Publications by authors named "Seung-hak Cho"

Exposure to tamoxifen can exert effects on the human liver, and esterases process prodrugs such as antibiotics and convert them to less toxic metabolites. In this study, the porcine liver esterase (PLE)-inhibitory activity of tamoxifen has been investigated. PLE showed inhibition of a PLE isoenzyme (PLE5).

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Unlabelled: To investigate the molecular characteristics and antibiotic resistance of isolates from patients with diarrhea in Korea, 327 strains were collected between 2007 and 2022. The presence of staphylococcal enterotoxin (SE) and toxic shock syndrome toxin-1 (TSST-1) genes in isolates was determined by PCR. The highest expression of the TSST-1 gene was found in the GIMNO type (43.

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Mtb (Mycobacterium tuberculosis) is a pathogenic bacterium that causes tuberculosis infection (TB). Mtb-secreted proteins have recently been investigated as virulence factors, as well as therapeutic and vaccine possibilities. The early-secreted antigen target MTB48 is one of these proteins that has been explored as a cocktail antigen in the serodiagnosis of active tuberculosis.

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Enterotoxigenic Escherichia coli (ETEC) is a major cause of illness and death but has no effective therapy. The heat-labile enterotoxin LT is a significant virulence factor produced by ETEC. The heat-labile enterotoxin-B (LT-B) subunit may enter host cells by binding to monosialotetrahexosylganglioside-a (GM1a), a monosialoganglioside found on the plasma membrane surface of animal epithelial cells.

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Tuberculosis (TB) is caused by Mycobacterium tuberculosis (Mtb) and is still one of the global health burdens. The occurrence of various cases and multidrug resistance confirm that TB has not been completely conquered. For these reasons, the present research has been conducted to explore TB vaccine and drug candidate possibility using Mtb-secreted proteins.

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Background: Enterotoxigenic (ETEC) is a major cause of diarrhea through two enterotoxins, a heat-labile toxin and a heat-stable toxin. These toxins alter the cellular signaling pathways, ultimately triggering an increase in chloride secretion and watery diarrhea.

Objective: For the development of an ETEC vaccine, we attempted to construct a peptide-specific monoclonal antibody library against heat-labile enterotoxin A subunit (LT-A) by epitope mapping using synthetic peptides.

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In this study, we tried to develop a FimH inhibitor that inhibits adhesion of enterohemorrhagic (EHEC) on the epithelium of human intestine during the initial stage of infections. Using a T7 phage display method with a reference strain, EHEC EDL933, FimH was selected as an adherent lectin to GM1a and Gb3 glycans. In order to detect the ligand binding domain (LBD) of FimH, we used a docking simulation and found three binding site sequences of FimH, i.

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Microorganisms, such as bacteria, viruses, and fungi, and host cells, such as plants and animals, have carbohydrate chains and lectins that reciprocally recognize one another. In hosts, the defense system is activated upon non-self-pattern recognition of microbial pathogen-associated molecular patterns. These are present in Gram-negative and Gram-positive bacteria and fungi.

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Objectives: In order to prevent infections through dummies used during Cardiopulmonary Resuscitation (CPR) training, we analyzed the microbiological contamination on dummies used in CPR institutions.

Methods: A total of 31 dummy samples were collected from 13 different institutions in Korea, and were evaluated for the number of contaminating bacteria and fungi on the surface. PCR and biochemical tests were performed to identify pathogenic bacteria and fungi, including Methicillin-Resistant Staphylococcus aureus (MRSA).

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Objective: Lectin-like adhesins of enteric bacterial pathogens such as Escherichia coli are an attractive target for vaccine or drug development. Here, we have developed e-Membranome as a database of genome-wide putative adhesins in Escherichia coli (E. coli).

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Enterohemorrhagic (EHEC) causes hemorrhagic colitis and hemolytic uremic syndrome. EHEC infection begins with bacterial adherence to the host intestine via lectin-like adhesins that bind to the intestinal wall. However, EHEC-related lectin-glycan interactions (LGIs) remain unknown.

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N-glycolylneuraminic acid (Neu5Gc), a generic form of sialic acid, is enzymatically synthesized by cytidine-5'-monophospho-N-acetylneuraminic acid hydroxylase (CMAH). Although expression of pig CMAH gene pcmah encoding CMAH has been reported to be regulated by pathogenic infection and developmental processes, little is known about the mechanisms underlying the regulation of pcmah gene expression. The objective of this study was to determine mechanism(s) involved in intestine specific regulation of pcmah gene by identifying several cis-acting elements and nuclear transcription factors that could directly interact with these cis-acting elements.

