• Genomics & Informatics
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• v.21 no.1
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• pp.5.1-5.13
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• 2023

Neisseria gonorrhoeae is a Gram-negative aerobic diplococcus bacterium that primarily causes sexually transmitted infections through direct human sexual contact. It is a major public health threat due to its impact on reproductive health, the widespread presence of antimicrobial resistance, and the lack of a vaccine. In this study, we used a bioinformatics approach and performed subtractive genomic methods to identify potential drug targets against the core proteome of N. gonorrhoeae (12 strains). In total, 12,300 protein sequences were retrieved, and paralogous proteins were removed using CD-HIT. The remaining sequences were analyzed for non-homology against the human proteome and gut microbiota, and screened for broad-spectrum analysis, druggability, and anti-target analysis. The proteins were also characterized for unique interactions between the host and pathogen through metabolic pathway analysis. Based on the subtractive genomic approach and subcellular localization, we identified one cytoplasmic protein, 2Fe-2S iron-sulfur cluster binding domain-containing protein (NGFG RS03485), as a potential drug target. This protein could be further exploited for drug development to create new medications and therapeutic agents for the treatment of N. gonorrhoeae infections.

• Korean Journal of Environmental Biology
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• v.26 no.3
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• pp.240-246
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• 2008

From the 4 sampling stations located in the basin of the Han River, total 46 strains of Enterococcus spp. composed of 15 E. faecium strains, 26 E. casseliflavus strains, 1 E. faecalis strain and 4 E. hirae strains were isolated. Among the 46 strains, 45 strains exhibited streptomycin-resistance, while 21 and 19 stains were resistant against tetracycline and quinupristin/dalfopristin, respectively. As for gentamicin and vancomycin, 15 strains and 1 strain showed resistance against the respective antimicrobial agents. Among the 46 strains, 39 strains showed resistance against more than 2 antimicrobial agents, and 10 strains demonstrated resistance to more than 5 antimicrobial agents. Especially, the strain isolated from the station C at Anyangcheon, exhibited resistance against all the 8 kinds of the antimicrobial agents. As the sampling site approached to the lower stream of the Han-river, the antibiotic resistant strains and the multi-drug resistant strains were detected more frequently. The MIC values of the antibiotic resistant strains measured by the disc diffusion method disclosed that 16 strains possessed maximum MIC value of 4,096 ${\mu}g$ mL$^{-1}$ against streptomycin and 17 strains possessed maximum MIC value of 2,048 ${\mu}g$ mL$^{-1}$ against gentamicin. Meanwhile, 1 strain exhibited maximum MIC value of 5121 ${\mu}g$ mL$^{-1}$ against vancomycin. As for quinupristin/dalfopristin and tetracycline, 2 and 33 strains showed maximum MIC value of 641 ${\mu}g$ mL$^{-1}$, respectively. Comparison of the MIC values of the strains of the this study with those of the strains of the other research groups isolated from the hospital drainage and also those from the live stock farm drainage indicated that the strains resistant against vancomycin and quinupristin/dalfopristin may be originated from the livestock farm drainage.

• Pediatric Infection and Vaccine
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• v.7 no.2
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• pp.233-239
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• 2000

Purpose : A great deal of youngsters suffer from otitis media, for which antimicrobials are frequently prescribed. Increased antimicrobial resistance forces physicians to judiciously use antimicrobial agents in treating patients with acute otitis media. There have however been few references with regard to otitis media in Korean children, and authors proceeded investigation to look for the causative agents of otitis media in Korean children and their antimicrobial susceptibility. Methods : The study included 65 patients younger than 15 years old who had been cared at the department of pediatrics and otolaryngology in Hanyang University Hospital from July 1994 to June 1999, and diagnosed of otitis media with otorrhea which contained microorganisms isolated in otorrhea culture. The medical records were reviewed for demographic data, isolated organisms and their antimicrobial susceptibility. Results : Among 65 patients, 37(57%) were boys and 28(43%) girls. Distribution of the patients was reciprocal to the age of the patients; 27 patients(41.5%) were younger than 1 year old, 24(36.9%) were 1 to 3 years old with the average of 2.9 years of age. Staphylococus aureus was isolated in 32 patients(49.2%), Streptococcus pneumoniae in 19 patients(29.2%) Haemophilus influenzae in 9 patients(13.8%), Streptococcus oralis in 3 patients(4.6%), Moraxella catarrhalis in 1 patient(1.5%). The isolated microorganisms were not different whether patients had cleft lip/palate or not. The antibiotic resistance rates of S. aureus were ${\geq}90%$ to erythromycin, imipenem, cephalothin, and clindamycin, 86.2% to oxacillin, 25% to chloramphenicol, 12.5% to trimethoprim/sulfamethoxazole(TMP/SMX), and 0% to vancomycin and teicoplanin. The antibiotic resistance rates of S. pneumoniae were 71.4% to penicillin and greater than 60% to erythromycin, tetracycline, TMP/SMX, 7.1% to chloramphenicol, and 0% to vancomycin and teicoplanin. The antibiotic resistance rates of H. influenzae were 55% to ampicillin and TMP/SMX, and 0% to chloramphenicol, ceftriaxone, aztreonam, imipenem and ciprofloxacin. Conclusion : With otorrhea culture, the causative organisms of otitis media appear to be S. aureus, S. pneumoniae and H. influenzae. The high antibiotic resistance rates of the isolated organisms should affect the choice of antibiotics in treating patients with otitis media. Prospective investigations utilizing tympanocentesis in microbiologic studies are needed.

