• Korean Journal of Veterinary Service
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• v.22 no.2
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• pp.121-128
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• 1999

The present study was conducted to investigate the incidence of pneumonic lesions with special regard to enzootic pneumonia and the microbiology of pneumoic lungs from 544 slaughter pigs during the period from October 1995 to September 1996. The incidence of enzootic pneumonic lesion was 76.3% (41s/s44) and pleurisy was detected from 7.9% of slaughter pigs. Seasonal prevalence of pneumonic lesions in slaughter pigs were in order of prevalence of 82.9% in spring, 76.8% in winter, 74.8% in autumn and 69.0% in summer, respectively. Pasteurella multocida, Streptococcus sp, Str suis, Corynebacterium sp, Actinobacillus pleuropneumoniae, Hemophilus parasuis, and Klebsiella pneumoniae were detected in order of prevalence from 16.9%, 15.9%, 7.5%, 6.0%, 1.4%, 1.0% and 0.5% of 415 pneumonic lungs, respectively. P multocida were susceptible to oxytetracycline, polymyxin-B, streptomycin, and vancomycin, while the majority of them were resistant to amoxicillin, ampicillin, cephalothin, kanamycin, and penicillin-G. Str suis were susceptible to amoxicillin, ampicillin, cephalothin, penicillin-G, although the majority of them were resistant to erythromycin, oxytetracycline, streptomycin, vancomycin. A pleuropneumoniae were susceptible to ampicillin, and cephalothin, but the majority of them were resistant to oxytetracycline.

• Korean Journal of Veterinary Research
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• v.30 no.4
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• pp.413-420
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• 1990

The present study was conducted to investigate biochemical properties and antimicrobial drug susceptibilities of 47 strains of E rhusiopathiae isolated from the cases of acute septicemic swine erysipelas in Youngnam and Kyunggi provinces during the period from June 1988 to December 1989. The isolants were identified as E rhusiopathiae on the basis of cellular and colonial morphology, and characteristic reactions in some biochemical tests. All the organisms produced hydrogen sulfide in triple sugar iron agar and showed the characteristic "pipe cleaner" type of growth in gelatin stab cultures. The majority of biochemical and cultural properties of E rhusiopathiae isolated from pigs affected with acute erysipelas were identical to those of the reference strains employed. All the isolates were highly susceptible to penicillin G, ampicillin, erythromycin (MIC:0.025~0.39IU or ${\mu}g/ml$), and moderately susceptible to oleandomycin, oxytetracycline, chloramphenicol(MIC:$0.78{\sim}25{\mu}g/ml$). Kanamycin and sulfadimethoxine showed no activity against the isolates(MIC:>$400{\mu}g/ml$). The MICs of dihydrostreptomycin presented two distribution peaks; of 47 strains, 5(10.6%) were resistant to dihydrostreptomycin (MIC:$400{\mu}g/ml$), while the majority of them were susceptible to the drug.

• Korean Journal Plant Pathology
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• v.14 no.5
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• pp.386-392
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• 1998

Reproduction of the soybean cyst nematode (SCN), Heterodera glycines Ichinohe on the susceptible soybean cultivar, Lee 74, was significantly reduced by pre-, post- and simultaneous treatments of acetylsalicylic acid (ASA, aspirin). The control efficiencies were 60%, 64% and 87% for pre-, post- and simultaneous treatments, respectively. ASA had no significant effect on the survival of 2nd stage juveniles and their penetration into the soybean root tissues, but significantly inhibited the early stage nematode growth in the roots. Syncytia were formed 2∼3 days after inoculation in the susceptible soybean without ASA treatment, characterized by dense cytoplasm and increased cellular organelles such as mitochondria and endoplasmic reticulum. The nematode stylet was penetrated into the syncytial cell, and feeding tube was formed at the nematode stylet was penetrated into the syncytial cell, and feeding tube was formed at the nematode stylet entry. However, in the ASA treatments, syncytium was not formed or degenerated, depending on the root tissues. In the pre-treatments of ASA, nematode stylets did not penetrate into cells, showing callose-like cell wall thickening formed at the nematode probing sites, or retracted from the infected cells. The stylet penetration sites of syncytial cells appeared to be sealed off with fibrillar materials. With post-treatment of ASA, syncytia formed by the nematode were degenerated, characterized by degradation of syncytial cytoplasm.

