• Clinical and Experimental Pediatrics
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• 제55권2호
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• pp.42-47
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• 2012

$Mycoplasma$ $pneumoniae$ (MP), the smallest self-replicating biological system, is a common cause of upper and lower respiratory tract infections, leading to a wide range of pulmonary and extra-pulmonary manifestations. MP pneumonia has been reported in 10 to 40% of cases of community-acquired pneumonia and shows an even higher proportion during epidemics. MP infection is endemic in larger communities of the world with cyclic epidemics every 3 to 7 years. In Korea, 3 to 4-year cycles have been observed from the mid-1980s to present. Although a variety of serologic assays and polymerase chain reaction (PCR) techniques are available for the diagnosis of MP infections, early diagnosis of MP pneumonia is limited by the lack of immunoglobulin (Ig) M antibodies and variable PCR results in the early stages of the infection. Thus, short-term paired IgM serologic tests may be mandatory for an early and definitive diagnosis. MP infection is usually a mild and self-limiting disease without specific treatment, and if needed, macrolides are generally used as a first-choice drug for children. Recently, macrolide-resistant MP strains have been reported worldwide. However, there are few reports of apparent treatment failure, such as progression of pneumonia to acute respiratory distress syndrome despite macrolide treatment. The immunopathogenesis of MP pneumonia is believed to be a hyperimmune reaction of the host to the insults from MP infection, including cytokine overproduction and immune cell activation (T cells). In this context, immunomodulatory treatment (corticosteroids or/and intravenous Ig), in addition to antibiotic treatment, might be considered for patients with severe infection.

• Journal of Microbiology and Biotechnology
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• 제27권5호
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• pp.1010-1022
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• 2017

Hybrid histidine kinase is part of a two-component system that is required for various stress responses and pathogenesis of pathogenic fungi. The Tco1 gene in human pathogen Cryptococcus neoformans encodes a hybrid histidine kinase and is important for pathogenesis. In this study, we identified a Tco1 homolog, UmTco1, in the maize pathogen Ustilago maydis by bioinformatics analysis. To explore the role of UmTco1 in the survival of U. maydis under environmental stresses and its pathogenesis, ${\Delta}umtco1$ mutants were constructed by allelic exchange. The growth of ${\Delta}umtco1$ mutants was significantly impaired when they were cultured under hyperosmotic stress. The ${\Delta}umtco1$ mutants exhibited increased resistance to antifungal agent fludioxonil. In particular, the ${\Delta}umtco1$ mutants were unable to produce cytokinesis or conjugation tubes, and to develop fuzzy filaments, resulting in impaired mating between compatible strains. The expression levels of Prf1, Pra1, and Mfa1, which are involved in the pheromone pathway, were significantly decreased in the ${\Delta}umtco1$ mutants. In inoculation tests to the host plant, the ${\Delta}umtco1$ mutants showed significantly reduced ability in the production of anthocyanin pigments and tumor development on maize leaves. Overall, the combined results indicated that UmTco1 plays important roles in the survival under hyperosmotic stress, and contributes to cytokinesis, sexual development, and virulence of U. maydis by regulating the expression of the genes involved in the pheromone pathway.

• 한방비만학회지
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• 제9권1호
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• pp.1-14
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• 2009

Complex microbial communities play an important role in the human health and co-evolved with human in the form of symbiosis. Many literatures provide new evidences that the increased prevalence of obesity cannot be attributed solely to changes in the human genome, nutritional habits, or reduction of physical activity in our daily lives. The intestinal flora was recently proposed as an environmental factor responsible for the control of body weight and energy metabolism. A number of studies suggest that the modulation of gut microbiota affects host metabolism and has an impact on energy storage and demonstrated a role for the gut microbiota in weight gain, fat increase, and insulin resistance. Variations in microbiota composition are found in obese humans and mice and the microbiota from an obese mouse confers an obese phenotype when transferred to an axenic mouse. As well, the gut microbial flora plays a role in converting nutrients into calories. Specific strategies for modifying gut microbiota may be a useful means to treat or prevent obesity. Dietary modulations of gut microbiota with a view to increasing bifidobacteria have demonstrated to reduce endotoxemia and improve metabolic diseases such as obesity. The fermentation of medicinal herbs is intended to exert a favorable influence on digestability, bioavailability and pharmacological activity of herbal extract. Therefore we also expect that the fermented herbal extracts may open up a new area to treat obesity through modulating gut microbiota.

