• Fisheries and Aquatic Sciences
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• v.13 no.2
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• pp.96-101
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• 2010

Norovirus, which causes gastroenteritis in humans, is an important food-borne pathogen worldwide. In an effort to discover an antiviral substance against norovirus, extracts from several seaweeds were evaluated for antiviral activity against feline calicivirus (FCV), which was used as a surrogate. The methanolic extract of Undaria pinnatifida exhibited the most significant antiviral activity and virucidal efficacy against FCV. The concentrations of the extract that reduced viral replication by 50% ($EC_{50}$) and resulted in the death of 50% of the host cells ($CC_{50}$) were 0.05 mg/mL and 1.02 mg/mL, respectively. The selectivity index, calculated from the ratio of the $CC_{50}$ and $EC_{50}$ was 20.4. No FCV infection of host cells occurred following a 1-h incubation in the presence of 12.50 mg/mL U. pinnatifida extract, indicating that the virus was completely inactivated by the extract treatment. The results obtained in this study will contribute to the development of a natural antiviral substance that will prevent food-borne disease caused by norovirus.

• Clinical and Experimental Pediatrics
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• v.61 no.9
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• pp.291-300
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• 2018

Purpose: Understanding changes in pathogen and pneumonia prevalence among pediatric pneumonia patients is important for the prevention of infectious diseases. Methods: We retrospectively analyzed data of children younger than 18 years diagnosed with pneumonia at 117 Emergency Departments in Korea between 2007 and 2014. Results: Over the study period, 329,380 pediatric cases of pneumonia were identified. The most frequent age group was 1-3 years old (48.6%) and the next was less than 12 months of age (17.4%). Based on International Classification of Diseases, 10th revision diagnostic codes, confirmed cases of viral pneumonia comprised 8.4% of all cases, pneumonia due to Mycoplasma pneumoniae comprised 3.8% and confirmed cases of bacterial pneumonia 1.3%. The prevalence of confirmed bacterial pneumonia decreased from 3.07% in 2007 and 4.01% in 2008 to 0.65% in 2014. The yearly rate of pneumococcal pneumonia also decreased from 0.47% in 2007 to 0.08% in 2014. A periodic prevalence of M. pneumoniae pneumonia (MP) was identified. Conclusion: The increased number of patients with pneumonia, bacterial pneumonia, pleural effusion, and empyema in 2011 and 2013-2014 resulted from an MP epidemic. We provide evidence that the frequency of confirmed cases of bacterial pneumonia and pneumococcal pneumonia has declined from 2007 to 2014, which can simultaneously reflect the effectiveness of the pneumococcal conjugate vaccine.

• Research in Plant Disease
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• v.21 no.3
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• pp.161-179
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• 2015

Plant have developed sophisticated defence mechanisms against microbial pathogens. The recent accumulated information allow us to understand the nature of plant immune responses followed by recognition of microbial factors/determinants through cutting-edge genomics and multi-omics techniques. However, the practical approaches to sustain plant health using enhancement of plant immunity is yet to be fully appreciated. Here, we overviewed the general concept and representative examples on the plant immunity. The fungal, bacterial, and viral determinants that was previously reported as the triggers of plant immune responses are introduced and described as the potential protocol of biological control. Specifically, the role of chitin, glucan, lipopolysaccharides/extracellular polysaccharides, microbe/pathogen-associated molecular pattern, antibiotics, mimic-phytohormones, N-acyl homoserine lactone, harpin, vitamins, and volatile organic compounds are considered. We hope that this review stimulates scientific community and farmers to broaden their knowledge on the microbial determinant-based biological control and to apply the technology on the integrated pest management program.

• The Plant Pathology Journal
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• v.29 no.2
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• pp.182-192
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• 2013

