• Title/Summary/Keyword: Pathogenic Agents

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Antimicrobial Property of $(+)-Lyoniresinol-3{\alpha}-O-\beta-D-Glucopyranoside$ Isolated From the Root Bark of Lycium chinense Miller Against Human Pathogenic Microorganisms

  • Lee Dong Gun;Jung Hyun Jun;Woo Eun-Rhan
    • Archives of Pharmacal Research
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    • v.28 no.9
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    • pp.1031-1036
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    • 2005
  • [ $(+)-Lyoniresinol-3{\alpha}-O-\beta-D-glucopyranoside$ ] (1) was isolated from an ethyl acetate extract of the root bark from Lycium chinense Miller, and its structure was determined using 1D and 2D NMR spectroscopy including DEPT, HMQC, and HMBC. $(+)-Lyoniresinol-3{\alpha}-O-\beta-D-glucopyranoside$ exhibited potent antimicrobial activity against antibiotic-resistant bacterial strains, methicillin-resistant Staphylococcus aureus (MRSA) isolated from patients, and human pathogenic fungi without having any hemolytic effect on human erythrocytes. In particular, compound 1 induced the accumulation of intracellular trehalose on C. albicans as stress response to the drug, and disrupted the dimorphic transition that forms pseudo-hyphae caused by the pathogenesis. This indicates that $(+)-Lyoniresinol-3{\alpha}-O-\beta-D-glucopyranoside$ has excellent potential as a lead compound for the development of antibiotic agents.

Study on the Identification of Enteropathogenic Bacteria from Diarrheal Patients (설사 환자에서의 원인균 분리동정에 관한 연구)

  • Jun, Sung-Sook;Seo, Su-Yung;Kim, Yung-Bu;Oh, Yang-Hyo;Yang, Hak-Do
    • The Journal of the Korean Society for Microbiology
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    • v.21 no.4
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    • pp.417-422
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    • 1986
  • The specimens were collected from 89 diarrheal patients who had visited Pusan National University Hospital from June to September 1985. They were cultured and tested for the bacteriological identification of causative agents. In this study we identified 5 strains of Salmonella species, 5 strains of Shigella species, 2 strains of Y. enterocolitica, and 17 strains of enteric pathogenic E. coli. Enteric pathogenic E. coli were classified into enterotoxigenic E. coli, enteropathogenic E. coli, and enteroinvasive E. coli by serological type. We tried to isolate V. cholerae and V. parahaemolyticus too but we cannot find them out.

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A Case of Bacteremia by Hafnia alvei (Hafnia alvei에 의한 균혈증 1예)

  • Hong, Seung-Bok;Shin, Kyeong-Seob
    • Korean Journal of Clinical Laboratory Science
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    • v.37 no.2
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    • pp.84-87
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    • 2005
  • Hafnia alvei is a gram-negative facultatively anaerobic bacillus that is rarely isolated from human specimens and is rarely considered to be pathogenic. It has been associated with gastroenteritis, pneumonia, meningitis, bacteremia, and nosocomial wound infections. But, only one case of extraintestinal H. alvei infection was documented in Korea to our knowledge. A 74-years old women with bronchial tuberculosis and cerebral infarct was admitted to out hospital via the internal medicine department due to the use of anti-tuberculotic agents. The two consecutive blood cultures yielded H. alvei. The organism was susceptible to all antimicrobial agents tested, except ampicillin and amoxacillin-clavulanic acid. The patients was treated with ceftriaxone and recovered effectively.

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Microbial Forensics: Bioterrorism and Biocrime

  • Eom, Yong-Bin
    • Biomedical Science Letters
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    • v.24 no.2
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    • pp.55-63
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    • 2018
  • Microbes and their toxins can be bioweapons that bioterrorists use them to commit bioterrorism and biocrime. Due to the potential and relative ease of the bioattack, life-threat pathogenic agents (bacteria, viruses, and toxins) as bioweapon revealed the need for a new field of microbial forensics. Microbial forensics is a new scientific discipline combining microbiology and forensic science, which is focused on characterization of evidence from a bioterrorism, biocrime, and an inadvertent release of biothreat agents. The sophisticated analytical tool and knowledge of microbial forensics can provide investigative leads and help determine who was responsible for the biocrime, the source of the bioweapon, and how and where the bioweapon was produced. Among the fields of microbial forensics, this paper will briefly describe evidence collection, handling, packaging, transportation, storage, analytical methods of evidence, and review microbial forensics as a response to bioterrorism and biocrime.

