유세포분석법으로 조사한 Orientia tsutusgamushi Boryong주의 항균제 감수성

김은실,김미경,이혜명,정문현,이진수,박재은,강재승 대한감염학회 2008 Infection and Chemotherapy Vol.40 No.4

Background : Scrub typhus, an infectious disease caused by Orientia tsutsugamushi, is endemic in Korea. With the introduction of tetracycline and chloramphenicol in clinical practice, the mortality due to scrub typhus has markedly decreased. In 1995, scrub typhus poorly responsive to doxycycline was reported in Thailand; the need for safe antibiotics for the treatment of scrub typhus acquired during pregnancy or for children is emerging; also, broader spectrum antibiotics having anti-Orientia activity may be preferred for empirical therapy of enteric fever syndrome and for complicated scrub typhus. The anti-Orientia activities of various antibiotics, including recently licensed antibiotics, were investigated by flow cytometry. Materials and Methods : O. tsutsugamushi strain Boryong was inoculated into the ECV304 cell line. The infected cells were stained with FS15, a monoclonal antibody reacting against a linear epitope on 56-kDa major outer membrane protein of O. tsutsugamushi. Then the antimicrobial susceptibilities were measured by flow cytometry and expressed as a growth index (total mass of Orientia). A concentration at which no further decrease in growth index occurred was defined as the minimal inhibitory concentration (MIC). Microbial susceptibilities to the following antibiotics were measured: quinupristin-dalfopristin (Synercid), levofloxacin, ciprofloxacin, moxifloxacin, metronidazole, linezolid, clindamycin, chloramphenicol, doxycycline, azithromycin, and rifampin. Results : Considering the usual serum concentrations of rifampin (MIC=0.025-0.05 µg/mL), azithromycin (MIC=0.05-0.5 µg/mL) and doxycycline (MIC=0.05-0.1 µg/mL), these antibiotics exhibited very low MICs. Synercid (MIC=0.2-1.0 µg/mL), clindamycin (MIC=1.0 µg/mL) and chloramphenicol (MIC=1-2 µg/mL) exhibited moderately low MICs; moxifloxacin (MIC=8 µg/mL), ciprofloxacin (MIC=25.6 µg/mL or more) and levofloxacin (MIC=30 µg/mL) exhibited relatively high MICs; and cefotaxime (MIC>50 µg/mL), metronidazole (MIC>30 µg/mL) and linezolid (>30 µg/mL) exhibited high MICs. Conclusions : Among the new antibiotics, none was superior to doxycycline, azithromycin or rifampin with respect to anti-Orientia activity. Synercid, clindamycin, and moxifloxacin may show moderate therapeutic efficacies in human. Background : Scrub typhus, an infectious disease caused by Orientia tsutsugamushi, is endemic in Korea. With the introduction of tetracycline and chloramphenicol in clinical practice, the mortality due to scrub typhus has markedly decreased. In 1995, scrub typhus poorly responsive to doxycycline was reported in Thailand; the need for safe antibiotics for the treatment of scrub typhus acquired during pregnancy or for children is emerging; also, broader spectrum antibiotics having anti-Orientia activity may be preferred for empirical therapy of enteric fever syndrome and for complicated scrub typhus. The anti-Orientia activities of various antibiotics, including recently licensed antibiotics, were investigated by flow cytometry. Materials and Methods : O. tsutsugamushi strain Boryong was inoculated into the ECV304 cell line. The infected cells were stained with FS15, a monoclonal antibody reacting against a linear epitope on 56-kDa major outer membrane protein of O. tsutsugamushi. Then the antimicrobial susceptibilities were measured by flow cytometry and expressed as a growth index (total mass of Orientia). A concentration at which no further decrease in growth index occurred was defined as the minimal inhibitory concentration (MIC). Microbial susceptibilities to the following antibiotics were measured: quinupristin-dalfopristin (Synercid), levofloxacin, ciprofloxacin, moxifloxacin, metronidazole, linezolid, clindamycin, chloramphenicol, doxycycline, azithromycin, and rifampin. Results : Considering the usual serum concentrations of rifampin (MIC=0.025-0.05 µg/mL), azithromycin (MIC=0.05-0.5 µg/mL) and doxycycline (MIC=0.05-0.1 µg/mL), these antibiotics exhibited very low MICs. Synercid (MIC=0.2-1.0 µg/mL), clindamycin (MIC=1.0 µg/mL) and chloramphenicol (MIC=1-2 µg/mL) exhibited moderately low MICs; moxifloxacin (MIC=8 µg/mL), ciprofloxacin (MIC=25.6 µg/mL or more) and levofloxacin (MIC=30 µg/mL) exhibited relatively high MICs; and cefotaxime (MIC>50 µg/mL), metronidazole (MIC>30 µg/mL) and linezolid (>30 µg/mL) exhibited high MICs. Conclusions : Among the new antibiotics, none was superior to doxycycline, azithromycin or rifampin with respect to anti-Orientia activity. Synercid, clindamycin, and moxifloxacin may show moderate therapeutic efficacies in human.

