• Microbiology and Biotechnology Letters
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• v.47 no.4
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• pp.651-661
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• 2019

Targeting the pathogen viability using drugs is associated with development of drug resistance due to selective pressure. Hence, there is an increased interest in developing agents that target bacterial virulence. In this study, the inhibitory effect of ciclopirox, an antifungal agent with iron chelation potential, on the microbial virulence factors was evaluated in 26 clinical MDR Pseudomonas aeruginosa isolates collected from Alexandria Main University Hospital, a tertiary hospital in Egypt. Treatment with 9 ㎍/ml ciclopirox inhibited the hemolytic activity in 70% isolates, reduced pyocyanin production, decreased protease secretion in 46% isolates, lowered twitching and swarming motility, and decreased biofilm formation by 1.5- to 4.5-fold. The quantitative real-time PCR analysis revealed that treatment with ciclopirox downregulated the expression levels of alkaline protease (aprA) and pyocyanin (phzA1). Ciclopirox is used to treat hematological malignancies and the systemic administration of ciclopirox is reported to have adequate oral absorption with a satisfactory drug safety profile. It is important to calculate the appropriate clinical dose and therapeutic index to reposition ciclopirox from a topical antifungal agent to a promising virulence-modifying agent agent against P. aeruginosa, a problematic Gram-negative pathogen.

• Journal of Microbiology and Biotechnology
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• v.23 no.9
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• pp.1304-1307
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• 2013

Growth of Microcystis aeruginosa could be inhibited significantly within 24 h by the extracellular substances prepared from Aeromonas sp. strain FM. During the treatment, the concentration of extracellular soluble carbohydrates increased significantly in algal culture. Morphological and ultrastructural changes in M. aeruginosa cells, including breakage of the cell surface, secretion of mucilage, and intracellular disorganization of thylakoids, were observed. HPLC-MS analysis showed that the extracellular substances of Aeromonas sp. strain FM were a mixture of free amino acids, tripeptides, and clavulanate. Among these, the algaelysis effects of lysine and clavulanate were confirmed.

• Journal of Microbiology and Biotechnology
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• v.22 no.9
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• pp.1208-1213
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• 2012

Microcystis aeruginosa is a cyanobacterium that can form harmful algal blooms (HABs) producing toxic secondary metabolites. We provide here draft genome information of four strains of this freshwater cyanobacterium that was obtained by the Next Generation Sequencing approach to provide a better understanding of molecular mechanisms at the physiological and ecological levels. After gene assembly, genes of each strain were identified and annotated, and a genome database and G-browser of M. aeruginosa were subsequently constructed. Such genome information resources will enable us to obtain useful information for molecular ecological studies with a better understanding of modulating mechanisms of environmental factors associated with blooming.

• Korean Journal of Environmental Agriculture
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• v.25 no.3
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• pp.228-235
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• 2006

Pseudomonas aeruginosa $GRC_2$, siderophore-producing strain, inhibited growth of Macrophomina phaseolina in vitro and reduced charcoal rot in seeds of Brassica juncea in field when coated with adaptive strains. P. aeruginosa $GRC_2$ and Azotobacter chroococcum $AC_1$ produced indole-3-acetic acid and solubilized insoluble phosphate. A. chroococcum $AC_1$ fixed nitrogen asymbiotically. Urea and diammonium phosphateadaptive variant strains of P. aeruginosa and A. chroococcum strongly inhibited M. phaseolina in comparison to parental strains. Bacterization of seeds induced seed germination, seedling growth, and enhanced yield of B. juncea by 10.87% as compared to full doses of urea and diammonium phosphate. Both adaptive strains of chemical fertilizers aggressively colonized roots, showing effectiveness to growth and developments of B. juncea.

• Archives of Pharmacal Research
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• v.18 no.3
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• pp.173-178
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• 1995

Ciprofloxacin resistance mechanisms were studied by investigating the inhibitory effect of ciprofloxacin on the gyrase-mediated DNA supercoiling and the intracellular accumulation of ciprofloxacin in clinical isolates of Pseudomonas aeruginosa. A higher amount of ciprofloxacin was required to inhibit the gyrases purified from the ciprofloxacin-resistant strains than that from the sensitive strain. Reconstitution of heterologous gyrase subunits from different strains revealed alterations in the A and/or the B subunits of gyrase in these strains. In addition, the resistant strains accumulated approximately a half amount of ciprofloxacin inside the cells, compared to the sensitive strain. However, when the active efflux was blocked by carbonyl cyanide m-chlorophenyl hydrazone treatment, intracellular concentration of ciprofloxacin was elevated about 4-7 fold in these strains, while the sensitive strain was not significantly affected by this treatment, indicating that the ciprofloxacin-resistant strains developed a drug efflux system. Interestingly, these resistant strains expressed an envelope protein of approximately 51 kD. These studies suggest that alterations in the gyrase as well as the active drug-efflux system conferred dual ciprofloxacin resistance mechanisms to these clinical isolates of P. aeruginosa.

