• 대한의생명과학회지
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• 제27권4호
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• pp.195-207
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• 2021

Methicillin-resistant Staphylococcus aureus (MRSA) is a bacterial pathogen capable of causing human diseases, such as soft tissue infection, bacteremia, endocarditis, toxic shock syndrome, pneumonia, and sepsis. Although the incidence rate of diseases caused by MRSA has declined in recent years, these diseases still pose a clinical threat due to their consistently high morbidity and mortality rates. However, the role of virulence factors in staphylococcal infections remains incompletely understood. Methicillin resistance, which confers resistance to all β-lactam antibiotics in cellular islets, is mediated by the mecA gene in the staphylococcal cassette chromosome mec (SCCmec). Differences in SCCmec types and differences in their sizes and structures serve epidemiological purposes and are used to differentiate between hospital-associated (HA)-MRSA and community-associated (CA)-MRSA. Some virulence factors of S. aureus are also providing a distinction between HA-MRSA and CA-MRSA. These factors vary depending on the presence of toxins, adhesion, immune evasion, and other virulence determinants. In this review, we summarized an overview of MRSA such as resistance mechanisms, SCCmec types, HA- and CA-MRSA, and virulence factors that enhance pathogenicity or MRSA epidemiology, transmission, and genetic diversity.

• 한국응용약물학회:학술대회논문집
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• 한국응용약물학회 1996년도 춘계학술대회
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• pp.186-186
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• 1996

Streptococcus pneumoniae (pneumococcus), the most common cause of bacterial pneumonia, has an ample polysaccharide(PS) capsule that is highly antigenic and is the source of PS vaccine. This investigation was undertaken to optimize the culture conditions for the production of capsular PS by type 1 pneumococcus. Among several culture media, brain heart infusion (BHI) and Casitone based media were found to support luxuriant growth of pneumococcus type 1 at the same level. Because BHI medium is rather expensive and more complex than the Casitone based media, the Casitone based media was used to study optimization of the culture condition. The phase of growth which accomodated maximum PS production was logarithmic phase. Concentrations of glucose greater than 0.2% did not enhance growth or PS production. Substitution of nitrogen sources with other resources or supplemention of various concentrations of metal ion (with the exception of calcium ion) had adverse effects on growth and PS production. On the other hand, low level aeration was beneficial for increased PS production. Addition of 3 mg/I concentration of methionine, phenylalanine, and threonine were found to enhance growth and PS production. The synergistic effect of all the favorable conditions observed in pneumococcal growth assays provided a two-fold cumulative increase in capsular PS production.

• Clinical and Experimental Pediatrics
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• 제48권11호
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• pp.1193-1200
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• 2005