Orientia tsutsugamushi에 대한 항균제 병용의 실험실 효과

김은실,김미경,이혜명,정문현,이진수,강재승 대한감염학회 2008 Infection and Chemotherapy Vol.40 No.6

Background : Occasionally, combinations of antibiotics are used for the treatment of scrub typhus. However, the effectiveness of such combined therapies has rarely been evaluated. To date, no experimental studies have been performed; only 1 clinical study has assessed the efficacy of combined doxycycline and rifampin therapy. To elucidate the efficacies of other antibiotic combinations, we performed an experiment to evaluate the in vitro efficacy of antibiotic combinations against Orientia tsutsugamushi. Materials and Methods : O. tsutsugamushi strain Boryong was inoculated into the ECV304 cell line. The infected cells were cultured in antibiotic-containing media for 3-5 days and stained with FS15, a monoclonal antibody reacting against the linear epitope on the 56-kDa major outer membrane protein of O. tsutsugamushi. Thereafter, antimicrobial susceptibility was measured by flow cytometry and expressed as a growth index (total mass of Orientia). The growth indices of doxycycline (0.1 µg/ mL), azithromycin (0.1 µg/mL), rifampin (0.0125 µg/mL), cefotaxime (2 and 20 µg/mL), and their various combinations (doxycycline+cefotaxime, doxycycline+rifampin, azithromycin+cefotaxime, and rifampin+cefotaxime) were measured. The above mentioned antibiotic concentrations, except for that of cefotaxime, represent the minimal inhibitory concentrations of each antibiotic. Results : The growth indices of doxycycline (4.67% and 0.52%), rifampin (2.35% and 0.26%), and azithromycin (7.54%) were within the range of full suppression of O. tsutsugamushi; in contrast, cefotaxime (87.60%) was in effective. The growth indices of doxycycline + rifampin were 0.10% and 0.10%, which were similar to those obtained with doxycycline or rifampin alone. The growth indices of doxycycline+cefotaxime were 3.99% and 3.65% in low-dose cefotaxime (2 µg/mL), and 3.69% and 4.40% in high-dose cefotaxime (20 µg/mL). The growth indices of rifampin + cefotaxime (2.19% and 2.19% at 2 µg/mL; 1.84% and 2.04% at 20 µg/mL cefotaxime) were similar to those obtained with rifampin alone (2.35% and 0.26%). Azithromycin+cefotaxime (11.06-14.63%) showed higher growth indices than azithromycin alone; this suggests that this combination may be antagonistic. Conclusions : The anti-Orientia efficacies of doxycycline+rifampin, doxycycline+cefotaxime, and rifampin+cefotaxime were not antagonistic. The efficacy of the azithromycin+cefotaxime combination needs to be confirmed by more sensitive methods to exclude the possibility