Publications by authors named "Seung-chun Park"

Livestock-associated fusidic acid-resistant Staphylococcus aureus (FRSA) is frequently linked to global public health hazards. This study aimed to ascertain the prevalence and molecular characteristics of FRSA isolated from food animal products in South Korea from 2010 to 2021. We obtained a total of 3980 S.

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  • Extended-spectrum β-lactamase (ESBL) and AmpC β-lactamase-producing bacteria are becoming a major global health issue due to their resistance to third-generation cephalosporins, particularly in food animals.
  • A study conducted in South Korea collected 409 serovar Infantis isolates from various healthy and diseased food animals, revealing that 61.9% were resistant to ceftiofur, mainly from chickens, highlighting significant multidrug resistance patterns across the isolates.
  • Molecular analysis indicated that all ceftiofur-resistant strains produced specific β-lactamase enzymes, with the majority belonging to sequence type ST32, suggesting widespread dissemination of resistance genes among food animal populations.
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  • The study investigates the issue of multicollinearity among genes in high-throughput RNA-Seq data, which can affect the reliability of predictive models.
  • Six genes associated with embryotoxicity were identified and validated using qPCR after being exposed to various substances, with Zfp42 and Hoxb1 highlighted as potential early biomarkers.
  • The researchers implemented a systematic methodology combining machine learning and statistical analyses, successfully reducing redundancies and improving predictive accuracy, ultimately benefiting embryotoxicity screening research.
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  • * The study introduces a mouse embryoid body test (EBT) model using a 384-well format, aimed at improving screening for early developmental toxicity of chemicals.
  • * The EBT model showed an 84.38% accuracy in predicting developmental toxicity for various compounds, offering a promising solution for efficient chemical safety assessments.
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  • Tylosin, an antibiotic used for respiratory infections in pigs, was studied to see how it affects gut bacteria in healthy versus infected pigs.
  • The study found that infected pigs had less diversity in their gut microbiota compared to healthy pigs after receiving tylosin treatment, with notable differences in specific bacterial groups.
  • Although gut microbiota changes were significant, the relationship between these changes and tylosin pharmacokinetics (how the drug behaves in the body) was not clearly established.
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In the present study, we investigated the potential immunomodulatory effects of heat-killed (hLR) and live PSC102 (LR; formerly PSC102) in RAW264.7 macrophage cells and Sprague-Dawley rats. RAW264.

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  • Gentamicin is an aminoglycoside antibiotic that is used in pigs, but its pharmacokinetics/pharmacodynamics (PK/PD) in piglets have not been previously studied.
  • A study was conducted to compare the effects of a single IM dose of gentamicin in healthy piglets and those co-infected with bacteria, revealing that the drug's effectiveness and clearance were significantly reduced in infected piglets.
  • The findings highlight the need to consider both PK data and antibiotic susceptibility when selecting treatment strategies for infections in piglets.
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Peptidoglycan recognition protein 1 (PGLYRP1) is a pattern-recognition protein that mediates antibacterial actions and innate immune responses. Its expression and role in neuroinflammatory conditions remain unclear. We observed the upregulation of PGLYRP1 in inflamed human and mouse spinal cord and brain, with microglia being the primary cellular source.

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This study aimed to conduct a bioequivalence study of applying three pour-on ivermectin formulations at a dose of 1 mg/kg on the back of Korean native beef cattle (Hanwoo). To conduct bioequivalence testing, the pharmacokinetics of three groups (control Innovator, test Generic A, and test Generic B) of five clinically healthy Korean Hanwoo cattle (average weight 500 kg) were studied. After topical application to the skin, blood samples were drawn at the indicated times.

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  • - The study reports the first detection of novel swine orthopneumovirus (SOV) infections in South Korea, with a 4.4% detection rate in oral fluid samples from pigs across four provinces.
  • - Two complete genome sequences and one glycoprotein gene sequence of the SOV strains from South Korea show significant genetic similarity (98.2% and 95.4%) to previously identified SOV strains from the USA and China.
  • - A genetic analysis classifies the Korean SOV strains into a distinct group (G2) compared to other orthopneumoviruses, contributing to a better understanding of the virus's genetic diversity and distribution in global pig populations.
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Formulating a therapeutic strategy that can effectively combat concurrent infections of () and () can be challenging. This study aimed to 1) establish minimum inhibitory concentration (MIC), minimum bactericidal concentration (MBC), time kill curve, and post-antibiotic effect (PAE) of tylosin against and pig isolates and employ the MIC data for the development of epidemiological cutoff (ECOFF) values; 2) estimate the pharmacokinetics (PKs) of tylosin following its intramuscular (IM) administration (20 mg/kg) in healthy and infected pigs; and 3) establish a PK-pharmacodynamic (PD) integrated model and predict optimal dosing regimens and PK/PD cutoff values for tylosin in healthy and infected pigs. The MIC of tylosin against both 89 and 363 isolates of and strains spread widely, ranging from 1 to 256 μg/mL and from 0.

