• Journal of Veterinary Clinics
• /
• v.22 no.2
• /
• pp.114-118
• /
• 2005

Bacterial disease caused by Aeromonas are among the most common and troublesome diseases of fish raised in aquaculture systems. In this study, some strains identified as belonging to the Aeromonas were isolated from neon tetra (Hyphessobrycon herbertaxelrodi) skin and fin, as well as from water samples. VITEK system and API ZYM examination of the isolated strains were undertaken, and it seemed to correlate with the Aeromonas, proved to be Aeromonas veronii. The antibiotic susceptibility test of isolated strains to different groups of antibiotics was evaluated using the disc diffusion method. Cefixime was the most sensitive antibiotic.

• Korean Journal of Microbiology
• /
• v.53 no.3
• /
• pp.193-199
• /
• 2017

This study was aimed to evaluate the antimicrobial activity of Penicillium purpurogenum ED76 on several clinically important microorganisms. The endophytic fungus P. purpurogenum ED76 was previously isolated from Swietenia macrophylla leaf. The antimicrobial efficacy of P. purpurogenum ED76 dichloromethane extract was determined via disc diffusion and broth microdilution assay. A kill curve study was conducted and the morphology of extract treated bacterial cells were viewed under scanning electron microscope. The dichloromethane extract showed significant inhibitory activity on 4 test bacteria and 2 test yeasts. The minimal inhibitory concentration of the extract ranged from 125 to $1,000{\mu}g/ml$, which indicates the different susceptibility levels of the test microorganisms to the fungal extract. The kill curve study has revealed a concentration-dependent inhibition for all test microorganisms. With the increase of the extract concentration, the microbial growth was significantly reduced. The scanning electron micrograph of dichloromethane extract-treated Staphylococcus aureus cells showed the total damage of the cells. The cell wall invagination of the bacterial cells also indicates the loss of cellular materials and metabolic activity. The gas chromatography mass spectrometry analysis of the extract also showed that the major compound was stigmasterol, which constitutes 45.30% of the total area. The dichloromethane extract of P. purpurogenum ED76 exhibited significant inhibitory activity on several clinically important bacteria and yeasts. The study proposed a possible mode of action that the extract cause significant damage to the morphology of S. aureus cells.

• Journal of Korean Ophthalmic Optics Society
• /
• v.13 no.2
• /
• pp.69-73
• /
• 2008

Purpose: The purpose of this study is to investigate the antibacterial activity Xanthium strumarium L. extract against bacteria causing eye disease and to examine the possibility as a natural preservative on behalf of synthetic preservatives which are added to the contact lens solution. Methods: Antibacterial activity of Xanthium strumarium L. extract against the bacteria causing eye disease was assessed using agar diffusion method, and determined by whether clear zone was formed around paper disc and in terms of the size(mm) of clear zone.Staphylococcus aureus and Pseudomonas aeruginosa were used in the study. Results: Xanthium strumarium L. extract provided activity against Staphylococcus aureus KCCM 40050 in a concentration of $1000{\mu}g/20{\mu}l$with an clear zone of 11.5 mm. Moreover, Xanthium strumarium L. extract showed an activity against Pseudomonas aeruginosa KCCM 11803 in a concentration of $1000{\mu}g/20{\mu}l$with an clear zone of 9.0 mm, and against Pseudomonas fluorescens KCCM 40223 with an clear zone of 7.0 mm. Conclusions: Antibacterial activity of Xanthium strumarium L. extract against the bacteria causing eye disease was proved. This result suggests that Xanthium strumarium L. extract can be a potential natural preservative, which is added to contact lens solution.