• Parasites, Hosts and Diseases
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• v.44 no.1 s.137
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• pp.43-48
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• 2006

Experimental murine models with high, intermediate and low levels of genetically based susceptibility to Leishmania major infection reproduce almost entire spectrum of clinical manifestations of the human disease. There are increasing non-comparative studies on immune responses against isolated antigens of L. major in different murine strains. The aim of the present study was to find out whether there is an antigen that can induce protective immune response in resistant and susceptible murine strains. To do that, crude antigenic extract of procyclic and metacyclic promastigotes of L. major was prepared and subjected to SDS-PAGE electrophoresis. Western-blotting was used to search for antigen(s) capable of raising high antibody level of IgG2a versus IgG1 in the sera of both infected resistant and susceptible strains. Two novel antigens from metacyclic promastigotes of L. major (140 and 152 kDa) were potentially able to induce specific dominant IgG2a responses in BALB/c and C57BU6 mice. The 2 antigens also reacted with IgG antibody of cutaneous leishmaniasis patients. We confirm that 140 and 152 kDa proteins of L. major promastigotes are inducing IgG production in mice and humans.

• Journal of the Korean Society of Tobacco Science
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• v.19 no.1
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• pp.11-17
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• 1997

A flue-cured tobacco variety (Nicotiana tabacum cv. Wisconsin) was used for Plant transformation with the complementary DNA (cDNA) of potato virus Y-necrosis strain (PVY-VN) replicase gone (Nb) which was synthesized through reverse-transcription Primed with oligo(dT) and Polymerization using RNase H-digested template. The cDNA was cloned into Plant expression vector Plasmid (PMBP2), and introduced into tobacco plants by co-culturing tobacco leaf disks with Agrobacterium tumefaciens LBA4404 containing the plasmid before Plant regeneration. Eight Plants, in which the inserted cDNA fragment was detected by Polymerase chain reaction (PCR), out of 70 putative transformants inserted with sense-oriented Mb cDNA showed no symptom at 3 weeks after inoculation, while the other 62 plants, and all plants with vector gone only and antisense-oriented NIb cDNA had susceptible vein-necrosis symptoms. However, only 2 of the 8 resistant plants were highly resistant, which remained symptomless up to 10 weeks after inoculation. Among the first progenies (T1) from self-fertilized seeds of the two resistant transgenic plants, less than 10 % of 71 plants appeared highly resistant (with no symptom), 70% moderately resistant (with mild symptoms on 1 - 2 leaves), and about 20% susceptible (with susceptible symptoms on 3 or more leaves) at 3 weeks after inoculation. These results suggest that the PVY resistance was inherited in the 71 generation. Key words : potato virus Y. viral replicase gene, transgenic tobacco Plants, resistance.

• International Journal of Industrial Entomology and Biomaterials
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• v.29 no.2
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• pp.145-152
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• 2014

The variation in the level of immune response related gene expression in silkworm, Bombyx mori following infection with Bombyx mori nucleopolyhedrovirus (BmNPV) was analyzed at different time intervals. The occlusion bodies of BmNPV orally inoculated to the two most divergent silkworm races viz., Sarupat (resistant to BmNPV infection) and CSR2 (susceptible to BmNPV infection) were subjected to oral BmNPV inoculation. The expression profile of gp 41 gene of BmNPV in the Sarupat and CSR2 races revealed that the virus could invade the midguts of both susceptible and resistant races. However, its multiplication was significantly less in the midgut of resistant race, while, in the susceptible race, the viral multiplication reached maximum level within 12 h. These findings indicate that potential host genes are involved in the inhibition of viral multiplication within larval midgut. The immune response genes arylphorin, cathepsin B, gloverin, lebocin, serpin, Hsp 19.9, Hsp 20.1, Hsp 20.4, Hsp 20.8, Hsp 21.4, Hsp 23.7, Hsp 40, Hsp 70, Hsp90 revealed differential level of expression on NPV infection. The gloverin, serpin, Hsp 23.7 and Hsp 40 genes are significantly up-regulated in the resistant race after NPV infection. The early up-regulation of these genes suggests that these genes could play an important role in baculovirus resistance in the silkworm, B. mori.

