• Korean Journal of Poultry Science
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• v.7 no.2
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• pp.18-27
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• 1980

Infectious bursal disease, so called Gumboro disease, is found world-wide in areas of intensive poultry farming. The clinical signs of the disease are very indicative, but most infections occur unnoticed due to the age of infection of chicken as well as the degree of virulence of virus affected. Edematous and hemorrhagic lesions in BF at early course of infection and the complete atrophies of BF in later are the most characteristic. The infection is considered highly contagious by direct contact, by fecal material and by contaminated feed and water. The virus is also highly resistant in environment and belongs to Diploma virus with size of 55 to 60nm of Ribovirus group. IBDV grows in embryos, embryonic cells and BF of susceptible chickens. Immune-diffusion using agar gel is the method of a choice to determine IBDV infection in chickens. Maternal immunity is very effective in protecting chickens of critical age when IBDV infection severely damages the function of BF. Immunosuppressive effect of IBDV causes more production losses than direct effects of clinical disease of IBD. Inclusion body hepatitis, infectious anemia and gangrenous dermatitis syndrome are the disease associated with the immunosuppressive condition of chickens.

• Journal of Life Science
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• v.25 no.12
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• pp.1399-1407
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• 2015

Klebsiella pneumoniae is found in the normal flora of the skin, mouth, respiratory tract, urinary tract, and intestines in human. However, the stain is opportunistic pathogen, which is the causative agent of community acquired pneumonia. Corn silk has been known to be effective for antimicrobial activity against pathogenic bacteria, including K. pneumoniae, Staphylococcus aureus, Bacillus subtilis, Shigella spp., Salmonella spp., Escherichia coli, Pseudomonas aeruginosa, et al. In this study we focused on the antimicrobial properties of con silk water extract of K. penumoniae. K. pneumoniae isolates K. pneumoniae ATCC 13883 and broad-spectrum β-lactamase (BSBL), exteded-spectrum β-lactamase (ESBL), carbapenemase-producers. Antimicrobial susceptibilities were determined by the disk diffusion method. Searches for bla genes were performed by PCR amplication and direct sequencing. MacConkey agar plate medium was prepared using the corn silk extracts (50% or 100%) instead of distilled water for antimicrobial activity test. The microbial growth inhibitory potential of K. pneumoniae was determined by using the MacConkey agar plate spreading method, and the plate was incubated 18 hr at 37℃. Genes encoding β-lactamases including SHV-1 (n=8), SHV-2a (n=8), SHV-5 (n=2), SHV-11 (n=2), SHV-12 (n=18), TEM-1 (n=10), CTX-M-3 (n=2), CTX-M-14 (n=2), CTX-M-15 (n=1), GES-5 (n=5), KPC-2 (n=6), KPC-3 (n=4), and NDM-1 (n=2) were detected. The corn silk extract showed significantly antimicrobial activity against K. pneumoniae ATCC 13883, but BSBLs, ESBLs, and carbapenemase producers were not. Therefore, corn silk extract is thought to be able to assist in the prevention and rapid recovery of infectious disease caused by K. pneumoniae.

• Journal of the Korean Society of Food Science and Nutrition
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• v.39 no.11
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• pp.1587-1594
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• 2010