Therapeutic Agents against Bacteria Causing Porcine Pneumonia

  • Lee, Joo-Yong;Lyoo, Young-Soo;Park, Dong-Ki;Jung, Ji-Hyun;Lee, Chul-Hoon;Kim, Min-Kyun;Lim, Yoon-Gho
    • Journal of Microbiology and Biotechnology
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    • v.11 no.6
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    • pp.1102-1105
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    • 2001
  • In order to find therapeutic agents for porcine pneumonia, we screened far antibacterial activities of methanol extracts of 81 higher plants against four pathogenic microorganisms of Heamophilus parasuis, Pasteurella multocida, Actinobacillus pleuropneumonia, and Bordetella bronchiseptica, and found the bark of Cinnamomi cortex showed potent activities. Since this was inexpensive, we purified active compounds from it. The structures of the final active fractions were obtained through an activity-guided fractionation and their antibacterial activities are reported here.

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Ameliorative effects of ginseng and ginsenosides on rheumatic diseases

  • Yi, Young-Su
    • Journal of Ginseng Research
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    • v.43 no.3
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    • pp.335-341
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    • 2019
  • Background: Inflammation is a host-defensive innate immune response to protect the body from pathogenic agents and danger signals induced by cellular changes. Although inflammation is a host-defense mechanism, chronic inflammation is considered a major risk factor for the development of a variety of inflammatory autoimmune diseases, such as rheumatic diseases. Rheumatic diseases are systemic inflammatory and degenerative diseases that primarily affect connective tissues and are characterized by severe chronic inflammation and degeneration of connective tissues. Ginseng and its bioactive ingredients, genocides, have been demonstrated to have antiinflammatory activity and pharmacological effects on various rheumatic diseases by inhibiting the expression and production of inflammatory mediators. Methods: Literature in this review was searched in a PubMed site of National Center for Biotechnology Information. Results: The studies reporting the preventive and therapeutic effects of ginseng and ginsenosides on the pathogenesis of rheumatic diseases were discussed and summarized. Conclusion: Ginseng and ginsenosides play an ameliorative role on rheumatic diseases, and this review provides new insights into ginseng and ginsenosides as promising agents to prevent and treat rheumatic diseases.

In vitro efficacy of N-acetylcysteine in combination with antimicrobial agents against Pseudomonas aeruginosa in canine otitis externa

  • Son, Youngmin;Bae, Seulgi
    • Korean Journal of Veterinary Research
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    • v.61 no.2
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    • pp.16.1-16.6
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    • 2021
  • Pseudomonas aeruginosa is one of the most common pathogenic species associated with canine otitis externa (OE). Their resilience is achieved by forming a biofilm, which allows these bacteria to evade even the harshest of treatments. This study evaluated the in vitro synergistic efficacy of N-acetylcysteine (NAC) with different antimicrobial agents against P. aeruginosa isolated from dogs with OE to develop an effective treatment against P. aeruginosa. The antimicrobial activity was evaluated by the minimum inhibitory concentration test using the microdilution method. The efficacy of antibiofilm formation was evaluated using a crystal violet stain method. The treatment solutions included NAC alone, and in synergy with enrofloxacin, polymyxin B, and gentamicin. NAC alone exhibited antimicrobial and antibiofilm abilities. On the other hand, the combination of NAC and the antibiotics did not show any significant synergistic effects against P. aeruginosa.