of antagonistic interactions between the antibiotics. Background : Occasionally, combinations of antibiotics are used for the treatment of scrub typhus. However, the effectiveness of such combined therapies has rarely been evaluated. To date, no experimental studies have been performed; only 1 clinical study has assessed the efficacy of combined doxycycline and rifampin therapy. To elucidate the efficacies of other antibiotic combinations, we performed an experiment to evaluate the in vitro efficacy of antibiotic combinations against Orientia tsutsugamushi. Materials and Methods : O. tsutsugamushi strain Boryong was inoculated into the ECV304 cell line. The infected cells were cultured in antibiotic-containing media for 3-5 days and stained with FS15, a monoclonal antibody reacting against the linear epitope on the 56-kDa major outer membrane protein of O. tsutsugamushi. Thereafter, antimicrobial susceptibility was measured by flow cytometry and expressed as a growth index (total mass of Orientia). The growth indices of doxycycline (0.1 µg/ mL), azithromycin (0.1 µg/mL), rifampin (0.0125 µg/mL), cefotaxime (2 and 20 µg/mL), and their various combinations (doxycycline+cefotaxime, doxycycline+rifampin, azithromycin+cefotaxime, and rifampin+cefotaxime) were measured. The above mentioned antibiotic concentrations, except for that of cefotaxime, represent the minimal inhibitory concentrations of each antibiotic. Results : The growth indices of doxycycline (4.67% and 0.52%), rifampin (2.35% and 0.26%), and azithromycin (7.54%) were within the range of full suppression of O. tsutsugamushi; in contrast, cefotaxime (87.60%) was in effective. The growth indices of doxycycline + rifampin were 0.10% and 0.10%, which were similar to those obtained with doxycycline or rifampin alone. The growth indices of doxycycline+cefotaxime were 3.99% and 3.65% in low-dose cefotaxime (2 µg/mL), and 3.69% and 4.40% in high-dose cefotaxime (20 µg/mL). The growth indices of rifampin + cefotaxime (2.19% and 2.19% at 2 µg/mL; 1.84% and 2.04% at 20 µg/mL cefotaxime) were similar to those obtained with rifampin alone (2.35% and 0.26%). Azithromycin+cefotaxime (11.06-14.63%) showed higher growth indices than azithromycin alone; this suggests that this combination may be antagonistic. Conclusions : The anti-Orientia efficacies of doxycycline+rifampin, doxycycline+cefotaxime, and rifampin+cefotaxime were not antagonistic. The efficacy of the azithromycin+cefotaxime combination needs to be confirmed by more sensitive methods to exclude the possibility of antagonistic interactions between the antibiotics.

