• The Korean Journal of Physiology and Pharmacology
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• v.17 no.4
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• pp.315-320
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• 2013

Here, we show that radicicol, a fungal antibiotic, resulted in marked inhibition of inducible nitric oxide synthase (iNOS) transcription by the pancreatic beta cell line MIN6N8a in response to cytokine mixture (CM: TNF-${\alpha}$, IFN-${\gamma}$, and IL-$1{\beta}$). Treatment of MIN6N8a cells with radicicol inhibited CM-stimulated activation of NF-${\kappa}B$/Rel, which plays a critical role in iNOS transcription, in a dose-related manner. Nitrite production in the presence of PD98059, a specific inhibitor of the extracellular signal-regulated protein kinase-1 and 2 (ERK1/2) pathway, was dramatically diminished, suggesting that the ERK1/2 pathway is involved in CM-induced iNOS expression. In contrast, SB203580, a specific inhibitor of p38, had no effect on nitrite generation. Collectively, this series of experiments indicates that radicicol inhibits iNOS gene expression by blocking ERK1/2 signaling. Due to the critical role that NO release plays in mediating destruction of pancreatic beta cells, the inhibitory effects of radicicol on iNOS expression suggest that radicicol may represent a useful anti-diabetic activity.

• Journal of Aquaculture
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• v.11 no.1
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• pp.91-97
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• 1998

This paper introduces to a simple culture method and growth of axenic (bacteria-free) rotifer Brachionus rotundiformis for seed stock of rotifer mass culture. This rotifer axenic culture method is based on the washing and transferring with sterilized sea water and modified antibiotic mixture AM9 solution. Population growth (final density on day 16) of axenic cultured rotifer were maintained with a high density and stable growth compared with the control of non-axenic culture (general culture style) through the 3 times-rerunning experiments (trial 1, 2 and 3). But the egg carrying rates of amictic females were not different between the axenic-and non-axenic culture condition. Although, rotifer density was higher in axenic culture, the food (Nannochloropsis oculata) was still remained unutilized than that of the non-axenic culture in third trial culture. These results suggest the possible existence of harmful bacteria for the rotifer population growth in the trial 1 and 3 of non-axenic culture compared to the trial 2. This axenic rotifer culture method is valuable for seed stock of the stable rotifer mass cultures.

• The Plant Pathology Journal
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• v.32 no.3
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• pp.228-241
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• 2016

In our previous study, we reported that a novel endophytic bacterium Bacillus oryzicola YC7007 has suppressed bacterial diseases of rice via induced systemic resistance and antibiotic production. This endophytic strain, B. oryzicola YC7007 was used as a biological control agent against bakanae disease of rice caused by Fusarium fujikuroi, and its mechanism of interaction with the pathogen and the rice was further elucidated. Root drenching with B. oryzicola YC7007 suspension reduced the disease severity of bakanae significantly when compared with the untreated controls. The treatments of B. oryzicola YC7007 suspension ($2.0{\times}10^7cfu/ml$) to the rice rhizosphere reduced bakanae severity by 46-78% in pots and nursery box tests containing autoclaved and non-autoclaved soils. Moreover, in the detached rice leaves bioassay, the development of necrotic lesion and mycelial expansion of F. fujikuroi were inhibited significantly by spraying the culture filtrate of B. oryzicola YC7007. Drenching of ethyl acetate extracts of the culture filtrate to the rhizosphere of rice seedlings also reduced the bakanae disease severity in the plant culture dish tests. With the root drenching of B. oryzicola YC7007 suspension, the accumulation of hydrogen peroxide was observed at an early stage of rice seedlings, and a hormonal defense was elicited with and without pathogen inoculation. Our results showed that the strain B. oryzicola YC7007 had a good biocontrol activity against the bakanae disease of rice by direct inhibition, and was also capable of inducing systemic resistance against the pathogen via primed induction of the jasmonic acid pathway.

• The Plant Pathology Journal
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• v.25 no.2
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• pp.179-183
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• 2009

To facilitate the genetic manipulation of Cladosporium phlei, a causal agent of leaf spot disease in timothy (Phleum pretense), protoplast-mediated transformation of C. phlei has been developed and the resulting transformants were characterized in this study. Hygromycin B resistance was applied as a dominant selection marker due to the sensitivity of C. phlei to this antibiotic. The transformation efficiency ranged from approximately 20-100 transformants per experiment. Southern blot analysis of stable transformants revealed that transformation occurred by way of stable integration of the vector DNA into the fungal chromosome. PCR analysis and plasmid rescuing of randomly selected transformants suggested that integration of tandem repeat copies of vector DNA was common. In addition, multiple integrations of the transforming vector at different chromosomal sites were also observed. The establishment of a transformation method for C. phlei facilitates strain improvement of this fungus and can be applied as an initial step in the molecular analysis of pigment production in this fungus.