목 적 : 침습성 세균 감염은 소아 연령에서 가장 중요한 질환중의 하나로 이환 및 사망의 주요한 원인이다. 연구자들은 면역학적으로 이상이 발견되지 않은 환아들을 대상으로 침습성 감염의 원인균, 임상 진단 및 연령별 분포를 분석하여 향후의 임상진료에 도움이 되도록 하였다. 방 법 : 1996년 8월부터 2004년 12월까지의 기간동안 서울대학교 어린이병원을 방문하여, 침습성 감염으로 진단받았던 환아들을 대상으로 하였다. 면역학적으로 이상이 있거나, 감염에 취약한 기저 질환, 병원 감염이 있는 환아들은 제외하였다. 최종적으로 총 98례의 침습성 감염을 후향적인 의무기록 분석을 통하여 연령, 임상 진단, 원인균 및 치료 결과를 분석하였다. 결 과 : 침습성 감염의 원인균으로 황색 포도상구균, 폐구균이 각각 33례씩으로 전체 증례의 67%를 차지하였다. B군 연쇄상구균이 8례(8%)로 3번째로 많은 증례를 보였고, A군 연쇄상구균이 5례(5%), 인플루엔자균이 4례(4%), 살모넬라균종이 4례(4%), 대장균이 3례(3%)를 차지하였다. 연령대별로 생후 3개월 미만 환아의 연령군에서는 B군 연쇄상구균이 8례(38%)로 가장 많았다. 3개월에서 4세까지의 연령군에서는 폐구균이 28례(54%), 황색 포도상구균이 10례(20%)가 주요 원인균이었다. 5세에서 15세 미만 사이의 연령군에서는 황색 포도상구균이 19례(73%)로 대부분을 차지하였고, 폐구균이 4례(15%)로 그 뒤를 이었다. 전체 침습성 감염 98례 중 균혈증이 26례로 가장 많았다. 균혈증의 원인균으로는 폐구균이 11례(42%)였고, A군 연쇄상구균 4례, 살모넬라균종 3례였다. 수막염은 22례였고, 원인균으로는 폐구균이 11례로 전체 증례 중 50%였다. 폐렴은 총 13례가 있었는데, 폐구균이 9례(69%)를 차지하였다. 세균성 관절염은 19례중 황색포도상구균이 13례(68%)를 차지하였고, 골수염은 12례 모두에서 황색 포도상구균이 원인균이었다. 폐구균 감염 33례 중에서는 균혈증과 수막염이 각각 11례(33%), 폐렴이 9례(27%)를 차지하였다. 황색 포도상구균 감염에서는 세균성 관절염 13례(39%), 골수염이 12례(36%)였다. B군 연쇄상구균 감염은 모든 증례가 3개월 미만이었는데, 뇌수막염과 균혈증이 대부분이었다. 인플루엔자균은 모두 4례였는데, 뇌수막염이 3례를 차지하였다. 총 8례가 사망했고, 사망률은 8.1%였다. 사망한 증례는 뇌수막염이 4례였고, 국소 병소 없는 균혈증이 3례, 뇌농양이 1례였다. 결 론 : 1996년부터 2004년까지의 서울대학교병원에서의 15세 미만 환아의 침습성 감염 양상을 분석한 결과 폐구균과 황색 포도상구균에 의한 감염이 높았다. 인플루엔자균과 살모넬라균에 의한 침습성 감염은 그 빈도가 이전의 10년간에 비해 현저히 감소하였다. 어린 영아에서는 B군 연쇄상구균이 가장 중요한 균주였으며, A군 연쇄상구균에 의한 감염도 나이가 어린 군에서 많은 증례를 보였다. 이 같은 추세를 아는 것이 앞으로의 임상의들에게 적절한 초기 항생제의 선택에 도움이 될 수가 있을 것이다.

• 한국작물학회지
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• 제60권2호
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• pp.239-247
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• 2015

This experiment was conducted to obtain the have higher contents of pharmaceutical constituents as well as higher yield from colchicine induced diploid and tetraploid extracts of Platycodon grandiflorum. In order to determine the biological activity, this study was focused to evaluate the cytotoxicity, antimicrobial on the bronthus disease bacteria, antioxidant enzyme activity of diploid and tetraploid extracts in P. grandiflorum. The activities of antioxidant enzyme according to different solvent extracts were measured as superoxide dismutase (SOD), catalase (CAT), peroxidase (POD), and ascorbate peroxidase (APX). The cytotoxicity of methanol extracts of P. grandiflorum showed significant differences between tetraploid and diploid. That is, the cytotoxic effect against human cancer cell was higher in tetraploid than in diploid. At all extracts concentration, tetraploid samples showed high toxicity and the $IC_{50}$ (concentration causing 50% cell death) value showed the highest on HCT-116 cell ($105.91{\mu}g/mL$), and exhibited significant activity against the Hep 3B cell ($140.67{\mu}g/mL$), SNU-1066 cell ($154.01{\mu}g/mL$), Hela cell ($158.37{\mu}g/mL$), SNU-601 cell ($182.67{\mu}g/mL$), Calu-6 cell ($190.42{\mu}g/mL$), MCF-7 cell ($510.19{\mu}g/mL$). Antimicrobial activities of diploid P. grandiflorum were relatively low compared to tetraploid P. grandiflorum on most of the bacterial strains. In tetraploid P. grandiflorum, K. pneumoniae showed the clear zone formation (18~19 mm) of growth inhibition, followed by the clear zone formation of 13~15 mm on C. diphtheria and S. pyogenes. The antimicrobial activities in diploid P. grandiflorum were the highest on K. pneumonia (14~15 mm), and showed the clear zone formation of 11~12 mm on C. diphtheria and 12~13 mm on S. pyogenes. The antimicrobial activity is thought to look different depending on the bacterial strains and the polyploidy of P. grandiflorum. The root extract of P. grandiflorum had the highest (97.2%) SOD enzyme activity in ethyl acetate partition layer of tetraploid while water partition layer of diploid showed the lowest (48.6%) SOD enzyme activity. The activity of CAT showed higher values in the root of tetraploid than in the diploid of P. grandiflorum in all partition layers except butyl alcohol. The activities of APX and POD showed higher values in the root of tetraploid than in the diploid of P. grandiflorum in all fraction solvents except water layer. These results indicate that the tetraploid P. grandiflorum can be used as a source for developing cytotoxic agent and antimicrobials which can act against bronchus diseases bacterial strains.

