• 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.

• 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.

• 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.

• Food Science and Biotechnology
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• v.17 no.1
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• pp.191-194
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• 2008

The antagonistic activity of probiotic strains (Bifidobacterium animalis BB-12, Bifidobacterium bifidum A, Bifidobacterium longum B6, Lactobacillus acidophilus ADH, Lactobacillus paracasei ATCC 25598, and Lactobacillus rhamnosus GG) against nalidixic acid resistant ($NA^R$) Escherichia coli O157:H7 MF1847, E. coli O157:H7 H2439, E. coli O157:H7 ATCC 43894, and E. coli O157:H7 C7927 was investigated using the agar-overlay, well diffusion, and broth culture tests. L. paracasei ATCC 25598 was the most effective probiotic strain in terms of in vitro antagonistic activity against $NA^R$ E. coli O157:H7, followed by L. rhamnosus GG, B. longum B6, and L. acidophilus ADH. The use of selected probiotic strains could be an effective pre-harvest intervention strategy to reduce the risk of $NA^R$ E. coli O157:H7 by maintaining a balanced microflora in animals and might provide many potential benefits in lieu of using antimicrobials.

• 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.

• Journal of Microbiology and Biotechnology
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• v.23 no.9
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• pp.1229-1243
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• 2013

In this paper, an air isolate (NITT6L) has been screened based on hemolytic activity, emulsification activity, drop collapsing test, and oil displacement test, as well as lipase activity. It was found that strain NITT6L was able to reduce the surface tension of the medium from 61.5 to 39.83 mN/m and could form stable emulsions with tested vegetable oils. Morphological, biochemical, 16S rRNA sequencing analyses, and fatty acid methyl ester analysis using gas chromatography confirmed that the air isolate under study was Pseudomonas aeruginosa. Characterization of the biosurfactant using agar double diffusion assay revealed that the biosurfactant was anionic in nature, and CTAB-methylene blue assay and Molisch test revealed its glycolipid nature. The FT-IR spectrum confirmed that the crude biosurfactant was a rhamnolipid. Using unoptimized medium containing sucrose as the carbon source, the isolate was found to produce 0.3 mg/ml of rhamnolipid in batch cultivation (shake flask) at $37^{\circ}C$ and pH 7. Optimization of the medium components was carried out using design of experiments and the yield of rhamnolipid has been enhanced to 4.6 mg/ml in 72 h of fermentation.

• Journal of Dairy Science and Biotechnology
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• v.38 no.1
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• pp.53-57
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• 2020

Culture concentrate of probiotic Lactobacillus johnsonii PF01 inhibited the growth of Staphylococcus aureus, which was confirmed by agar well diffusion method. Protease treatment of PF01 culture concentrate indicated that the antimicrobial substance of PF01 was a bacteriocin. Investigation of PF01 genome revealed the existence of a gene similar to that of helveticin, which showed 34.9% and 41.0% identity with those of L. helveticus 481 and L. crispatus K313, respectively, thereby suggesting that the bacteriocin produced by strain PF01 is a helveticin homolog.

• Natural Product Sciences
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• v.20 no.3
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• pp.152-159
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• 2014

A phytochemical investigation of Spergularia marina (L.) Griseb. growing in Egypt, has been carried out, which resulted in the isolation of seven compounds from the different extracts of the plant namely; ${\beta}$-sitosterol glucoside, tricin (1) dihydroferulic acid (2), vanillic acid (3), 4-hydroxybenzoic acid (4), uracil (5) and 8-hydroxy cuminoic acid (6) Structure elucidation of the isolated compounds was carried out using different spectroscopic techniques. This is the first report for the isolation of these compounds from genus Spergularia. Furthermore, 8-Hydroxy cuminoic acid and uracil were isolated for the first time from family Caryophyllaceae. The chemical composition of the volatile components present in the petroleum ether extract of Spergularia marina (L.) Griseb. using combined gas chromatography-mass spectrometry (GC-MS) is reported here for the first time. Of the 97 components present, 59 were identified including three sulfur containing compounds which represented about 1.8% of the volatiles of the total petroleum ether extract. This prompted us to study and report its possible antimicrobial activity. In addition, the antibacterial and antifungal screening of different extracts of Spergularia marina (L.) Griseb. as well as some isolates have been performed using agar diffusion method.

• Journal of Applied Biological Chemistry
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• v.43 no.1
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• pp.54-58
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• 2000

Methanol extracts of 27 Brazilian plant samples and 10 oriental medicinal plant samples (27 families), using spectrophotometric and paper disc agar diffusion methods under anaerobic conditions, were tested in vitro for their growth-inhibiting activities against Bifidobacterium longum, Bifidobacterium bifidum, Bifidobacterium adolescentis, Clostridium perfringens, and Bacteroides fragilis. The responses varied with bacterial strains, plant species, and tissues sampled. In a test with B. longum and B. bifidum(20 mg/disc), extracts of Acanthopanax sessilifolinus stem bark and Ampelozizyphus amazonicus leaves strongly inhibited the growth of B. longum, whereas other plant samples did not inhibit any intestinal bacteria tested. At 5 mg/disc, adding extracts of Aralia eleta, Euterpe oleracea, and Syzygium guineense to the media strongly inhibited the growth of C. perfringens and B. fragilis without growth inhibition of B. adolescentis, B. longum, and B. bifidum. Extracts of Jacaranda mimosifolia and Ulmus paraifolia significantly inhibited the growth of C. perfringens and B. fragilis as well as B. adolescentis. These results may be indications of at least one of the pharmacological actions of the five Brazilian plants but not oriental medicinal plants tested.

• Journal of Pharmacopuncture
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• v.25 no.1
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• pp.37-45
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• 2022

Objectives: The quorum-sensing-inhibitory and anti-biofilm activities of the methanol extract of E. globulus leaves were determined against clinically isolated multidrug-resistant Pseudomonas aeruginosa. Methods: The preliminary anti-quorum-sensing (AQS) activity of eucalyptus was investigated against a biosensor strain Chromobacterium violaceum ATCC 12472 (CV12472) by using the agar well diffusion method. The effect of sub-minimum inhibitory concentrations (sub-MICs) of the methanol extract of eucalyptus on different quorum-sensing-regulated virulence factors, such as swarming motility, pyocyanin pigment, exopolysaccharide (EPS), and biofilm formation, against clinical isolates (CIs 2, 3, and 4) and reference PA01 of Pseudomonas aeruginosa were determined using the swarm diameter (mm)-measurement method, chloroform extraction method, phenol (5%)-sulphuric acid (concentrated) method, and the microtiter plate assay respectively, and the inhibition (%) in formation were calculated. Results: The preliminary AQS activity (violacein pigment inhibition) of eucalyptus was confirmed against Chromobacterium violaceum ATCC 12472 (CV12472). The eucalyptus extract also showed concentration-dependent inhibition (%) of swarming motility, pyocyanin pigment, EPS, and biofilm formation in different CIs and PA01 of P. aeruginosa. Conclusion: Our results revealed the effectiveness of the E. globulus extract for the regulation of quorum-sensing-dependent virulence factors and biofilm formation at a reduced dose (sub-MICs) and suggest that E. globulus may be a therapeutic agent for curing and controlling bacterial infection and thereby reducing the possibility of resistance development in pathogenic strains.