• Korean Journal of Clinical Pharmacy
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• v.20 no.1
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• pp.78-84
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• 2010

Background: Clostridium difficile is the primary reason of the nosocomial diarrhea. The antimicrobial therapy plays a central role in the pathogenesis of Clostridium difficile associated diarrhea (CDAD). Although nearly all classes of antimicrobial agents have been associated with CDAD, clindamycin and the third-generation cephalosporins have traditionally been considered to the greatest risk factor. Recent studies have also implicated fluoroquinolones as high-risk agents due to increasing use of the agents. This study was to determine the incidence and the risk factors of CDAD related to the administered antibiotics and to assess the therapeutic regimen of metronidazole or vancomycin based on the C. difficile toxin assay Methods: A retrospective study was performed in patients with Clostridium difficile toxin assay at I Hospital (Incheon, South Korea) during the period from January 2007 through December 2007. Administrative, laboratory, and pharmacy data were collected from Electronic Medical Databases. Results: The analysis included 129 reported C.difficile toxin assay results, with 42 positive cases and 87 negative cases. Significant antibiotic risk factors for CDAD included the use of the fourth-generation cephalosporinse (OR=5.97, 95% CI 1.37-25.98, P=0.017). Administration of metronidazole was protective against CDAD (OR=0.30, 95% CI 0.12-0.74, P=0.009). Prolonged antimicrobial therapy has been associated with an increased risk of CDAD. The third-generation cephalosporins (OR=3.81, 95% CI 1.08-13.41, P=0.037) and aminoglycoside (OR=5.50, 95% CI 1.43-21.10, P=0.013) demonstrated greater risk for CDAD over 15 days than 8days or less days of treatment duration. Conclusions: The fourth and third generation cephalosporin, aminglycoside were the significant risk factors compared with other antibiotics, whereas metronidazole appears to be protective. The longer duration of antiobiotic use increased CDAD.

• Korean Journal of Microbiology
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• v.48 no.1
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• pp.22-28
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• 2012

Vibrio parahaemolyticus is one of the major agents responsible for food poisoning during summer in Korea, which is transmitted via seawater or seafoods. Recently, distribution of the bacteria in the marine environment has been increased due to global warming. Great concern also has been raised regarding public hygiene as well as marine culture by the emergence of pathogens with antibiotic resistance. Therefore, distribution of V. parahaemolyticus and antibiotic resistance of the isolates were monitored in 7 coastal areas of Kyonggi Province and Incheon by sampling seawater, fishes and clams monthly. V. parahaemolyticus was detected from 47.7% of 966 samples (seawater 61.9%, seafoods 41.8%) analyzed using $CHROMagar^{TM}$ and TCBS agar plates as well as multiplex PCR. Among 13 antibiotics tested, resistance to vancomycin and ampicillin was observed in 97.3% and 87.3% of the isolates, respectively, and the ratios of them resistant to cephalothin (48.8%) and rifampin (46.1%) were also high. The isolates were most highly sensitive to chloramphenicol (91.7%) and trimethoprim-sulfamethoxazole (91.8%). The ratio of sensitivity for other antibiotics was also high in the descending order of gentamycin (82.3%), tobramycin (74.8%), nalidixic acid (71.6%), tetracyclin (69.4%), cefotaxime (63.0%). About 69% of the isolates showed multiple drug resistance toward 3 antibiotics including vancomycin and ampicillin. Two of them exhibited resistance for 11 antibiotics used in this study. Plasmid profile analysis of the isolates with antibiotic resistance revealed that 55.1% of them retained plasmids of 24 different types. However, no clear inter-relationship between the resistance and the plasmid profile has been observed.

