• Korean Journal of Veterinary Service
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• v.31 no.2
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• pp.195-205
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• 2008

Yersinia enterocolitica is a zoonotic agent, and to cause food poisoning. This study was carried out to get some basic information for the control of Yersinia infection. A total of 1,680 samples were collected from beef and pork carcasses from January 2006 to December 2007 in Seoul. The isolation rate was higher in pork carcass than in beef carcass. Five (0.59%) Yersinia enterocolitica were isolated from the 840 of beef carcasses, and eighteen(2.14%) were isolated from the 840 of pork carcasses. Among 23 strains, 22 were classified into biotype 1A, and one was biotype 6. In serotyping of Y enterocolitica isolates, 21 strains were untypable (UT), and 2 were O5 and O8 respectively. In PCR, Ail gene was not detected in all of 23 strains that determined non-pathogenic. In antimicrobial susceptibility test, twelve strains (52.2%) of 23 isolates showed the multi -resistant patterns with over 3 drugs. PFGE was performed after the genomic DNA of twenty three isolates, which was digested with Xba I. the 23 isolates showed 12 ($A{\sim}L$) PFGE type.

• Journal of the Korean Chemical Society
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• v.55 no.2
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• pp.262-267
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• 2011

The denaturing high performance liquid chromatography(DHPLC) with fluorescence detector assay is very useful tool for detecting nucleic acids. Furthermore, loop-mediated isothermal amplification(LAMP) constitutes a potentially valuable tool for rapid diagnosis of pathogenic microorganisms. In this study, we evaluated the specificity, detection limit, and sensitivity of a LAMP method and DHPLC method for rapid detection of the hepatitis b virus(HBV). As a result, the LAMP assay reported here has the advantage of rapid detection whereas, DHPLC assay has more sensitivity than other assays. These findings suggest that LAMP and DHPLC assay may be good tool for rapid diagnosis of clinical HBV infection.

• Research in Plant Disease
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• v.11 no.1
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• pp.80-84
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• 2005

Bacterial canker of sweet cherry (Prunus avium L.) was observed in farmers\' orchards in Goesan, Chungbuk in 2003. Typical canker symptoms occurred on the branches or twigs of sweet cherry in early spring and bacterial exudates oozed out of the cracked barks of diseased trees. Watersoaked brown symptoms appeared on the leaves and severe infection caused thorough defoliation on the branches or twigs of sweet cherry. When severely infected branches or twigs were cut, irregular and rusty-colored symptoms in sapwood and heartwood were clearly found, indicating that they can serve as specific symptoms of bacterial canker of sweet cherry. The causal bacterium responsible for the symptoms was isolated purely from the infected sapwood of sweet cherry. Based on its morphological, physiological and biochemical characteristics, the causal bacterium was identified as Pseudomonas syringae pv. morsprunorum. The bacterium was pathogenic on sweet cherry and Japanese apricot, but not on peach, cherry, and kiwifruit. It is proposed that the disease be named as bacterial canker of sweet cherry.

• Korean Journal of Veterinary Research
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• v.44 no.4
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• pp.607-613
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• 2004

Helicobacter pylori (H. pylori)-infection is an important pathogen of stomach cancer after chronic gastritis and ulceration in the stomach and duodenum. However, the virulences of H. pylori strains have not been well-defined between clinical isolates. This study was designed to establish water-immersion-restraint stress (WIRS) model in mongolian gerbil for comparison of pathogenicity of H. pylori strains. To determine an optimal duration time for WIRS model in gerbil, 5-week-old Mongolian gerbils were divided into different groups by WIRS duration time. After graded duration of WIRS, the macroscopic ulcer index (UI) was measured with the stomach and duodenum of sacrificed animal. There were no significant differences between male and female in same duration group. However, the UI increased significantly in a time-dependent fashion. The group of 6 hours-WIRS animals showed severe hemorrhage and ulceration in their stomach and duodenum. On the other hand, the very mild lesions induced in 2 hours-treated animals. Therefore, we determined an optimal duration time for WIRS model in gerbil as 4 hours. Thereafter, we evaluated whether this WIRS model in gerbil could be used as an useful tool for in vivo comparison of pathogenicity of H. pylori strains by enhancement of pathological severity in H. pylori-infected gerbils. Mongolian gerbils were divided into H. pyloriinfected and PBS-inoculated groups. Thereafter, they were divided again into 4 hours-WIRS and no WIRS subgroups. After treatment, the severity of pathological changes was evaluated in a same manner with previous duration-determining experiment. When the animals were exposed to WIRS, the UI was significantly higher in the infected group than in the uninfected group. These results suggested that the established gerbil-WIRS model in this study enhanced effectively the severity of pathogenic changes in the H. pylori-infected Mongolian gerbils and could be used as an useful tool for in vivo comparison of pathogenicity of H. pylori strains.

