• Mycobiology
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• 제30권1호
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• pp.18-21
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• 2002

Four arbuscular mycorrhizal fungal(AMF) inocula collected from three arable sites in Korea were used to determine plant growth, mycorrhizal root colonization rate and spore production in three different host plant species; Sorghum bicolor, Allium fistulosum, Tagetes patula. Growth of plant treated with AMF differed from those without AMF. Different AMF inocula showed significantly different root colonization rates and spore production of AMF on the wild plants, A. fistulosum and T. patula, but did not on the cultivated plant, S. bicolor. Results suggested that indigenous mycorrhizal fungal community would be important factors in mycorrhizal symbiosis, and play important roles in the plant succession.

• Mycobiology
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• 제46권4호
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• pp.388-395
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• 2018

Radionuclides were deposited at forest areas in eastern parts of Japan following the Fukushima Daiichi Nuclear Power Plant incident in March 2011. Ectomycorrhizal (EM) fungi have important effects on radiocaesium dynamics in forest ecosystems. We examined the effect of colonization by the EM fungus Astraeus hygrometricus on the uptake of cesium (Cs) and potassium (K) by Pinus densiflora seedlings. Pine seedlings exhibited enhanced growth after the EM formation due to the colonization by A. hygrometricus. Additionally, the shoot Cs concentration increased after the EM formation when Cs was not added to the medium. This suggests that A. hygrometricus might be able to solubilize Cs fixed to soil particles. Moreover, the shoot K concentration increased significantly after the EM formation when Cs was added. However, there were no significant differences in the root K concentration between EM and non-EM seedlings. These results suggest that different mechanisms control the transfer of Cs and K from the root to the shoot of pine seedlings.

• Clinical and Experimental Pediatrics
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• 제64권11호
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• pp.543-551
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• 2021

The human microbiome, which consists of a collective cluster of commensal, symbiotic, and pathogenic microorganisms living in the human body, plays a key role in host health and immunity. The human nasal cavity harbors commensal bacteria that suppress the colonization of opportunistic pathogens. However, dysbiosis of the nasal microbial community is associated with many diseases, such as acute respiratory infections including otitis media, sinusitis and bronchitis and allergic respiratory diseases including asthma. The nasopharyngeal acquisition of pneumococcus, which exists as a pathobiont in the nasal cavity, is the initial step in virtually all pneumococcal diseases. Although the factors influencing nasal colonization and elimination are not fully understood, the adhesion of opportunistic pathogens to nasopharyngeal mucosa receptors and the eliciting of immune responses in the host are implicated in addition to bacterial microbiota properties and colonization resistance dynamics. Probiotics or synbiotic interventions may show promising and effective roles in the adjunctive treatment of dysbiosis; however, more studies are needed to characterize how these interventions can be applied in clinical practice in the future.

• 한국미생물·생명공학회지
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• 제44권4호
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• pp.540-549
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• 2016

토양에 존재하는 식물의 잔사는 식물 병원균의 확산 및 월동을 위한 자원으로써 역할을 수행 할 수 있다. 본 연구에서는 식물 잔사인 밀짚에서 식물 병원균인 Fusarium solani의 군락 형성에 대한 생물학적 방제균인 Trichoderma harzianum의 억제 효과를 조사하였다. 두 종류의 토양 수분 조건(-50, -500 kPa)의 멸균하지 않은 토양에서 연구를 수행하였다. T. harzianum ThzID1-M3와 F. solani를 밀짚과 함께 토양에 첨가 한 후 ThzID1-M3, Trichoderma spp. 및 F. solani를 quantitative real-time PCR을 사용하여 21일 동안 관찰하였다. 모든 토양 수분 조건에서 ThzID1-M3는 F. solani의 밀짚 점유를 감소하고(p < 0.05), 반면에 F. SOLANI는 ThzID1-M3 및 Trichoderma spp.의 밀짚 점유를 감소시켰다(p < 0.05). 이 결과는 F. solani와 ThzID1-M3 사이의 경쟁적 억제를 보여주고 있다. 높은 수분 조건의 토양(-50 kPa)에서 ThzID1-M3 및 Trichoderma spp.는 더 높은 밀짚의 점유를 보여주었다(p < 0.05), 반면에 F. solani의 밀짚 점유는 두 수분조건에서 차이가 없었다. 따라서 ThzID1-M3의 병원균 억제 효과는 높은 수분 조건의 토양에서 더 컸다(p < 0.05). 토양내 식물 잔사를 점유할 때 발생되는 ThzID1-M3와 F. solani 사이의 강력한 경쟁 관계는 생물학적 방제 균인 T. harzianum가 작물 시스템에서 식물 병원균의 생존과 증식을 감소시킬 수 있음을 시사한다.

