• Journal of Veterinary Clinics
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• v.32 no.6
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• pp.504-507
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• 2015

Coxiella burnetii is an obligate intracellular rickettsial organism and the causative agent of Query fever, a zoonosis that occurs worldwide. In Korea, C. burnetii infection had occurred in humans and animals. However, the studies were only conducted in geographically limited area for detection of C. burnetii. The objective of this study was to detect C. burnetii in Korean native cattle and dairy cattle nationwide by real-time PCR. The total of 807 blood samples from 622 Korean native cattle and 185 dairy cows, 170 individual milk samples of dairy cows, and 348 bulk tank milk samples of dairy herds were collected nationwide. From blood samples, C. burnetii was detected in 17 (2.7%) out of 622 Korean native cattle and 2 (1.1%) of 185 dairy cows. From milk samples, C. burnetii was detected in 27 (15.9%) out of 170 individual milk samples of dairy cows. And C. burnetii was detected in 84 (24.1%) of 348 bulk tank milk samples. In conclusion, this study revealed that the detection rates are considerably high in cattle and the infection of C. burnetii has been continuously occurring in cattle of Korea. In order to prevent the hazards of a zoonosis Q-fever that occur both humans and domestic animals, further studies are needed to clarify the epidemiology of Q-fever of domestic animals and humans in Korea.

• Korean Journal of Microbiology
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• v.47 no.4
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• pp.328-334
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• 2011

Leucine zipper motif consists of multiple periodic leucine residues, which forms amphipathic alpha helix. The hydrophobic nature of leucine zipper motif can dimerize proteins which contain this motif. Leucine zipper motif addition at C-terminus of single-chain Fv (ScFv) antibody induces its dimerization. Since the dimeric ScFv antibody contains two antigen binding sites (bivalency) like Y-shaped complete antibody, it could increase avidity. As a result, it could show higher antigen binding activity than monomeric ScFv antibodies. Based on this concept, monomeric chicken 8C3 ScFv antibody previously developed from chicken hybridoma was dimerized by the addition of leucine zipper motif at C-terminus of ScFv antibody. The dimeric 8C3 ScFv antibody specifically reacted with Eimerian sporozoite which causes Avian Coccidiosis. As expected, dimeric 8C3 ScFv antibody showed 3-folds higher antigen binding activity than monomer due to increased avidity. In addition, protien yields of dimer expression were 2-folds higher than monomer.

• Weed & Turfgrass Science
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• v.5 no.4
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• pp.256-259
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• 2016

An obligate plant pathogenic fungus Puccinia zoysiae Dietel, the causal agent of rust disease, which is implicated in the damage of zoysiagrass (Zoysia spp.) in Korea. The fungus is one of the important pathogens, which attacks and colonizes susceptible zoysiagrass. Zoysia rust disease was observed in Jangseong, Hoengseong and Hapcheon in 2014 and 2015, Korea. The typical symptoms of the disease appeared first as small white spots on the leaf and stem of zoysiagrass plants, and turn brownish, dark brown spores revealed on the lesions. Uredospores were light brown in color, ellipsoid or spherical in shape and $22.0{\sim}25.0{\times}15.0{\sim}17.5{\mu}m$ in size. On the basis of the morphological characteristics, the fungus was identified as P. zoysiae. Pathogenicity of the fungus was proved by artificial inoculation on Z. japonica. The rust disease firstly appeared approx. early or middle June and then increased middle of October in Korea. In field, Z. matrella ecotypes were more resistant than Z. japonica ecotypes against the pathogen. Disease response against the pathogen was different among ecotypes of each species, respectively.

• Parasites, Hosts and Diseases
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• v.36 no.1
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• pp.1-6
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• 1998

An epidemiological survey was carried out to determine the first intermediate host of Clinostomum complanatum among freshwater snails in Korea. Two species of snails belonging to the family Lymnaeidae were collected in Kaum-ji (pond) , Uisong-gun, Kyongsangbuk-do. Twelve (0.9%) out of 1,273 Radiae auricularia corecna examined were found to liberate cercariae of C. complcnatum, which were identified by morphologital characteristics and experimental infections in freshwater fish, Pseunorosborc pnnjc. The cercariae were brevifurcate and clinostomatoid. They had a transparent dorsal fin, a well developed penetrating organ and a pair of eye spots. The body measured $119-147{\;}{\times}{\;}33-36{\mu\textrm{m}}$, tail stem, tailstem은 $275-370{\;}{\times}{\;}19-26{\;}{\mu\textrm{m}}$, and furcae, $72-104{\;}{\mu\textrm{m}}$. Rediae were demonstrated in the infected snail after crushing. Redia, $527-1,630{\;}{\mu\textrm{m}}$ long and 121-368${\;}{\mu\textrm{m}}$ wide, contained 10-45 germ balls and cercariae in various developmental stapes. The metacercariae recovered from fish experimentally infected with C. complanntum cercariae were morphologically identical to those from naturally infected fish.

