• Mycobiology
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• 제48권2호
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• pp.148-152
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• 2020

We investigated the antifungal susceptibilities and the cyp51 mutant strains among Aspergillus fumigatus clinical isolates obtained from 10 university hospitals in Korea. Of the 84 isolates examined, two itraconazole-resistant isolates were found with no amino acid substitution in the cyp51A/cyp51B genes. However, 19 (23.2%) azole-susceptible isolates harbored amino acid substitutions: Nine isolates harbored one to five mutations in cyp51A with high polymorphism, and 11 isolates exhibited the same Q42L mutation in cyp51B. Overall, a low azole resistance rate and high frequency of cyp51A/cyp51B amino acid substitutions were observed in the azole-susceptible A. fumigatus isolates in Korea.

• 한국지반신소재학회논문집
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• 제13권4호
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• pp.153-159
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• 2014

우리나라는 계절적 특성상 겨울철 지반동결과 봄철 해빙이 반복적으로 나타나 지반의 부등침하가 발생하고 이로 인해 철도나 도로, 상수관등의 구조물이 손상되거나 피해를 입는다. 이러한 현상을 방지하기 위해자갈 또는 잡석 등을 동상저감재로 이용하고 있다. 이 연구에서는 폐 PET를 가공하여 인공골재를 제작하고 이에 대한 공학적 특성 시험과 동상팽창실험을 통해 동상저감 대체 재료로 활용 가능여부를 판별하였다. 또한 동상저감 대체 재료로 폐 PET를 가공한 인공골재를 사용할 경우와 기존 재료를 사용할 경우의 경제성 비교를 통해 현장적용의 적절성에 대한 평가를 수행 하였다.

• The Plant Pathology Journal
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• 제17권2호
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• pp.94-100
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• 2001

Roots of Chinese cabbage (Brassica campestris var. chinensis) seedlings infected with Plasmodiophora brassicae were examined by light and electron microscopy to reveal histopathological changes related to pathogenesis in the susceptible host. The pathogen colonized the cortex and partly the stele as well, invading up to the xylem. Gall tissues could be differentiated from the initially infected tissues, involving less compact organization and new vascular development. The infected cells were much hypertrophied, and contained one to several plasmodia. Except cellular hypertrophy, no pathological ultrastructural modification was noted in the infected calls. Infected cytoplasm became dense with ground cytoplasm, inconspicuous central vacuole, and increased cellular organelles such as mitochondria and dictyosomes. There were two types of nuclear states of plasmodium, uninucleate and multinucleate. Both plasmodia were structurally similar, filled with lipid droplets, bounded with envelope, and containing mitochondria, endo-plasmic reticulum, and sometimes small vacuoles. Plasmodial fragmentation, which may be regarded as a way to discharge plasmodial materials into host cytoplasm, commonly occurred, forming plasmodial fragments by outgrowth of plasmodial cytoplasm and regional compartmentalization. Plasmodial fragments were degenerated sometimes followed by forming chains of spherical vesicles especially in the uninucleate plasmodial state. These ultrastructural features indicate the biotrophic nature of the pathogen associated with its pathogenesis in the susceptible host.

• 한국동물위생학회지
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• 제16권2호
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• pp.157-165
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• 1993

The present study was conducted to investigate biochemical properties, antimicrobial drug susceptibilities and epidemiology of 71 stranins of Salmonella pullorum isolated from about 110 diseased chickens of 23 poultry farms located in Cheongjoo, Cheongweon and Koesan county, Chungbuk province, from August 1991 to March 1993. The isolates were identified as S. pullorum by serological and biochemical means. S. pullorum were mostly isolated in chicken under 3weeks of age, and also isolated in 58, 72 days and 23 weeks of age. According to breeds, most of the cultures were isolated in colored broiler chicken (14 to 23 cases), and also variously isolated in native chicken, white broiler chicken, black bone chicken and laying hen. According to organs of diseased chickens, most of the cultures were isolated in liver (37 to 71 strains), and also variously isolated in spleen, lungs, blood, heart, oviduct and brain. According to media used for primary culture from organs, most of the cultures were isolated purely with SS and BHI medium. The majority of biochemical properties of S. pullorum isolated from diseased chickens were identical to those of the standard strains, but in the properties of rhamnose, and arabinose fermentation, some isolates were negative in spite of positive in those of standard S. pullorum. All the isolates were highly susceptible to colistin, amikacin, kanamycin, gentamicin, carbenicillin, ampicillin, sulfamethxazole, cephalothin, tetracycline and piperacillin regardless of isolated years, but no susceptible to penicillin, erythromycin, vancomycin, tylosin and novobiocin.

