• Journal of Microbiology and Biotechnology
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• 제23권5호
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• pp.731-737
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• 2013

Seventy-four Shiga toxin-producing Escherichia coli (STEC) isolates belonging to the serotype O91:H21 were isolated from 1,643 asymptomatic human carriers in a STEC outbreak at Gwangju in Korea. Although the isolates did not cause any symptoms, all of them produced Shiga toxins 1 (Stx1) and 2 (Stx2). In order to determine why these strains cause no symptoms, we explored the differences in virulence potential between the asymptomatic STEC O91:H21 isolates and symptomatic STEC O91:H21 strains (ATCC 51435 and ATCC 51434). The asymptomatic STEC O91:H21 isolates showed strongly reduced cytopathic effects compared with the symptomatic strains when intact bacterial cells were used as an inoculant. Moreover, we found a reduced adherence phenotype when testing asymptomatic strains on HeLa cells. Real-time quantitative PCR results suggest that transcriptional repression of the genes encoding type-1 fimbriae occurs in the asymptomatic isolates but not in the symptomatic strains.

• Pediatric Infection and Vaccine
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• 제5권2호
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• pp.215-220
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• 1998

목 적 : A군 연쇄구균 무증상 감염자는 증상은 없지만 A군 연쇄구균이 분리되고 ASO(antistreptolysin O)치가 높은 사람으로서 이들은 류마티스열이나 사구체신염 등 후유증을 일으킬 수 있다. 저자들은 무증상 감염자를 대상으로 경구용 페니실린을 복용하게 하여 이들에서 페니실린 치료 효과를 조사하였다. 방 법 : 상기도 감염 증상이 없는 건강한 초등 학생들을 대상으로 인두배양과 ASO치를 정량적으로 측정하였다. A군 연쇄구균이 분리되고 ASO 치가 400IU/mL 이상인 아동 36명을 대상으로 하여 그 중 22명의 학생은 경구용 페니실린 제제(penicillin V, 500mg. 하루 2회)를 10일간 복용하게 하였고, 14명은 대조군으로 삼고 항생제를 복용하지 않았다. 한달 후 두 그둡 아동에서 동시에 인두배양을 시행하여 A군 연쇄구균 제거율을 비교하고 ASO치를 측정하여 농도 변화를 관찰하였다. 결 과 : 항생제를 복용한 그룹과 복용하지 않은 그음의 A군 연쇄구균 제거율은 각각 91%(20/22)와 50%(7/14)로서 항생제를 사용한 그룹에서 유의하게 높았다(P<0.05). 항생제를 사용한 그룹과 사용하지 않은 그룹에서 ASO치가 100IU/mL 이상 상승한 경우는 각각 22%(4/18)와 30%(3/10)이었고 200IU/mL이상 감소한 경우는 각각 44.4%(8/18)와 40%(4/10)로서 유의한 차이가 없었다. 결 론 : 무증상 감염자를 대상으로 페니실린을 투여했을 때 인두에서 균이 효과적으로 제거되어 페니실린 치료의 타당성을 확인하였다. 그러나 ASO치 감소는 두 그룹간에 유의한 차이가 없었는데, 이는 ASO의 반감기가 걸고 경구용 페니실린의 경우 순응도가 낮기 때문으로 사료된다. 항생제 치료에도 불구하고 ASO치가 상승한 것을 치료 실패로 판정할 때 22%의 치료 실패율을 보였다.

• Parasites, Hosts and Diseases
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• 제57권3호
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• pp.233-242
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• 2019

Detailed description of malaria in low transmission areas is crucial for elimination. The current study aimed to provide a comprehensive description for malaria transmission in Jazan, a low transmission district, southwestern Saudi Arabia. Patients at a tertiary care hospital were recruited in our study between August 2016 and September 2018. Malaria diagnosis was performed through a species-specific nested polymerase chain reaction (nested PCR), microscopy and Paramax-$3^{TM}$ rapid detection test (RDT). Malaria was detected in 30 patients by the PCR, with point prevalence of 10.9%. Of these malaria infections, 80% was imported, 26.6% was asymptomatic and 23.3% was sub-microscopic. Malaria was reported throughout the year, with February/March and September/October peaks. Infection was significantly more in males than in females (P=0.01). Likewise, infections were detected more in febrile than in non-febrile patients (P=0.01). Adult aged 15-24 years, fever and travel were identified as high-risk factors. Malaria was primarily attributed to Plasmodium falciparum mono-infections, followed by P. vivax mono-infections and lastly to falciparum/vivax mixed infections accounting 76.6%, 16.6%, and 6.6% of PCR-confirmed malaria cases, respectively. The nested PCR was superior to the smear microscopy (sensitivity 76.6%; specificity 100%) and the RDT (sensitivity 83.3%, specificity 94.2%). The overall percent agreement between microscopy and the RDT was 92.7% (kappa=0.63). High proportion of imported malaria including sub-microscopic and sub-patent cases were described. We suggest that incorporation of molecular tool into the conventional malaria diagnosis is beneficial in Jazan district.

