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PubMed | Inha University, National Fisheries Research and Development Institute NFRDI and South Korean National Fisheries Research and Development Institute
Type: Journal Article | Journal: Environmental science and pollution research international | Year: 2016

Vibrio parahaemolyticus is the most prevalent gastroenteritis-causing pathogen in Korea and in some other Asian countries. It is frequently found in oysters and other seafood. This study monitored changes in the prevalence of V. parahaemolyticus and environmental parameters in oyster aquaculture environments in Korea. From June to October 2014, we tested oysters (Crassostrea gigas) from shellfish-harvesting areas off the west coast of Korea. These 71 isolates were the sum of 16 (22.5%), 19 (26.8%), 23 (32.4%), and 13 (18.3%) isolates collected in July, August, September, and October, respectively. These 71 isolates had the following profiles of resistance against 16 antibiotics: all isolates were resistant to ampicillin and vancomycin, and 52.2, 50.7, and 50.7% of isolates exhibited resistance to cephalothin, rifampin, and streptomycin, respectively. PCR analysis for the presence of the species-specific toxR gene confirmed that 38 (53.5%) of the total 71 isolated strains were positive for V. parahaemolyticus. In PCR analysis for virulence of V. parahaemolyticus, of the 71 isolates tested in the present study, only 38 (53.5%) were positive for the trh virulence gene and 71 (100%) was negative for the tdh virulence gene.


Kim H.-H.,Korea Advanced Institute of Science and Technology | Lee H.,Korea Advanced Institute of Science and Technology | Kim H.-E.,Korea Advanced Institute of Science and Technology | Seo J.,Korea Advanced Institute of Science and Technology | And 3 more authors.
Water Research | Year: 2015

The production of reactive oxidants from nanoparticulate zero-valent iron (nZVI) and ferrous ion (Fe(II)) in the presence of oxygen was greatly enhanced by the addition of tetrapolyphosphate (TPP) as an iron-chelating agent. Compared to other ligands, TPP exhibited superior activity in improving the oxidant yields. The nZVI/TPP/O2 and the Fe(II)/TPP/O2 systems showed similar oxidant yields with respect to the iron consumed, indicating that nZVI only serves as a source of Fe(II). The degradation efficacies of selected organic compounds were also similar in the two systems. It appeared that both hydroxyl radical (OH) and ferryl ion (Fe(IV)) are produced, and OH dominates at acidic pH. However, at pH>6, little occurrence of hydroxylated oxidation products suggests that Fe(IV) is a dominant oxidant. The degradation rates of selected organic compounds by the Fe(II)/TPP/O2 system had two optimum points at pH 6 and 9, and these pH-dependent trends are likely attributed to the speciation of Fe(IV) with different reactivities. © 2015 Elsevier Ltd.


PubMed | National Fisheries Research and Development Institute NFRDI
Type: Journal Article | Journal: Journal of microbiology (Seoul, Korea) | Year: 2015

A Gram-negative, aerobic, non-spore-forming, motile and ovoid or rod-shaped bacterial strain, designated MA2-16(T), was isolated from ark shell (Scapharca broughtonii) collected from the South Sea, South Korea. Strain MA2-16(T) was found to grow optimally at 30C, at pH 7.0-8.0 and in the presence of 2.0% (w/v) NaCl. Neighbour-joining, maximum-likelihood and maximum-parsimony phylogenetic trees based on 16S rRNA gene sequences revealed that strain MA2-16(T) clustered with the type strain of Sedimentitalea nanhaiensis. The novel strain exhibited a 16S rRNA gene sequence similarity value of 97.1% to the type strain of S. nanhaiensis. In the neighbour-joining phylogenetic tree based on gyrB sequences, strain MA2-16(T) formed an evolutionary lineage independent of those of other taxa. Strain MA2-16(T) contained Q-10 as the predominant ubiquinone and C18:1 7c and 11-methyl C18:1 7c as the major fatty acids. The major polar lipids of strain MA2-16(T) were phosphatidylcholine, phosphatidylglycerol, phosphatidylethanolamine, an unidentified aminolipid and an unidentified lipid. The DNA G+C content of strain MA2-16(T) was 57.7 mol% and its DNA-DNA relatedness values with the type strains of S. nanhaiensis and some phylogenetically related species of the genera Leisingera and Phaeobacter were 13-24%. On the basis of the data presented, strain MA2-16(T) is considered to represent a novel genus and novel species within the family Rhodobacteraceae, for which the name Aliisedimentitalea scapharcae gen. nov., sp. nov. is proposed. The type strain is MA2-16(T) (=KCTC 42119(T) =CECT 8598(T)).


