• 대한수의학회지
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• 제47권4호
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• pp.417-423
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• 2007

Serological surveillance programs in animal populations are becoming increasingly important to estimate prevalence of a specific disease and subsequently to document disease-free status in a region or a country. For these purposes, the programs need to be based on both theoretical and economical aspects from the designing phase. From Aujeszky's disease (AD)-eradication program point of view, group of animals (aggregates, herds) not individual animal is the more important sampling unit of concern. In this study the authors therefore attempted to compute an appropriate sample size tailored to a current surveillance program against AD, assuming that the goal of this program is either herd-level prevalence estimation or documentation of AD-freedom. For prevalence estimation, assuming a finite population with imperfect sensitivity (Se) and specificity (Sp) of ELISA kit for AD diagnosis, the number of herds present, expected herd prevalence, and desired accuracy for a certain level of confidence, sample size was estimated at herd-level in the first stage and individual animal-level in the second stage. A two-stage sampling design was used to calculate a sample size to indicate AD-freedom. In this instance, the computation was based on the possible detection of a predetermined prevalence at a certain herd-level Se and Sp. This study indicated that the sample size varied with predetermined confidence, tolerance, Se and Sp at herd- and animal-level, and within- and among-herd prevalence. In general, smaller sample size was required to estimate AD prevalence than to document of AD-freedom. Compared to individual-based samples, two-stage sampling strategy requires a larger sample size to show disease-freedom. Statistical considerations including herd-level test characteristics when designing surveillance program also are further discussed.

• 문화기술의 융합
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• 제8권5호
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• pp.369-375
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• 2022

이른바 코로나19 대유행으로 철도서비스 경영 역시 유례없는 상황을 맞이하고 있다. 본 연구에서는 코로나19 유행기간 동안 고속철도를 이용한 고객을 대상으로 설문조사를 진행하여 감염병이 철도서비스 고객경험에 미치는 영향을 탐색하였다. 연구결과, 철도운영기관이 제공하는 방역관련 서비스에 대해 고객이 높은 수준으로 지각할수록 고객만족도와 충성도가 증가하는 것으로 나타났다. 또한 고객 별로 코로나19에 대해 위험하게 생각하는 수준에 개인차가 있기 때문에, 고객의 코로나19 위험지각의 조절역할도 실증하였다. 그 결과, 코로나19에 대한 고객의 위험지각이 적정한 수준일 때에는 서비스 기관의 방역관련 서비스 속성이 고객만족 형성에 큰 영향을 미치지만, 고객의 위험지각수준이 상당히 높은 경우에는 그 영향력은 유의하지 않은 것으로 나타났다. 결국 감염병에 대한 위험이 완벽히 소멸되는 것만이 서비스 산업의 완벽한 회복을 가져다줄 것이다. 그럼에도 감염병 유행기간에는 서비스 운영기관이 방역활동을 철저히 하고, 고객에게 이에 대해 충실히 커뮤니케이션 하는 것이 주요한 서비스 속성이 된다는 것을 확인하였다.

• Journal of Microbiology and Biotechnology
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• 제25권9호
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• pp.1460-1466
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• 2015

In this study, the prevalence of Shiga toxin-producing Escherichia coli (STEC) was investigated among raw meat or meat products from slaughterhouses and retail markets in South Korea, and their potential for antibiotic resistance and virulence was further analyzed. A total of 912 raw meats, including beef, pork, and chicken, were collected from 2008 to 2009. E. coli strains were frequently isolated in chicken meats (176/233, 75.9%), beef (102/217, 42.3%), and pork (109/235, 39.2%). Putative STEC isolates were further categorized, based on the presence or absence of the Shiga toxin (stx) genes, followed by standard O-serotyping. Polymerase chain reaction assays were used to detect the previously defined virulence genes in STEC, including Shiga toxins 1 and Shiga toxin 2 (stx1 and 2), enterohemolysin (ehxA), intimin (eaeA), STEC autoagglutination adhesion (saa), and subtilase cytotoxin (subAB). All carried both stx1 and eae genes, but none of them had the stx2, saa, or subAB genes. Six (50.0%) STEC isolates possessed the ehxA gene, which is known to be encoded by the 60-megadalton virulence plasmid. Our antibiogram profiling demonstrated that some STEC strains, particularly pork and chicken isolates, displayed a multiple drug-resistance phenotype. RPLA analysis revealed that all the stx1-positive STEC isolates produced Stx1 only at the undetectable level. Altogether, these results imply that the locus of enterocyte and effacement (LEE)-positive strains STEC are predominant among raw meats or meat products from slaughterhouses or retail markets in Korea.