Numerous root-associated bacteria (rhizobacteria) are known to elicit induced systemic resistance (ISR) in plants. Bacterial cell-density-dependent quorum sensing (QS) is thought to be important for ISR. Here, we investigated the role of QS in the ISR elicited by the rhizobacterium, Serratia marcescens strain 90-166, in tobacco. Since S. marcescens 90-166 produces at least three QS signals, QS-mediated ISR in strain 90-166 has been difficult to understand. Therefore, we investigated the ISR capacity of two transgenic tobacco (Nicotiana tabacum) plants that contained either bacterial acylhomoserine lactone-producing (AHL) or -degrading (AiiA) genes in conjunction with S. marcescens 90-166 to induce resistance against bacterial and viral pathogens. Root application of S. marcescens 90-166 increased ISR to the bacterial pathogens, Pectobacterium carotovorum subsp. carotovorum and Pseudomonas syringae pv. tabaci, in AHL plants and decreased ISR in AiiA plants. In contrast, ISR to Cucumber mosaic virus was reduced in AHL plants treated with S. marcescens 90-166 but enhanced in AiiA plants. Taken together, these data indicate that QS-dependent ISR is elicited by S. marcescens 90-166 in a pathogen-dependent manner. This study provides insight into QS-dependent ISR in tobacco elicited by S. marcescens 90-166.

• Korean Journal of Veterinary Service
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• v.24 no.1
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• pp.83-88
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• 2001

It is impotent to identify the causative agents of abortion in equine for minimizing the loss of breeding costs in equine Industry. Recently, the abortion has often occurred in equine herds and thus the purpose of the study was aimed at the identification of equine herpesvirus-1, one of the frequent pathogens to abortion, using polymerase chain reaction. Six fetuses to be aborted at nine to ten months in pregnancy reared in six herds were used in the study. Two primers in the PCR were made from glycoprotein B gene of EHV-1. The primers specific for EHV-1 amplified 1880 bp of PCR products from DNA extracts from thorax fluids, livers, lungs, and spleens of four in six aborted fetuses. Consequently, PCR could be applied to diagnose the abortion of EHV-1 and also confirmed to play a major role of the viral pathogen associated with equine abortion in Jeju island.

• Korean Journal of Veterinary Research
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• v.39 no.6
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• pp.1126-1140
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• 1999

Renal failure is one of the main causes of economic impacts in the poultry industry and complex syndrome with different severity of clinical signs caused by multiple nephropathogenic factors such as infectious bronchitis viral infection and excess salt and calcium in diet. To evaluate the correlation between severity of renal failure and the causative nephropathogenic factors, one-day-old specific pathogen free chicks were treated with either single causative factor or multiple causative factors described as above. Each group was designed as control for non-treated control, IB for infectious bronchitis virus (IB virus) infection, IBHNa for IB virus infection with high diet salt, IBHCa for IB virus infection with high diet calcium, IBHNC for IB virus infection with high diet salt and calcium, HNa for high diet salt, HCa for high diet calcium and HNC for high diet salt and calcium. Chickens were inoculated with IB virus at 1-day-old and remained on their respective diets until 21 day of age. The high dietary salt feeding groups such as IBHNa, IBHNC, HNa, HNC increased water intake, watery diarrhea, general subcutaneous edema and the high dietary calcium feeding groups such as IBHCa and IBHNC showed severe visceral gout. Two more than treated groups caused high mortality in comparison with the single treated groups. IB virus exposure significantly increased urate deposition and lymphocytic interstitial nephritis. Especially urate deposition dramatically increased when excess diet calcium was combined together. In excess diet salt treated groups enlarged edematous kidneys were observed and hypertrophy of glomeruli were showed. These results suggest that IB virus enhanced the incidence and severity on chicken renal failure clearly related to the quantity of salt and calcium.

• Korean Journal of Veterinary Research
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• v.39 no.6
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• pp.1141-1150
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• 1999

Renal failure is one of the main causes of economic impacts in the poultry industry and complex syndrome with different severity of clinical signs caused by multiple nephropathogenic factors such as infectious bronchitis viral infection and excess salt and calcium in diet. To evaluate the correlation between severity of renal failure and the causative nephropathogenic factors, one-day-old specific pathogen free chickens were treated with either single causative factor or multiple causative factors described as above. Each group was designed as control for non-treated control, IB for infectious bronchitis virus (IB virus) infection, IBHNa for IB virus infection with high diet salt, IBHCa for IB virus infection with high diet calcium, IBHNC for IB virus infection with high diet salt and calcium, HNa for high diet salt, HCa for high diet calcium and HNC for high diet salt and calcium. Chickens were inoculated with IB virus at 1-day-old and remained on their respective diets until 21 day of age. Plasma $Na^+$, $Cl^-$, BUN, creatinine, calcium and uric acid values were examined. The results obtained were as follows ; IB virus and high dietary calcium combined treatment showed elevated plasma uric acid. BUN and creatinine values were not characteristic on chicken renal failure. But plasma uric acid values were increased according to renal lesion. Hypercalcemia and hyperuricemia did not induce urate deposition and mineralization in the kidney.

