• 대한수의학회지
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• 제45권1호
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• pp.55-61
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• 2005

Serum samples of 1,175 pigs from 148 Korean swine farms not using Mycoplasma hyopneumoniae (M. hyo) vaccines were collected for seroepidemiological study of M. hyo infection by indirect ELISA method. Informations of each farm were provided about province where the farm was located and season when blood samples were collected. Then, the selected farms were divided into farm units which had 5 serum samples according to production stages : sow, suckling piglet (<30 days old), nursery pig (30-70 days old), and growing pig (>70 days old). Seroprevalence of M. hyo infection according to production stages, province, and season was investigated by using ELISA-positve rate of the selected samples for each study. This study showed that 85.34% (78.94-91.78%, 95% CI) of farms were positive to M. hyo infection and 34.81% (32.09-37.53%, 95% CI) among pigs were sero-positive to M. hyo infection in Korean swine farms. In the study of seroprevalence by production stage, most farms had sows and growing pigs which were sero-positive to M. hyo infection (sow: 83.05%, growing pigs: 87.72%) and most pigs seemed to be naturally infected by M. hyo at 8-10 weeks of age. Also, M. hyo infection showed seasonal pattern that most pigs were infected in late fall to early winter. However, in the study of seroprevalence by province, there was no significant correlation between province and M. hyo sero-positive rate.

• 한국동물위생학회지
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• 제33권2호
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• pp.129-134
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• 2010

Canine brucellosis is a contagious disease of the reproductive tract that cause mainly abortion and infertility in dog. A serological and bacteriological survey was conducted for breeding kennels which were suffered from frequent outbreak of canine brucellosis in Gyeongbuk province in 2009. Among 138 samples, 45 serum samples were sero-positive. Brucella canis was isolated from 30 blood samples of the seropositive cases, and from 2 samples of 62 sero-negatives. The biochemical properties of 32 isolates were characterized with no production of H2S, no fermentation of carbohydrates, hydrolyzation of urea, and development of thionin dye medium. At amplification of BCSP and 16S-rRNA gene using PCR, 711bp and 905bp DNA fragments were detected in agarose. Three tandem repeat pattern was shown in genotyping by Multi-locus VNTR assay (MLVA).

• 대한바이러스학회지
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• 제29권1호
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• pp.11-22
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• 1999

Sero-epidemiologic survey has been carried out to establish serologically the presence of hantavirus in areas of South Africa. The survey was oriented to search natural infection in both of humans and wild rodents and involvement of human disease. The normal human sera were collected from the residents in urban and rural areas of Western Cape, and rural area of Eastern Cape province. The rodent sera came from various species of rodents trapped in Northern Cape and Western Free provinces. The patient sera were selected from the patients of renal failure, pulmonary syndrome and pyrexia of unknown origin (PUQ) according to diagnostic chart among the patients hospitalized in major hospitals of Cape Town area. The sera were screened and titrated by IFA test using antigens of Hantaan (HTN), Seoul (SEO), Puumala (PUU), and Prospect Hill (PH) viruses primarily. Positive cases were subjected to differential IFA test using HTN, PUU and PH antigens and plaque reduction neutralization test for further confirmation. Anti-hantavirus antibodies were detected from 2 of 352 rural, 1 of 172 urban residents of E. Cape, and 5 of 118 rural, 5 of 368 urban residents of W. Cape. The antibody was also demonstrated from 5 of 221 wild rodents, and it was appeared that 2 different species, Aethomys namaquensis and Tatem leucogaster, are involved. Among 318 patients tested, 3 who were diagnosed as chronic renal failure, acute respiratory distress syndrome (ARDS) and glomerulonephritis were proved to be positive. The reaction patterns obtained from all of these positive sera were distinct from hantaviral sero-patterns ever established. This result suggests that new viruses may exist in this area and play an possible etiologic role in human disease. The feature of serologic survey on anti-hantavirus antibody demonstrable newly from African wild rodents which are different from reservoir species in other continents elicits a conjecture that the virus may be different from known hantaviruses ever found. This fact also suggests that an expanded role in etiologic involvement with other unknown human diseases by newly emerging hantaviruses may be possible in this areas.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2003년도 ICCAS
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• pp.2492-2497
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• 2003

