measuring 13.9±0.6 μm in length and 13.8±0.8 μm in width. Two spherical polar capsules on opposite sides in the middle of the spore had a diameter range of 4.3±0.4 μm. Scanning electron microscopy revealed that spores a severely twisted the suture line. By the morphological comparison and analysis, it was identified as S. capsularis. In addition, we obtained the partial 18S rDNA of S. capsularis and first registered it in NCBI. Phylogenetic analysis showed that S. capsularis clustered with Zschokkella subclade infecting the urinary system of marine fish, and it supported the infection site tropism effect on phylogeny of marine myxosporeans as well as the origin of Sinuolinea is not monophyly.
Capsules ; DNA, Ribosomal ; Flounder ; Microscopy, Electron, Scanning ; Olea ; Parasites ; Phylogeny ; Polymerase Chain Reaction ; Republic of Korea ; Spores ; Sutures ; Tropism ; Urinary Bladder

OBJECTIVES: Investigations into foodborne illness, potentially caused by Kudoa septempunctata, has been ongoing in Korea since 2015. However, epidemiological analysis reporting and positive K septempunctata detection in feces in Korea has been limited. The aim of this study was to provide epidemiologic data analysis of possible food poisoning caused by K septempunctata in Korea. METHODS: This study reviewed 16 Kudoa outbreak investigation reports, including suspected cases between 2015 and 2016 in Gyeonggi province, Korea. Suspected Kudoa foodborne illness outbreak was defined as “evidence of K septempunctata in at least one sample.” The time and place of outbreak, patient symptoms and Kudoa (+) detection rate in feces was analyzed. RESULTS: Kudoa foodborne illness outbreaks occurred in most patients in August (22.6%) and in most outbreaks in April (25%). The attack rate was 53.9% and the average attack rate in patients who had consumed olive flounder was 64.7%. The average incubation period was 4.3 hours per outbreak. Diarrhea was the most common symptom which was reported by 91.5% patients. The Kudoa (+) detection rate in feces was 69.2% of cases. CONCLUSION: Monthly distribution of Kudoa foodborne illness was different from previous studies. The Kudoa (+) detection rate in feces decreased rapidly between 25.5 and 28.5 hours of the time interval from food intake to epidemiologic survey. To identify effective period of time of investigation, we believe additional study with extended number of cases is necessary.
Diarrhea ; Disease Outbreaks* ; Eating ; Feces ; Flounder ; Foodborne Diseases ; Gyeonggi-do* ; Humans ; Korea* ; Myxozoa ; Olea ; Seafood* ; Statistics as Topic

OBJECTIVES: Confirmation of Kudoa septempunctata (K. septempunctata) as the pathogenic agent causing acute food poisoning remains under debate owing to inconsistencies in the reproducibility of experimental evidence. Higher intake of olive flounder infected with K. septempunctata would result in increased diagnosis of food poisoning by K. septempunctata, if the latter was one of the causal agents of acute food poisoning. The aim was to evaluate the relationship between the shipping amount of olive flounder aquacultured from Jejudo and the incidence of K. septempunctata food poisoning in 2015, Korea.METHODS: Data of shipping amounts between March 2014 and February 2016 and of monthly reported events of Kudoa food poisoning were taken from Jejudo Fish-Culture Fisheries Cooperatives and Korea Centers for Disease Control and Prevention, respectively. Non-parametric correlation analyses were conducted.RESULTS: Shipping amounts indicated the seasonal changes according to variation of consumption. Spearman's rho and Kendall's tau-a between the monthly shipping amounts and the reported events in 2015 were 0.39 (p=0.21) and 0.27 (p=0.20), respectively.CONCLUSIONS: An independent relationship was noted between the shipping amount and the reported events, which contrasted with the claim that the virulence of K. septempunctata caused acute food poisoning.
Bias (Epidemiology) ; Centers for Disease Control and Prevention (U.S.) ; Diagnosis ; Fisheries ; Flounder ; Food Parasitology ; Foodborne Diseases ; Incidence ; Intestinal Diseases, Parasitic ; Jeju-do ; Korea ; Myxozoa ; Olea ; Seasons ; Ships ; Virulence