This study was designed to investigate the effect of Artemisia capillaris extracts on the intestinal microflora. In agar diffusion method, the solvent fractions of Artemisia capillaris showed growth inhibition against the intestinal microflora. In particular, the chloroform fraction of Artemisia capillaris had strong antibacterial activity against Clostridium perfringens, Clostridium difficile, Eubacterium limosum, and Bacteroides fragilis, but did not show antibacterial activity against Bifidobacterium bifidum and Lactobacillus acidophilus. Most chloroform fraction of Artemisia capillaris inhibitory activities were not reduced by heat treatment or pH variation against C. perfringens, C. difficile, E. limosum, and B. fragilis. MICs of the chloroform fraction were 1.25 mg/mL against C. perfringens, E. limosum and B. fragilis and 2.5 mg/mL against C. difficile. MBCs of chloroform fraction were 5 mg/mL against C. perfringens, E. limosum and 2.5 mg/mL against C. difficile, B. fragilis. The ethyl acetate fraction of Artemisia capillaris showed $3.08{\pm}0.03$ mg/10 mg total polyphenol and $1.91{\pm}0.03$ mg/10 mg total flavonoid contents. In vivo tests were performed to investigate the influence of Artemisia capillaris extract on the intestinal microflora in rats. The results showed the possibilities of utilizing Artemisia capillaris extracts as a functional food component to control intestinal microflora.

• Food Science and Preservation
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• v.21 no.3
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• pp.427-433
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• 2014

Ethanol and hot water extracts were prepared from Lindera obtusiloba Blume (LO) and Zanthoxylum piperitum DC (ZP) and used to evaluate their antimicrobial activities and thermal stability against six foodborne pathogens (3 gram-positive and 3 gram-negative bacteria). The antimicrobial activities were assessed using the agar diffusion method, and the thermal stabilities of extracts were examined after heat treatment at 60, 70, 80, and $100^{\circ}C$ for 10 min. The zones of inhibition by the LO extract or the ZP extract of the tested microorganisms were in the range of 21-30 mm and 19-25 mm, respectively, at 100 mg/mL concentrations. The 60% ethanol extract and the hot water extracts from LO showed the strongest antimicrobial effects against MRSA and Staphylococcus aurues, respectively. For the extract from ZP, the strongest antimicrobial effect was shown against S. aurues by 60% ethanol, and the weakest antimicrobial effect was shown against E. coli by the hot water extracts. The ZP extracts showed that the gram-positive bacteria were more sensitive than gram-negative bacteria. For the thermal stability of the extracts, the antimicrobial effects stabilized after heat treatment. Overall, the data suggest that the extracts have a potential for application in various food products for which a natural antimicrobial additive is desired.

• Korean Journal of Food Science and Technology
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• v.48 no.6
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• pp.560-564
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• 2016

The objective of this study was to investigate the anti-Bacillus cereus activity of actinonin. Actinonin inhibited the growth of B. cereus in a dose dependent manner. The growth-inhibitory activity of actinonin was evaluated using a broth micro-dilution method, and minimum inhibitory concentration (MIC) and agar disk diffusion tests. B. cereus showed high susceptibility to actinonin in a concentration-dependent manner and MIC was determined to be $0.192{\mu}g/mL$. Additionally, 1 and 2 mM actinonin induced formation of B. cereus inhibition zones. In addition, as compared to B. cereus alone, B. cereus added with $10{\mu}M$ actinonin showed a lower level of cytotoxicity in HeLa cells in vitro. Thus, this study revealed that actinonin could be a potential source of a natural antimicrobial agent or a pharmaceutical component against B. cereus.

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

• Korean Journal of Food Science and Technology
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• v.33 no.5
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• pp.582-588
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• 2001

To control the growth of Salmonella on raw chicken supplied in food service, they were isolated and analysed for their physiological characteristics. Total viable microbe counts under the skin of the chicken amounted to 10% of numbers on their skin. Fifty one of Salmonella were isolated and identified from 75 chicken carcass samples. About 70% of the isolates showed resistance to more than four antibiotics, which indicated very high resistance among the strains ever reported in Korea. Lactic acid and trisodium phosphate(TSP) as sanitizing agent were applied to the Salmonella spp. isolates by agar diffusion method. The resistance by isolates to those sanitizing agents was compared with type strains of S. typhimurium ATCC 14028, S. typhimurium ATCC 12023, S. heidelberg and S. enteritidis. The isolates showed similar or less resistance to the type strains as for the lactic acid. However, as for trisodium phosphate known recently as a good sanitizer, 50% of the isolates showed more resistant compared with the type strains. Also, the treatment time and regeneration medium affected significantly the resistance of the isolates, which indicates that more careful test might be needed for TSP's practical application to raw chicken. Therefore, From the results, it is suggested that antibiotic treatment during breeding broiler and contamination after slaughtering should be minimized along with careful use of sanitizing agent in order to ensure more safe raw chicken supply.