• Journal of Veterinary Science
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• v.22 no.4
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• pp.50.1-50.10
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• 2021

Background: Bovine papillomatosis is a type of proliferative tumor disease of skin and mucosae caused by bovine papillomavirus (BPV). As a transboundary and emerging disease in cattle, it poses a potential threat to the dairy industry. Objectives: The aim of this study is to detect and clarify the genetic diversity of BPV circulating in dairy cows in Xinjiang, China. Methods: 122 papilloma skin lesions from 8 intensive dairy farms located in different regions of Xinjiang, China were detected by polymerase chain reaction. The genetic evolution relationships of various types of BPVs were analyzed by examining this phylogenetic tree. Results: Ten genotypes of BPV (BPV1, BPV2, BPV3, BPV6, BPV7, BPV8, BPV10, BPV11, BPV13, and BPV14) were detected and identified in dairy cows. These were the first reported detections of BPV13 and BPV14 in Xinjiang, Mixed infections were detected, and there were geographical differences in the distribution of the BPV genotypes. Notably, the BPV infection rate among young cattle (< 1-year-old) developed from the same supply of frozen sperm was higher than that of the other young cows naturally raised under the same environmental conditions. Conclusions: Genotyping based on the L1 gene of BPV showed that BPVs circulating in Xinjiang China displayed substantial genetic diversity. This study provided valuable data at the molecular epidemiology level, which is conducive to developing deep insights into the genetic diversity and pathogenic characteristics of BPVs in dairy cows.

• Journal of Microbiology and Biotechnology
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• v.31 no.4
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• pp.610-620
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• 2021

There has been increasing interest in the head and neck squamous cell carcinoma (HNSCC) that is caused by high-risk human papillomavirus (HR-HPV) and has posed a significant challenge to Otolaryngologists. A rapid, sensitive, and reliable method is required for the detection of HR-HPV in clinical specimens to prevent and treat HPV-induced diseases. In this study, a multiple cross-linking spiral amplification (MCLSA) assay was developed for the visual detection of HPV-16. In the MCLSA assay, samples were incubated under optimized conditions at 62℃ for 45 min, and after mixing with the SYBR Green I (SGI) dye, the positive amplicons showed bright green fluorescence while the negative amplicons exhibited no obvious change. The specificity test revealed that the developed MCLSA technique had high specificity and could effectively distinguish all five HPV-16 strains from other pathogenic microorganisms. In terms of analytical sensitivity, the limit of detection (LoD) of MCLSA assay was approximately 5.4 × 101 copies/tube, which was 10-fold more sensitive than loop-mediated isothermal amplification (LAMP) and RT-PCR. The detection results of laryngeal cancer specimens collected from 46 patients with suspected HPV infection in the Liaoning region demonstrated that the positive detection rates of MCLSA and hybridized capture 2 kit were 32.61% (15/46). The true positive rate of the MCLSA assay was higher than that of RT-PCR (100% vs. 93.33%) and LAMP (100% vs. 86.67%). Therefore, the MCLSA assay developed in the present study could be a potentially useful tool for the point-of-care (PoC) diagnosis of HR-HPV, especially in resource-limited countries.

• Journal of Microbiology and Biotechnology
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• v.29 no.6
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• pp.863-876
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• 2019

