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Kwon J.-W.,National Veterinary Research and Quarantine Service NVRQS
Bulletin of Environmental Contamination and Toxicology | Year: 2011

The widespread use of the pharmaceutical chlortetracycline to treat human and animal infectious diseases is raising concern in Korea regarding the potential development of antibiotic-resistant bacteria. This study investigated the fate of chlortetracycline in Korean arable soils, to assess its environmental impact. The estimated half-life of chlortetracycline was 26.70-27.17 days indoors and 18.63-30.16 days outdoors. The chlortetracycline epimers and metabolites, 4-epichlortetracycline and 4-epi-anydrochlotetracycline were determined using liquid chromatography tandem mass spectroscopy. The respective concentrations of 4-epi-anydrochlotetracycline and 4-epichlortetracycline were 1.91%-9.71% and 11.12%-23.92% of the total chlortetracycline residual concentration indoors and 2.96%-11.44% and 17.61%-40.73% outdoors. © 2011 Springer Science+Business Media, LLC.

Kwon J.-W.,National Veterinary Research and Quarantine Service NVRQS
Bulletin of Environmental Contamination and Toxicology | Year: 2011

Sulfonamides and tetracyclines are pharmaceuticals widely used to treat human and animal diseases. They are of considerable concern in Korea because of the potential risk of residues in aquatic and terrestrial environments. This study investigated the mobility of veterinary drugs in the soil column with the application of manure compost to assess the risk of groundwater contamination by leaching in the Korean agricultural environment. The degree of sulfonamides and tetracyclines mobility, measured by the concentration of leachates from silty loam soil for 9 days, was observed being on the first day of this study, in the order sulfathiazole, sulfamethazine > sulfamethoxazole > chlortetracycline > oxytetracycline, and the sulfonamides concentrations were about ten times higher than the tetracyclines concentrations with continuous leaching. The results indicate that sulfonamides pose a high risk of ground and surface water contamination and tetracyclines have the potential to persist in soils with bioactive epimers. © 2011 Springer Science+Business Media, LLC.

Choe S.-E.,National Veterinary Research and Quarantine Service NVRQS | Nguyen T.T.-D.,National Veterinary Research and Quarantine Service NVRQS | Nguyen T.T.-D.,Vietnam Academy of Science and Technology | Kang T.-G.,Nothern Branch Veterinary Service Laboratory | And 2 more authors.
Parasitology Research | Year: 2011

Nuclear ribosomal DNA sequence of the second internal transcribed spacer (ITS-2) has been used efficiently to identify the liver fluke species collected from different hosts and various geographic regions. ITS-2 sequences of 19 Fasciola samples collected from Korean native cattle were determined and compared. Sequence comparison including ITS-2 sequences of isolates from this study and reference sequences from Fasciola hepatica and Fasciola gigantica and intermediate Fasciola in Genbank revealed seven identical variable sites of investigated isolates. Among 19 samples, 12 individuals had ITS-2 sequences completely identical to that of pure F. hepatica, five possessed the sequences identical to F. gigantica type, whereas two shared the sequence of both F. hepatica and F. gigantica. No variations in length and nucleotide composition of ITS-2 sequence were observed within isolates that belonged to F. hepatica or F. gigantica. At the position of 218, five Fasciola containing a single-base substitution (C>T) formed a distinct branch inside the F. gigantica-type group which was similar to those of Asian-origin isolates. The phylogenetic tree of the Fasciola spp. based on complete ITS-2 sequences from this study and other representative isolates in different locations clearly showed that pure F. hepatica, F. gigantica type and intermediate Fasciola were observed. The result also provided additional genetic evidence for the existence of three forms of Fasciola isolated from native cattle in Korea by genetic approach using ITS-2 sequence. © 2011 Springer-Verlag.

Her M.,National Veterinary Research and Quarantine Service NVRQS | Kang S.-I.,National Veterinary Research and Quarantine Service NVRQS | Kim J.-W.,National Veterinary Research and Quarantine Service NVRQS | Kim J.-Y.,National Veterinary Research and Quarantine Service NVRQS | And 5 more authors.
Journal of Microbiology and Biotechnology | Year: 2010

The MLVA assay is known to have a high ability to identify and discriminate Brucella species, so that it can be used as an epidemiological tool to discriminate Brucella isolates originating from restricted geographic sources. In this study, the genetic profiles of 38 B. abortus isolates from humans were analyzed and compared with genotypes from animal isolates in South Korea. As a result, it was found that they did not show high genetic diversity and were compacted. They were clustered together with animal isolates, showing a significant correlation to regional distributions. With its ability to prove a significant genetic correlation among B. abortus isolates from animals and humans in South Korea, the MLVA assay could be utilized as part of a program to control and eradicate brucellosis, one of the major zoonoses. This study represents the first data of genetic correlation of B. abortus isolates from humans and animals in South Korea.

Song M.-S.,Chungbuk National University | Lee J.H.,Chungbuk National University | Pascua P.N.Q.,Chungbuk National University | Baek Y.H.,Chungbuk National University | And 7 more authors.
Journal of Clinical Microbiology | Year: 2010

As the pandemic (H1N1) 2009 influenza virus continues to infect human populations globally, reports on epidemiologically linked animal infections are also on the rise. Since December 2009, pandemic (H1N1) 2009-like viruses have been isolated in pigs from different swine farms of South Korea. Genetic and phylogenetic analyses of viral segments demonstrated several events of human-to-swine transmission with no apparent signs of reassortment. These events were also supported by serological surveillance in pig sera collected from April to December, suggesting that reverse transmission probably started between June and July with a drastic increase in prevalence the following months. Although molecular characterization indicates that the swine isolates are generally stable, some viruses are genetically evolving, most notably in their surface proteins. Animal studies (ferrets and mice) reveal that swine pandemic isolates epitomize biological properties attributed to the currently circulating human pandemic viruses, including replication kinetics and efficient transmission, indicating their potential to return to circulation among humans. Overall, these results indicate widespread human-to-animal transmission of pandemic (H1N1) 2009 influenza viruses in South Korea. With the significant role of pigs in the ecology of influenza viruses, these transmission events should be closely monitored and minimized to prevent the risk of generating viruses with greater human health concerns. Copyright © 2010, American Society for Microbiology. All Rights Reserved.

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