Antimicrobial susceptibility and pathogenic genes of Staphylococcus aureus isolated from the oral cavity of patients with periodontitis

  • Kim, Ga-Yeon;Lee, Chong Heon
    • Journal of Periodontal and Implant Science
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    • v.45 no.6
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    • pp.223-228
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    • 2015
  • Purpose: The goal of this study was to characterize the patterns of antimicrobial resistance and virulence genes in samples of Staphylococcus aureus (S. aureus) isolated from periodontitis patients. Methods: From July 2015 to August 2015, oral saliva was collected from a total of 112 patients diagnosed with periodontitis, including 80 outpatients in dental hospitals and 32 patients in dental clinics located in Seoul and Cheonan. The samples were subjected to a susceptibility test to evaluate the prevalence of antimicrobial resistance, and the pathogenic factors and antimicrobial resistance factors in the DNA of S. aureus were analyzed using polymerase chain reaction. Results: A susceptibility test against 15 antimicrobial agents showed that 88% of cultures were resistant to ampicillin, 88% to penicillin, and 2% to oxacillin. Resistance to at least two drugs was observed in 90% of cultures, and the most common pattern of multidrug resistance was to ampicillin and penicillin. Enterotoxins were detected in 65.9% of samples. The cell hemolysin gene hld was detected in 100% of cultures and hla was detected in 97.6% of samples. All strains resistant to penicillin and ampicillin had the blaZ gene. The aph(3')IIIa gene, which encodes an aminoglycoside modifying enzyme, was detected in 46.3% of samples. Conclusions: In the treatment of oral S. aureus infections, it is important to identify the pathogenic genes and the extent of antimicrobial resistance. Furthermore, it is necessary to study patterns of antimicrobial resistance and cross-infection in the context of periodontological specialties in which antimicrobials are frequently used, such as maxillofacial surgery, where the frequency of antimicrobial use for minor procedures such as implant placement is increasing.

Recent Trends in Salmonella Outbreaks and Emerging Technology for Biocontrol of Salmonella Using Phages in Foods: A Review

  • Oh, Jun-Hyun;Park, Mi-Kyung
    • Journal of Microbiology and Biotechnology
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    • v.27 no.12
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    • pp.2075-2088
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    • 2017
  • Salmonella is one of the principal causes of foodborne outbreaks. As traditional control methods have shown less efficacy against emerging Salmonella serotypes or antimicrobial-resistant Salmonella, new approaches have been attempted. The use of lytic phages for the biocontrol of Salmonella in the food industry has become an attractive method owing to the many advantages offered by the use of phages as biocontrol agents. Phages are natural alternatives to traditional antimicrobial agents; they have proven effective in the control of bacterial pathogens in the food industry, which has led to the development of different phage products. The treatment with specific phages in the food industry can prevent the decay of products and the spread of bacterial diseases, and ultimately promotes safe environments for animal and plant food production, processing, and handling. After an extensive investigation of the current literature, this review focuses predominantly on the efficacy of phages for the successful control of Salmonella spp. in foods. This review also addresses the current knowledge on the pathogenic characteristics of Salmonella, the prevalence of emerging Salmonella outbreaks, the isolation and characterization of Salmonella-specific phages, the effectiveness of Salmonella-specific phages as biocontrol agents, and the prospective use of Salmonella-specific phages in the food industry.

Antiherpetic Activities of Natural Quercitrin Alone and in Combinations with Nucleoside Antiherpetic Agents (천연 Quercitrin의 항허피스바이러스작용과 Nucleoside계 항허피스바이러스제와의 병용효과)

  • 김영소;어성국;김홍진;이도익;김기호;한성순
    • Biomolecules & Therapeutics
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    • v.7 no.2
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    • pp.158-163
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    • 1999
  • In order to find less toxic antiherpetic agents, antiviral activities of quercitrin against two strains of pathogenic viruses such as herpes simplex virus type 1 (HSV-1) and type 2 (HSV-2) were determined in Vero cells using plaque reduction assay in vitro. Quercitrin showed a concentration-dependent decrease in plaque formation of HSV-1 and HSV-2. It also exhibited more potent antiherpetic activity on HSV-1 with 50% effective concentration (EC$_{50}$) of 20.4 $\mu$g/ml than on HSV-2 with EC$_{50}$ of 30.4 $\mu$g/ml. The combined antiherpetic effects of quercitrin with nucleoside antiherpetic agents, acyclovir and vidarabine, were examined on the multiplication of these two strains of herpesviruses in Vero cells by the combination assay. The results of combination assay were evaluated by the combination index (CI) that was calculated by the multiple drug effect analysis. The combinations of quercitrin with acyclovir and vidarabine on HSV-1 showed more potent synergism with CI values of 0.27-0.81 for 50%, 70%, 90% effective levels than those on HSV-2 with CI values of 1.03~2.20..20.

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