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  • * A study on infected Siberian tigers identified the virus strain KTPV-2305, closely related to FPV strains in Korean cats, suggesting transmission from stray cats near the zoo.
  • * Vaccinated tigers contracted the virus due to potential vaccine failure or insufficient immunity, highlighting the need for improved vaccination strategies to protect wild carnivores.
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Probiotics are being used as feed/food supplements as an alternative to antibiotics. It has been demonstrated that probiotics provide several health benefits, including preventing diarrhea, irritable bowel syndrome, and immunomodulation. Alongside probiotic bacteria-fermented foods, the different structural components, such as lipoteichoic acids, teichoic acids, peptidoglycans, and surface-layer proteins, offer several advantages.

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Employing affordable and uncomplicated sample preparation techniques to recommend the most efficient antibacterial therapy could help reduce antibiotic-resistant bacteria. This study evaluated the suitability of immunoassays and microbiological assays as alternatives for liquid chromatography/mass spectrometry (LC/MS) in determining plasma tylosin concentrations after intramuscular administration at a dose of 20 mg/kg to both healthy and diseased pigs in clinical veterinary practice. The diseased pigs were confirmed using the target genes () and ().

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  • Porcine deltacoronavirus (PDCoV) emerged in the U.S. in 2014 and causes diarrhea in nursing piglets, with the latest detection in Korea being the KPDCoV-2201 strain in June 2022 after a six-year absence.
  • The KPDCoV-2201 strain was isolated and sequenced, showing high genetic similarity (up to 99.2%) to other global PDCoV strains, and phylogenetic classification places it in group G1b.
  • This strain exhibits unique genetic features, suggesting it evolved from a different lineage than previous Korean strains and indicates potential transboundary transmission, highlighting PDCoV's genetic diversity in Korea.
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Macrolide antibiotics are important drugs to combat infections. The pharmacokinetics (PK) of these drugs are essential for the determination of their optimal dose regimens, which affect antimicrobial pharmacodynamics and treatment success. For most drugs, the measurement of their concentrations in plasma/serum is the surrogate for drug concentrations in target tissues for therapy.

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We isolated and characterized PSC102 and evaluated its probiotic, antioxidant, and antibacterial properties. We preliminarily isolated 154 candidates from pig feces and analyzed their Gram nature, morphology, and lactic acid production ability. Based on the results, we selected eight isolates and tested their ability to produce digestive enzymes.

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In South Korea, testing disinfectants against foot-and-mouth disease virus (FMDV) that are contagious in livestock or that require special attention with respect to public hygiene can be manipulated only in high-level containment laboratories, which are not easily available. This causes difficulties in the approval procedure for disinfectants, such as a prolonged testing period. Additionally, the required biosafety level (BSL) in the case of FMDV has hindered its extensive studies.

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() infections are becoming increasingly difficult to treat, as antibiotic-resistant variants proliferate. Studies on novel methods to combat the spread of resistance and improve the performance of current antibiotics are vital. We aimed to boost the efficacy of the antibiotic orbifloxacin (ORB) against by combining it with a phenolic component, propyl gallate (PG).

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  • Porcine respirovirus 1 (PRV1) is a new respiratory virus affecting pigs, first identified in Hong Kong in 2009, and has now been found in several countries, including Korea.
  • In Korea, PRV1 was detected in pigs across 16 farms in seven provinces, with a high prevalence rate of 71.4% in oral fluid samples, indicating widespread infection.
  • Genetic analysis revealed that the Korean PRV1 strains belong to European lineage 1 and are closely related to strains from other countries, although the origin of the virus remains unclear due to limited sequence data.
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Hypercoagulability is frequently observed in patients with severe coronavirus disease-2019 (COVID-19). Platelets are a favorable target for effectively treating hypercoagulability in COVID-19 patients as platelet hyperactivity has also been observed. It is difficult to develop a treatment for COVID-19 that will be effective against all variants and the use of antivirals may not be fully effective against COVID-19 as activated platelets have been detected in patients with COVID-19.

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Pyrus ussuriensis Maxim (Korean pear) has been used for hundreds of years as a traditional herbal medicine due to its strong phytochemical profile and pharmacological efficacy. In this study, we evaluated the anti-obesity potential of Pyrus ussuriensis Maxim extracts (PUE) and investigated the underlying mechanisms using a combination of in vitro, in vivo, and microbiota regulation approaches. In an adipogenesis assay, the fermented (F)PUE and non-fermented (NF)PUE significantly reduced the differentiation of 3T3-L1 preadipocyte in a dose-dependent manner with an IC of 85.

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The immune functions of heat-killed PSC102 (hLR) were investigated in cyclophosphamide (CP)-treated immunosuppressed mice. BALB/c mice were randomly divided into five groups: normal control group, CP group, CP treated with levamisole (positive control group), and CP treated with low- and high-dose hLR. After receiving the samples for 21 days, mice were sacrificed, and different parameters, such as immune organ index, immune blood cells, splenocyte proliferation, lymphocyte subpopulations, cytokines, and immunoglobulins, were analyzed.

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Background: Recent years, a soaring number of marketed Trifolium pratense (red clover) extract products have denoted that a rising number of consumers are turning to natural alternatives to manage postmenopausal symptoms. T. pratense ethanolic extract (TPEE) showed immense potential for their uses in the treatment of menopause complications including osteoporosis and hormone dependent diseases.

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Obesity is becoming a global epidemic as a result of high-calorie food intake and unhealthy lifestyles. Different marine plants, especially brown algae (), are traditionally used to treat different health-related issues. The study was carried out to investigate the anti-obesity properties of 70% ethanol extract.

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