국내 환자에서 분리된 Orientia tsutsugamushi에서 doxycycline 내성

김은실,김미경,이혜명,길세희,정문현,이진수,강재승 대한감염학회 2008 Infection and Chemotherapy Vol.40 No.5

Background : Doxycycline has been the drug of choice for the treatment of scrub typhus. However, scrub typhus with poor response to doxycycline was first reported in Thailand in 1996. To date, it is not known whether doxycycline resistant scrub typhus is present in Korea. To investigate the doxycycline resistance of scrub typhus in Korea, we performed an experiment to evaluate the degree of growth inhibition of Orientia tsutsugamushi at the minimal inhibitory concentration (MIC) of doxycycline. Materials and Methods : 37 isolates of Orientia tsutsugamushi were collected from Korean patients with scrub typhus during 10 year period (from 1997 to 2007). 34 isolates consisted of Boryong serotype or related serotypes. These strains were stained with FS15, a monoclonal antibody against the linear epitope on the protein located at the outer membrane of O. tsutsugamushi. Three isolates were confirmed as serotype Gilliam, which was stained by anti-Gilliam antibody. The antibody- stainable 35 isolates were incubated in media containing 0.1 and 0.2 µg/mL of doxycycline for 3 days. Then the growth indices of Orientia were measured by flow cytometry. If the growth index was greater than 10%, the isolate was tentatively classified as an isolate resistant to doxycycline and its MIC was measured. Results : Demographic and treatment data were similar to the results of previous reports. Infection was mainly observed in Inchon and the Chungcheongnam province. No patient showed delayed response to antibiotics. Of 35 hospitalized patients, 4 (11.4%) were managed at the intensive care unit, and 1 (2.9%) died of nosocomial pneumonia. All the 2 patients whose isolates were serotype Gilliam Yonchon/Ikeda-like strain were managed at the intensive care unit. Six of the 34 isolates from Korean patients exhibited growth indices greater than 10% at the MIC of doxycycline; however, the MICs of these isolates did not exceed 0.2 µg/mL. One isolate of serotype Gilliam showed an MIC of 0.0125 ug/mL, which seemed to be underestimated due to weak fluorescence of the anti-Gilliam antibody. Conclusions : Although the number of tested isolates is small, insensitivity of scrub typhus to doxycycline is not a major reason for treatment failure in Korea. Serotype Gilliam, especially Yochon/ Ikeda-like strain, may be associated with severe form of scrub typhus. More studies concerning the antibiotic susceptibility for serotype Gilliam are warranted. Background : Doxycycline has been the drug of choice for the treatment of scrub typhus. However, scrub typhus with poor response to doxycycline was first reported in Thailand in 1996. To date, it is not known whether doxycycline resistant scrub typhus is present in Korea. To investigate the doxycycline resistance of scrub typhus in Korea, we performed an experiment to evaluate the degree of growth inhibition of Orientia tsutsugamushi at the minimal inhibitory concentration (MIC) of doxycycline. Materials and Methods : 37 isolates of Orientia tsutsugamushi were collected from Korean patients with scrub typhus during 10 year period (from 1997 to 2007). 34 isolates consisted of Boryong serotype or related serotypes. These strains were stained with FS15, a monoclonal antibody against the linear epitope on the protein located at the outer membrane of O. tsutsugamushi. Three isolates were confirmed as serotype Gilliam, which was stained by anti-Gilliam antibody. The antibody- stainable 35 isolates were incubated in media containing 0.1 and 0.2 µg/mL of doxycycline for 3 days. Then the growth indices of Orientia were measured by flow cytometry. If the growth index was greater than 10%, the isolate was tentatively classified as an isolate resistant to doxycycline and its MIC was measured. Results : Demographic and treatment data were similar to the results of previous reports. Infection was mainly observed in Inchon and the Chungcheongnam province. No patient showed delayed response to antibiotics. Of 35 hospitalized patients, 4 (11.4%) were managed at the intensive care unit, and 1 (2.9%) died of nosocomial pneumonia. All the 2 patients whose isolates were serotype Gilliam Yonchon/Ikeda-like strain were managed at the intensive care unit. Six of the 34 isolates from Korean patients exhibited growth indices greater than 10% at the MIC of doxycycline; however, the MICs of these isolates did not exceed 0.2 µg/mL. One isolate of serotype Gilliam showed an MIC of 0.0125 ug/mL, which seemed to be underestimated due to weak fluorescence of the anti-Gilliam antibody. Conclusions : Although the number of tested isolates is small, insensitivity of scrub typhus to doxycycline is not a major reason for treatment failure in Korea. Serotype Gilliam, especially Yochon/ Ikeda-like strain, may be associated with severe form of scrub typhus. More studies concerning the antibiotic susceptibility for serotype Gilliam are warranted.