• International Journal of Industrial Entomology and Biomaterials
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• 제35권1호
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• pp.58-62
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• 2017

The two-spotted spider mite (Tetranychus urticae) has sustained damage on more than 200 host plants worldwide. Many farmers have relied on chemical acaricides to control mite, but the abuse of acaricides has caused serious resistance to mite. To overcome this problem, microbial control using entomopathogenic fungi have been studied. Entomopathogenic fungi have been an important role against the control of pest, and most of their culture products have been demonstrated to have virulence against pest population. In this study, we evaluated and compared the virulence of culture filtrates, aerial conidia and blastospores of selected Metarhizium anisopliae 4-2 and Beauveria bassiana 2R-3-3-1, respectively, among two-spotted spider mite-pathogenic fungi. As a result, the virulence was confirmed in all treatments, and the accumulated mortality rates were between 77 and 100% within 7 days. Especially, treatment with the fungal culture filtrate alone exhibited quite high virulence, and combined treatment with aerial conidia or blastospores enhanced activity. However, the median lethal time of treatments was not significantly different. When two isolates were compared, M. anisopliae 4-2 showed higher virulence than B. bassiana 2R-3-3-1. These results suggest that the selected two fungal isolates and their culture products could be used effectively for the control of two-spotted spider mite.

• Parasites, Hosts and Diseases
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• 제49권4호
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• pp.341-347
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• 2011

Acanthamoeba infection is difficult to treat because of the resistance property of Acanthamoeba cyst against the host immune system, diverse antibiotics, and therapeutic agents. To identify encystation mediating factors of Acanthamoeba, we compared the transcription profile between cysts and trophozoites using microarray analysis. The DNA chip was composed of 12,544 genes based on expressed sequence tag (EST) from an Acanthamoeba ESTs database (DB) constructed in our laboratory, genetic information of Acanthamoeba from TBest DB, and all of Acanthamoeba related genes registered in the NCBI. Microarray analysis indicated that 701 genes showed higher expression than 2 folds in cysts than in trophozoites, and 859 genes were less expressed in cysts than in trophozoites. The results of real-time PCR analysis of randomly selected 9 genes of which expression was increased during cyst formation were coincided well with the microarray results. Eukaryotic orthologous groups (KOG) analysis showed an increment in T article (signal transduction mechanisms) and O article (posttranslational modification, protein turnover, and chaperones) whereas significant decrement of C article (energy production and conversion) during cyst formation. Especially, cystein proteinases showed high expression changes (282 folds) with significant increases in real-time PCR, suggesting a pivotal role of this proteinase in the cyst formation of Acanthamoeba. The present study provides important clues for the identification and characterization of encystation mediating factors of Acanthamoeba.

• 생명과학회지
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• 제11권2호
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• pp.121-125
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• 2001

Some attempts were made to investigate the biological characterisitcs of the green rice leafhopper(GLH) , Nepthotettix cincticeps Uhler in terms of nymphal development, emergence ratio. preovipositional period, growth index, adult longevity and fecundity fed on rice cultivar, Chucheongbyeo with no resistance gene and water foxtail, Alpecurus aequalis Sobol. var. amurensis Ohwi at 20 and $25^{\circ}C$ with a 16L;8D photoperiod. Development period of nymph on rice cultivar and water foxtail at $25^{\circ}C$ was shorter than that at 2$0^{\circ}C$ by twofold. The nymphal period of female was about one day longer than that of male. The mean emergence ratio of female and male on rice cultivar and water foxtail was 40.0, 76.7, 38.3, 73.3% at 20 and $25^{\circ}C$, respectively. Preovipositional period on rice cultivar and water foxtail at $25^{\circ}C$ was shorter that at 2$0^{\circ}C$ by twofold. Growth index on rice cultivar adn water foxtail at $25^{\circ}C$was higher than that at 2$0^{\circ}C$ by fourfold. Under the 20 and $25^{\circ}C$ condition, the longevity of female and male was longer on water foxtail than on rice cultivar, but the fecundity of GLH was higher on rice cultivar than on water foxtail. In conculsion, water foxtail seems to be adequate for spring host of GLH.

• 대한화장품학회지
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• 제27권1호
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• pp.17-27
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• 2001

A cell-based assay system for monitoring NF-$textsc{k}$B activity was developed to determine the influence of activated NF-$textsc{k}$B in human HaCaT cells. The pNF-$textsc{k}$B-SEAP-NPT plasmid that permits expression of the secreted alkaline phosphatase (SEAP) reported gene in response to the NF-$textsc{k}$B activity and contains neomycin phosphotransferase (NPT) gene for the geneticin resistance in host cells was constructed and transfected into human keratinocyte cell line HaCaT. Human HaCaT transfectant cells secreted the SEAP enzyme into the culture medium in a time-dependent manner until 72h. NF-$textsc{k}$B activities were measured in the SEAP reporter gene assay using a fluorescent detection method. The treatment of HaCaT cell transfectants with known antioxidants [e.g., N-acetyl-L-cysteine and vitamin C] showed inhibition of NF-$textsc{k}$B activity in a time-and concentration-dependent manner. The phorbol 12-myristate 13-acetate (PMA) known as a stimulator of NF-$textsc{k}$B expression demonstrated that it increased NF-$textsc{k}$B activity in a time- and concentration-dependent manner. This assay system could be used to determine the quantitative measurement of NF-$textsc{k}$B activity in the human skin and allow the screening of anti-inflammatory agents from various synthetic chemicals and natural products for dermatological purpose. Abbrevitions used: NF-$textsc{k}$B, nuclear factor kappa B; I-$textsc{k}$B, Inhibitory kappa B; SEAP, secreted alkaline phosphatase; NPT, neomycin phosphotransferease; PCR, polymerase chain reaction: dNTP, deoxynucleoside triphosphates; DMEM, dulbecco’s modified eagle medium; FBS, fetal bovine serum; PBs, phosphate-buffered saline; MUP, 4-methylumbellifery phosphate; NAC, N-acetyl-L-cysteine; DMSO, dimethyl sulfoxide; PMA, phorbol 12-myristate 13-acetate.