Farm animals such as piglets are often affected by environmental stress, which can disturb the gut ecosystem. Antibiotics were commonly used to prevent diarrhea in weaned piglets, but this was banned by the European Union due to the development of antibiotic resistance. However, the use of probiotics instead of antibiotics may reduce the risk posed by pathogenic microorganisms and reduce the incidence of gastrointestinal diseases. Therefore, this study was conducted to investigate the effects of Lactobacillus casei Zhang on the mechanical barrier and immune function of early-weaned piglets infected using Escherichia coli K88 based on histomorphology and immunology. Fourteen-day-old weaned piglets were divided into a control group and experimental groups that were fed L. casei Zhang and infected with E. coli K88 with or without prefeeding and/or postfeeding of L. casei Zhang. The L. casei Zhang dose used was $10^7CFU/g$ diet. Jejunum segments were obtained before histological, immunohistochemical, and western blot analyses were performed. In addition, the relative mRNA expression of toll receptors and cytokines was measured. Piglets fed L. casei Zhang showed significantly increased jejunum villus height, villus height-crypt depth ratio, muscle thickness, and expression of proliferating cell nuclear antigen and tight junction proteins ZO-1 and occludin. The use of L. casei Zhang effectively reduced intestinal inflammation after infection. We found that L. casei Zhang feeding prevented the jejunum damage induced by E. coli K88, suggesting that it may be a potential alternative to antibiotics for preventing diarrhea in early-weaned piglets.

• Food Science of Animal Resources
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• v.39 no.1
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• pp.84-92
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• 2019

Listeria monocytogenes is a major cause of serious foodborne illness in the dairy foods. Although Caenorhabditis elegans model is well established as a virulence model of pathogenic bacteria, its application on L. monocytogenes is critically unclear. The objective of this study was to carry out an evaluation of L. monocytogenes toxicity using C. elegans nematode as a simple host model. We found that C. elegans nematodes have high susceptibility to L. monocytogenes infection, as a consequence of accumulation of bacteria in the worms' intestine. However, L. innocua, which is known to be non-toxic, is not accumulate in the intestine of worms and is not toxic similarly to Escherichia coli OP50 known as the normal feed source of C. elegans. Importantly, immune-associated genes of C. elegans were intensely upregulated more than 3.0-fold when they exposed to L. monocytogenes. In conclusion, we established that C. elegans is an effective model for studying the toxicity of L. monocytogenes and we anticipate that this system will result in the discovery of many potential anti-listeria agents for dairy foods.

• Journal of Ginseng Research
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• v.43 no.2
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• pp.218-225
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• 2019

Background: Streptococcus pneumoniae, more than 90 serotypes of which exist, is recognized as an etiologic agent of pneumonia, meningitis, and sepsis associated with significant morbidity and mortality worldwide. Immunization with a pneumococcal pep27 mutant (${{\Delta}}pep27$) has been shown to confer comprehensive, long-term protection against even nontypeable strains. However, ${{\Delta}}pep27$ is effective as a vaccine only after at least three rounds of immunization. Therefore, treatments capable of enhancing the efficiency of ${{\Delta}}pep27$ immunization should be identified without delay. Panax ginseng Mayer has already been shown to have pharmacological and antioxidant effects. Here, the ability of Korean Red Ginseng (KRG) to enhance the efficacy of ${{\Delta}}pep27$ immunization was investigated. Methods: Mice were treated with KRG and immunized with ${{\Delta}}pep27$ before infection with the pathogenic S. pneumoniae strain D39. Total reactive oxygen species production was measured using lung homogenates, and inducible nitric oxide (NO) synthase and antiapoptotic protein expression was determined by immunoblotting. The phagocytic activity of peritoneal macrophages was also tested after KRG treatment. Results: Compared with the other treatments, KRG significantly increased survival rate after lethal challenge and resulted in faster bacterial clearance via increased phagocytosis. Moreover, KRG enhanced ${{\Delta}}pep27$ vaccine efficacy by inhibiting reactive oxygen species production, reducing extracellular signal-regulated kinase apoptosis signaling and inflammation. Conclusion: Taken together, our results suggest that KRG reduces the time required for immunization with the ${{\Delta}}pep27$ vaccine by enhancing its efficacy.

• Korean journal of applied entomology
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• v.59 no.4
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• pp.451-454
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• 2020

Sericulture is a main insect industry in Sangju (Kyungpook, Korea). This study reports an occurrence of a viral disease in the sericulture farms in 2020. More than 20% silkworm larvae (Bombyx mori) suffered diarrhea and melted tissues with pathogenic lethality at 4th or 5th instars. PCR diagnosis showed a positive response against B. mori nucleopolyhedrosis virus (BmNPV) infection. Tissue extract of the infected larvae was applied to healthy larvae by a leaf-dipping method and exhibited the same viral symptoms. The viral extract was used to be overlaid on Sf9 cells. The infected Sf9 cells showed polyhedra in the cytoplasm. These results indicate that the silkworm larvae reared in the sericulture farms in Sangju were infected with BmNPV.