• 한국생물공학회:학술대회논문집
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• 2005.04a
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• pp.474-477
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• 2005

Surface Plasmon Resonance(SPR) sensor system can be applicable for detecting of many biospecific interactions. In this study, the feasibility of the experimental $SPREETA^{TM}$ evaluation kit to analyze human IgG, Pseudomonas aeruginosa, was investigated. The sensor prepared for detecting of anti-human IgG has response on $0.1{\mu}{\ell}$ of the anti-human IgG solution. SPREETA was able to detect P. aeruginosa solution in the range above $10^8\;CFU/mL$ with the chitosan/ alginate multilayers.

• Journal of Environmental Science International
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• v.11 no.9
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• pp.979-985
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• 2002

Laboratory experiments were conducted to investigate the effect of ceramic-treated water on the inhibition of algal growth. The growth of Scenedesmus quadricauda and Chlorella vulgaris was enhanced by the ceramic-treated water in Allen medium containing high concentration of nutrients, but inhibited in natural water containing low concentration of nutrients. The growth of Oscillatoria tenuis and Microcystis aeruginosa was inhibited in both Allen medium and natural water. When comparing the effects of ceramic-treated water 1 (NC1) and 2 (NC2), the growth of O. tenuis and M. aeruginosa was somewhat enhanced by NC1, whereas inhibited by NC2. Therefore, it is suggested that NC2 can be more effective than NC1 in controlling the algal growth.

• Journal of Korean Society of Environmental Engineers
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• v.35 no.6
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• pp.430-435
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• 2013

A seasonal variation of phytoplankton community in the middle-lower part of the Nakdong River was studied in four sampling stations at monthly intervals from January to December 2012. We identified 40 genera 72 species of phytoplankton. Among these, diatoms were 36 species (50.0%), green algae 20 species (27.8%), blue-green algae 9 species (12.5%) and others 7 species (9.7%), respectively. The phytoplankton standing crops were recorded a maximum of 29,640 cells/mL at the Mulgeum (St. 4) in June and a minimum of 236 cells/mL at the Goryung (St. 1) in October. Also, Standing crops were increased with proceeding from middle part to lower part. Ecological important species were Stephanodiscus hantzschii, Cyclotella meneghiniana, Synedra acus, Aulacoseira granulata, Pediastrum sp. and Microcystis aeruginosa. Seasonal succession of phytoplankton represented that Stephanodiscus hantzschii was dominant species in winter, Cyclotella meneghiniana, Synedra acus was dominant species in spring, Microcystis aeruginosa, Cyclotella meneghiniana, Fragilaria crotonensis, Synedra acus, Aulacoseria granulata was dominant species in summer, and Aulacoseria granulata, Cyclotella meneghiniana, Fragilaria crotonensis was dominant species in autumn. In the community analysis, diversity index and dominant index were higher May~July and December~February, respectively. Also, diversity index and dominant index were decreased and increased with proceeding from middle part to lower part.

• Korean Journal of Environmental Biology
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• v.25 no.2
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• pp.81-87
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• 2007

The removal of Microcystis aeruginosa and Chlorella zofingiensis by ceramic powder was investigated on the basis of both the particle size (under 0.05, 0.1, 1 mm) and the dosage (0.1, 1, $10\;g\;L^{-1}$) of the ceramic powder. The removal efficiencies of M. aeruginosa and C. zofingiensis were highest with a particle size of 0.05 mm and a dosage of $1\;g\;L^{-1}$ of the ceramic powder in laboratory experiment. $chlorophyll-{\alpha}$ concentrations decreased in both field and enclosure samples with a particle size of 0.05 mm and a dosage of $1\;g\;L^{-1}$ of ceramic powder, resulting in the removal efficiencies of 67 and 69%, respectively. Consequently, it was concluded that the ceramic powder could be used to control algal bloom by removing $chlorophyll-{\alpha}$ in eutrophic waters.

• Advances in Traditional Medicine
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• v.8 no.1
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• pp.24-31
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• 2008

In the present investigation, we studied the effect of alcoholic extract of Moringa oleifera (M. oleifera) seed kernels on various experimental models of bronchial asthma. Significant (P < 0. 05) increase in preconvulsion time was observed due to pretreatment with M. oleifera when the guinea pigs were exposed to either acetylcholine (Ach) or histamine aerosol. This bronchodilating effect of M. oleifera was comparable to ketotifen fumarate. Spasmolytic effect of M. oleifera was also observed by dose dependent inhibition of ideal contractions induced by Ach, 5HT, histamine and $BaCl_2$. Alcoholic extract of M. oleifera produced significant dose dependent protection by egg albumin and compound 48/80 induced mast cell degranulation. Pretreatment with alcoholic extract of M. oleifera also decreased carrageenan induced rat paw edema, which was comparable to that of standard diclofenac sodium. Minimum inhibitory concentration for alcoholic extract of M. oleifera was low as compared to cold-water extract and hot water extract when antimicrobial activity was tested against various respiratory pathogens like Escherichia coli (E. coli), Staphylococus aureus (S. aureus) and pseudomonas aeruginosa (P. aeruginosa). Our data suggest that antiasthmatic activity of M. oleifera seed kernels may be due to its bronchodilator, anti-inflammatory, mast cell stabilization and antimicrobial activity.