• Asian-Australasian Journal of Animal Sciences
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• v.15 no.7
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• pp.1040-1044
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• 2002

The efficacy of an organic acid solution in the prevention of neonatal kid diarrhoea, was examined in this study and was compared with that of different antibiotics. In a goat farm, kids and their mothers were divided in 4 experimental groups. The kids of Group I were not given any treatment serving as negative controls. The kids of Group II were treated orally for 3 consecutive days with a solution of organic acids starting approximately 12 h after their birth. The kids of Groups III and IV were treated once orally with ampicillin and oxytetracycline respectively, approximately 12 h after birth. All groups were compared as regards the occurrence of diarrhoea, its duration, and the rate of mortality. The results have shown that the number of cases and the duration of diarrhoea were significantly reduced in all treated groups, when compared to the control group (p<0.05). However, no or little difference was noted with respect to morbidity, mortality and diarrhoea characteristics when treated groups were compared with each other (p>0.05). Samples of diarrhoeic faeces from kids in the control group resulted in the isolation of K88 and K99 strains of Escherichia coli. It was concluded that, early oral administration of organic acids can be effective in the prevention of scours in neonatal kids, possibly caused by enterotoxigenic E. coli strains, and to a degree of protection similar to that seen with the used antibiotic schemes.

• Asian-Australasian Journal of Animal Sciences
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• v.18 no.6
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• pp.848-854
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• 2005

We examined the effect of dietary Turkish propolis and flavomycin on growth performance, carcass characteristics, internal organ weights and some serum variables in quail (Coturnix coturnix japonica) birds. One hundred and fifty day-old quails were randomly divided into five groups, with ten replicate pens per treatment and three birds per pen. One group received the basal diet (antibiotic-free), the control. The flavomycin at 10 mg/kg diet and propolis at 0.5, 1 and 1.5 g/kg diet were added to the basal diet. Body weight gain, feed consumption and feed efficiency were determinated weekly. Carcass characteristics, internal organ weights and serum variables were determinated at the end of the study (35 day). The results showed that body weight gain, feed efficiency and carcass weight were improved significantly (p<0.01) when compared to control group for birds fed diets containing propolis and flavomycin between 14 to 35 days. The addition of 1 g/kg propolis to the diet resulted in significantly (p<0.01) better-feed efficiency as compared to control and other treatment groups. There were no significant differences in carcass yield, abdominal fat, liver gizzard, proventriculus and intestinal weight and intestinal pH among the groups. In addition, serum ALP, total protein, uric acid, cholesterol and triglyceride were not influenced by the any supplementation. However, birds fed with propolis tended to have higher serum HDL and lower level than birds fed the control diet. In conclusion, supplementation of propolis and flavomycin during the growth period showed similar effects on growth performance in quail. Therefore, it can serve as a natiral substitute for antibiotics in poultry diets.

• Korean Journal of Agricultural Science
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• v.11 no.1
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• pp.53-60
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• 1984

The followings are the results obtained from the investigation of isolation and cultural conditions of a fungus producing antibiotic from humus, spring soil, paddy, field and etc. 1. Among fungi which were capable of antimicrobial sub stance producing at the $45^{\circ}C$, Strain H-3 was selected as test st rain because of its efficiency in antimicrobial substance producing. 2. Strain H-3 was identified as a Aspergullus fumigatus by the mophological properties. 3. The compositions of optimun media for the production of antimicrobial substance were followed;glucose 20g, $NaNO_3$ 3g, $K_2HPO_4$ 1g, $CaCl_2$ 0.5g, $MgSo_4$ 0.5g, $FeSO_4$ 0.005g. 4. Optimum culture conditions were founded to be pH 5.0, $40^{\circ}C$ respectively. 5. The maximum antimicrobial substance producing obtained in this study was showed 14mm of clear zone after 72 hrs incubation under the optimum conditions. 6. AF-c substance was active against Gram-positive, Gram-negative bacteria, and yeast but not mold in its biological properties.