PubMed | National Fisheries Research and Development Institute NFRDI
Type: Journal Article | Journal: Journal of microbiology (Seoul, Korea) | Year: 2011

A Gram-staining-negative, motile, non-spore-forming and rod-shaped bacterial strain, 20-23R(T), was isolated from intestine of bensasi goatfish, Upeneus bensasi, and its taxonomic position was investigated by using a polyphasic study. Phylogenetic analyses based on 16S rRNA gene sequences revealed that strain 20-23R(T) belonged to the genus Shewanella. Strain 20-23R(T) exhibited 16S rRNA gene sequence similarity values of 99.5, 99.2, and 97.5% to Shewanella algae ATCC 51192(T), Shewanella haliotis DW01(T), and Shewanella chilikensis JC5(T), respectively. Strain 20-23R(T) exhibited 93.1-96.0% 16S rRNA gene sequence similarity to the other Shewanella species. It also exhibited 98.3-98.4% gyrB sequence similarity to the type strains of S. algae and S. haliotis. Strain 20-23R(T) contained simultaneously both menaquinones and ubiquinones; the predominant menaquinone was MK-7 and the predominant ubiquinones were Q-8 and Q-7. The fatty acid profiles of strain 20-23R(T), S. algae KCTC 22552(T) and S. haliotis KCTC 12896(T) were similar; major components were iso-C(15:0), C(16:0), C(16:1) 7c and/or iso-C(15:0) 2-OH and C(17:1) 8c. The DNA G+C content of strain 20-23R(T) was 53.9 mol%. Differential phenotypic properties and genetic distinctiveness of strain 20-23R(T), together with the phylogenetic distinctiveness, revealed that this strain is distinguishable from recognized Shewanella species. On the basis of the data presented, strain 20-23R(T) represents a novel species of the genus Shewanella, for which the name Shewanella upenei sp. nov. is proposed. The type strain is 20-23R(T) (=KCTC 22806(T) =CCUG 58400(T)).


PubMed | National Fisheries Research and Development Institute NFRDI and Korea Advanced Institute of Science and Technology
Type: | Journal: Water research | Year: 2015

The production of reactive oxidants from nanoparticulate zero-valent iron (nZVI) and ferrous ion (Fe(II)) in the presence of oxygen was greatly enhanced by the addition of tetrapolyphosphate (TPP) as an iron-chelating agent. Compared to other ligands, TPP exhibited superior activity in improving the oxidant yields. The nZVI/TPP/O2 and the Fe(II)/TPP/O2 systems showed similar oxidant yields with respect to the iron consumed, indicating that nZVI only serves as a source of Fe(II). The degradation efficacies of selected organic compounds were also similar in the two systems. It appeared that both hydroxyl radical (OH) and ferryl ion (Fe(IV)) are produced, and OH dominates at acidic pH. However, at pH > 6, little occurrence of hydroxylated oxidation products suggests that Fe(IV) is a dominant oxidant. The degradation rates of selected organic compounds by the Fe(II)/TPP/O2 system had two optimum points at pH 6 and 9, and these pH-dependent trends are likely attributed to the speciation of Fe(IV) with different reactivities.

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