• Asian-Australasian Journal of Animal Sciences
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• v.23 no.3
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• pp.410-416
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• 2010

Methane emitted from ruminant livestock is regarded as a loss of feed energy and also a contributor to global warming. Methane is synthesized in the rumen as one of the hydrogen sink products that are unavoidable for efficient succession of anaerobic microbial fermentation. Various attempts have been made to reduce methane emission, mainly through rumen microbial manipulation, by the use of agents including chemicals, antibiotics and natural products such as oils, fatty acids and plant extracts. A newer approach is the development of vaccines against methanogenic bacteria. While ionophore antibiotics have been widely used due to their efficacy and affordable prices, the use of alternative natural materials is becoming more attractive due to health concerns regarding antibiotics. An important feature of a natural material that constitutes a possible alternative methane inhibitor is that the material does not reduce feed intake or digestibility but does enhance propionate that is the major hydrogen sink alternative to methane. Some implications of these approaches, as well as an introduction to antibiotic-alternative natural materials and novel approaches, are provided.

• Journal of Microbiology and Biotechnology
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• v.27 no.4
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• pp.759-767
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• 2017

Lactophoricin (LPcin), which is a part of proteose peptone isolated from bovine milk, is a cationic amphipathic ${\alpha}-helical$ antimicrobial peptide. Its truncated variants and mutated analogs were designed and their antimicrobial activities were evaluated by using various assays, like broth dilution methods and disk diffusion methods as well as hemolysis assay. Three analogs, LPcin-C8 (LPcin-YK1), LPcin-T2&6W (LPcin-YK2), and LPcin-T2&6W-C8 (LPcin-YK3), which showed better antibiotic activities than LPcin, were selected. Their secondary structures were also characterized by using CD spectropolarimetry. These three analogs of LPcin could be used as an alternative source of powerful antibacterial agents.

• Korean Journal of Veterinary Service
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• v.21 no.1
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• pp.21-27
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• 1998

In order to investigate reproductive disorder in dairy cows, 312 uterine from abattroirs and 56 cows from dairy farms were examined. The ovary and uterine were collected from abattroirs and rectal palpation was carried out in the case of reproductive disorder at dairy farm. Microbiological examination was also carried out from the collected samples. 1. Out of 312 ovaria from slaughter-house, cystic ovary and endometritis were classified as 51(16%) and 134(43%), respectively. And of 56 dairy cow from farms, 43(77%) were identifies as endometritis. 2. The main cause of reproductive disorder was classified as hormonal imbalances, endometritis and cystic ovary, singly or in combination. 3. The main causative agents of endometritis was encountered as E coli, Staphylococcus aureus, Bacillus sp and Corynebacterium sp. 4. The highest susceptible antibiotics to the isolates was cephalosporin.

• Journal of Plant Biotechnology
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• v.3 no.3
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• pp.113-121
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• 2001

The use of a marker gene in a transformation process aims to give a selective advantage to the transformed cells, allowing them to grow faster and better, and to kill the non-transformed cells. In general, the selective gene is introduced into plant genome along with the genes of interest. In some cases, the marker gene can be the gene of interest that will confer an agronomic characteristic, such as herbicide resistance. In this review we list and discuss the use of the most common selective marker genes on plant transformation and the effects of their respective selective agents. These genes could be divided in categories according their mode of action: genes that confer resistance to antibiotics and herbicides; and genes for positive selection. The contention of the marker gene flow through chloroplast transformation is further discussed. Moreover, strategies to recover marker-free transgenic plants, involving multi-auto-transformation (MAT), co-transformation, site specific recombination and intragenomic relocation of transgenes through transposable elements, are also reviewed.

• Journal of Microbiology and Biotechnology
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• v.16 no.1
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• pp.109-117
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• 2006

The Rev binding to Rev Responsive Element (RRE) of HIV-1 mRNA plays an important role in the HIV-I viral replication cycle. The disruption of the Rev-RRE interaction has been studied extensively in order to develop a potential antiviral drug. In order to provide the basis for a more promising approach to develop a Rev-RRE binding inhibitor against HIV-I infection, it is necessary to understand the binding modes of the aminoglycoside antibiotics to RRE. In the present study, the binding mode of a modified antibiotic, a neamine conjugated with pyrene and arginine (NCPA), to RRE has been studied by the methods of $T_m$ measurement and spectroscopic analysis of RRE with or without antibiotics. The results confirmed that NCPA competes with Rev in binding to RRE.