• Journal of Microbiology and Biotechnology
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• 제27권8호
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• pp.1529-1538
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• 2017

Klebsiella pneumoniae is an opportunistic and clinically significant emerging pathogen. We investigated the relative roles of Toll-like receptor (TLR) 2 and TLR4 in initiating host defenses against K. pneumoniae. TLR2 knockout (KO), TLR4 KO, TLR2/4 double KO (DKO), and wild-type (WT) mice were inoculated with K. pneumoniae. Mice in each group were sacrificed after either 12 or 24h, and the lungs, liver, and blood were harvested to enumerate bacterial colony-forming units (CFU). Cytokine and chemokine levels were analyzed using enzyme-linked immunosorbent assay and real-time PCR, and pneumonia severity was determined by histopathological analysis. Survival was significantly shortened in TLR4 KO and TLR2/4 DKO mice compared with that of WT mice after infection with $5{\times}10^3CFU$. TLR2 KO mice were more susceptible to infection than WT mice after exposure to a higher infectious dose. Bacterial burdens in the lungs and liver were significantly higher in TLR2/4 DKO mice than in WT mice. Serum $TNF-{\alpha}$, MCP-1, MIP-2, and nitric oxide levels were significantly decreased in TLR2/4 DKO mice relative to those in WT mice, and TLR2/4 DKO mice showed significantly decreased levels of $TNF-{\alpha}$, IL-6, MCP-1, and inducible nitric oxide synthase mRNA in the lung compared with those in WT mice. Collectively, these data indicate that TLR2/4 DKO mice were more susceptible to K. pneumoniae infection than single TLR2 KO and TLR4 KO mice. These results suggest that TLR2 and TLR4 play cooperative roles in lung innate immune responses and bacterial dissemination, resulting in systemic inflammation during K. pneumoniae infection.

• Neonatal Medicine
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• 제15권1호
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• pp.61-66
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• 2008

목 적 : 본 연구는 발열로 입원한 신생아 중 임상 경과가 불량했던 환자의 특징을 조사하고 입원 후 경과가 양호했던 환자와의 임상증상, 이학적 진찰 소견과 검사 결과를 비교하여 중증 감염의 가능성을 예측하는 척도로 이용할 수 있는지 평가하였다. 방 법 : 2000년부터 2006년까지 입원한 30일 이하의 만삭아 중 액와 체온으로 38$^{\circ}C$ 이상의 발열을 보인 123명을 대상으로 하였다. 산전 위험요인이 있었거나 선천성 기형아, 병원을 방문하기 전까지 항생제를 투여받거나 원내 감염이 의심되는 경우는 제외하였다. 입원기록을 후향적으로 검토하여 진단명과 임상경과를 기준으로 고위험군과 저위험군으로 분류하고 두 군 간에 증상, 진찰 소견 및 검사 결과를 비교하였다. 결 과 : 고위험군에는 30명(24.4%)이 포함되었고 진단명을 빈도순으로 나열하면 무균성 수막염, 요로감염, 세균성 수막염, 감염성 장염, 파종성 혈관내 응고장애를 동반한 패혈증, 균혈증, 폐렴, 연조직 감염, 제대 감염순이었다. 총 백혈구 수의 증가와 혈소판 감소증은 두군 간에 통계적으로 유의한 차이를 보였으나 C-반응 단백은 그렇지 않았다. 경련, 끙끙거림, 맥박수, 입원 전까지의 발열 일수, 총 발열 기간 및 입원시까지의 최고체온은 고위험군과 저위험군 사이에서 차이가 있었다. 결 론 : 본 저자들은 이전의 보고와 달리 배양검사 양성인 경우 외에도 임상적으로 명확한 패혈증이나 무균성 수막염 환자 등을 고위험군으로 포함시켰다. 그러나 이런 대상 선정의 차이에도 불구하고 두 군은 백혈구의 수의 증가, 혈소판 감소증 및 활력징후의 이상에서 유의한 차이를 보였다.

