• Korean Journal of Veterinary Service
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• v.32 no.4
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• pp.325-334
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• 2009

Salmonella spp. are the important pathogens both economically and clinically in animals as well as human. Some of them have highly zoonotic potentials even though they are asymptomatic in animals. Therefore, the prevalence of Salmonella spp. in animals is highly concerned for human health. The present study was carried out to investigate the prevalence, antimicrobial resistance and PFGE patterns of Salmonella spp. isolated from chickens at slaughterhouse in Incheon area. The overall isolation rate of Salmonella spp. from cloaca and cecum specimens was 7.3 % (37/510). Thirty seven isolates of Salmonella spp. were identified to 5 serotypes; S. Enteritidis, S. Newport, S. Typhimurium, S. Gallinarum, and S. Derby with prevalence of 46.0%, 40.5%, 8.1%, 2.7%, and 2.7%, respectively. Resistance to nalidixic acid was found in 97.3% of Salmonella spp. isolated, followed by streptomycin (16.2%), tetracycline (16.2%), ampicillin (5.4%). Only 6 isolates (16.2%) showed resistance to more than two antimicrobials. In PFGE analysis of chicken and human isolates with Xba I, S. Enteritidis isolates from chicken showed very high similarity over 82.8% and also the similarity was very high in the comparison with human isolates. However, the higher similarity (100%) was observed among chicken isolates of S. Typhimurium. These results suggest the close genetic relatedness of Salmonella spp. isolated from chickens with human.

• Parasites, Hosts and Diseases
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• v.50 no.3
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• pp.229-231
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• 2012

Toxoplasma gondii is a zoonotic parasite resulting in human infections and one of the infectious pathogens leading to uveitis and retinochoroiditis. The present study was performed to assess T. gondii infection in 20 ocular patients with chronic irregular recurrent uveitis (20 aqueous humor and 20 peripheral blood samples) using PCR. All samples were analyzed by nested PCR targeting a specific B1 gene of T. gondii. The PCR-positive rate was 25% (5/20), including 5% (1) in blood samples, 25% (5) in aqueous humor samples, and 5% (1) in both sample types. A molecular screening test for T. gondii infection in ocular patients with common clinical findings of an unclear retinal margin and an inflammatory membrane over the retina, as seen by fundus examination, may be helpful for early diagnosis and treatment.

• Korean Journal of Veterinary Research
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• v.46 no.4
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• pp.371-379
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• 2006

Newcastle disease virus (NDV) is a single-stranded negative sense RNA virus, which has been classified as a member of the Avulavirus genus of the Paramyxoviridae family. It is also one of the most important pathogens in the poultry industry. The glycoproteins, fusion (F) and hemagglutinin-neuraminidase (HN), determine the virulence of NDV, and the relevant molecular structures have already been determined. NDV isolates differ in terms of virulence, and at least 2 of 9 genotypes (I-IX) have been shown to co-circulate. Therefore, it is clearly important to differentiate between vaccine strains and field isolates. In vivo pathogenicity tests have been the standard protocol for some time, but molecular methods appear preferable in terms of the rapidity of diagnosis, as well as animal welfare concerns. In this study, we have designed primer sets from HN gene for phylogenetic analysis and restriction enzyme analysis, and from F gene for pathotype-specific RT-PCR. Via the combination of 2 methods, 106 Korean NDV isolates obtained from 1980 to 2005 were differentiated into vaccine strains, and virulent genotypes VI and VII. The genotype VI viruses were only rarely isolated after 1999, and genotype VII, after it was initially isolated from poultry in 1995, recurred in 2000, and then became the main NDV constituting a threat to the Korean poultry industry.

