• 한국임상수의학회지
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• 제23권2호
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• pp.169-174
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• 2006

This work described 3 infection cases caused by Rhodococcus equi in foals between 3 and 5 months of age. The disease histories were not fully taken from local veterinarians. At least 1 sick foal has been treated with cephalothins followed by penicillins during approximately 1 week, but died without effectiveness and other foals rearing with the animal have been suffering from severe pneumonia which show high fever, laboring respiration, cough and/or nasal discharge. There were many abscessations into lungs of 2 foals in postmortem examination and another 1 sample was pus collected from abscess around the shoulder, indicating the osteomyelitis. Those bacteria were grampositive coryneform and were identified as a R. equi by a polymerase chain reaction (PCR) using primers for R. equi-specific vapA gene. The pathogens were usually resistant to penicillin, ampicillin, amoxycillin/clavulanic acid, cefazolin, clindamycin, sulfamethoxazol/trimethoprim, kanamycin, and tetracycline, while were sensitive to ciprofloxacin, norfloxacin, orfloxacin, gentamicin, erythromycin, neomycin, and vancomycin. Some more foals with respiratory symptoms in 1 horse farm were treated by orally administration with erythromycin during 2 weeks. Because the combination of erythromycin and rifampin has recommended as the treatment for R. equi infections in foals, the local equine veterinarian can choose those antibiotics for the treatment of this disease in future. However, another antimicrobial agent may be necessary if R. equi resistant to both agents is isolated.

• 한국동물위생학회지
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• 제36권2호
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• pp.111-119
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• 2013

The aim of this study was to investigate the isolation frequency and antimicrobial resistance of Escherichia coli (E. coli) and Enterococcus spp. from domestic beef and pork on sale in Seoul, Korea. A total of 106 (10.4%) E. coli and 114 (11.2%) Enterococcus spp. from 635 domestic beef and 381 pork samples were isolated and examined for susceptibility to 15 and 11 antimicrobial agents, respectively. The most frequent antimicrobial resistance observed in E. coli isolates was to ampicillin (38.6%), followed by streptocmycin (34.9%) and tetracycline (32.0%). The most frequent antimicrobial resistance in E. faecium isolates was to erythromycin (53.8%) and rifampin (46.1%), and in E. faecalis isolates was to tetracycline (55.7%) and rifampin (55.0%). Among the isolates, multi-drug resistant (MDR) E. coli and Enterococcus spp. strains showing resistances to more than two antimicrobial agents tested were 10.4% and 11.2%, respectively. As a result, appropriate protocols for antimicrobial agents and strategies to reduce antimicrobial resistance will be needed in future.

• Tuberculosis and Respiratory Diseases
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• 제81권1호
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• pp.6-12
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• 2018

The role of the treatment for latent tuberculosis infection (LTBI) has been underscored in the intermediate tuberculosis (TB) burden countries like South Korea. LTBI treatment is recommended only for patients at risk for progression to active TB-those with frequent exposure to active TB cases, and those with clinical risk factors (e.g., immunocompromised patients). Recently revised National Institute for Health and Care Excellence (NICE) guideline recommended that close contacts of individuals with active pulmonary or laryngeal TB, aged between 18 and 65 years, should undergo LTBI treatment. Various regimens for LTBI treatment were recommended in NICE, World Health Organization (WHO), and Centers for Disease Control and Prevention guidelines, and superiority of one recommended regimen over another was not yet established. Traditional 6 to 9 months of isoniazid (6H or 9H) regimen has an advantage of the most abundant evidence for clinical efficacy-60%-90% of estimated protective effect. However, 6H or 9H regimen is related with hepatotoxicity and low compliance. Four months of rifampin regimen is characterized by less hepatotoxicity and better compliance than 9H, but has few evidence of clinical efficacy. Three months of isoniazid plus rifampin was proved equivalence with 6H or 9H regimen in terms of efficacy and safety, which was recommended in NICE and WHO guidelines. The clinical efficacy of isoniazid plus rifapentine once-weekly regimen for 3 months was demonstrated recently, which is not yet introduced into South Korea.