• 대한임상검사과학회지
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• 제53권3호
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• pp.225-232
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• 2021

본 연구는 인천지역에 위치한 단일기관의 비결핵항산균의 분포 및 항균제 내성률과 동반 세균 빈도를 조사한 것으로, 2015년부터 2020년까지 TB/NTM real-time PCR 검사가 의뢰된 8,258건의 환자 데이터를 후향적으로 검토하였다. 총 296건의 검체가 NTM 양성이었고, 발생률은 2015년 2.5% (30/1,209)에서 2020년 3.8% (66/1,740)로 증가하였다. NTM으로 확인된 296건 중, 54.7% (162/296)는 M. avium complex (MAC)에 속하는 균종으로 확인되었고, 그다음으로 M. abscessus complex (MABC) 20.9% (62/296), M. fortuitum 6.4%(19/296) 및 M. flavescens 3.4% (10/296) 순이었다. NTM 양성 검체 중, 약제내성검사가 의뢰된 검체는 76.7% (227/296)였다. 다제내성 NTM은 40.1% (91/227)였고, 광범위 내성 NTM은 59.9% (136/227)였다. NTM과 동시 감염은 43.4% (63/145)이었고 가장 흔한 균종은 Klebsiella pneumonia (23.8%, 15/63)였다. 본 연구는 인천지역의 NTM 분포 및 항균제 내성률과 동반 세균 빈도에 관한 최초 보고이다. NTM 감염의 비율은 점차적으로 증가하는 추세이며 효과적인 관리를 위해 적극적인 진료와 철저한 감염관리가 필요할 것이다.

• 대한한방소아과학회지
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• 제12권1호
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• pp.111-131
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• 1998

1. In oriental medicine, the case of sinusitis can be explained, not only external invasion such as PUNG HAN(wind-cold), PUNG YUL(wind-hot), SHUP YUL(damp-heat), but also functional disorder of internal organ such as spleen(脾), lung(肺), kidney(腎) The western medicine classified the cause of sinusitis as two factors. That is bacterial infection factor-Haemophilus influenza, streptococcus pyogeues, streptococcus pneumonia- and viral infection factor-Rhinovirus, parainfluenza, Echo28, Coxsacki21, Sinusitis is complicated to allergic rhinitis, chronic otitis media purulent, chronic tonsilitis, sinubronchitis. On the condition of nasal septum deformity, turbinates deformity, nasal septum deviation, sinusitis can be developed. the predisposing factors of sinusitis is swimming, air pollution, malnutrition, shortage of immunity.2. According to survey, sinusitis occurred that children from 4 to 12 years old and from 5 to 7 years old occupied 70% 3. From the past history data, they experienced chronic tonsillar hypertropy(20%), otitis media, atopic dermatitis, allergic rhinitis, bronchial asthma, pneumonia, bronchiolitis, chronic sore throat, urticaria, milk allergy in sequence. 4. the symptoms of sinusitis is nasal obstruction, postnasal dripping, purulunt(yellow)or white discharge, cough, nose bleeding in sequence. nasal obstruction take the portion of 95%, postnasal dripping 65%, night time or early morning cough 60%. 5. The suffering period of sinusitis is 6 month minimum, 4 years maximum, most cases are included in a year. The suffering period of children was shorter than adult. 6. Diagnosis depend on inspection of nasal cavity, postnasal dripping, X-ray finding. 75% of patient(15case) showed both maxillary sinusitis, 25%(5cases) showed left or right maxillary sinusitis. 7. Treatment of oriental medicine, consist of Herb-medicine, acupuncture and exposing of Lazer beam. Kamihyunggyeyungyotang(加味荊芥蓮翹湯) is administered mainly as the medical therapy, Kamigwaghyangjeungkisan(加味藿香正氣散) Kimizwakwieum(加味左歸飮), Kamihyangsosan(加味香蘇散) is administered for a additional symptoms which occurred by influenza recurrence. Kamijeonxibackchulsan(加味錢氏白朮散) is administered to treat gastro-intestine trouble patients who have sinusitis. 8. The period of treatment is varied with patient conditions and X-ray finding. The minimal period is 35days, maximal period is 202days. So it took about 86days in average and about 50% of patient(10cases) is recovered in one or two month.