2000년대 초에 유행한 Orientia tsutsugamushi에 의한 간염

박재일,한성희,조승철,조용현,홍상모,이학현,윤혜련,양선영,윤재훈,윤영섭,문지용,조경란,백상현,손주현,김태화,이동후 대한간학회 2003 Clinical and Molecular Hepatology(대한간학회지) Vol.9 No.3

목적: Orientia tsutsugamushi 감염은 삼림에 서식하는 매개충인 진드기(Leptotrombidium)의 유충이 우연히 사람의 피부를 통하여 전파되어 생기는 급성 발열 질환이다. 저자들은 지난 3년 동안 쯔쯔가무시병으로 진단된 환자들에서 간 기능 이상을 확인하고 가을철 간염환자의 감별진단 특히 non-A, non-B, non-C 간염의 진단에 주의를 환기하고자 관찰 결과를 보고하는 바이다. 대상과 방법: 한양대학교 서울병원과 구리병원에 2000년 10월부터 2002년 11월까지 hemagglutinin법으로 쯔쯔가무시병으로 진단된 환자 22명을 조사 대상으로 삼아 그 진료기록을 조사하였다. 결과: 남녀 비는 1:3.4로 여자가 많았다. 연령(범위 31-83세)은 56.4±2.6(평균±표준오차)세였다. 입원시기는 9월 23일부터 11월 15일 사이였고 10월 중순 이후 11월 상순 사이가 제일 많았다. 증상은 발열이 21예로 가장 많았고, 근육통 13예, 관절통 12예, 오한 6예, 피부발진 6예 순이었다. 잠복기는 7-9일이 10예로 가장 많았고 13-15일이 4예, 10-12일 3예, 3일 이내 3예, 4-6일 2예였다. ALT(범위 18-345 IU/L)는 93.2±17.3 IU/L(평균±표준오차)였고, AST(범위 34-255 IU/L)는 92.5±11.7 IU/L, GGTP (범위 19-251 IU/L)는 132.2±14.5 IU/L로 상승하였지만 혈중 총 빌리루빈은 정상이었다. 모든 환자들은 doxycycline 투여로 호전되었다. 결론: Orientia tsutsugamushi 감염은 대부분, 경도의 간 기능 이상을 동반하므로 특히 가을철 간 기능 이상을 보이는 열성 질환 환자들에게서 다른 간 질환과 감별해야 할 질환으로 인지하는 것이 중요하다. Background/Aims: Orientia -tsutsugamushi infection is an acute febrile disease due to the accidental transmission through human skin of forest dwelling vector Leptotrombidium larva. The authors observed liver dysfunctions in patients diagnosed with tsutsugamushi disease (Scrub typhus) in the past 3 years and report the data in the hope of bringing attention to this disease in the differential diagnosis of autumn-season hepatitis, especially of non-A, non-B and non-C hepatitis. Methods: Medical records of 22 patients diagnosed with tsutsugamushi disease by the hemagglutinin method between October 2000 and November 2002 were reviewed. Results: Female gender was dominant in the ratio of 3.4:1. Mean age was 56.4±2.6. Admission was between 23rd September and 15th November with the peak between mid October and early November. Fever, being the most common symptom, was observed in 21 cases, myalgia in 13, arthralgia in 12, chills in 6, and skin rash in 6. An incubation period of 7-9 days was most common (10 cases), 13-15 days (4), 10-12 days (3), within 3 days (3), and 4-6 days (2). Average ALT, AST and GGTP were increased to 93.2±17.3 IU/L (18±345 IU/L), 92.5±11.7 IU/L (34-255 IU/L) and 132.2±14.5 IU/L (19-251 IU/L), respectively, but total bilirubin was normal. All the patients improved with doxycycline therapy. Conclusions: since it usually shows liver dysfunction, it is important to take Orientia tsutsugamushi into consideration in differential diagnosis of autumn-season, febrile hepatic disease.(Korean J Hepatol 2003;9:198-204)