• The Plant Pathology Journal
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• v.27 no.1
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• pp.14-19
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• 2011

Early blight of potato, caused by Alternaria solani, is a ubiquitous disease in many countries around the world. Our previous screening of several Iranian potato cultivars found that significant variation in resistance phenotypes exists between two cultivars: resistant 'Diamond' and susceptible 'Granula'. Our previous analysis of five different pathogen isolates also identified varying degrees of aggressiveness regardless of the host cultivar. Here, a bioassay was used to study the role of liquid culture exudates produced in vitro on pathogenicity and elicitation of disease symptomology in seedlings as well as detached leaves. Responses of host genotypes to the exudates of the two A. solani isolates were significantly different. Detached leaves of the resistant cultivar 'Diamond' elicited fewer symptoms to each isolate when compared to the susceptible cultivar 'Granula'. Interestingly, the phytotoxicity effect of the culture filtrate from the more aggressive isolate A was higher than from isolate N suggesting an increased concentration or strength of the toxins produced. Our results are significant because they indicate a correlation between symptoms elicited by A. solani phytotoxins and their aggressiveness on the host.

• International Journal of Industrial Entomology and Biomaterials
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• v.3 no.2
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• pp.187-190
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• 2001

Inheritance pattern of resistance to Bombyx mori nuclear polyhedrosis virus (BmNPV) was studied in an Indian silkworm stock TX by single back-cross test method. The resistant parent ［TX］, susceptible parent ［HM］, their Fl, F2, and Fl progeny back-crossed to TX [BC(R)] and HM [BC(S)] were inoculated per os with a fixed concentration of BmNPV($0.5{\times}10^{th} PIB/ml$) on the first day of second stadium. The cumulative mortality was recorded until day $10^{\times}$ post-inoculation. The results show that the resistance to BmNPV in TX fellow mono Mendelian inheritance pattern. The resistance dominated over the susceptibility at Fl. At F2, the resistant and susceptible offspring segregated in 3:1 ratio whereas at BC(S), the resistant and susceptible offspring segregated in 1:1 ratio. The response of BC(R) was more or less like the resistant parent TX which confirms the involvement of a major dominant gene conferring resistance to BmNPV in TX. The possible mechanism of inheritance of resistance in TX is discussed.

• Journal of Applied Biological Chemistry
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• v.62 no.3
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• pp.293-297
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• 2019

Leaf rust is the most widespread and destructive fungal disease, and outbreaks have always caused considerable losses in wheat yields. Thus, worldwide increases in wheat production depend on the development of leaf rust-resistant wheat varieties. In this study, we evaluated the resistance of forty Korean wheat cultivars to leaf rust at the seedling stage. Only two Korean wheats, Ol and Jonong, were resistant to leaf rust, whereas the remaining thirty-eight Korean wheats were susceptible to leaf rust. The Ol and Jonong varieties presented larger dry seed weights and higher antioxidant activity in response to leaf rust than the susceptible wheat varieties. No differences in ${\beta}$-1,3-glucanase activity or chlorophyll content between resistant and susceptible wheat varieties were observed. Overall, these results are important for the development of wheat varieties that are highly resistant to leaf rust and to understand the underlying mechanisms that confer leaf rust resistance.

• Microbiology and Biotechnology Letters
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• v.50 no.2
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• pp.193-201
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• 2022

Methicillin-resistant Staphylococcus aureus (MRSA) and methicillin-susceptible S. aureus (MSSA) are major causes of hospital- and community-acquired infections. The treatment of biofilm-related infections caused by these bacteria is a global healthcare challenge. Therefore, the development of alternative therapeutics is required. An essential oil extracted from Curcuma zedoaria (CZ) Rosc, also known as white turmeric, has been reported to possess various antimicrobial activities. In the present study, we evaluated the antibiofilm activities of an ethanolic extract of the CZ rhizome against MRSA and MSSA. The results showed that the CZ extract with the highest sub-minimum inhibitory concentration (sub-MIC), 1/2 MIC (0.312 mg/ml), significantly inhibited biofilm production by up to 80-90% in both tested strains. Subsequently, we evaluated the ability of the CZ extract to prevent cell-surface attachment to a 96-well plate and extracellular DNA (eDNA) release from the biofilm. The CZ extract demonstrated an inhibitory effect on bacterial attachment and eDNA release from the biofilm biomass. The CZ extract may inhibit biofilm formation by preventing eDNA release and cell-surface attachment. Therefore, this CZ extract is a potential candidate for the development of alternative treatments for biofilm-associated MRSA and MSSA infections.