• Parasites, Hosts and Diseases
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• 제58권5호
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• pp.559-564
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• 2020

A survey of rodents and chiggers associated with Orientia tsutsugamushi was conducted in a rural region of the Republic of Korea (Korea) between 2014 and 2018. Overall Apodemus agrarius 15.2% had the highest seropisitive for O. tsutsugamushi, followed by Myodes regulus 11.4%. Monthly risk factors using logistic regression analysis were not associated with O. tsutsugamushi infections in rodents. The overall prevalence rate of O. tsutsugamushi among chiggers was 0.3%. The chigger (Leptotrombidium scutellare) and monthly (October) risk factors were associated with O. tsutsugamushi human infections (P<0.05). Orientia tsutsugamushi infections are endemic in rodents in Korea and people, for example, soldiers who are active outdoors, must employ preventive measures, especially during October (P<0.05). When there are many reports of O. tsutsugamushi infections in Korea. The Boryong strain 85.7% (2/14) was the most common strain detected in chiggers, followed by the Shimokoshi 7.1% (1/14) and Karp 7.1% strains.

• 미생물학회지
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• 제41권3호
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• pp.232-235
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• 2005

Scrub typhus의 원인병원체인 Orientia tsutsugamushi에 감염된 인간 피부 미세혈관 내피세포(HMEC-1)에서 superoxide dismutase 유전자의 발현이 증가하였다. O. tsutsugamushi 접촉 후 5 시간 이내에 감염된 세포에서 세포내 peroxide 존재를 유세포 분석을 통하여 관찰할 수 있었다. 또한 감염된 세포는 세포 내 glutathione이 심하게 고갈됨을 관찰하였다. 이 결과들은 이 절대세포내 기생세균에 감염된 숙주세포가 산화-매개 손상 받음을 시사한다.

• Journal of Yeungnam Medical Science
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• 제4권1호
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• pp.173-176
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• 1987

저자들은 경북 고령지방에서 발생한 tsutsugamushi 병 1예를 Weil-Felix test로 확진하였으며 Doxycycline으로 치료하여 그 경과를 보았기에 문헌 고찰과 함께 보고하는 바이다. 특히 환자의 거주지가 경북지역이고 최근 타지역을 여행한 경험이 없었다는 사실에 미루어 휴전선, 강원도, 경기도 지역뿐만 아니라 남부 지방에서도 tsutsugamushi 병이 발생가능하다는 사실을 본 증례를 통해서 확인할 수 있었다.

• Parasites, Hosts and Diseases
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• 제59권3호
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• pp.319-324
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• 2021

Incidence of tsutsugamushi disease (scrub typhus) caused by Orientia tsutsugamushi, is steadily increasing. It is a mite-borne disease transmitted by chigger mites. In this study, the chigger mites were collected from field small mammals in Hwaseong-si (city), Gyeonggi-do (province), Korea, 2019 and 2020. The field small mammals captured were 56 Apodemus agrarius (94.9%) and 3 Crocidura lasiura (5.1%). A total of 7,531 chigger mites were collected from the captured small mammals. Using PCR test, 153 chigger mite pools were examined and 17 pools were reported positive for O. tsutsugamushi. The O. tsutsugamushi were identified to 5 strains; Jecheon strain was most prevalent, followed by Boryong strain. The other strains were OI011, Taguchi, and Shimokoshi. Collectively, these results provide essential regional information on mite-borne tsutsugamushi disease in the Hwaseong-si, and further contribute to bring awareness and rapid diagnosis for the tsutsugamushi disease.

• 대한바이러스학회지
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• 제26권2호
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• pp.235-244
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• 1996

Rickettsia tsutsugamushi의 원형균주인 Karp주와 Gilliam주를 초대 배양된 사람 정상 2배체 폐세포(LuMA cell)를 이용하여 증식과 세포병변들의 속도를 비교할 수 있었고, 배양된 균주는 네스티드 프라이머를 사용하여 혈청형을 동정할 수 있었다. R. tsutsugamushi의 세포벽 외막에 존재하며 혈청형을 결정하는 주요항원은 54-56Kd 단백인 것으로 밝혀지고 있는데, 이 단백 유전자의 DNA 염기서열을 분석하여 Karp주와 Gilliam주의 공통서열로 첫번째 프라이머쌍을 만들었고 첫번째 프라이머쌍의 안쪽에 위치한 혈청형 사이에 차이가 있는 서열로 두번째 프라이머쌍을 만들었다. 네스티드 뉴클레오티드 프라이머는 중합효소 연쇄반응의 특이성을 증가시킬 수 있는데 이 실험 결과로 이 PCR 방법은 scrub typhus의 진단과 혈청형의 동정에 적용될 수 있을 것으로 보여진다.