This paper presents optimal walking trajectory generation for a quadruped robot with genetic-fuzzy algorithm. In order to move a quadruped robot smoothly, both generations of optimal leg trajectory and free walking are required. Generally, making free walking is difficult to realize for a quadruped robot, because the patterned trajectory may interfere in the free walking. In this paper, we suggest the generation method for the leg trajectory satisfied with free walking pattern so as to avoid obstacle and walk smoothly. We generate via points of leg with respect to body motion, and then we use the genetic-fuzzy algorithm to search for the optimal via velocity and acceleration information of legs. All these methods are verified with PC simulation program, and implemented to SERO-V robot.

• 한국동물위생학회지
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• 제30권3호
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• pp.363-374
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• 2007

A biochemical characterization and antimicrobial drugs susceptibility study was conducted in four breeding kennel which was canine abortion caused by Brucella canis in Gyeongbuk province in 2003-2006. Total of 267 dogs domesticated in the four kennel were examination. Among them, 143 (53.6%) dogs were sero-positive and 25 of blood samples were isolated to Brucella canis. At amplification of 35KDa-BCSP gene using PCR, 711 bp DNA fragment was same visible in 25 isolates and B canis RM6/66. Biochemical characterization of B canis isolated was non-hemolytic, no production of $H_2S$, no fermentation of carbohydrates, catalase-positive, oxidase-positive, indol-negative, hydrolyzation of urea, reduction of nitrate and development of thionin dye medium. Using disk-diffusion method, all of 25 strains tested were found to be highly susceptible to tetracycline, aminoglycoside, quinolone, macrolide antibiotics, rifampin and ampicillin in vitro. Using PFGE with restriction enzyme Smi I, 25 isolates tested were typed to 2 pattern, S1 and S2.

• 한국축산식품학회지
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• 제36권6호
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• pp.779-786
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• 2016

This study aimed to evaluate the prevalence of Listeria monocytogenes on livestock farms in Korea and determine their serotypes and genetic correlations. Twenty-five livestock farms in Korea (central: 15, south west: 7, south east: 3) were visited 2-3 times, and 2,018 samples (feces: 677, soil: 680, silage: 647, sludge: 14) were collected. Samples were enriched in LEB (Listeria enrichment broth) and Fraser broth media, and then plated on Palcam agar. The isolates were identified by PCR and 16S rRNA gene sequencing. Then, the sero-types, presence of virulence genes (actA, inlA, inlB, plcB, and hlyA), and antibiotic resistance were determined. Genetic correlations among the isolates were evaluated by analyzing the restriction digest pattern with AscI. Of the 2,018 samples, only 3 (0.15%) soil samples (FI-1-FI-3) from 1 farm in the south east region were positive for L. monocytogenes. Based on biochemical tests and multiplex PCR, the serotype of the isolates were 4ab (FI-1 and FI-3) and 3a (FI-2), which are not common in foodborne L. monocytogenes. The 3a sero-type isolate was positive for all tested virulence genes, whereas the 4ab serotype isolates were only positive for hlyA, actA, and inlA. The isolates were resistant to all 12 tested antibiotics, especially FI-3. The genetic correlations among the isolates were 100% for those of the same serotype and 26.3% for those of different serotypes. These results indicate that the prevalence of L. monocytogenes on livestock farms in Korea is low; however, the isolates are pathogenic and antibiotic resistant.

• 환경위생공학
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• 제3권2호
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• pp.23-41
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• 1988