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Background: Enterotoxigenic (ETEC) is a common cause of bacterial infection that leads to diarrhea. Although some studies have proposed a potential association between the toxic profile and genetic background, association between toxin of ETEC and phylo-group has not been reported yet. The objective of this study was to examine genomic and phylogenetic characteristics of ETEC strain NCCP15731 and NCCP15733 by whole genome sequencing and comparative genomic analysis of two phylo-groups of O159 reference strains.

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Natural compound esculentoside B (EsB), (2S,4aR,6aR,6aS,6bR,8aR,9R,10R,11S,12aR,14bS)-11-hydroxy-9-(hydroxymethyl)-2 methoxycarbonyl-2,6a,6b,9,12a-pentamethyl-10-[(2S,3R,4S,5R)-3,4,5-trihydroxyoxan-2-yl]oxy-1,3,4,5,6,6a,7,8,8a,10,11,12,13,14b-tetradecahydropicene-4a-carboxylic acid with molecular weight of 664.833, isolated from roots of Phytolacca acinosa Roxb has been widely used as a constituent of traditional Chinese medicine (TCM). However, the anti-inflammatory capacity of EsB has not been reported yet.

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A water-soluble saponin, Esculentoside H (EsH), 3-O-(O-β-d-glucopyranosyl-(1→4)-β-d-xylopyranosyl)-28-β-d-glucopyranosylphytolaccagenin has been isolated and purified from the root extract of perennial plant Phytolacca esculenta. EsH is known to be an anticancer compound, having a capacity for TNF-α release. However, the effects of EsH on migration and growth in tumor cells have not yet been reported.

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Article Synopsis
  • - The study examined the relationship between antibiotic residues and antibiotic resistance in chicken meats, analyzing 58 samples from grocery stores in Korea, with a 45% detection rate of residues.
  • - The most commonly detected antibiotics were amoxicillin, enrofloxacin, and sulfamethoxazole, but all residues were within legal limits set by the Ministry of Food and Drug Safety.
  • - Among 51 isolated strains of bacteria, the highest resistance was found to ampicillin, followed by tetracycline and ciprofloxacin, highlighting the need for further research to enhance food safety regarding antibiotic resistance patterns.
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  • A study in Korea aimed to gather epidemiological data on imported systemic mycoses, a serious fungal infection affecting healthy individuals, due to a lack of existing information.
  • From 2008 to 2012, the prevalence of imported systemic mycoses rose slightly, with coccidioidomycosis showing the most significant increase, particularly among children and the elderly, and varying by region.
  • Treatment costs for these infections were substantial, with most patients being treated as outpatients, and the study's findings may help track trends in imported systemic mycoses over time.
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  • The study focused on the epidemiological characteristics of isolates from patients with Clostridium difficile-associated disease (CDAD) in Korea, where such research is limited.
  • A total of 43 stool samples were found positive for C. difficile, with the main patient conditions including pneumonia, cancer, diabetes, and colitis.
  • The results highlighted a significant level of antibiotic resistance among isolates, noting that while many were resistant to common antibiotics, all were susceptible to vancomycin and metronidazole, which can inform future treatment strategies.
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  • * Whole-genome sequencing revealed that the strain had a size of 4,795,873 bp, with particular enterotoxin genes and serotype characteristics being identified; it belonged to the O6:H16 serotype and had detectable heat-stable and heat-labile toxins.
  • * Despite having the same MLST sequence type as ETEC strains from the USA, NCCP15740 exhibited different colonization factors and virulence profiles, highlighting its unique characteristics which may aid in developing an
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Gangliosides are known to specifically inhibit vascular leukocyte recruitment and consequent interaction with the injured endothelium, the basic inflammatory process. In this study, we have found that the production of nitric oxide (NO), a main regulator of inflammation, is suppressed by GM3 on murine macrophage RAW 264.7 cells, when induced by LPS.

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  • * A significant majority (83.3%) of the isolated bacteria exhibited insecticidal toxicity, with specific toxin genes identified as prevalent, although one particular gene was absent in all samples.
  • * The findings indicate that the bacteria could pose a risk of foodborne illness due to their toxin-producing capabilities, highlighting the need for further research on the safety of organic vegetables.
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The disialoganglioside GD3 has been considered to be involved in tumor progression or suppression in various tumor cells. However, the significance of the biological functions of GD3 in breast cancer cells is still controversial. This prompted us to study the possible relationship(s) between GD3 expression and the metastatic potential of a breast cancer MDA-MB231 cells as an estrogen receptor negative (ER-) type.

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