• Journal of Digital Convergence
• /
• v.12 no.10
• /
• pp.477-484
• /
• 2014

The purpose of this study is to verify the antimicrobial effect of garlic and black garlic against pathogenic bacteria. For the comparative analysis of antibacterial effects of garlic, Ampicillin $10{\mu}g$ (BBL) was used as control antibiotics. Research experiments were conducted on each of November 2013 and January 2014. Susceptibility to the antimicrobial effect was measured through Kirby-Bauer disc diffusion method and verified according to the standard proposed by the CLSI. Antimicrobial effect of fresh garlic was higher regardless of the method to extract than Ampicillin $10{\mu}g$. In contrast, the manufacturing methods of the black garlic had no effective differentiations. In antimicrobial susceptibility test, black garlic showed resistance to all of 4 strains. However, in the ethanol-extract of fermented black garlic(natural aging of 15 days.) was found the small changes of the growth-inhibition-zone against S. aureus (8 mm)and E. coli(7 mm). This study proposes a variety attempts about the extraction methods of black garlic for the possibility of food preservation.

• Journal of Food Hygiene and Safety
• /
• v.27 no.4
• /
• pp.449-455
• /
• 2012

The purpose of this study is to evaluate antimicrobial effects of organic acid and some natural occurring antimicrobials against Staphylococcus aureus isolated from various origins (vegetables, peanut, pea leaf, kim-bab, person, perilla leaf, and animal) and to calculate their MIC and MBC values. Five organic acids (acetic, lactic, citric, malic, and propionic acid), three essential oils (carvacrol, thymol, and eugenol), and two other natural antimicrobials (nisin and cinnamic acid) were evaluated for their antimicrobial effects against 113 strains of S. aureus using combination treatments. Propionic acid (7%), nisin (1%), thymol (1%), carvacrol (1%) showed antimicrobial activities against S. aureus strains in agar disc diffusion test. And, carvacrol, thymol, and nisin were found to be the most effective with the lowest MIC values of 0.0313%, 0.0625%, and 0.0625% against S.aureus, respectively. Propionic acid (0.2313%) and citric acid (0.6000%) were the most effective among organic acids tested. Therefore, these five antimicrobials were selected for next combination treatments. Combination of propionic acid and citric acid were showed the strongest inhibitory effectiveness against S. aureus among combination treatments. These results suggest that organic acid such as propionic and citric acid, and natural occurring antimicrobial such as nisin, carvacrol, and thymol might be possibly used as preservatives for inhibiting S. aureus in foods.

• Journal of Applied Biological Chemistry
• /
• v.44 no.4
• /
• pp.185-189
• /
• 2001

Essential oils of 21 herb plant samples, using spectrophotometric and paper disc agar diffusion methods under anaerobic conditions, were tested in vitro for their growth-inhibiting activities against Bifidobacterium bifidum, B. longum, Lactobacillus casei, Clostridium perfringens, and Escherichia coli. The responses varied with bacterial strains and plant oils. At 10 mg/disk, all essential oils did not inhibit beneficial intestinal bacteria, except for the oil of Alpinia officinarum and Melaleuca alternifolia against L. casei. Due to their strong growth-inhibitory activities against C. perfringens, E. coli, and L. casei, the activites of nine oils were evaluated at low concentrations. In test with C. perfringens at 1 mg/disk, the oils of Amyris balsamifera, Curcuma longa, M. alternifolia, and Trachyspermum ammi showed moderate activities. Moderate activities against E. coli were observed with the oils of M. alternifolia and T. ammi. These results may be indications of at least one of the pharmacological actions of the four herb plants.

• Journal of Environmental Health Sciences
• /
• v.37 no.2
• /
• pp.133-140
• /
• 2011