1986년 1월부터 12월 사이에 전국 시$\cdot$도 보건연구소 및 주요종합 병원으로부터 일차분리 수집된 Salmonelle균속 286주를 실험균주로 하여 확인동정 실험, 항균제 감수성검사, plasmid DNA분리 및 접합에 의한 내성전달 실험을 실시하여 다음과 같은 결과를 얻었다. 1. 분리된 균주를 sero-group별로 보면 B group이 158주 $(55.2\%)$로 가장 많이 분리되었고, A group이 45주 $(15.7\%)$, D1 group이 43주 $(15\%)$, Cl, C2 group이 22주 $(7.7\%)$등의 순으로 분리되었다. serovar별 분리수는 Salmonella typhimurium이 92주$(32.2\%)$로 가장 많이 분리되었고, S. paratyphi-A 45주 $(15.7\%)$, S. enteritidis 41주$(14.3\%)$, S. paratyphi-B 27주 $(9.4\%)$ 등의 순으로 분리되었다. 분리균주의 월별 분포를 보면 9월 $(17.5\%)$, 5월$(16\%)$, 6월 $(14.7\%)$, 7월 $(10.5\%)$, 8월과 10월$(7.3\%)$등의 순으로 분리되었으며 5월에서 10월 사이에 $73.4\%$인 210주가 분리되었다. 분리균주의 지역별 분포는 강원$(29.7\%)$, 서울 $(27.6\%)$, 충남 $(14.3\%)$등으로 분리되었고, 성별 분포에서는 남성이 $41.6\%$로 여성$(28.6\%)$에서 보다 많이 분리되었으며, 연령별 분리분포는 1세에서 60세까지 고르게 나타났다. 2. 항균제 감수성 검사에서는 제1 이상의 항균제에 내성을 나타내는 균주가 85주$(29.7\%)$로 나타났다. 각 항균제별 내성균주는 tetracycline에서 80주 $(28\%)$가 내성을 보여 가장 많은 내성을 나타냈으며, streptomycin 65주 $(22.7\%)$, ampilcillin, carbenicillin 54주 $(18.8\%)$, chloramphenicol 51주$(17.8\%)$ kanamycin 7주 $(2.4\%)$, co-trimoxazole 2주$(0.7\%)$, tobramycin 1주$(0.3\%)$로 나타났다. 또한 1제내성균이 $8\%$, 2제 내성균이 $2.4\%$, 4제 내성균이 $1.8\%$, 5제 내성균이 $15.4\%$, 6제 내성균이 $1.8\%$, 7제 내성균이 $0.3\%$로 나타났으며, 그 중에서도 AmCbCmSmTc에 동시 내성인 균주가 $15\%$로 가장 많이 나타났다. Sero-group별 내성 양상은 B group에서 $26.2\%$로 가장 많았고, C2 group $(2.4\%)$, D1, E4 group$(0.3\%)$로 나타났다. 3. 접합에 의한 내성전달 결과 1제에서 7제까지 다양한 내성패턴에서 내성전달이 일어났으며, 내성전달은 전달성 R-plasmid에 의한 것이었다. 4. plasmid DNA분리 결과 내성균주 전체에서 한 개에서 네 개의 plasmid를 가지고 있었으며, 그 분자량은 1.6에서 70 megadalton 사이에 있었다. 같은 도에서 분리된 균주들중 내성패턴이 같은 균주들의 plasmid 패턴은 유사하였다. 접합에 의해 전달된 plasmid의 분자량은 42-57 megadalton이었다.

• 한국임상수의학회지
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• 제32권1호
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• pp.78-84
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• 2015

Although researches have highlighted the important role of enhanced farm biosecurity to reduce the severity and prevalence of diseases in livestock, to date there has been little study in Korea on farmers' adoption of biosecurity measures to control porcine reproductive and respiratory syndrome virus (PRRSV) infection. To mitigate the risk of PRRSV infection in pigs, the risk factors by which PRRSV is introduced in pig farms must be determined. The primary aim of this study was to investigate pig producers' perceptions about on-farm biosecurity practices. We also analyzed data obtained from a cross-sectional study on 196 farrow-to-finish farms conducted between March 2013 and February 2014 to identify risk factors for PRRSV infection at farm level. Standardized questionnaires with information about basic demographical data and management practices were collected in each farm by on-site visit of trained veterinarians. Farms were classified as negative or positive through the use of infection profiles that combined data on PCR positive pigs and serological testing including antibody titer, sero-conversion pattern at each age category, and vaccination status. Data on biosecurity practices, farm management and environmental characteristics were analyzed using multivariate ordinal logistic regression. Generally, the biosecurity level in the pig farms included in this study were insufficient to reduce/prevent the risk of PRRSV infection given the high pig density areas and the considerable extent of vehicle movement. Factors associated with PRRSV infection were those where owners used on-farm vaccination programs had a lower risk of infection (OR = 0.19, 95% CI 0.06-0.61). The results from the analysis may guide to tailor biosecurity measures in the reduction or prevention of PRRS to the specific circumstances of pig farms in different localities of the world. To the best knowledge of the authors, this is the first study to report information on the biosecurity practices currently implemented on Korean pig farms.