• 한국동물위생학회지
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• 제20권2호
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• pp.151-159
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• 1997

This study was carried out to isolate of causative agents from CMT-positive and mean somatic cell count(SCC) $\geq$500,000 cells/ml mastitic milk, and evaluate to antimicrobial susceptibility of isolates in Iksan branch area from January to November, 1996. 1. The CMT-positivity(SCC 500,000 cells/ml) of 610 heads was 36.2% (221), and of 2,373 quarter milks was 16.1% (383). 2. The Gram-positive isolates were 153 strains which was Staphylococcus sp (115), Micrococcus sp (18), Streptococcus sp (10), Listeria monocytogenes (5) and Enterococcus faecalis(5). 3. The Gram-negative isolates were 66 strains including E coli(14), Yersinia sp (13), Shigella sp(8), Enterobacillus sp(8), Cedecea sp(5), Pseudomonas aeruginosa(5), Proteus sp(5), Klebsiella sp(4), Salmonella sp(2), kluyvera ascorbate(1) and Tatumella ptyseos (1). 4. The Gram positive strains of isolates were moderately susceptible to T/s, Cp, Fd, Imp, Aug, Rif, Cft and Va. And the Gram negative strains of Isolates were moderately susceptible to T/s, Cp, Imp, Pi and Ti, In order. 5. Multiple antimicrobial resistant patterns were encountered 62 and 36 from Gram positive and negative isolates, respectively.

• 대한수의학회지
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• 제60권1호
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• pp.15-18
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• 2020

Canine heartworm disease is a vector-borne disease that is transmitted from dog to dog by mosquitoes. It causes epidemics that disrupt the health environments of dogs and are burdensome for many dog owners. Recent trends of changing temperatures and weather conditions in South Korea may have an impact on the population of mosquitoes, and it affects the population of dogs at risk of heartworm infection. Mathematical modeling has become an important measure for analyzing the epidemiological characteristics of infectious diseases. However, canine heartworm infection transmission has not been reported yet through mathematical modeling. We develop a mathematical model of canine heartworm infection to predict the population of infected dogs depending on the vector (mosquito) population using a susceptible, exposed, infected, and recovered model. Simulation results show that after 1 year, 3,289 dogs out of 73,602 (about 4.5%) are exposed and 134 (about 0.2%) are infected. Only 0.2% of susceptible dogs become infected after 1 year. However, if all exposed dogs are maintained in the same circumstances without any treatment, then the number of infected subjects will increase over time. This may increase the possibility of other dogs, especially dogs that live outside, being infected.

• Preventive Nutrition and Food Science
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• 제3권2호
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• pp.157-162
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• 1998

As a part of investigation for listeriosis, we attmepted iolationof Listeria spp. from commerical frozen and refrigerated foods at the supermarket level. Seven strains of Listeria spp. were isolate from 6 samples (7.15) among 84 samples of frozen foods, and ten strains of Listeria spp. were also isolated from 8 samples (7.6%)_ among 105 samples of refrigerated foods at the supermarkets in Pusan area. From a total of 189 commerical foods, the number of isolated Listeria spp. and ratio were 6 strains(3.25) of L. grayi, one strain (0.5%) of L. welshimeri, 6 strains (3.2%) of L. innocua and 4 strains (2.15) of L monocytogenes. Listeria spp. isolates except L. monocytogenes did not show $\beta$-hemolysis on blood agar and positive reaction in CAMP test with Staphyloccccus aureus. In the antibiotic susceptibility,most isolates of Listeria spp. were susceptible to 12 antibiotics such as ampicillin , cephalotin, penicillin, amikacin, gentamicin, erythromycin, kanamycin, vancomycin, tobramycin, carbenicillin , tetracycline and trimethoprim /sulfamethoxiazole. Four strains of L. monocytogenes were susceptible to ntibiotics used in this study except nitrofurantio. The serotype of 3 strains and one strain of L. monocytogenes were classified into Listeria O serotype 1 and 4, respectively.