• Parasites, Hosts and Diseases
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• v.36 no.3
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• pp.207-212
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• 1998

In the present study, genomic DNAs were purified from Korean isolates (KT8, KT6, KT-Kim and KT-Lee) and foreign strains (CDC85, IR78 and NYH 286) of 1Trichomonas voslnalis, and hybridized with a probe based on the repetitive sequence cloned from T. uqfinolis to observe the genetic differences. By Southern hybridization, all isolates of T. uoSinoLis except the NYH386 strain had 11 bands. Therefore all isolates examined were distinguishable into 3 groups according to their banding patterns; i) KT8, KT6 and KT-Kim isolates had 11 identical bands such as 1 kb, 1.2 kb, 1.6 kb, 1.9 kb, 2.3 kb. 27 kb, 3.2 kb, 2.4 kb, 3.8 kb, 4.9 kb and 6.0 kb, ii) The metronidazole-resistant IR78 strain had the some bands as KT-Lee isolate at bands of 1 kb, 1.2 kb, 1.6 kb. 1.8 kb, 2.1 kb, 2.5 kb, 2.7 kb, 2.9 kb, 3.4 kb, 5.0 kb and 6.0 kb, Bands of CDC85, metronidazole-resistant strain, were similar to those of IR78 and KT-Lee, except that 3.2 kb replaced 2.9 kb. iii) NYH286 particularly had 12 bands and bun patterns were similar to IR78 with a few exceptions as follows; i) 6.2 kb in place of 6.0 kb, ii) 2.0 kb and 2.2 kb instead of 2.1 kb. Through the results obtained, genetic variance of T. uoginnlis isolates was demonstrated by Southern hybridization.

• Parasites, Hosts and Diseases
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• v.36 no.3
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• pp.191-198
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• 1998

The responses to antifolales of ToxopLasmc Bondii were investigated by measuring the dihydrorolate redLlctase (DHFR) activity. quantity of DHFR mRNA, and single-strand conformational polymorphism (SSCP) pattern. Pyrimethamine (PYM) and methotrexate (MTX) were tested ds anlifolates. When T. gondii was treated wish PYM, the viability was decreased by the increasing concentration of PYM. DHFR activity tended to increase as the passage proceeded. and the quantity of mRNA expressed was also increased according to passages. The viability of 7. gonnii was decreased by the increasing concentration of MTX, but it was maintained over 40% up to $100{\;}{\mu\textrm{m}}$ MTX. DHFR activity was 77.4% in the 1st passage ($1{\;}{\mu\textrm{m}}$). 82.2% in the 4th passage ($10{\;}{\mu\textrm{m}}$), and 141.3% in the 7th passage ($100{\;}{\mu\textrm{m}}$) But no changes were detected in SSCP pattern of T gondii rxposvd to FYM and MTX. both. These results suggested that the response of T gondii to FYN was rofulalcd by transrriptional level and that, in MTX. the viability of T. gonnii was derived from increasing DHFK activity.

• Parasites, Hosts and Diseases
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• v.29 no.1
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• pp.9-20
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• 1991

The present study intended to evaluate the influences of MetagonimMi yokogawai on the activities of brush border membrane bound enzymes of the small intestine. Mice were infected with 500 metacercariae respectively, and the worm recovery, morphological changes and enzyme activities were observed chronologically. A part of them were followed after the treatment. Recovered worms decreased in number continuously after the infection, and they were less than 10% after 2 weeks and almost Bero after 28 weeks. Villous atrophy and stromal inflammation were found at two locations of the proximal jejunum from 2 weeks to 4 weeks after the infection. The enzymes, alkaline phosphatase, leucine aminopeptidase and disaccharidases (sucrase, lactase, maltase, and trehalase), showed lowered activities in the duodenum and proximal jejunum of the infected mice but they increased in the distal jejunum for the first two weeks. From three weeks after the infection, the activities were gradually recovered. In one week treated mice, they recovered the activities at 2 weeks from the treatment, but there found no differences of the activities between the 3 week treated group and infected controls. The present data reveal that M. yckogawai infection induces degenerative changes of the host's intestinal mucosa not only morphologically but functionally during the initial phase of infection. The lowered enzyme activities in acute metagonimiasis should be associated with malabsorption and diarrhea.