이중 중합효소연쇄반응을 이용한 Orientia tsutsugamushi의 혈청형의 동정

송해준,김수남,최영주,노주영,김우주,기선호,송기준,홍승민 대한감염학회 1997 감염 Vol.29 No.3

목적: 임상적으로 쯔쯔가무시병이 의심되는 환자의 혈청에서 면역형광항체검사를 실시함과 동시에 피부 병변 조직에서 혈청형 특이 이중 PCR을 시행하여 신속하고 정확한 진단 및 혈청형의 동정을 위한 임상가검물로서의 적용 가능성을 보고자 하였다. 방법: 1994년 9월부터 11월까지 고려대학교 부속병원에 내원한 환자중 임상 및 면역혈청학적 검사상 쯔쯔가부시병으로 진단된 환자 8명에서 건조 가피 및 홍반성 구진 또는 반점 부위 11개를 조직생검으로 하여 실험에 사용하였다 Karp, Kato, Gilliam, Boryong/Kuroki를 효과적으로 증폭 시키기 위한 혈청형 특이 이중 PCR을 시행하여 혈청형을 분류하고, PCR 산물로 주기적 염기서열 분석법을 실시하여 염기서열의 변이를 관찰하였다. 결과: 1) 총 8명의 환자의 혈청에서 실시한 간접 면역형광항체검사는 비교적 높은 민감도를 보였지만, 1명의 환자에서 발병 2일째 시행한 검사상 음성소견을 보였으며, 면역형광항체 검사로 분류된 혈청형은 비특이적 양상을 보였다. 2) 8명의 환자의 11개 조직병변에서 시행한 PCR은 한가지 혈청형에만 특이한 band를 관찰할 수 있어, 진단과 동시에 혈청형 분류가 가능하였다. 8명중 7명에서 보령/Kuroki에 감염된 것으로 밝혀졌고, 1명이 Karp균주에 감염되어 있음을 확인할 수 있었다. 3) PCR 산물을 확인하는 한편 O. tsutsugamushi의 주단백 항원인 56kDa단백을 전사하는 부분의 염기서열을 분석하기 위하여, PCR산물로 주기적 염기서열 분석법을 시행한 결과, 78개의 보령 균주는 모두 정상 염기서열을 보였고, 1개의 Karp균주는 한 염기의 점돌연변이로 glutamine에서 histidine으로 아미노산 서열의 변이를 보였다. 결론: 쯔즈가무시병의 초기환자에서 피부병변을 이용한 혈청형 특이 이중 PCR법은 혈청형의 동정 및 신속하고 정확한 조기진단법으로 유용하리라 사료된다. Background: For the early diagnosis of tsutsugamushi disease, polymerase, chain reaction(PCR) using skin specimen might be a precise and useful diagnostic tool. The purpose of this study is to detect and identify the serotype of the Orientia tsutsugamushi from the skin lesions of the patients with tsutsugamushi disease by nested PCR. Methods: Nested PCR was used to diagnose tsutsugamushi disease and identify the serotype of the O. tsutsugamushi; Karp, kato, Gilliam or Boryong/Kuroki. The primer sets were derived from serotype-specific DNA sequences encoding the 56kDa antigen of O.tsutsugamushi. The PCR products were analyzed by using direct cyclic sequencing. Results: The serotype-specific DNA bands with 1% agarose gel electrophoresis of amplified DNAs by nested PCR were observed in all 11 skin biopsy specimens from 8 patients with tsutsugamushi disease. Among 8 patients, 7were proved to be infected with Boryong/Kuroki strains and one with Karp. One Karp strain showed one base mutation with amino acid sequence variation, but all the Boryong/ Kuroki strains showed no mutation. Conclusion: We suggest that serotype-specific nested PCR is a simple, rapid and precise diagnostic method, and useful for early diagnosis of tsutsugamushi disease. Furthermore, we might detect the sequence variations of serotype-specific DNA sequences encoding 56 kDa antigen among strains.