OBJECTIVES: Recently kudoa septempuctata in olive flounders is suggested as a cause of food poisoning, however whether kudoa septempuctata can affect human gastrointestinal systems is controversial and its pathogenecity remains unclear. In view of the field epidemiology, food poisonings caused by kudoa septempuctata should be distinguished from those caused by Staphylococcus aureus and bacillus cereus.METHODS: The statistics of food poisoning investigations published by Korea Centers for Disease Control and Prevention in 2013-2015 were reviewed. The characteristics of kudoa septempuctata food poisoning reported by Korea Centers for Disease Control and Prevention were reviewed. Information regarding clinical symptoms or epidemiology was extracted.RESULTS: Total eleven kudoa septempuctata food poisoning cases were analyzed. Food poisonings caused by kudoa septempuctata, Staphylococcus aureus and bacillus cereus have clinical and epidemiological similarities. Forty five percent of food poisoning outbreaks occurred in Korea was concluded as unknown. The food poisoning caused by Staphylococcus aureus and bacillus cereus accounted for 4.5% (50/1,092) of all food poisoning outbreaks in Korea between 2013 and 2015.CONCLUSIONS: This study suggests the possibilities of misdiagnosis in the investigations of food poisoning by Staphylococcus aureus and bacillus cereus with kudoa septempuctata.
Bacillus cereus ; Centers for Disease Control and Prevention (U.S.) ; Diagnosis, Differential ; Diagnostic Errors ; Disease Outbreaks ; Epidemiology ; Flounder ; Food Parasitology ; Foodborne Diseases ; Humans ; Korea ; Myxozoa ; Olea ; Staphylococcus aureus

OBJECTIVES: Confirmation of Kudoa septempunctata (K. septempunctata) as the pathogenic agent causing acute food poisoning remains under debate owing to inconsistencies in the reproducibility of experimental evidence. Higher intake of olive flounder infected with K. septempunctata would result in increased diagnosis of food poisoning by K. septempunctata, if the latter was one of the causal agents of acute food poisoning. The aim was to evaluate the relationship between the shipping amount of olive flounder aquacultured from Jejudo and the incidence of K. septempunctata food poisoning in 2015, Korea. METHODS: Data of shipping amounts between March 2014 and February 2016 and of monthly reported events of Kudoa food poisoning were taken from Jejudo Fish-Culture Fisheries Cooperatives and Korea Centers for Disease Control and Prevention, respectively. Non-parametric correlation analyses were conducted. RESULTS: Shipping amounts indicated the seasonal changes according to variation of consumption. Spearman's rho and Kendall's tau-a between the monthly shipping amounts and the reported events in 2015 were 0.39 (p=0.21) and 0.27 (p=0.20), respectively. CONCLUSIONS: An independent relationship was noted between the shipping amount and the reported events, which contrasted with the claim that the virulence of K. septempunctata caused acute food poisoning.
Bias (Epidemiology) ; Centers for Disease Control and Prevention (U.S.) ; Diagnosis ; Fisheries ; Flounder* ; Food Parasitology ; Foodborne Diseases* ; Incidence ; Intestinal Diseases, Parasitic ; Jeju-do* ; Korea* ; Myxozoa ; Olea* ; Seasons ; Ships* ; Virulence

OBJECTIVES: Recently kudoa septempuctata in olive flounders is suggested as a cause of food poisoning, however whether kudoa septempuctata can affect human gastrointestinal systems is controversial and its pathogenecity remains unclear. In view of the field epidemiology, food poisonings caused by kudoa septempuctata should be distinguished from those caused by Staphylococcus aureus and bacillus cereus. METHODS: The statistics of food poisoning investigations published by Korea Centers for Disease Control and Prevention in 2013-2015 were reviewed. The characteristics of kudoa septempuctata food poisoning reported by Korea Centers for Disease Control and Prevention were reviewed. Information regarding clinical symptoms or epidemiology was extracted. RESULTS: Total eleven kudoa septempuctata food poisoning cases were analyzed. Food poisonings caused by kudoa septempuctata, Staphylococcus aureus and bacillus cereus have clinical and epidemiological similarities. Forty five percent of food poisoning outbreaks occurred in Korea was concluded as unknown. The food poisoning caused by Staphylococcus aureus and bacillus cereus accounted for 4.5% (50/1,092) of all food poisoning outbreaks in Korea between 2013 and 2015. CONCLUSIONS: This study suggests the possibilities of misdiagnosis in the investigations of food poisoning by Staphylococcus aureus and bacillus cereus with kudoa septempuctata.
Bacillus cereus ; Centers for Disease Control and Prevention (U.S.) ; Diagnosis, Differential* ; Diagnostic Errors ; Disease Outbreaks ; Epidemiology ; Flounder ; Food Parasitology ; Foodborne Diseases ; Humans ; Korea ; Myxozoa ; Olea ; Staphylococcus aureus