• 한국축산식품학회지
• /
• 제31권1호
• /
• pp.47-53
• /
• 2011

Salmonella enterica serovar Typhimurium (ST) is one of the most common serovars isolated from humans and animals. It has been suggested that ST infections in Koreans are largely due to the consumption of contaminated pork and beef. To investigate the genotypes, phage types, and antimicrobial resistance patterns for ST isolates of different origins, a total of 70 ST strains, including 19 isolates from humans, 44 isolates from pigs, and 6 isolates from cattle, were analyzed using pulsedfield gel electrophoresis (PFGE), phage typing, and antimicrobial susceptibility tests. Forty-three distinct PFGE patterns were generated from 70 ST isolates, which were grouped into 14 PFGE groups (from A to N) at the level of 75% similarity. The most prevalent group was the A (A1-A17 subtypes) group, encompassing 54.5% (38/70) of ST isolates. ST isolates from pigs and cattle mostly belong to groups A and L, whereas ST isolates from humans mostly belong to groups F and C. Antimicrobial susceptibility tests using 11 antimicrobial agents showed that resistance to tetracycline (TE) (81.4%) was highly prevalent, followed by streptomycin (S) (64.3%) and nalidixic acid (NA) (31.4%) resistance. A total of seventeen antimicrobial resistance patterns were observed. Only 8.6% of isolates, including a reference strain, were susceptible to all antimicrobial agents tested. The most prevalent resistance pattern was TE-S (37.1%), which was seen in 66.6% of bovine, 40.8% of swine and 21.1% of human isolates. Three ST isolates from humans (15.9%) showed resistance to 7-8 antimicrobials. The most predominant phage type (PT) was U302 (64.3%), followed by DT170 (10.0%). PFGE types did not coincide with antimicrobial resistance patterns and phage types; therefore, the combination of those types allowed for further differentiation between tested ST isolates.

• 생명과학회지
• /
• 제28권5호
• /
• pp.555-562
• /
• 2018

Swine influenza virus (SIV)는 돼지 개체군에서 가장 흔한 질병을 일으키는 바이러스 중 하나이며 그 subtype은 hemagglutinin (HA)와 neuraminidase (NA)에 의해 결정됩니다. 최근 SIV subtype 진단 방법이 개발되고 있으나 SIV의 리보뉴클레오타이드 서열의 많은 변이로 인해 PCR 보다는 항원-항체 반응을 이용하는 방법이 주로 사용되고 있다. 본 연구에서는 SIV 하위 유형의 신속한 결정을 위하여 2008년 이후 국내에서 발생한 SIV의 다중염기서열 정렬을 통하여 10개의 subtype 진단 프라이머 세트를 개발하고 이를 이용한 one-step RT-PCR 반응을 최적화하였다. 또한 감염력이 높고 독성이 있는 인플루엔자 H1N1 (pH1N1)의 아형에서 확인된 독특한 M 유전자서열을 검출함으로써 pandemic SIV를 조기에 결정하도록 특이적 프라이머를 설계하였다. 2008년부터 2014년까지 한국에서 발생한 9종의 SIV RNA를 활용하여 SIV의 아형 및 pandemic 가능성을 결정하기 위해 시험 분석한 결과 모든 진단 프라이머 세트는 SIV 아형을 정확하게 결정하였으며 pandemic SIV를 검출할 수 있는 것으로 확인되었다. 결과적으로 이들 프라이머 세트를 이용한 최적화된 one-step RT-PCR 분석이 SIV 아형의 신속한 진단에 유용하다는 것이 확인하였다. 이러한 결과는 SIV 하위 유형 및 pandemic SIV가 확산되기 전에 조기 발견을 위한 키트로 개발될 수 있음을 시사한다.

• Parasites, Hosts and Diseases
• /
• 제45권2호
• /
• pp.153-156
• /
• 2007

The small intestines of 6 species of rodents and 1 species of insectivore were examined seasonally for Plagiorchis muris infection in 3 different localities in northern Gyeonggi-do (Province), near the demilitarized zone (DMZ). A total of 1,496 animals, including 1,366 Apodemus agrarius, 54 Crocidura iasiura (insectivore), 32 Mus musculus, 28 Micronytus fortis, 9 Eothenomys regulus, 6 Micronys minutus, and 3 Cricetulus triton, were live-trapped at Yeoncheon-gun (n = 351), Paju-shi (804) and Pocheon-gun (343) at 3-mo intervals from December 2004 to September 2005. A total of 1,647 P. muris were collected from 72 (5.3%) A. agrarius. The infection rate was the high-est in Pocheon-gun (8.2%), followed by Yeoncheon-gun (5.0%) and Paju-shi (4.2%). A higher infection rate was observed in A. agrarius captured during September (19.4%) than those captured during December (3.0%), June (2.6%), or April (0%). However, the worm burden was the highest in June (av. 32.1/animal), followed by September (24.7), December (4.0), and April (0). None of the other animal species were found infected with P. muris. The results reveal that A. agrarius is a natural definitive host for P. muris, and infection rates and worm burdens vary seasonally and geographically.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
• /
• 제31권5호
• /
• pp.379-389
• /
• 2005