• Restorative Dentistry and Endodontics
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• 제36권6호
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• pp.498-505
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• 2011

연구목적: 본 연구는 원발성 치근단 치주염(primary apical periodontitis)을 갖는 치아에서 임상증상 유무에 따른 미생물 군집의 차이를 GS FLX Titanium pyrosequencing을 이용하여 species level까지 분석하였다. 연구 재료 및 방법: 원발성 치근단 치주염을 갖는 6개의 표본에서 pysequencing을 시행하였다. 중합효소 연쇄반응(PCR)에 의해 얻어진 small-subunit ribosomal RNA의 초가변 영역(hypervariable region)의 amplicon을 이용하여 GS FLX Titanium pyrosequencing 을 시행하였다. 결과: 평균적으로 무증상군 및 증상군에서 각각 10,639 및 45,455개의 16S rRNA sequence을 얻었으며 평균길이는 440bases였다. Ribosomal Database Project Classifier을 이용한 분석결과 142종의 genera 및 13종의 phylum 수준에서의 세균종을 검출하였다. 검출된 13개의 phyla 가운데 Actinobacteria, Bacteroidetes, Firmicutes, Fusobacteria, Proteobacteria, Spirochetes, and Synergistetes 종이 상대적으로 호발하였으며, genus 수준에서는 Pyramidobacter, Streptococcus, Leptotrichia이 무증상의 근관의 50%를 차지하였으며, Neisseria, Propionibacterium, Tessaracoccus 균종은 증상이 있는 근관의 69%를 차지하였다. Operational taxonomic units (3%)로 나눈 결과 증상이 없는 치아에서 450개, 증상이 있는 치아에서 1,997개의 species가 발견되었다. 증상이 있는 치아에서 통계적으로 유의성 있게 많은 수의 세균이 검출되었다(p < 0.05). 결론: GS FLX Titanium Pyrosequencing 기법을 통해 원발성 감염근관에서 이전에 검출하지 못했던 다양한 근관내 분포세균을 검출할 수 있었다.

• Pediatric Infection and Vaccine
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• 제24권2호
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• pp.108-111
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• 2017

영아에서의 결핵은 소아나 성인의 결핵에 비해 더 심한 증상과 합병증을 초래할 수 있다. 하지만 증상이 전형적이지 않거나 균 검출이 잘 되지 않는 경우가 많아 진단에 어려움이 있다. 본 증례는 폐결핵으로 진단된 3개월 환아에 대한 보고이다. 환아는 광범위한 양측 폐의 병변에도 불구하고 발열이나 호흡곤란, 기침 등의 증상을 보이지 않았으며 항결핵제 투약 6개월째 폐병변이 호전되었다. 일부 영아 결핵에서 증상이 나타나지 않는 것은 면역반응의 미성숙으로 부분적으로 설명될 수 있을 것이다. 따라서 영아에서 결핵 접촉자 검진의 중요성이 강조된다.

• 한국어병학회지
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• 제23권1호
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• pp.17-25
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• 2010

We have identified an iridovirus CH-1 from sea perch Lateolabrax sp. healthy externally and imported from China to Korea. In a comparison of the nucleotide sequences of the five different genomic regions, the CH-1 appears to be closely related to the ISKNV, IVS-1 and Ehime-1 strains detected in China, Korea and Japan respectively. In quantitative comparison of the viral DNA, level of CH-1 in tissue of imported fish was 10,000 times lower than that of IVS-1 strain presented in the infected rock bream Oplegnathus fasciatus of moribund stage. It allowed us to speculate the possibility of the asymtomatic iridovirus infection in the culturing sea perch. Such possibility of asymptomatic infection was supported by result of no appearance of dead fish with typical symptoms of iridoviral disease in keeping experiment of the imported sea pearch in laboratory for more than three weeks. Such asymptomatic infections with iridovirus were also found in spleen of the culturing and externally healthy sea perch of Korea by the presence of the iridoviral DNA in nested PCR.