• Pediatric Infection and Vaccine
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• 제22권1호
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• pp.16-22
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• 2015

목적: 소아에서 VRE의 자발적 소실 기간에 대한 영향인자들을 밝히는 것이다. 방법: 2005년 1월부터 2010년 11월까지 VRE 양성인 환자의 의무기록을 후향적으로 분석하였다. 집락소실 기간의 평균 325일을 기준으로 하여 조기소실군과 만기소실군을 나누어 임상특징을 비교하였다. 결과: VRE가 확인된 환자 중 관찰기간이 1년 이상이 되었거나 VRE 집락 소실이 확인된 수는 151명이었다. 조기소실군(41명)에서 처음 VRE 집락이 되었을 때 나이는 만기소실군(110명)에 비하여 많았다(44.9개월 vs 40.9개월, P=0.040). 그리고 조기소실군보다 만기소실군에서 VRE 집락 후 반코마이신 치료를 한 경우가 더 많았다(7% vs 27.2%, P=0.008). 결론: VRE 집락기간에 있어, 처음 VRE를 획득하였을 당시의 나이와 항생제의 사용여부가 중요하다. 감염질환을 치료하고 항생제 저항성 세균의 집락을 억제하기 위하여 적절하고 신중한 항생제 사용이 필요하다.

• Pediatric Gastroenterology, Hepatology & Nutrition
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• 제21권1호
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• pp.43-50
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• 2018

Purpose: Clostridium difficile colonization and infection are commonly associated with poor outcomes in patients with pediatric inflammatory bowel disease (PIBD). We aimed to investigate the prevalence of C. difficile colonization and infection at the time of diagnosis and to evaluate risk factors associated with the development of C. difficile infection during the course of PIBD treatment. Methods: We retrospectively enrolled a total of 59 children who were newly diagnosed with PIBD at the tertiary medical center. All patients underwent C. difficile toxin assays and cultures initially and at every follow-up during the disease course. Kaplan-Meier survival analysis and Cox regression test were used for statistical analysis. Results: Initial cultures for C. difficile were positive in 13 (22.0%) of 59 PIBD patients, whereas initial toxin assays were positive in 3 patients (5.1%). During treatment, C. difficile cultures converted to positive in 28 (47.5%) in addition to 13 patients who were initially culture-positive, and C. difficile toxins converted to positive in 13 (22.0%) in addition to 3 originally toxin-positive patients. Antibiotic usage alone was significantly associated with the development of C. difficile colonization (p=0.011), and the length of hospitalization was associated with the development of C. difficile infection (p=0.032). Conclusion: C. difficile colonization and infection occur frequently during the disease course of PIBD. Antibiotic usage and longer hospital stay were significant risks factors for the conversion of C. difficile status in PIBD patients undergoing treatment.

• The Plant Pathology Journal
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• 제25권4호
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• pp.333-343
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• 2009

Here, we show that an endophytic bacterial strain, Enterobacter asburiae B1 exhibits the ability to elicit ISR in cucumber, tobacco and Arabidopsis thaliana. This indicates that strain B1 has a widespread ability to elicit ISR on various host plants. In this study, E. asburiae strain B1 did not show antifungal activity against tested major fungal pathogens, Colletotrichum orbiculare, Botrytis cinerea, Phytophthora capsici, Rhizoctonia solani, and Fusarium oxysporum. Moreover, the siderophore production by E. asburiae strain B1 was observed under in vitro condition. In greenhouse experiments, the root treatment of strain B1 significantly reduced disease severity of cucumber anthracnose caused by fungal pathogen C. orbiculare compared to nontreated control plants. By root treatment of strain B1 more than 50% disease control against anthracnose on cucumber was observed in all greenhouse experiments. Simultaneously, under the greenhouse condition, the soil drench of strain B1 and a chemical inducer benzothiadiazole (BTH) to tobacco plants induced GUS activity which is linked with activation of PR promoter gene. Furthermore, in Arabidopsis thaliana plants the soil drench of strain B1 induced the defense gene expression of PR1 and PDF1.2 related to salicylic acid and jasmonic acid/ethylene signaling pathways, respectively. In this study, for the main focus on root colonization by strain B1 associated with defense responses, bacterial cells of strain B1 was tagged with the gfp gene encoding the green fluorescent protein in order to determine the colonization pattern of strain B1 in cucumber. The gfp-tagged B1 cells were found on root surface and internal colonization in root, stem, and leaf. In addition to this, the scanning electron microscopy observation showed that E. asburiae strain B1 was able to colonized cucumber root surface.