• Journal of Microbiology and Biotechnology
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• v.33 no.4
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• pp.441-448
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• 2023

Brucellosis is a contagious zoonotic disease that infects millions of people annually with hundreds of millions more being exposed. It is caused by Brucella, a highly infectious bacterial species capable of infecting humans with an estimated dose of 10-100 organisms. Sirtuin 1 (SIRT1) has been reported to contribute to prevention of viral diseases as well as a chronic infection caused by Mycobacterium bovis. Here, we investigated the role of SIRT1 in the establishment of Brucella abortus infection in both in vitro and in vivo systems using the reported SIRT1 activators resveratrol (RES), piceatannol (PIC), and ginsenoside Rg3 (Rg3). In RAW264.7 cells, SIRT1 activators did not alter the adherence of Brucella or Salmonella Typhimurium. However, reduced uptake of Brucella was observed in cells treated with PIC and Rg3, and survival of Brucella within the cells was only observed to decrease in cells that were treated with Rg3, while PIC treatment reduced the intracellular survival of Salmonella. SIRT1 treatment in mice via oral route resulted in augmented Brucella resistance for PIC and Rg3, but not RES. PIC treatment favors Th2 immune response despite reduced serum pro-inflammatory cytokine production, while Rg3-treated mice displayed high IL-12 and IFN-γ serum production. Overall, our findings encourage further investigation into the complete mechanisms of action of the different SIRT1 activators used as well as their potential benefit as an effective alternative approach against intracellular and extracellular pathogens.

• Journal of Microbiology and Biotechnology
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• v.19 no.9
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• pp.1041-1050
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• 2009

Equine respiratory disease is a common cause of poor performance and training interruptions. The higher incidence rate of infectious upper respiratory disease (IURD) in thoroughbred racehorses at the Seoul Race Park coincided with the frequent stabling season, shorter stabling periods, and younger ages in this study. Incidence rates were also correlated with significantly lower proportions of cells expressing MHC class II-, CD2 antigen-, $CD4^+$- or $CD8^+$-T lymphocyte-, and B lymphocyte in IURD patients compared with healthy control groups in the summer and fall and in 2-and-3-year-old groups. The data suggested that movement and new environments may have resulted in immunosuppression and inappropriate responses to respiratory pathogens in IURD patients. The IURD incidence decreased with age, perhaps by the acquisition of immunity, and study results suggested that immunologic protection was associated with IURD, particularly in young thoroughbred racehorses. Streptococci isolates were identified in 11 of 72 IURD horses, and 3 of these isolates were identified as Streptococcus. equi subsp. equi. S. equi subsp. zooepidemicus was isolated from 2 of 23 IURD horses in the spring (8.7%), 5 of 23 in the summer (21.7%), and 1 of 6 in winter (16.7%). S. equi subsp. zooepidemicus (5%) was also identified in 3 of 61 isolates from clinically normal horses. Racetracks should implement anti-IURD protective measures by assessing the capacity of equine immunologic protection at the Park and by limiting the introduction of specific respiratory pathogens (such as S. equi subsp. equi) by preventing the access of infected but subclinical horses with a specified respiratory pathogen-free certification system prior to Park entry.

• Korean Journal of Microbiology
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• v.41 no.1
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• pp.38-46
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• 2005

To determine the actual hygienic status of domestic chicken meats sold in public markets (conventional markets and department stores), microbial contamination levels (Total cells, Coliforms and Staphylococcal cells) and zoonotic pathogens (Salmonella species, Campylobacter species, Listeria species, and Staphylococcus aureus) isolation tests were conducted. Chicken meats and eggs tested were collected from the conventional markets (Si-Jang) and department-stores located in Seoul and Kyung-gi regions in 1996. In total cells and coliforms contamination tests, chicken meats sold in department stores were much lesser contamination status than those of Si-Jang, but staphylococcal cells level was much more higher than that of conventional markets. Salmonella isolation frequency was investigated as $68.8\%$, but Campylobacter jejuni and Listeria monocytogenes isolation frequency were appeared both $64.0\%\;and\;63.3\%$. In case of eggs sold in public markets, one of S. gallinarum strain $(0.7\%)$ was isolated only on the egg-shell part among the four-hundred and fourty-six. In comparison with foreign imported chicken meats, there were no big differences in microbial contamination status. On the other hand, both Salmonella and L. monocytogenes were isolated only in the chicken wings from Korea and China, but not from U.S.A. This data suggest that more hygienic control system in order to produce the safe and hygienic chicken meats and eggs is need in our country as soon as possible.