• Journal of Aquaculture
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• v.21 no.1
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• pp.13-18
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• 2008

Marine birnavirus(MABV) are well known fish pathogens in Asian countries such as Korea, Japan, and China. Prevalence of viral disease, geological distribution and host or reservoir of viruses were investigated from wild marine fishes in southern coast of Korea in 2003 and 2005. RT-PCR results showed that MABV were detected in 17 fishes(10.6%) from 160 fishes. Comparative analysis of the nucleotide sequences and the deduced amino acids of MABV genome from wild fishes were similar to reference strains of MABV and distinguished with IPNV strains.

• Safety and Health at Work
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• v.8 no.1
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• pp.49-58
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• 2017

Background: This study determined current status of laboratory biosafety in Nigerian veterinary research facilities. Methods: A questionnaire was developed to obtain information from researchers across Nigeria from July 2014 to July 2015. Information regarding demographics, knowledge of laboratory biosafety, availability and proper use of personal protective equipment (PPE), any priority pathogens researched, attitude on and use of standard laboratory practices, and biosafety awareness was obtained using a numeric scoring system. Data were analyzed with descriptive statistics, and univariate and multivariate logistic regression. Results: A total of 74 participants from 19 facilities completed the questionnaire. General knowledge scores ranged from 3 to 28 (out of 28 possible points), with 94.6% of respondents receiving low scores (scores < mean + 1 standard deviation). Very few (17.6%) reported availability or use PPE. Many participants (63.5%) reported no access to biosafety level (BSL)-1-3 facilities. None reported availability of a BSL-4 facility. Knowledge scores pertaining to biosafety management practices ranged from 0 to 14 (out of 14 possible points) with 47.3% of respondents receiving good scores (scores > mean + 1 standard deviation). Only 16.2% of respondents (from four facilities) reported having biosafety officers. Rabies virus was the most researched pathogen (31.1% of respondents). The majority (71.6%) were unaware of laws guiding biosafety. Researchers [odds ratio (OR) = 18.0; 95% confidence interval (CI): 1.63, 198.5; p = 0.023], especially in BSL-2 (OR = 258.5; 95% CI: 12.71, 5256; p < 0.001) facility of research institute (OR = 25.0; 95% CI: 5.18, 120.6; p < 0.001), are more likely to have adequate access to and properly utilize biosafety devices and PPE. Conclusions: Current knowledge of laboratory biosafety is limited except among a few researchers.

• Journal of Microbiology and Biotechnology
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• v.17 no.2
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• pp.280-286
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• 2007

We evaluated a commercial biopreparation of plant growth-promoting rhizobacteria (PGPR) strains Bacillus subtilis GB03 and B. amyloliquefaciens IN937a formulated with the carrier chitosan (Bio Yield) for its capacity to elicit growth promotion and induced systemic resistance against infection by Cucumber Mosaic Virus (CMV) and Pseudomonas syringae pv. tomato DC3000 in Arabidopsis thaliana. The biopreparation promoted plant growth of Arabidopsis hormonal mutants, which included auxin, gibberellic acid, ethylene, jasmonate, salicylic acid, and brassinosteroid insensitive lines as well as each wild-type. The biopreparation protected plants against CMV based on disease severity in wild-type plants. However, virus titre was not lower in control plants and those treated with biopreparation, suggesting that the biopreparation induced tolerance rather than resistance against CMV. Interestingly, the biopreparation induced resistance against CMV in NahG plants, as evidenced by both reduced disease severity and virus titer. The biopreparation also elicited induced resistance against P. syringae pv. tomato in the wild-type but not in NahG transgenic plants, which degrade endogenous salicylic acid, indicating the involvement of salicylic acid signaling. Our results indicate that some PGPR strains can elicit plant growth promotion by mechanisms that are different from known hormonal signaling pathways. In addition, the mechanism for elicitation of induced resistance by PGPR may be pathogen-dependent. Collectively, the two-Bacilli strain mixture can be utilized as a biological inoculant for both protection of plant against bacterial and viral pathogens and enhancement of plant growth.