• Tuberculosis and Respiratory Diseases
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• 제85권3호
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• pp.264-272
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• 2022

Background: The current conventional drug susceptibility test (DST) for Mycobacterium tuberculosis (Mtb) takes several weeks of incubation to obtain results. As a rapid method, molecular DST requires only a few days to get the results but does not fully cover the phenotypic resistance. A new rapid method based on the ability of viable Mtb bacilli to hydrolyze fluorescein diacetate to free fluorescein with detection of fluorescent mycobacteria by flow cytometric analysis, was recently developed. Methods: To evaluate this cytometric method, we tested 39 clinical isolates which were susceptible or resistant to isoniazid (INH) or rifampin (RIF), or ethambutol (EMB) by phenotypic or molecular DST methods and compared the results. Results: The susceptibility was determined by measuring the viability rate of Mtb and all the isolates which were tested with INH, RIF, and EMB showed susceptibility results concordant with those by the phenotypic solid and liquid media methods. The isolates having no mutations in the molecular DST but resistance in the conventional phenotypic DST were also resistant in this cytometric method. These results suggest that the flow cytometric DST method is faster than conventional agar phenotypic DST and may complement the results of molecular DST. Conclusion: In conclusion, the cytometric method could provide quick and more accurate information that would help clinicians to choose more effective drugs.

• Tuberculosis and Respiratory Diseases
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• 제44권2호
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• pp.251-263
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• 1997

연구배경 : 다제내성결핵의 증가는 효과적인 결핵 치료를 어렵게 할 뿐만 아니라 결핵관리 사업에 큰 장애로 대두되고 있다. 따라서 다제내성결핵균의 내성획득 기전에 대한 이해와 조기진단 방법의 개발이 시급한 실정이다. 최근 분자생물학의 발달로 결핵균의 유전학적인 검검출방법은 기존 배양검사의 감수성에 필적하는 수준이며, 더 나아가 1차 약제인 INH와 RMP 등의 핵산 수준에서 내성기전에 대한 최근의 연구 결과는 더욱 새롭고 빠른 감수성 검사의 기틀을 마련할 것으로 생각된다. RMP에 대한 M. tuberculosis의 주 내성기전은 RNA polymerase $\beta$subunit (rpoB)의 돌연변이로 보고되고 있다. 방 법 : 본 실험에서 42예의 결핵균 배양검체 (RMP 내성 32예, 감수성 10예)를 선택하여 rpoB 유전자의 돌연변이를 분석하였다. 역교잡법(reverse hybridization)을 이용한 상용화된 INNO-LiPA Line Probe Assay (LiPA)를 이용하여 돌연변이 양상을 검사하고 직접염기서열 방법으로 분석한 결과와 비교하였다. 결 과 : LiPA에서 RMP 감수성균주는 S띠의 발색이 모두 나타났으며, 내성균주는 모두 R띠의 발색이냐 S띠의 소실이 나타나 내성임을 확인할 수 있었다. 내성균주 32예중 22예(68.8%)는 4개의 R띠중 하나의 소실이 있어 바로 돌연변이 양상을 확인할 수 있었으며 R5(S531L)형이 17예(77.3%)로 제일 많았다. LiPA에서 확인되지 않았던 10예는 직접염기서열 분석법으로 내성양상을 검사한 바, 총 11예와 점돌연변이와 1예의 염기결실을 확인하였다. 이중 S522W와 9염기쌍의 결실은 현재까지 보고된 바 없는 처음으로 보고되는 유형의 돌연변이었다. 결 론 : 한국인의 결핵균에서 RMP 내성의 주 기전은 rpoB 유전자의 돌연변이에 의한 RNA polymerase의 구조 변화에 기인하는 것을 알 수 있었고 직접염기서열 결정법으로 그 양상을 확인하였으며, LiPA법이 RMP 내성의 조기진단에 유용하게 이용될 수 있는 것으로 판단되었다.