• Journal of Veterinary Clinics
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• v.31 no.3
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• pp.194-198
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• 2014

Methicillin-resistant staphylococci (MRS) are emerging as important pathogens in humans and animals worldwide. The aim of this study was to investigate the prevalence of MRS in the racehorse population and in horse-related personnel in Korea. A total of 195 horses and 18 humans (eight veterinarians, three veterinary hospital staff, and seven horse-handlers) from racehorse farms in Korea were included in the study. The samples were collected from nasal cavities using bacterial transport medium and were cultivated on tryptic soy agar with 5% sheep blood for 3 days at $37^{\circ}C$ to confirm the presence of Staphylococcus spp. Presumptive Staphylococcus spp. isolates were identified by 16S ribosomal RNA gene analysis. The coagulase test and oxacillin susceptibility tests were performed using the tube dilution and disk diffusion methods, respectively. The presence of the mecA gene was determined using a polymerase chain reaction assay. Of the 195 horses, 29 (15.6%) yielded 29 MRS isolates. Twelve (66.7%) of the 18 horse-related personnel yielded 12 MRS isolates. All of the MRS isolates from horses or horse-related personnel were identified as methicillin-resistant coagulase-negative staphylococci (MRCNS). The result of this study suggest that the prevalence of MRS increased with the duration of antibiotic use (p = 0.002). This study also provides evidence for the zoonotic transmission of MRCNS between horses and humans, although further investigations are needed.

• Journal of Veterinary Clinics
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• v.31 no.3
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• pp.206-211
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• 2014

Anaplasmosis is a rickettsial zoonosis mediated by blood-sucking arthropods, such as ticks, flies, and mosquitos. Migratory birds are common hosts of ticks that are mediators of anaplasmosis, in particular, the tick infection rate in thrushes (family Turdidae) has been known to be high. The main purpose of this study is to survey the occurrence and prevalence of Anaplasma spp. from the migratory thrushes in Jeju island. We collected blood samples from 6 thrushes rescued at the Jeju Wildlife Rescue Center and from 34 wild-caught thrushes on Mara island which is a satellite island of Jeju. As a result, the nested PCR confirmed that seven out of 40 individuals (17.5%) were infected by Anaplasma spp. and all of them were identified as A. phagocytophilum based on sequences obtained from partial 16S rRNA. All the infected birds were on their northward migration in spring, our results suggest that the Turdidae family, which is a common and abundant migrant group passing through Jeju island, may act a role as active reservoir and disperser of A. phagocytophilum causing potential influx of the zoonotic pathogens from its wintering grounds in lower latitude to the mainland Korea as well as Jeju.

• Journal of Veterinary Clinics
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• v.31 no.1
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• pp.6-10
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• 2014

Siberian Roe deer which inhabits Jeju Island is unique native species. Most of all the roe deer infect a lot of ticks, which can affect its population directly and can act as a vector to spread vector-borne diseases. The purposes of this study were to identify the ticks and detect the piroplamsosis on the roe deer in Jeju island. We collected ticks and blood samples in 23 roe deer rescued and treated at the Jeju Wildlife Rescue Center. As a result, we identified the one species of ticks, Haemaphysalis longicornis in roe deer and detected the closely related to Theileria luwenshuni in all blood samples (100%) and 8 pooled ticks (34.8%). These results indicate that there may be a high prevalence particularly of T. luwenshuni infection in Jeju wild roe deer and H. longicornis is a major vector of these diseases. It suggested that Jeju roe deer may act as reservoirs for these zoonotic pathogens.

• Journal of Animal Science and Technology
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• v.54 no.1
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• pp.59-63
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• 2012

Bovine serum contains various nutrients and growth factors that can be potentially used in biological experiments, drug manufacturing process and food industry. However, almost all the bovine blood has been wasted during slaughter process in Korea, thus there is a high demand for alternative uses of the wasted sera. In order to produce high quality and safe sera, it is necessary to screen zoonotic pathogens as well as other microbial contaminants to prevent any downstream contamination. The present research has been undertaken to assess biological safety of Hanwoo sera by determining microbiological contamination during slaughtering and handling processes. Serological tests have been performed to detect bacteria, mycoplasma and virus contamination in total of 52 Hanwoo sera. No sera were found to be contaminated with mycoplasma or virus, but only two sera were found to be contaminated with Bacillus thuringiensis. The present result shows that Hanwoo sera obtained from slaughtering process are biologically safe and have potentials to be developed as a biological reagent. Moreover, the methods employed in our study may provide basic standard for microbiological screening methods once wasted Hanwoo sera gain industrial values.