• Parasites, Hosts and Diseases
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• v.25 no.1
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• pp.13-23
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• 1987

Total of 216 animals conserved in Seoul Grand Park were examined on the antibody titers of Toxoplasma by the indirect latex agglutination test, 20 out of 131 cases (15.3%) in mammals, 2 out of 75 cases (2.7%) in birds, and none in reptiles, according to species, 15 out of 68 species (22.1%) in mammals, 2 out of 36 species (5.6 %) in birds showed positive antibody titers when the titers of 1 : 32 or higher were regarded as positive. In mammals, it appeared as positive in 2 out of 6 cases (1 out of 3 species) in marsupials, 1 out of 15 cases (1 out of 11 species) in primates, lout of 1 case in bats, 6 out of 13 cases (5 out of 10 species) in carnivores, 1 in 12 cases (1 species out of 3) in odd-toed ungulates, 9 out of 80 cases (6 species out of 38) in even-toed ungulates, and none in rodents and in whales. In birds, 1 out of 21 cases (1 out of 7 species) in gallinaceous birds and lout of 6(5 species) in parrots appeared to have the positive antibody titers of Toxoplasma. And, none of reptiles showed positive. Frequencies of positive antibody titers were high in 1 : 64, 9 cases in mammals, followed by 1 : 32, 6 cases, 1 : 128, 3 cases, and 1 : 256, 2 cases, respectively. Two positive cases in birds appeared to be 1 : 64.

• Parasites, Hosts and Diseases
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• v.25 no.1
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• pp.51-58
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• 1987

Tegumental ultrastructures of Echinochasmus japonicus were observed by scanning electron microscopy. The worms were recovered from albino rats which were experimentally infected with the metacercariae obtained from Pseudorasbora parva. Followings are summarized findings. 1. The worms were minute and plumpy gourdshaped with attenuated anterior and round posterior end. The tegument of whole body was wrinkled transversely and covered with cobblestone-like cytoplasmic processes. 2. Head crown was armed with 24 collar spines which were embedded in cytoplasmic pockets. The spines were arranged in a row with an interruption at dorsomedian line, however, the 2nd and the 4th spines were outstretched more than others. Oral and ventral suckers were muscular with numerous type II sensory papillae, and genital pore opened between the two suckers. 3. Tegumental spines were spade-shaped with broad base and pointed tip. They were compact in ventra-lateral tegument or dorsal surface of anterior body. They were not found between the two suckers and dorsal surface of posterior body. 4. Two types of sensory papillae, uni-ciliated (Type I) and roundly swollen sensory papillae (Type II), were observed. The type I papillae were chiefly distributed on ventral surface of tegument and type II were on the lips of suckers. Arrangement of collar spines, shape and distribution of tegumental spines or sensory papillae are regarded as characteristic features of E. japonicus.

• Parasites, Hosts and Diseases
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• v.25 no.2
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• pp.129-140
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• 1987

The present study was undertaken to demonstrate the surface structure of Paragonimus westermani metacercaria in Korea with special reference to the distribution of sensory papillae. Metacercariae were isolated from crayfish, one of the second intermediate tost of P. westermani in Bogil island, Chollanam-do (Province), Korea, where has been known as an endemic area of human paragonimiasis. Isolated metacercariae were encysted and examined with light. scanning and transmission electron microscopes for morphological features. On the surface of iBetacercariae, three types of sensory FaFillae were identified. Large domed papillae ($3~5{\mu\textrm{m}}$), which were covered with wrinkled plasma n!embrane of the worm, were distributed on the oral and ventral suckers only. On the oral sucker, these large domed papillae were 12~13 in number. On the other hand large domed papillae on the ventral sucker were constantly 6 in number and hexagonal in distribution. Small domed papillae ($2~3{\mu\textrm{m}}$), of which surface was more smooth than those of large ones, were distributed symmetrically on the ventral (30~32 pairs) and dorsal surfaces (40~42 Pairs). Ciliated Papillae ($0.8~1.5{\mu\textrm{m}}$) were observed about 5~6 in number around the oral sucker and 3~5 pairs each on the ventral and dorsal surface of the body. Single Fcinted spines covered the entire surface of the body except around the excretory pore. Spines on the anterior fart of the body were 0.9~2.0${\mu\textrm{m}}$ in length and $45~55/100{\mu\textrm{m}}$2 in number, and were gradually reduced in length ($0.4~1.4{\mu\textrm{m}}$) and in nuns.her ($12~27/100{\mu\textrm{m}}$2) toward the posterior part. The body wall of p. westermoni metacercariae was consisted with anucleated syncytium layer, fibrous interstitial layer and musclar layer. In the anucleated syncytium, biconcave ($0.15~0.55{\mu\textrm{m}}$) and spherical ($0.08~0.16{\mu\textrm{m}}$) secretory granules, which were transferred from epidermal cells via protoplasmic tubules, mitochondria and rihoEorses, T-ere observed. Spines originated around the basement membrane protruded externally. Epidermal cells were consisted with a nucleus and a cytoplasm, and connected to syncytium with protoplasmic tubules. In the cytoplasm many secretory granules, mitochondria, Golgi complex, endoplasmic reticula, ribosomes and lipid droplets were observed.