• Childhood Kidney Diseases
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• 제28권2호
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• pp.59-65
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• 2024

Hydronephrosis, characterized by dilation of the renal pelvis and calyces due to urine flow obstruction, poses a significant clinical challenge. Although often asymptomatic and capable of spontaneous resolution, surgical intervention is necessary for specific scenarios such as febrile urinary tract infections, deteriorating hydronephrosis, or declining renal function. The efficacy of continuous antibiotic prophylaxis in preventing urinary tract infections remains controversial. Yet, it may benefit high-risk patients, emphasizing the importance of individualized patient selection, as surgical treatment methods for patients with hydronephrosis have become less invasive than in previous decades. However, long-term follow-up outcomes are lacking, necessitating further clarification. This review presents an overview of the etiology, natural progression, and modern management of hydronephrosis, encompassing advancements in minimally invasive procedures.

• 한국미생물·생명공학회지
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• 제17권6호
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• pp.634-644
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• 1989

Listeria monocytogenes, one of five species in the genus Listeria and the only one currently believed to be pathogenic for humans, is a small gram-positive, nonsporeforming, aerobic, motile and hemolytic rod-shaped bacterium. The bacterium is widespread in the environment, having been isolated from soil, dust, animal feed, water, sewage, almost every type of animal that has been cultured, and asymptomatic humans. L. monocytogenes causes listeriosis, a disease which most often affects humans with a compromised immune system. Included are pregnant woman, infants and adults suffering from such diseases as cancer, cirrhosis of liver or AIDS or are being treated with drugs such as corticosteroids. Listeriosis is manifested by such syndromes as pregnancy infections, granulomatosis infantiseptica, sepsis, meningoencephalitis, and focal infections. Infections, can be treated successfully with penicillin, ampicillin, or erythromycin. However, a mortality rate of about 30％ has occurred in outbreaks of listeriosis. Food-associated outbreaks of listeriosis have been attributed to coleslaw (Canada, 1981), pasteurized milk (U.S., 1983), and soft cheese (U.S., 1985). Presence of L. monocytogenes in various dairy foods has prompted recall of such products from the U.S. market-place. L. monocytogenes also has been found in raw meats and seafood.

• Journal of Medicine and Life Science
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• 제17권1호
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• pp.29-32
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• 2020

As respiratory syncytial virus(RSV) is transmitted either via directly contact with an infected case or via indirectly contaminated fomites or skin, the major preventive measures are strict hand hygiene, early detection of transmitted sources, and rapid isolation of RSV patients. Especially early detection of hidden cases is the most critical control measure when an index case was notified in a postpartum center. The Guideline of Korea Centers for Diseases Control and Prevention defines potential contacts in an epidemiologic survey as admitted newborns, parents of index cases, center's workers, and visitors for 10 days before the first diagnosis day of index case. However, it needs to classify potential contacts in more detail in order to conduct a successful survey. Authors conducted to search related literatures and appraise the evidences. Firstly, potential contacts would be classified into RSV-related symptomatic contacts(SxC) and asymptomatic contacts. And then, mother, caring workers, and visitors of the index cases among asymptomatic contacts would be defined as the asymptomatic close contacts(ASCC). Finally, the rest would be defined as the asymptomatic regular contacts(ASRC). The defined test using reverse transcription-PCR is applied to SxC and ASCC, and decision of isolation or regular activities are made according to the results. The rapid antigen detection test kits are applied to ASRC. These suggestions might be helpful to detect hidden cases earlier and prevent a further infection.

• 대한한의학회지
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• 제42권1호
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• pp.99-109
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• 2021

Objectives: Objective: The purpose of this study is to investigate the treatment of herbal medicine for patients with COVID-19 asymptomatic infections. Method: In English, search engines such as 'PubMed', 'Science Direct', and 'Cumulative Index to Nursing and Allied Health Literature (CINAHL)' were used. In Chinese, search engines such as 'China National Knowledge Infrastructure (CNKI)' and Wanfang were used. The keywords for the search engines were 'COVID-19', 'asymptomatic infection', 'Korean Medicine', 'traditional Chinese medicine', 'herbal medicine', and etc. Only clinical studies using herbal medicine for patients without fever or respiratory symptoms were selected. We excluded the cases that do not fit the research topic. Results: A total of 5 studies were finally selected. Among them, four of them used integrated herbal medicine and Western medicine, and one of the studies treated exclusively for herbal medicine. There were a total of seven prescriptions for herbal medicine used in the study. Outcome variables were used as following: lab test, nucleic acid conversion time, hospitalization period, chest CT, and etc. In the RCT study, herbal medicine and Western medicine decreased nucleic acid conversion time, average hospitalization time compared to the control group, but it was not statistically significant. No other adverse reactions were reported in all studies. Conclusion: According to the results, integrated herbal medicine and Western medicine might be an effective treatment for patients with COVID-19 asymptomatic infection reducing hospitalization period, time of nucleic acid turning negative. No severe adverse effects were reported. However, it is thought that better-designed research will be needed in the future.