• Tuberculosis and Respiratory Diseases
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• 제50권1호
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• pp.29-41
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• 2001

결핵환자에 있어 rpoB 유전자 염기서열 돌연변이로 인해 생겨나는 rifampin(RIF)내성은 화학요법치료에서 나타나는 다제내성의 표지자로서 많은 연구가 되어 있으며 rifabutin(RIB)은 이러한 RIF의 내성을 보이는 일부 점돌연변이에 대하여 감성 또는 내성을 보이는 것으로 보고되고 있다. 그러므로 본 연구에서는 mycobacteria rpoB 유전자의 특정 DNA 서열(17 bp)을 고정한 올리고뉴클레오티드 칩을 개발하여 rpoB 유전자의 점돌연변이으로 인한 RIF과 RIB의 감수성을 조사하고자 하였다. 방법 : 사용된 올리고뉴클레오티드 칩은 RIF 내성 프로브 및 RIB 감성 프로브를 포함하도록 고안되었으며, 각각의 돌연변이에 상응하는 야생형 프로브를 동일한 염기서열에서 선정하여 형광 시그날 세기의 직접비교에 의해 보다 정확한 탐지를 가능하게 하였다. 결과 : 15개의 임상 분리체를 검사한 결과 RIF 내성으로 밝혀진 돌연변이중 13개의 임상 분리체에서 RIB 감수성 돌연변이 종류를 판별할 수 있었다. 결론 : 올리고뉴레오티드 칩으로 rpoB 유전자에 대한 점돌연변이 연구는 결핵환자에 대한 RIF과 RIB 약제내성 유무를 판단케 함으로써 효과적인 화학요법치료를 가능케 할 것이며 기존 방법과 비교시 효율 및 재현성이 매우 높다고 판단되었다.

• Tuberculosis and Respiratory Diseases
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• 제74권6호
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• pp.251-255
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• 2013

Tuberculosis (TB) is one of the largest health problems in the world today. And the incidence of nontuberculous mycobacteria (NTM) lung disease appears to be increasing worldwide. Recently, an automated, nucleic acid amplification assay for the rapid detection of both Mycobacterium tuberculosis and rifampin resistance was developed (Xpert MTB/RIF). And fixed-dose combinations of anti-TB drugs and linezolid have been introduced in the treatment of TB. And new NTM species, named Mycobacterium massiliense, which is very closely related to Mycobacterium abscessus was reported. In this review, these recent advances in the diagnosis and treatment of TB and clinical characteristics of M. massiliense lung disease are discussed.

• Tuberculosis and Respiratory Diseases
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• 제72권2호
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• pp.173-176
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• 2012

We report a rare case of lung disease caused by Mycobacterium terrae in a previously healthy woman. A 45-year-old woman was referred to our hospital due to a chronic cough with sputum. A computed tomography scan of the chest revealed bronchiolitis in conjuction with bronchiectasis in both lungs. Nontuberculous mycobacteria were identified and isolated from the bronchoalveolar lavage fluid collected from each lung. All isolates were identified as M. terrae by various molecular methods that characterized the rpoB and hsp65 gene sequences. Antibiotic therapy using clarithromycin, rifampin, and ethambutol improved the patient's condition and successfully resulted in sputum conversion.

• 대한수의학회지
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• 제48권2호
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• pp.139-143
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• 2008

We report here two cases of Rhodococcus (R.) equi-causing pneumonia of Throughbred foals in Gyeonggi-do in 2006. R. equi was isolated from the lung lesions of the dead foals, and from the feces and soils on the farms where the clinical cases of R. equi infection occurred. The isolates were characterized by biochemical properties, polymerase chain reaction for vapA gene and antimicrobial susceptibility. In drug susceptibility test, erythromycin, gentamycin, vancomycin, and rifampin were found to be the most susceptible for all isolates. These results suggest that R. equi pneumonia may be endemic in the horse-breeding farms in inland Korea and the farm environment may be widely contaminated with virulent R. equi.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2003년도 하계학술대회 논문집 D
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• pp.2809-2811
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• 2003

Biochip-based diagnostic technology is an effective, time- and money-saving way of identifying Rifampin and Isoniazid resistant tuberculosis strains. In this paper, we suggest the optical system which is designed with the simple structure and has an appropriate specification for biochip analyzer including a CCD camera system. It consists of two parts with the same structure but opposite direction. each part is made by one lens, achromatic doublet and meniscus. We changed the working distance of the optical system and observed its characteristics.