유세포분석법으로 조사한 Orientia tsutsugamushi Boryong주의 항균제 감수성

김은실,김미경,이혜명,정문현,이진수,박재은,강재승 대한감염학회 2008 감염과 화학요법 Vol.40 No.4

Background : Scrub typhus, an infectious disease caused by Orientia tsutsugamushi, is endemic in Korea. With the introduction of tetracycline and chloramphenicol in clinical practice, the mortality due to scrub typhus has markedly decreased, In 1995, scrub typhus poorly responsive to doxycycline was reported in Thailand; the need for safe antibiotics for the treatment of scrub typhus acquired during pregnancy or for children is emerging; also, broader spectrum antibiotics having anti-Orientia activity may be preferred for empirical therapy of enteric fever syndrome and for complicated scrub typhus. The anti-Orientia activities of various antibiotics, including recently licensed antibiotics, were investigated by flow cytometry. Materials and Methods : O. tsutsugamushi strain Boryong was inoculated into the ECV304 cell line. The infected cells were stained with FS15, a monoclonal antibody reacting against a linear epitope on 56-kDa major outer membrane protein of 0. tsutsugamushi. Then the antimicrobial susceptibilities were measured by flow cytometry and expressed as a growth index (total mass of Orientia). A concentration at which no further decrease in growth index occurred was defined as the minimal inhibitory concentration (MIC). Microbial susceptibilities to the following antibiotics were measured: quinupristin-dalfopristin (Synercid), levofloxacin, ciprofloxacin, moxifloxacin, metronidazole, linezolid, clindamycin, chloramphenicol, doxycycline, azithromycin, and rifampin. Results : Considering the usual serum concentrations of rifampin (M1C=0.025-0.05 ug/mL), azithromycin (M1C=0.05-0.5 ug/mL) and doxycycline (MIC=0.05-0.1 ug/mL), these antibiotics exhibited very low MICs. Synercid (MIC=0.2-1.0 ug/mL), clindamycin (MIC=1.0 ug/mL) and chloramphenicol (MIC=1-2 ug/mL) exhibited moderately low MICs; moxifloxacin (MIC=8 ug/mL), ciprofloxacin (M1C=25.6 ug/mL or more) and levofloxacin (M1C=30 ug/mL) exhibited relatively high MICs; and cefotaxime (MIC>50 ug/mL), metronidazole (MIC>30 ug/mL) and linezolid (>30 ug/mL) exhibited high MICs. Conclusions : Among the new antibiotics, none was superior to doxycycline, azithromycin or rifampin with respect to anti-Orientia activity. Synercid, clindamycin, and moxifloxacin may show moderate therapeutic efficacies in human.

Lack of Effect of Dexamethasone on Growth of Orientia Tsutsugamushi Gilliam in Mouse L929 Cells

김창오,김준명,허애정,염준섭,이꽃실,진범식,한상훈,정수진,최준용,송영구 연세대학교의과대학 2011 Yonsei medical journal Vol.52 No.4

Purpose: Previous studies and our own clinical experience suggest that concurrent corticosteroid treatment for severe rickettsial disease with multiorgan failure may improve the clinical course or reduce mortality. However, the use of corticosteroids as adjunctive treatment for rickettsial diseases is controversial. We attempted to determine the influences of corticosteroid on the growth of Orientia tsutsugamushi in vitro to justify and evaluate the clinical applicability of corticosteroid in rickettsial disease. Materials and Methods: L929 cells were infected with Orientia tsutsugamushi Gilliam. Dexamethasone was added to the cells at final concentrations of 10^1 and 10^7 pg/mL. Cultures were incubated at 35°C and processed for flow cytometry on the 6th day after addition of dexamethasone. Results: Observation on the 6th day after treatment with dexamethasone in infected cultures revealed that there was no difference in fluorescence intensity among the treatment wells. Treatment of the cells with dexamethasone at concentrations of 10^1 and 10^7 pg/mL showed no influence on the growth of Orientia tsutsugamushi. Conclusion:Our results to show that isolated corticosteroid does not enhance the replication of Orientia tsutsugamushi in vitro. Concurrent use of anti-inflammatory or immunosuppressive doses of corticosteroids in conjunction with antibiotics may not have detrimental effects on the course of scrub typhus.