Obstructive adenitis of the salivary gland following salivary stone or infectious disease of the gland and surrounding tissues is a common disease. It is often difficult to decide whether to perform total excision of the gland or to consider conservative treatment. The present study was designed to investigate histological, histochemical changes of submandibular gland after ligating the excretory duct for identifying the results of gland duct obstruction. A group of 40 rat of Sprague-Dawley weighing about $200{\sim}220gm$ were used in the present study. 30 rats had ligation of the main excretory ducts of submandibular glands just at the exit from the glands. For controls, 10 rats had a sham operation without duct ligation. They were inducted into euthanagia state by intracardial Ketamine injection in 1, 2, 3, 5, 7, 14, 21, 28, 35 and 42 days after the ligation. In each ligation period, 3 animals were used for ligation and one animal was for control. The submandibular glands were dissected out at sacrifice and stained with H&E, PAS, mucicarmine stain and histological examination were carried out under the light microscope. After examination and comparison of all specimens, the results were as follows: 1. In the features of H&E stain, acini disappeared by degrees after the ligation of the excretary duct and interstitial cells were displaced into fibrous connective tissue. Salivary gland had been atrophied with enlarging ducts and proliferating ductal cells. 2. Through total experimental period, a lot of vessels were observed and the atrophy of serous gland was severer than that of mucous gland. 3. The deep portion of submandibular glands showed severe degeneration rather than superficial portion of them after the ligation. 4. The changes which had enlarged ducts and proliferating ductal cells were observed in entire gland and more prominent in serous gland than mucous gland after the ligation. 5. Although PAS and mucicarmine reactions were decreased gradually after the ligation with the lapse of time, since 2 to 3 weeks they were strong positive reactions on entire gland, especially on duct-like structure. So, we can suggest that salivary gland will be atrophied but, survived acini will be redistributed around the ducts.

• 대한소아치과학회지
• /
• 제35권1호
• /
• pp.73-82
• /
• 2008

치아우식은 주로 mutans streptococci에 의해 야기되는 감염성 질환으로서 주 원인균에는 streptococcus mutans가 있다. S. mutans가 치아우식을 유발하는 분자 생물학적 기전은 몇 가지 단계를 포함한다. 먼저 S. mutans는 AgI/II와 같은 세포 표면의 섬유성 단백질을 매개로 치면의 타액성 피막에 일차적으로 부착한다. 두번째 단계에서 자당의 존재하에 glucosyltransferase(GTF)는 glucan과 같은 다당체를 합성하게 된다. 마지막으로 이렇게 합성된 glucan은 glucan binding proteins와 상호작용하여 치면세균막을 형성해서 세균의 군집화를 가능하게 한다. 많은 실험과 임상연구에서 S. mutans의 주요 항원(Ag I/II, GTFs, GBPs)들이 치아우식 병리기전에 영향을 준다고 알려져 왔고, 따라서 이런 항원들이 면역계에 작용하여 치아우식을 막는 백신으로 이용 가능하다. 본 실험은 streptococcus mutans GS-5로부터, GTFb, GTFc, GTFd 유전자를 복제하고 염기서열분석을 하였으며, 이중 GTFd가 먼저 재조합 단백질 생산을 위해 발현 벡터에 클로닝 되었으며, 이로부터 단백질이 발현됨을 확인하였다. 이번 실험에서 얻은 순수 GTF 항원은 동물실험을 통해 특정 GTF 활성부위에 대한 항체 생산에 이용될 수 있을 것이다.