• 생명과학회지
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• 제19권10호
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• pp.1451-1455
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• 2009

Porcine cytomegalovirus (PCMV) is a betaherpesvirus which causes reproductive failure in breeding sows and generalized infection in newborn piglets. It has worldwide distribution including Korea. Serological survey on this virus has been reported in 76.3% of pigs, but virological survey and epidemiological analysis on PCMV distribution have been reported in only a few papers in Korea. In this study, we investigated the virological prevalence and infection status of PCMV on a farm level in selected swine farms with respiratory diseases. A total of 1,938 blood samples taken from groups of pigs of different ages were collected from 31 farms distributed nationwide in 2006 and 2007 and tested by PCR to detect the presence of PCMV. Virological prevalence at farm level and pig level were 96.8% and 17.5%, respectively, suggesting that PCMV has endemically infected Korean pig herds. The prevalence at farm level in gilts, sows and suckling piglet groups were 16.7%, 36.7% and 56.7%, indicating that vertical infections frequently occurred in conception or newborn stage. Thereafter, detection rates of PCMV were slightly increased in pig groups aged 40 and 70 days (70.0% and 73.3%), and then gradually decreased as they aged - 33.3% in 100, 26.7% in 130 and 16.7% in 160 day old pig groups. The prevalence at pig level has similar patterns to that at farm level. With the passage of time, the variation of infection patterns of PCMV was investigated in four PCMV-positive farms. Three blood samples were collected at intervals of 6 months in each farm, and examined for presence of PCMV using PCR. The results revealed that once PCMV was introduced to the pig farms, it continuously circulated between and within groups of sows and piglets in those farms. Taken together, it can be concluded that PCMV has endemically infected Korean pig farms and has the potential risk for emerging pathogen in combination with the known endemic pathogens including porcine reproductive, respiratory syndrome virus and porcine circovirus type 2. Therefore, more research is needed on diagnosis, epidemiology and control strategy for PCMV on the field.

• 한국응용곤충학회지
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• 제60권2호
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• pp.193-199
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• 2021

벌목 개미과의 일본열마디개미는 국내 토착종이다. 지금까지 야외에서 이 종의 월동기작을 이해하기 위한 내한성 연구는 진행되지 않았다. 저온에서 다양한 온도별 노출시간에 따른 발육태별 저온 저항성을 조사하였다. 성충인 일개미가 다른 발육태와 비교하여 5℃와 10℃의 저온에서 높은 생존율을 보였으며, 급속내한성 유기 조건인 15℃에서 12시간 노출 후 내한성을 획득하였다. 급속내한성 유기는 10℃에서 최대 44%까지 생존율이 향상되었으며, 체내과냉각점과 체내빙점은 각각 -10.0℃에서 -14.2℃, -11.3℃에서 -15.3℃까지 낮아졌다. 저온처리는 저온 또는 스트레스 관련 유전자인 글리세롤 인산화효소와 열충격 단백질의 발현을 증가시켰다. 이상의 결과는 일본열마디개미의 내한성이 급속내한성 유기에 의해 야기된다는 것을 의미한다.

• 보건행정학회지
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• 제32권1호
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• pp.45-52
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• 2022

Background: There are regional variations in the incidence of coronavirus disease 2019 (COVID-19), which means that some regions are more exposed to the risk of COVID-19 than others. Therefore, this study aims to investigate regional variations in the incidence of COVID-19 in Korea and identify risk factors associated with the incidence of COVID-19 using community-level data. Methods: This study was conducted at the districts (si·gun·gu) level in Korea. Data of COVID-19 incidence by districts were collected from the official website of each province. Data was also obtained from the Korean Statistical Information Service and the Community Health Survey; socio-demographic factor, transmission pathway, healthcare resource, and factor in response to COVID-19. Community risk factors that drive the incidence of COVID-19 were selected using a least absolute shrinkage and selection operator regression. Results: As of June 2021, the incidence of COVID-19 differed by more than 80 times between districts. Among the candidate factors, sex ratio, population aged 20-29, local financial independence, population density, diabetes prevalence, and failure to comply with the quarantine rules were significantly associated with COVID-19 incidence. Conclusion: This study suggests setting COVID-19 quarantine policy and allocating resources, considering the community risk factors. Protecting vulnerable groups should be a high priority for these policies.

• 대한수의학회지
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• 제47권4호
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• pp.389-393
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• 2007

In this study, the levels of aflatoxin $M_1$ ($AFM_1$) in milk were determined by HPLC with derivatization method. Milk samples were purified using $C_{18}$ disposable cartridge followed by derivatization with trifluoroacetic acid and analysed using HPLC with fluorescence detection. The recoveries of AFM1 from milk samples added $AFM_1$ at a level of 0.025~0.1 ng/ml were 94.7~98.0% with detection limit of 0.009 ng/ml. The amounts of $AFM_1$ were determined below 0.05 ng/ml for all tested samples of commercial milk collected in 1999 and 2000.