• Journal of the Korean Society of Food Culture
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• v.16 no.3
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• pp.243-249
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• 2001

Antibacterial activities in each part of watercress(Oenanthe javanica D.C.) grown under different culture conditions were measured to determine the possibility to use watercress as a resource to develop the antibacterial substance. The leaves of watercress were extracted with methanol and the methanol extract was further fractionated with various organic solvents. Antibacterial activities against Shigella dysenteriae ATCC 9361 in all fractions were determined according to the agar diffusion method using paper disc. Methanol extract of watercress leaves was more effectively inhibited the growth of the tested bacteria than the extracts of roots or stems at the concentration of 0.5 g eq./disc, and the extract of watercress from Hwasoon was the most effective one as compared to others. Phenolic and neutral fractions fractionated from methanol extract of watercress had a considerable inhibiting activity on the growth of the bacteria, but acidic and basic fractions did not show any inhibitory effect. Minimum inhibitory concentrations of phenolic and neutral fractions against Shigella dysenteriae ATCC 9361 were $400\;{\mu}g/disc$ and $550\;{\mu}g/disc$, respectively.

• Food Science and Biotechnology
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• v.15 no.5
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• pp.817-819
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• 2006

8-Quinolinol and other quinolinol derivatives were evaluated with regard to their growth-inhibitory effects against intestinal bacteria, using the paper disk-agar diffusion method. The observed growth responses varied according to the chemicals and dosages used, as well as the bacterial species tested. 8-Quinolinol showed a significant inhibitory effect against Clostridium difficile, C. perfringens, and Escherichia coli, at 5, 2, 1, and 0.5 mg/disk, and also exhibited a very strong inhibitory effect at 0.25 mg/disk. At low concentrations, 8-quinolinol had strong inhibitory effects against C. perfringens at 0.1 and 0.05 mg/disk; 8-quinolinol also manifested a moderate inhibitory effect against C. perfringens at 0.025 mg/disk. Furthermore, 8-quinolinol revealed moderate and weak growth inhibition against C. difficile and E. coli at concentrations of 0.1 and 0.05 mg/disk, respectively, but 2-quinolinol, 4-quinolinol, and 6-quinolinol evidenced no growth inhibition against B. bifidum, B. longum, C. difficile, C. perfringens, E. coli, or L. casei. The inhibitory effects of 8-quinolinol against C. difficile, C. perfringens, and E. coli lead to its consideration as a possible therapeutic modality for the treatment of diseases associated with harmful intestinal bacteria.

• Asian-Australasian Journal of Animal Sciences
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• v.16 no.10
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• pp.1550-1554
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• 2003

One hundred of lactic cultures were evaluated for their ability to inhibit hazardous microbes, such as Salmonella enteritidis, Salmonella typhimurium, Escherichia coli, Listeria monocytogenes, and Bacillus cereus by agar well diffusion method. None of them showed inhibitory halo against S. enteritidis, while 27 strains showed inhibitory activity against S. typhimurium, 6 against E. coli, 9 against ampicillin resistant E. coli, 31 against L. monocytogens, 10 against B. cereus. pH of the culture does not explain for the inhibitory activity except against B. cereus. A neutralized culture from corn silage showed highest inhibitory activity against S. typhimurium, and the size of inhibitory halo was same as 10 ug/mL of ampicillin. The culture was identified to be Lactobacillus buchneri on the basis of biochemical characteristics and utilization of substrates. Using the culture as probiotics could be expected to reduce antibiotics for animal feeding.