• Pediatric Infection and Vaccine
• /
• 제20권3호
• /
• pp.123-130
• /
• 2013

목적: 아급성경화범뇌염은 퇴행성 신경질환으로 홍역바이러스의 지속적 중추신경계 감염으로 나타난다. 저자들은 마우스 모델을 통해 아급성경화범뇌염 발병에서 만성 바이러스 감염에 관여하는 PD-1 유전자의 역할을 알아보고자 하였다. 방법: 3주령의 동형 PD-1 유전자 제거 마우스, 이형 PD-1 유전자 제거 마우스, 야생 BALB/c 마우스를 대상으로 측뇌실내 홍역바이러스를 주입하여 동물 모델로 하였다. 바이러스 주입 3개월 후, 마우스의 뇌 조직학적 소견을 관찰하고 혈청을 분리하여 IL-21의 혈청 농도를 ELISA kit을 통해 측정하였다. 결과: 야생 BALB/c 마우스에서 가장 많은 국소적 뇌백질의 괴사 및 성상세포의 증가가 관찰되었다. 이형 마우스에서 뇌실질의 병변은 적었으며 동형 마우스는 거의 보이지 않았다. 세 그룹에서 모두 혈청 IL-21의 증가는 보이지 않았다. 결론: 이 결과는 PD-1 유전자가 만성 바이러스 감염에 중요한 역할을 함을 시사한다.

• 상하수도학회지
• /
• 제29권6호
• /
• pp.633-641
• /
• 2015

Waterborne infectious disease is induced by several pathogenic microbes such as bacteria, viruses and protozoans, and the cases caused by viral infection is currently increasing. Water treatment process could reduce the number of virus in the water, but there were many difficulties to completely remove the virus particles from water. Therefore, the membrane separation technology which was reported to effectively remove pollutants from raw water has attracted increasing attention and demand. Since its efficiency has been introduced, demands for evaluation method toward the membrane filtration process are increasing. However, progression of the method development is slow due to the difficulties in cultivation of several waterborne viruses from animal models or cell culture system. To overcome the difficulties, we used adenovirus, one of the commonly isolated pathogenic waterborne viruses which can grow in cell culture system in vitro. The adenovirus used in this study was identified as human adenovirus C strain. The adenovirus was spiked in the raw water and passed through the microfiltration membrane produced by Econity, a Korean membrane company, and then the viral removal rate was evaluated by real-time PCR. In the results, the amount of virus in the filtered water was decreased approximately by 5 log scale. Because coagulant treatment has been known to reduce filtering function of the membrane by inducing fouling, we also investigated whether there was any interference of coagulant. In the results, we confirmed that coagulant treatment did not show significant interference on microfiltration membrane. In this study, we found that waterborne virus can be effectively removed by membrane filtration system. In particular, here we also suggest that real-time PCR method can rapidly, sensitively and quantitatively evaluate the removal rate of virus. These results may provide a standard method to qualifying membrane filtration processes.

• Archives of Pharmacal Research
• /
• 제22권5호
• /
• pp.437-447
• /
• 1999

Type I diabetes, also known as insulin-dependent diabetes mellitus (IDDM) results from the destruction of insulin-producing pancreatic $\beta$ cells by a progressive $\beta$ cell-specific autoimmune process. The pathogenesis of autoimmune IDDM has been extensively studied for the past two decades using animal models such as the non-obese diabetic (NOD) mouse and the Bio-Breeding (BB) rat. However, the initial events that trigger the immune responses leading to the selective destruction of the $\beta$ cells are poorly understood. It is thought that $\beta$ cell auto-antigens are involved in the triggering of $\beta$ cell-specific autoimmunity. Among a dozen putative $\beta$ cell autoantigens, glutamic acid decarboxylase (GAD) has bee proposed as perhaps the strongest candidate in both humans and the NOD mouse. In the NOD mouse, GAD, as compared with other $\beta$ cell autoantigens, provokes the earliest T cell proliferative response. The suppression of GAD expression in the $\beta$ cells results in the prevention of autoimmune diabetes in NOD mice. In addition, the major populations of cells infiltrating the iselts during the early stage of insulitis in BB rats and NOD mice are macrophages and dendritic cells. The inactivation of macrophages in NOD mice results in the prevention of T cell mediated autoimmune diabetes. Macrophages are primary contributors to the creation of the immune environment conducive to the development and activation of $\beta$cell-specific Th1-type CD4+ T cells and CD8+ cytotoxic T cells that cause autoimmune diabetes in NOD mice. CD4+ and CD8+ T cells are both believed to be important for the destruction of $\beta$ cells. These cells, as final effectors, can kill the insulin-producing $\beta$ cells by the induction of apoptosis. In addition, CD8+ cytotoxic T cells release granzyme and cytolysin (perforin), which are also toxic to $\beta$ cells. In this way, macrophages, CD4+ T cells and CD8+ T cells act synergistically to kill the $\beta$ cells in conjunction with $\beta$ cell autoantigens and MHC class I and II antigens, resulting in the onset of autoimmune type I diabetes.