Orientia tsutsugamushi Infection Induces CD4+ T Cell Activation via Human Dendritic Cell Activity

( Hyuk Chu ),( Sung Moo Park ),( In Su Cheon ),( Mi Yeoun Park ),( Byoung Shik Shim ),( Byoung Cheol Gil ),( Woon Hee Jeung2 ),( Kyu Jam Hwang ),( Ki Duk Song ),( Kee Jong Hong ),( Manki Song ),( Hang 한국미생물 · 생명공학회 2013 Journal of microbiology and biotechnology Vol.23 No.8

Orientia tsutsugamushi, a gram-negative bacterium, causes severe acute febrile illness in humans. Despite this danger, the route of infection, infectivity, and protective mechanisms of the host``s immune response to O. tsutsugamushi are unclear. Dendritic cells (DCs) are one of the most important cell types in bridging the innate and adaptive immune responses. In this study, we observed that O. tsutsugamushi infects and replicates in monocyte-derived DCs (MODCs). During infection and replication, the expressions of the cytokines IL-12 and TNF-α, as well as the co-stimulatory molecules CD80, CD83, CD86, and CD40, were increased in MODCs. When O. tsutsugamushi-treated MODCs were co-cultured with autologous CD4+ T cells, they enhanced production of IFN-γ, a major Th1 cytokine. Collectively, our results show that O. tsutsugamushi can replicate in MODCs and can simultaneously induce MODC maturation and increase proinflammatory cytokine levels in MODCs that subsequently activate CD4+ T cells.

Orientia tsutsugamushi에 감염된 인간 피부 미세혈관 내피세포의 산화 활성

고영상,Koh Young-Sang 한국미생물학회 2005 미생물학회지 Vol.41 No.3

Transcripts levels of superoxide dismutases increase slightly following infection of human dermal microvascular endothelial cells(HMEC-1) by the obligae intracellular bacterium Orientia tsutsugamushi, the causative agent of scrub typhus. In addition, fluorescence-activated cell sorter analysis demonstrates significant intracellular peroxide activity in infected cells within 5 hr after exposure to O. tsutsugamushi. Furthermore, infected cells experienced a significant depletion of glutathiones. These results support hypothesis that cells infected by this intracellular bacterium experience oxidant-mediated injury. 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.

Cholestatic Hepatitis Caused by Tongyeong Strain of Orientia tsutsugamushi

주고운,김미경,김준미,강재승,정문현,길세희 대한감염학회 2009 Infection and Chemotherapy Vol.41 No.2

In Korea, the clinical manifestation of scrub typhus in humans appears to be severe in the northern regions of the country and mild in the southern areas. Studies on the geographic distribution of the serotype of Orientia tsutsugamushi revealed that the Boryong serotype is predominant in the southern Korean peninsula, whereas the Gilliam, Karp, and Gilliam-Karp serotypes prevail in the northern or central peninsula. We report a case of severe scrub typhus caused by the Japanese Gilliam type of Orientia tsutsugamushi in a 66-year-old woman from Tongyeong, a city located in the southern part of Korean peninsula. The patient was admitted to the hospital with fever on August 29th, 2001. Scrub typhus complicated by shock, pneumonitis, and encephalitis was diagnosed. Additionally, markedly elevated alkaline phosphatase levels was observed, which necessitated an ultrasonographic examination, which showed an ill-defined hyperechogenic mass on the right hepatic lobe. Liver biopsy showed cholestatic hepatitis and blood culture showed growth of O. tsutsugamushi. Gene sequencing of the amplicons of a polymerase chain reaction using primers for the amplification of the gene encoding the 56-kDa protein of O. tsutsugamushi revealed a nucleotide sequence that matched Yonchon strain of O. tsutsugamushi.