• 대한의생명과학회지
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• 제13권4호
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• pp.287-291
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• 2007

The factors and mechanisms by infection of Oriental Tsutsugamushi caused disease are not well understood. The onset of tsutsugamushi disease is characterized by chilliness, fever, malaise, headache and generalized aching. Infection of tsutsugamushi is the cause of impairment of function of a major organ often complicate the picture and immediately change the prognosis for the worse. Tsutsugamushi disease is reported that this disease is characterized by the histopathogenesis of liver, kidney, heart, and lung, but the variation of biochemical components in serum of tsutsugamushi disease patient are not clear. We analyzed total protein (TP), albumin (AL), aspartic aminotranferase (AST), alanine aminotransferase (ALT), alkaline phosphotase (ALP), urea nitrogen (UN), creatinine (CRE), glucose (GLD), cholesterol (CHOL) and total bilirubin (TB) in sera of patients with tsutsugamushi disease. In comparison with reference, total protein and albumin were abnormally decreased in 19.6% and 39.2% of patients, respectively. AST, ALT, ALP, creatinine, UN, glucose, cholesterol and total bilirubin were abnormally increased in 94.1 %, 72.5%, 25.5%, 15.7%, 9.8%, 62.7%, 25.5% and 6.0% of patients, respectively. The patients showed abnormal relative rate of protein electrophoretic fractions to total protein in serum compared to them of reference were 43.1% (albumin), 12.9% ($\alpha_1$-globulin), 58.8% ($\alpha_2$-globulin), 60.8% ($\beta$-globulin) and 70.6% ($\gamma$-globulin), respectively. These data suggest that infection of Oriental Tsutsugamushi causes impairment of function of a major organ and abnormal serum protein electrophoresis fractions to tsutsugamushi patients.

• 대한미생물학회지
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• 제35권1호
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• pp.61-68
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• 2000

Among wild chipmunks, Tamias sibiricus, captured in Kyunggi and Kangwon province in Korea, 1997, seropositivity for Orientia tsutsugamushi was determined. Serological test for Orientia tsutsugamushi infection was performed using indirect immunofluorescent antibody technique (IFA). Of 243 wild chipmunks, 61 against Gilliam strain and 64 against Karp strain of Orientia tsutsugamushi were IFA positive. Seropositivity against Gilliam strain was shown 33.3% in Kyunggi and 23.5% in Kangwon province, and against Karp strain was shown 33.3% and 25.4%, respectively.

• Journal of Microbiology
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• 제39권2호
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• pp.142-145
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• 2001

Changes in the Activities of several antioxidant enzymes in transformed human dermal microvascular endothelial Cells (HMEC-1) by infection with the obligate intracellular bacterium Orientia tsutsugamushi, the causative agent of scrub typhus, were investigated. The activities of glucose-6-phosphate dehydrogenase, catalase, and glutathione peroxidase were significantly decreased in HMEC-1 cells infected with Ο. tsutsugamushi. However, the level of superoxide dismutase increased slightly. Furthermore, Increased levels of intracellular peroxide was observed in HMEC-1 during infection. These results support the hypothesis that cells infected by this intracellular bacterium experience oxidant-mediated injury that may eventually contribute to cell death.

• 대한미생물학회지
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• 제34권5호
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• pp.435-443
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• 1999

Orientia tsutsugamushi is obligate intracellular bacterium that grows within the cytoplasm of the eukaryotic host cells. Therefore capability of the attachment, entry into the host cell and intracellular survival should be critical process for oriential infection. In this study we investigated the cellular invasion mechanism of Orientia tsutsugamushi and the role of transmembrane heparan sulfate proteoglycan, which binds diverse components at the cellular microenvironment and is implicated as host cell receptors for a variety of microbial pathogens. First of all Orientia tsutsugamushi can invade a wide range of nonprofessional phagocytic cells including fibroblast, epithelial cells and endothelial cells of various host species, including Band T lymphocytes. Thus, it was postulated that the attachment of O. tsutsugamushi requires the recognition of ubiquitous surface structures of many kinds of host cells. Treatments with heparan sulfate and heparin inhibited the infection of Orientia tsutsugamushi in dose-dependent manner for L cell, mouse fibroblast, whereas other glycosaminoglycans such as chondroitin sulfate had no effect. Collectively, these findings provide strong evidence that initial interaction with heparan sulfate proteoglycan is required for the oriential invasion into host cells.

• 농촌의학ㆍ지역보건
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• 제29권1호
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• pp.177-184
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• 2004

Objectives: Tsutsugamushi disease is one of the most significant acute febrile illnesses, increasing in frequency of occurrence during the late autumn in rural areas of Korea. Methods: I have conducted a case-control study on 30 cases who had the fever as a chief complaint, then had been ruled out as having the Tsutsugamushi disease. Data was collected retrospectively by review of chart regarding their general characteristics, clinical and laboratory findings, then was analysed by chi-test. Results: Of 30 cases, 16 cases were seropositive and 14 cases were seronegative against O. tsutsugamushi. Of seropositive for tsutsugamushi disease, 56.3% were female; 37.5% were in their seventies; 50.0% were farmers; 62,6% had chances of exposure to fields or mountains. And 75.0% occurred in November. The main symptoms and signs were fever and chill(100.0%), headache(75.0%). weakness and fatigue(93.8%), and eschar(68.8%). The characteristic laboratory findings were elevated AST(50.0%), ALT(62.5%), and abnormal urinalysis(56.3%). On the other hand, of seronegative cases, 57.1% were male; 50.0% were in their fifties; 42.9% were farmers; 57.2% had chances of exposure to fields or mountains. And 71.4% occurred in November. The symptoms and signs were fever and chill(100.0%), headache(85.7%), eschar(64.3%). weakness, fatigue and skin(57.1%). The laboratory findings were elevated AST(71.4%) and ALT(64.3%), and abnormal urinalysis(42.9%). However, there were no significant differences between the seropositive and seronegative cases(P>.05). Conclusions: Acute febrile community inhabitants who have the epidemiological, clinical as well as laboratory features should be focused upon for the early diagnosis and treatment for tsutsugamushi disease whether or not possessing the serological antibody against O. tsutsugamushi.