• 한국지형학회지
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• 제24권4호
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• pp.75-89
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• 2017

Sinkholes are key karst landforms that primarily evolve through the dissolution of limestone, and it posing a significant threat to roads, buildings, and other man-made structures. This study aims to analyze the area susceptible to sinkhole development using GIS and to identify potential danger area from sinkholes. Eight sinkhole related factors (slope angle, distance to caves, distance to faults, bedrock lithology, soil depth, drainage class, distance to mines, and distance to traffic routes) were constructed as spatial databases with sinkhole inventory. Based on the spatial database, sinkhole susceptibility maps were produced using nearest neighbor distance and frequency ratio models. The maps were verified with prediction rate curve and area under curve. The result indicates that the nearest neighbor distance and frequency ratio models predicted 95.3% and 94.4% of possible sinkhole locations respectively. Furthermore, to identify potential sinkhole danger area, the susceptibility map was compared with population distribution and land use map. It has been found that very highly susceptible areas are along Osipcheon and southeast southwest part of Hajang-myeon and south part of Gagok-myeon of Samcheok-si. Among those areas, it has been identified that potential sinkhole danger areas are Gyo-dong, Seongnae-dong, Jeongna-dong, Namyang-dong and Dogye-eup. These results can be useful in the aspects of land use planning and hazard prevention and management.

• 약학회지
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• 제52권3호
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• pp.219-224
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• 2008

Clinically isolated methicillin-resistant Staphylococcus aureus strains were exposed to subinhibitory concentration of DW286, DW-224a, gemifloxacin, trovafloxacin, sparfloxacin and ciprofloxacin during 26- to 39-days period. Subculturing led to resistance development, and most of the selected mutants were above susceptible breakpoints. Selected mutants had broad cross resistance to other quinolone antibiotics and only one mutant was completely susceptible to all fluoroquinolones. Twenty five among 42 mutants revealed mutations on DNA gyrase and topoisomerase IV by sequencing. Also 16 mutants had fluoroquinolones MICs that were 4-32 times lower in the presence of reserpine. In conclusion, alterations in DNA gyrase or topoisomerase IV and action of efflux pumping out system are the resistance mechanisms of DW-224a.

• Journal of Preventive Veterinary Medicine
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• 제42권4호
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• pp.148-156
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• 2018

Clostridium perfringens (C. perfringens) may cause diarrhea and enterotoxemia in adult and young livestock, leading to problems in the production and management of farms. Four hundred fecal samples were collected from 25 goat farms located in Gyeongsangbuk-do Province in the Republic of Korea. Sixteen C. perfringens strains were isolates from fecal samples, and the isolates were identified as type A (n=11) and type D (n=5). Additionally, ${\alpha}$- and ${\varepsilon}$-toxin genes were detected in 16 and 5 strains by PCR, respectively, and the enterotoxin gene was presented in 2 strains. The antibiotic susceptibility test was performed using the disk diffusion method and E-test method. In the disk diffusion method, ampicillin (n=16) and chloramphenicol (n=15) were highly susceptible to 16 C. perfringens isolates. In the E-test method, ampicillin, amoxicillin, amoxicillin/clavulanic acid and meropenem were susceptible to more than 14 of 16 C. perfringens isolates. This study indicates that administration of antibiotics such as ampicillin, amoxicillin/clavulanic acid and meropenem can prevent and treat C. perfringens infections in goats.