• 한국동물위생학회지
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• 제42권4호
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• pp.201-216
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• 2019

Porcine reproductive and respiratory syndrome (PRRS) is characterized by reproductive failure in sows and respiratory distress in all age pigs. Porcine respiratory disease complex (PRDC) is a disease caused by opportunistic bacterial infection secondary to a weakened immune system by a preceding respiratory infection. In this study, we tried to compare the immune responses in PRRS and PRDC groups to clearly characterize the disease severity. Eighty-five pigs were infected with various Korean field PRRS virus strains. Infected animals were classified into PRRS (n=32) and PRDC (n=53) groups based on lung lesions such as interstitial pneumonia, suppurative pneumonia, and pleuropneumonia. The immune cell population of bronchoalveolar lavage cells (BALc) was evaluated on 14 and 28 days post infection (dpi) and PMBC cytokine expression was measured on 0, 3, 7, 14 dpi to investigate early inflammatory reactions. Pulmonary lesion severity was negatively correlated with alveolar macrophage (AM) in both PRRS and PRDC groups on 14 and 28 dpi. AM in BALc was less populated in PRDC group on 28 dpi compared to PRRS group. AM in BALc was significantly less populated in PRDC group on 28 dpi compared to 14 dpi. In addition, cytotoxic T lymphocyte (CTL) in BALc was higher populated in PRDC group on 14 dpi and 28 dpi compared to PRRS group. In the case of PBMC cytokine TNF-α, IFN-α, IL-1β, IFN-γ, FoxP3, and IL-2, the PRRS group showed higher expression than the PRDC group on 7 dpi, 14 dpi, 7 dpi, 14 dpi, 14 dpi, and 14 dpi, respectively. On the other hand, in the case of IFN-β, IL-6, IL-8, IL-4, and IL-17, the PRDC group showed higher PBMC cytokine expression at 14 dpi, 7 dpi, 14 dpi, 3 dpi, and 3 dpi, respectively, than the PRRS group. Based on these results, our study could characterize differential immune responses in pigs with PRRS or PRDC.

• 한국동물위생학회지
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• 제42권1호
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• pp.39-42
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• 2019

Tetanus is an acute, often fatal, and infectious disease of all species of domestic animals caused by the neurotoxin of Clostridium tetani (C. tetani). This disease is usually known to develop after microbial contamination in the deep or penetrating wound sites. In February 2017, a farmer who was raising 76 cows injected foot and mouth disease vaccine to three or more cows with one syringe. Their clinical symptoms were observed 2 to 16 days after the vaccination. The initial symptoms were stiffness, rigidity of the neck and limbs, pricked ears, and prolapse of the third eyelid. Subsequently, there was recumbency with extension of the limbs, convulsions and opistotonus and the affected 20 cows were all died. Two dead cows were submitted to Animal and Plant Quarantine Agency for disease diagnosis. At necropsy, a focal edematous abscess of 15 to 20 cm in diameter was grossly observed in the subcutaneous and intramuscular tissue of scapular region and filled with a large amount of greenish pus. The feed was full in oral cavity and slightly observed in the trachea and lobes of lung. Histopathologically, focal granulomatous nodules with eosinophilic materials in the tissue were observed. In the lung, aspiration pneumonia and gram (+) bacteria were seen. The C. tetani was isolated in samples anaerobically cultured using reinforced clostridial medium and identified by PCR. To our knowledge, no previous outbreak of tetanus in cattle has affected such a high number of animals; neither has it been associated with misuse of the same syringe and needle to administer multiple individuals.