• Korean Journal of Veterinary Research
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• v.39 no.5
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• pp.995-1005
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• 1999

Staphylococcus aureus is one of most prevalent intramammary pathogens and have characteristics which are not easily eradicated. Recently, to understand the sources and transmission of S aureus, many studies have focused on the subtyping of field isolate. This study was preformed to investigate the distribution pattern and characteristics of the isolates using phenotyping and genotyping. Samples were collected from milk of each udder, cow bodies (perianal region, vagina, tail, udder skin, sole) and environment (floor, liner, milker's hands, water, towel, insect) from 6 herds located in Kyung-gi province. Forty five strains of S aureus were isolated from 3 dairy herds (A, B, C) and were typed by hemolytic pattern, antibiotic resistant pattern, enterotoxin typing and PCR-based DNA fingerprinting. Slime productivity was also compared by each subtype to examine potential infectiousness. Of 45 strains, 41 were isolated from milk samples and 4 were isolated from liners. No strains isolated in the bodies and environment. Forty five strains isolated were classified as 18 subtypes by phenotyping and genotyping. There was common subtype between A and B herd, but the subtype of C herd showed different pattern. Among predominant subtypes, 60% of S aureus strain isolated from A and B herd showed subtype I and 50% of S aureus strain isolated from C herd belonged to subtype VI and X II. Neither somatic cell count (SCC) nor slime production was significantly different between predominant and minor subtypes. In summary, the study revealed that liners play more important roles in the mode of transmission than environmental sources. Several subtypes can be found in a herd, only a few subtype, however, was largely associated with the majority of infection.

• Asian-Australasian Journal of Animal Sciences
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• v.25 no.8
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• pp.1153-1158
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• 2012

The objective of this study was to evaluate the antioxidant capacity of Lactobacillus plantarum ZLP001 and its effects on growth performance and antioxidant status in weaning piglets. The survival in hydrogen peroxide and free radical-scavenging activity of Lactobacillus plantarum ZLP001 were analysed in vitro. The Lactobacillus plantarum ZLP001 showed high viability in 1.0 mmol/L hydrogen peroxide and high scavenging ability against hydroxyl, superoxide anion, and DPPH (1,1-diphenyl-2-picrylhydrazyl) radicals which was dose dependent. Ninety-six weaning piglets were selected ($7.45{\pm}0.79kg$) and divided into three groups comprising of negative control without any supplementation, treatment group with supplemented $6.8{\times}10^7$ Lactobacillus plantarum ZLP001 CFU/g of diet, and positive control with antibiotic treatment (chlorotetracycline, 80 mg/kg diet). The results showed that Lactobacillus plantarum ZLP001 supplementation enhanced feed conversion rates in piglets compared with control (p<0.05). Supplementation of Lactobacillus plantarum ZLP001 increased the concentration of superoxide dismutase (p<0.05), glutathione peroxidase (p<0.01) and catalase in serum (p<0.10), while decreased the concentration of malondialdehyde (p<0.05). The present study implies that the strain Lactobacillus plantarum ZLP001 had high antioxidant ability and its supplementation improved the growth performance and antioxidant status of weaning piglets, so it can be considered useful to alleviate oxidative stress and increase productive performance of pigs.

• Asian-Australasian Journal of Animal Sciences
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• v.26 no.5
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• pp.683-690
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• 2013

A study was conducted to evaluate the effects of resveratrol and essential oils from medicinal plants on the growth performance, immunity, digestibility, and fecal microbial shedding of weaned piglets. A total of 48 weaned piglets (8 kg initial weight, 28-d-old) were randomly allotted to four dietary treatments with 3 replications of 4 piglets each. The dietary treatments were NC (negative control; basal diet), PC (positive control; basal diet+0.002% apramycin), T1 (basal diet+0.2% resveratrol), and T2 (basal diet+0.0125% essential oil blend). All piglets were orally challenged with 5 ml culture fluid containing $2.3{\times}10^8$ cfu/ml of Escherichia coli KCTC 2571 and $5.9{\times}10^8$ cfu/ml Salmonella enterica serover Typhimurium. The PC group (p<0.05) showed the highest average daily gain (ADG) and average daily feed intake (ADFI) throughout the experimental period, although feed conversion ratio (FCR) was improved in the T1 group (p>0.05). Serum IgG level was increased in the T1 group, whereas TNF-${\alpha}$ levels was reduced in the supplemented groups compared to control (p<0.05). The PC diet improved the dry matter (DM) digestibility, whereas PC and T2 diets improved nitrogen (N) digestibility compared to NC and T1 diets (p<0.05). Fecal Salmonella and E. coli counts were reduced in all treatment groups compared to control (p<0.05). Fecal Lactobacillus spp. count was increased in the T2 group compared to others (p<0.05). Dietary treatments had no significant effect on fecal Bacillus spp. count throughout the entire experimental period. Based on these results, resveratrol showed strong potential as antibiotic alternatives for reversing the adverse effects of weaning stress on growth performance, immunity and microbial environment in E. coli and Salmonella-challenged piglets.