• Journal of Applied Biological Chemistry
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• 제54권2호
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• pp.120-125
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• 2011

In order to exploit Methylobacterium oryzae CBMB20 as of plant growth promoting agent, different inoculation methods have been evaluated. The present study aimed to evaluate soil, foliar, and soil+foliar inoculations of M. oryzae CBMB20 to improve the growth, fruit yield, and nutrient uptake of red pepper (Capsicum annuum L.) under greenhouse conditions. The population range of green fluorescent protein (gfp)-tagged M. oryzae CBMB20 using the three inoculation methods was 2.5-2.9 ${\log}_{10}$ cfu/g in the rhizosphere and 4.5-6.0 ${\log}_{10}$ cfu/g in the phyllosphere of red pepper plants. Confocal laser scanning microscopy results confirmed the colonization of M. oryzae CBMB20 endophytically on leaf surface. Plant height, fruit dry weight, and total biomass were significantly higher ($p{\leq}0.05$) in all M. oryzae CBMB20 inoculation methods as compared to non-inoculated control. Furthermore, uptake of mineral nutrients such as N, P, K, Ca, and Mg in red pepper plants in all M. oryzae CBMB20 inoculation methods was higher than in non-inoculated control. Comparative results of inoculation methods clearly demonstrated that soil+foliar inoculation of M. oryzae CBMB20 lead to the highest biomass accumulation and nutrient uptake which may be due to its efficient colonization in the red pepper rhizosphere and phyllosphere.

• Journal of Korean Neurosurgical Society
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• 제46권2호
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• pp.123-129
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• 2009

Objective: This study was aimed to identify the incidence and risk factors of vancomycin-resistant enterococcus (VRE) colonization in neurosurgical practice of field, with particular attention to intensive care unit (ICU). Methods: This retrospective study was carried out on the Neurosurgical ICU (NICU), during the period from January. 2005 to December. 2007, in 414 consecutive patients who had been admitted to the NICU. Demographics and known risk factors were retrieved and assessed by statistical methods. Results: A total of 52 patients had VRE colonization among 414 patients enrolled, with an overall prevalence rate of 6.1%. E. faecium was the most frequently isolated pathogen, and 92.3% of all VRE were isolated from urine specimen. Active infection was noticed only in 2 patients with bacteremia and meningitis. Relative antibiotic agents were third-generation cephalosporin in 40%, and vancomycin in 23%, and multiple antibiotic usages were also identified in 13% of all cases. Multivariate analyses showed Glasgow coma scale (GCS) score less than 8, placement of Foley catheter longer than 2 weeks, ICU stay over 2 weeks and presence of nearby VRE-positive patients had a significantly independent association with VRE infection. Conclusion: When managing the high-risk patients being prone to be infected VRE in the NICU, extreme caution should be paid upon. Because prevention and outbreak control is of ultimate importance, clinicians should be alert the possibility of impending colonization and infection by all means available. The most crucial interventions are careful hand washing, strict glove handling, meticulous and active screening, and complete segregation.

• 성인간호학회지
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• 제28권6호
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• pp.628-636
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• 2016

Purpose: This study examined the effects of a program designed to prevent ventilator-associated pneumonia (VAP) on VAP rate and endotracheal colonization. The program focused on aspiration prevention and oral care. Methods: A nonequivalent control group post-test only design was utilized. One hundred patients admitted to a medical intensive care unit (MICU) or coronary care unit (CCU) were assigned to either a experimental group (n=50) or a control group (n=50). The participants were selected 48 hours following an endotracheal intubation. VAP prevention program given to the experimental group includes keeping the head of the bed to $30^{\circ}{\sim}45^{\circ}$ high, maintaining continuous endotracheal cuff pressure at 25 cm $H_2O$, performing endotracheal suction before change position, and providing oral care with 0.1% chlorhexidine every four hours. The control group received usual care. Data were analyzed using t-test, $x^2$ test, Mantel-Haenszel $x^2$ and Cox proportional harzard regression model. Results: The experimental group showed a lower VAP rate than the control group although the difference was not statistically significant ($x^2=0.79$, p=.375). The experimental group showed lower colonization in tracheal secretion than the control group ($x^2=14.59$, p<.001). Conclusion: Results showed that a VAP prevention program is effective in reducing colonization of tracheal secretion. Therefore, VAP prevention programs are recommended as an ICU nursing intervention.