• The Plant Pathology Journal
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• 제28권1호
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• pp.55-59
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• 2012

Northern stem canker caused by $Diaporthe$ $phaseolorum$ var. $caulivora$ ($Dpc$) has become a serious disease in soybean. The objectives of this study were to survey the existence of $Dpc$ on soybean in Korea, and to examine the potential pathogenicity of $Dpc$ in seed decay. One such isolate, SSLP-4, isolated from a field-grown plant of the Korean soybean cultivar Danbaekkong, was identified as $Dpc$, based on its morphological and molecular characteristics by sequences of internal transcribed spacer (ITS), translation elongation factor (TEF) 1-${\alpha}$ and ${\beta}$-tubulin regions, as well as pathogenic analyses. Moreover, morphological and molecular analyses revealed that isolate SSLP-4 was nearly identical to $Dpc$ strains from the United States. Pathogenicity tests on hypocotyls of soybean seedlings and detached leaves resulted in typical symptoms of soybean northern stem canker and inoculation on plants at R5-R7 stage caused seed decay. All results suggest that the $Dpc$ strain SSLP-4 can cause both stem canker and seed decay on soybean. Thus, the SSLP-4 isolate has the potential to contribute greatly to understanding of host plant resistance mechanisms, both at vegetative and reproductive growth stages in soybean.

• Journal of Plant Biotechnology
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• 제30권3호
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• pp.233-239
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• 2003

We have developed a reliable and high-frequency genetic transformation and regeneration system via somatic embryogensis of Eleutherococcus sessiliflorus. Embryogenic callus obtained from seed were co- cultivated with Agrobacterium tumefaciens strain EHA101/pIG121Hm harboring genes for intron-$\beta$-glucoronidase(GUS), kanamycin and hygromycin resistance. Following co-cultivation, two types of samples(fine embrogenic calli and early globular embryo clusters) were cultivated on Murashige and Skoog(MS) medium containing 1 mg/L2.4-D for 3day in dark. Transient expression of GUS gene was found to be higher in the early globular embryo clusters than in the embryogenic calli. Also, co-cultivated period affected expression of GUS gene; the best result was obtained when globular embryo clusters were co-cultivated with Agrobacterium for 3 days. Subsequently, this callus transferred to selective MS medium containing 1mg/L2.4-D, 50mg/L kanamycin or/and 30mg/L hygromycin and 300mg/L cefortaxime. These embryogenic calls were subcultured to the same selection medium at every 2 weeks intervals. Approximately 24.5% of the early globular embryos co-cultivated with Agrobacterium for 3days produced kanamycin or/and hygromycin-resistant calli. Transgenic somatic embryos were converted into plantlets in half strength MS medium supplemented with 3mg/L GA$_3$ kanamycin and were confirmed by GUS histochemical assay and polymerase chain reaction analysis. Genomic Southem blot hybridization confirmed the incorporation of NPT II gene into the host genome.

• Journal of Microbiology and Biotechnology
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• 제9권5호
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• pp.687-690
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• 1999

Bacillus stearothermophilus No. 236 isolated from the soil is a strong xylan degrader producing all the xylanolytic enzymes. However, the strain was discovered to be highly intractable to its transformation. In the present study, we have developed a reliable method for transformation of B. stearothermophilus No. 236 by a systematic examination of several factors which might have an influence on the efficiency of electrotransformation. Notably, we found that the most critical factor influencing the transformation efficiency (TE) was the incubation temperature after pulsing, with its optimum incubation of $37^{\circ}C.\; At\; 50^{\circ}C$, the optimum growth temperature of the B. stearothermophilus strain, the transformants could not be obtained at a recognizable level. The combination of field strength of 7.5 kV/cm along with pulse duration of 10 msec (resistance of $400{\Omega}\; and\; capacitance\; of\; 25{\mu}F$) was shown to be the best electrical parameters at the incubation temperature of $37^{\circ}$. A higher TE was obtained when the cells were harvested at an early-exponential phase. Twenty percent of PEG-8000 in a suspension buffer and an addition of 0.1% glycine in the growth medium resulted in about 4-fold and 3-fold increases in TE, respectively. We also found that the plasmid DNA which had been cycled through the host B. stearothermophilus cells enhanced TE by one order of magnitude higher. Under the presently described conditions, $2.5{\times}10^{5} transformants per ${\mu}g$ DNA was attained.