• 한국식품과학회지
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• 제49권2호
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• pp.117-122
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• 2017

신선 채소인 파프리카에 검역처리 선량의 전자선 처리(0, 0.4, 1, 2 kGy) 후 냉장저장 40일 동안 미생물학적, 이화학적 및 관능적 품질을 평가하였다. 파프리카의 미생물 농도는 총세균, 효모 및 곰팡이의 경우 $10^4CFU/g$, 대장균군은 $10^2CFU/g$ 수준이었고, 1 kGy 선량은 미생물 농도를 1 log cycle 감소시킬 수 있었다. 중량감소율은 조사처리에 따른 차이를 보이지 않았고, 경도와 카로티노이드 함량은 조사 직후 1 kGy 이상의 선량에서 유의적으로 감소하였으며, 저장 중에도 선량에 관계없이 감소하였다. 비타민 C 함량은 선량에 따른 유의적인 차이를 보이지 않았고, 0, 0.4 및 1 kGy 처리 시료는 저장 40일째 저장 초기 함량의 87-90% 수준으로 감소하였다. 파프리카에 대한 관능평가 결과, 2 kGy 수준의 전자선 처리는 색과 조직감 저하에 영향을 미치는 것으로 확인되었다. 이상의 결과, 수출용 파프리카의 해충구제 및 검역처리를 위한 0.4-1 kGy 수준의 전자선 처리는 냉장저장 동안 미생물학적 안전성을 확보하면서 이화학적 품질을 유지시키는 것으로 확인되었다.

• 식물병연구
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• 제17권3호
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• pp.376-380
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• 2011

P. syringae pv. tomato는 토마토에서 bacterial speck병을 일으키는 종자전염 세균으로, 감수성 품종에서 주로 발병하여 경제적으로 큰 손실을 입힌다. 따라서 P. syringae pv. tomato는 한국을 비롯한 많은 나라에서 식물 검역대상 세균으로 지정하여 관리되고 있다. 본 연구에서 우리는 토마토 종자로부터 PCR을 이용하여 Pst를 검출할 수 있는 방법을 개발하였다. P. syringae pv. tomato의 hrpZ 유전자에서 특이적인 프라이머를 개발하였다. 개발된 프라이머는 P. syringae pv. tomato에서만 501 bp 크기의 특이적 DNA를 증폭하였으며, P. syringae pv. glycinea, P. syringae pv. maculicola, P. syringae pv. atropurpurea, P. syringae pv. morsprunorum와 같은 다른 토마토 세균병원균과 P. syringae pathovar 균주들에서는 증폭되지 않았다. Nested PCR 프라이머를 이용한 PCR에서도 오직 P. syringae pv. tomato에서만 119 bp 크기의 특이적 DNA가 증폭되었고, 토마토 종자에서 P. syringae pv. tomato을 정확하고 민감하게 검출하였다. 본 연구는 현재까지 사용되고 있는 Pst의 검출방법의 민감도를 비교한 최초의 보고로 본 연구에서 개발된 PCR방법들은 토마토 종자에서 Pst을 검출하는 매우 유용한 방법으로 생각된다.

• 대한수의학회지
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• 제39권3호
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• pp.478-488
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• 1999

The contents of histidine dipeptides, a metabolic products of muscle protein, were investigated to compare muscle composition among the 9 domestic animals including cattle. In major domestic animals, analyzed the effects of age, part and sex of the animals on their muscle composition. Large amounts of carnosine($68.63{\pm}17.41{\mu}mol/g$) were detected in cattle and it was higher than other animals. Whereas the content of anserine showed high level in order of turkey, chickens and duck. The ratio of carnosine and anserine(C/A ratio) was different depending on the animal species. Statistical data indicated that difference among species was significant(p < 0.05). The contents of histidine dipeptides in heated muscle by boiling for 40 minutes at $110^{\circ}C$ was similar to thoes of raw muscle. C/A ratio in heated muscle was not different from that of raw muscle, indicating that no change has been made after heating process. The contents of carnosine and anserine were different according to the parts of their muscle. Especially chuck of the mammalian showed extremely low level of histidine dipeptides compared with other parts, while C/A ratio maintained certain level regardless of age, part, sex. Therefore, based on the content of histidine dipeptides, could be found the difference of muscle composition among the species. Also C/A ratio of horse, pig, cattle, duck, sheep and turkey were characteristic respectively.