Antimicrobial activity and bactericidal activity of Caesalpinia sappan L. extracts were investigated against five food-borne pathogens, E. coli, S. aureus, S. typhimurium, B. cereus and L. monocytogenes. Methanol extract of Caesalpinia sappan L. revealed antimicrobial activities against five pathogens. In particular, by paper disc diffusion the highest activity was shown against L. monocytogenes. Antimicrobial activities of methanol extracts showed the most potent activities, but hexane fraction had no activity. Fractions of ethyl acetate and butanol turned out to have higher antimicrobial activities against Gram(+) bacteria than Gram(-) bacteria. The minimum inhibitory concentration against five food-borne pathogens was 1.563 mg/ml on Gram(+) bacteria and 3.125 mg/ml on Gram(-) bacteria. The result of antimicrobial activity in a shaking flask method showed that bacterial growth rate fell by more than 99.999% at 3.125 mg/ml of methanol extract. The highest rate of viable reduction (99.998%) was shown at 0.781 mg/ml of methanol extract against L. monocytogenes. After five minutes of reaction between test strains and methanol extracts, the growth rates of five kinds of bacteria were reduced by more than 99.999% at a concentration of 100 mg/ml. Therefore, it is suggested that methanol extracts of Caesalpinia sappan L. can be developed as a natural sanitizer or disinfectant.

• KSBB Journal
• /
• v.26 no.6
• /
• pp.533-537
• /
• 2011

The aim of this study was to develop a new natural preservative system to improve the weak points of natural polyhydric alcohols together with the efficiency of natural plants as a preservative. Polyhydric alcohols (glyceryl caprylate and ethylhexylglycerin) and antimicrobial plants (S. radix, A. nilotica and C. reticulata) were tested using the disc diffusion method and minimum inhibitory concentration (MIC) method for their antimicrobial activity against the common poultry pathogens, respectively. A study of the preservative efficacy of the cosmetic formulations containing the optimized preservative system demonstrated sufficient preservative efficacy against bacteria and eukaryotic test microbes. These results suggest that the natural preservative system including polyhydric alcohol extracts containing natural plants could be incorporated in cosmetic formulations.

• Korean Journal of Clinical Laboratory Science
• /
• v.43 no.3
• /
• pp.124-132
• /
• 2011

The aim of this study was to evaluate the effects of the photosensitizer photogem with light-emitting diode (LED) on vancomycin-resistant enterococci (VRE). Two VRE strains isolated from the feces of patients. that was identificated Enterococcus faecium (vanA) and Enterococcus gallinarum (vanC1) using traditional biochemical tests and confirmed VRE genotyping from using polymerase chain reaction. In addition, three strains were used Enterococcus. faecalis CDC-286 (vanA), E. faecalis CDC-583 (vanB) and E. gallinarum CDC-42 (vanC1). To examine the antimicrobial effect of photogem mediated photodynamic therapy (PDT) against, CFU quantification and Disk diffusion antimicrobial susceptibility test were evaluated. The effects of Photodynamic therapy was not associated with genotype. Photogem mediated PDT perfectly inhibited the colony formation of E. faecalis CDC-286. The number of viable bacteria decreased greatly after PDT application with photogem $50{\mu}g/mL$ and energy density of $15J/cm^2$. The diameter of inhibition zone was increased to after PDT more than before PDT. The case of vancomycin disc on E. faecalis CDC-583 and E. galinanum-Patient were changed from resistant to intermediate resistant, from intermediate resistant to susceptable. These results demonstrate that lethal photosensitization of VRE can be achieved using photogem plus 630 nm LED irradiation.

• Advances in Traditional Medicine
• /
• v.8 no.1
• /
• pp.97-102
• /
• 2008

A total of five compounds namely, 2-methylanthracene-9, 10-dione (1), 1-hydroxy-6-methylanthracene-9,10-dione (2), $\beta$-sitosterol (3), stigmasterol (4) and sitosterone (5) were isolated from the stem extracts of Polygonum lanatum for the first time. The structures of the isolated compounds (1-5) were established by extensive spectroscopic studies, including 2D NMR such as $^{1}H-^{1}H$ COSY, HSQC and HMBC studies. The crude extracts and purified compound (1) were screened for antimicrobial activity against a wide range of Gram-positive and Gram-negative bacteria and fungi by the disc diffusion method. The n-hexane and dichloromethane soluble partitionates of the methanolic extract revealed mild to moderate inhibition of growth of the test organisms. The cytotoxic potential of the extractives and compound 1 was also determined by using brine shrimp lethality bioassay, where the extractives demonstrated significant cytotoxic activities.