• Journal of Preventive Medicine and Public Health
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• 제37권4호
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• pp.337-344
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• 2004

Objectives : This study was performed to determine the incidence density and the prevalence of sero-positive hepatitis C from 1999 to 2002 among adults aged 20 and over residing in Seoul and the Gyeonggi province. Method : The data for period was obtained from 114,635 adults, residing in Seoul or the Gyeonggi province, who had undertaken comprehensive health screening tests from Jan 1999 to Dec 2002 in a University hospital in Seoul. Among them, subjects with sero-negative status against hepatitis C were selected (21,408 in 1999, 28,830 in 2000) and then followed up until Dec 2002 to determine the incidence of hepatitis C during this period. The serum was tested with the immunoradiometric assay (IRMA) which uses third generation HCV antibody. Age adjusted rates were estimated by direct standardization using a reference population of 2000 aged from 20 to 80 years. Results : The prevalence of anti-HCV from 1999 to 2002 was 2.1 per 1000 persons(95% CI $1.8{\sim}2.4$). Male showed 1.7 per 1000 persons (95% CI $1.4{\sim}2.1$), while female showed 2.7 per 1000 persons(95% CI $2.2{\sim}3.2$). Age?sex adjusted rate showed 2.8 per 1000 persons (95% CI $2.64{\sim}2.96$), which is lower than the results of some previous study. The prevalence showed a significantly increasing pattern with age both in males and females (p<0.05). The incidence density of anti-HCV among the population aged 20 and over was 1.1 per 104 person-years at risk (95% CI $0.6{\sim}2.4$); 1.2 (95% CI $0.6{\sim}2.7$) for males and 0.8 (95% CI $0.6{\sim}4.2$) for females. Age adjusted incidence density was 2.91 per 104 person-years at risk (95% CI $2.43{\sim}3.38$) for those aged 20 and over. It showed an increasing pattern with age (p<0.05), especially for those age over 50 years. Conclusion : The study subjects for this study were supposedly healthier than the general population so the prevalence and incidence for the general population are thought to be higher than the results of the present study.

• 한국임상수의학회지
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• 제32권4호
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• pp.324-329
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• 2015

The primary aim of this study was to investigate biosecurity practices in pig farms and to determine the major risk factors associated with PCV2 infection for a sampled swine population in Korea. To this end, we analyzed data from a cross-sectional study of 296 farrow-to-finish farms, which was conducted between March and September 2014 to explore the prevalence of swine disease at farm level. Face-to-face interviews by on-site visit of trained veterinarians were conducted with the farm owners or managers using a standardized questionnaires with information about basic demographical data and management practices. Farms were classified as negative or positive through the use of infection profiles that combined data on serological testing including PCR antigen test result, antibody titer and sero-conversion pattern at each age category taking into account vaccination status. Data were analyzed using multivariate ordinal logistic regression. Results from this study indicated that biosecurity level of the farms was considered not good given low compliance of the biosecurity programs and facilities in the farm: off-site removal of dead stocks (7%), off-site location of storage facility for incoming feeds (12.6%), off-site pick-up location for finishers (19.3%), restrictions on feed supplier vehicles for farm entrance (19.6%), restriction of finisher trucks entering the farm (22.4%), and restriction on manure disposal trucks entering the farm (26.4%). In the final model (n = 255), allowance of finisher truck driver to the pig unit had increased risk of infection (OR = 2.4, 95% CI 1.22-4.67) whereas farms with a sign forbidding the entrance had decreased risk of infection (OR = 0.19, 95% CI 0.10-0.58). Further comprehensive research with larger sample size is required to better understand the multifactorial characteristic that some predisposing risk factors that were not available in this study. To the best knowledge of the authors, this was the first study to use empirical data to report risk factors associated with PCV2 infection in the Korean pig farms. Results from the current study could be used to decide optimal biosecurity measures to reduce the impact of PCV2 infection to farmers and policy makers.