• Title/Summary/Keyword: gram-positive and gram-negative bacteria

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Antibacterial Activity of CNT-Ag and GO-Ag Nanocomposites Against Gram-negative and Gram-positive Bacteria

  • Yun, Hyosuk;Kim, Ji Dang;Choi, Hyun Chul;Lee, Chul Won
    • Bulletin of the Korean Chemical Society
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    • v.34 no.11
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    • pp.3261-3264
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    • 2013
  • Carbon nanocomposites composed of carbon nanostructures and metal nanoparticles have become one of useful materials for various applications. Here we present the preparation and antibacterial activity of CNT-Ag and GO-Ag nanocomposites. Their physical properties were characterized by TEM, XPS, and Raman measurements, revealing that size-similar and quasi-spherical Ag nanoparticles were anchored to the surface of the CNT and GO. The antibacterial activities of CNT-Ag and GO-Ag were investigated using the growth curve method and minimal inhibitory concentrations against Gram-negative and Gram-positive bacteria. The antibacterial activities of the carbon nanocomposites were slightly different against Gram-positive and Gram-negative bacteria. The proposed mechanism was discussed.

A Rapid Method for Monitoring of Gram-positive Bacteria in Wastewater Treatment Systems (폐수처리시스템에서의 그람 양성 세균 모니터링 방법)

  • Nam, Ji-Hyun;Bae, Woo-Keun;Lee, Dong-Hun
    • Korean Journal of Microbiology
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    • v.47 no.1
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    • pp.50-55
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    • 2011
  • A simple and rapid method was developed for monitoring of Gram-positive bacteria in the wastewater treatment system. Culture suspensions of 4 Gram-positive and 4 Gram-negative strains were filtrated and stained with a polyethersulfone membrane filter and Toluidine Blue-O. To establish quantitative color image analysis, the intensity value of RGB (red-green-blue) color of a scanned filter image was analyzed with a photographic program. Red and green color values of Gram-positive bacteria were higher than those of Gram-negative bacteria. This method was applied to the activated sludge mixed with the Gram-positive bacteria. Although evaluation was difficult due to the irregular size and shape of flocs, the population of Gram-positive bacteria in the activated sludge could be monitored with floc dispersion technique. The more amounts of Gram-positive bacteria in the activated sludge led to the increase of red and green color values. This method provides a rapid and quantitative measurement of Gram-positive bacteria within the wastewater treatment systems.

Bactericidal Effects of Anodic Electrolyzed Water on the Selected Gram-Negative and Gram-Positive Bacteria (선별된 그람음성 및 그람양성 세균에 대한 양극 전리수의 살균효과)

  • Kim, Jum-Ji;Lee, Mi-Young
    • Journal of Environmental Science International
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    • v.16 no.11
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    • pp.1295-1300
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    • 2007
  • The antibacterial effects of anodic electrolyzed water against various bacteria were studied in this investigation. Complete inactivation of Gram-positive and Gram-negative bacteria occurred within 15 s after exposure to anodic electrolyzed water. Moreover, 1/2, 1/5 and 1/10 diluted anodic electrolyzed water by adding deionized water showed strong antibacterial effects. However, the inhibitory effect of anodic electrolyzed water on the anaerobe of Propionibacterium acnes was much weaker than that on the aerobes, including Gram-positive and Gram-negative bacteria. The degraded fragments of E. coli cell were observed upon treating anodic electrolyzed water for 1 min by using scanning electron microscopy.

Microbiologic Pollution of Indoor Air in Industrial Work-Places (산업체 작업환경의 실내 공기에서 미생물 오염도)

  • 강경희;장명웅
    • Journal of Life Science
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    • v.9 no.3
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    • pp.314-327
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    • 1999
  • This study was investigated to isolate identify the total bacteria and fungi from the indoor air of work-place of the shoes, paint, stainless steel, and plastic industries. The number of bacterial colonies on the nutrient agar plates were calculated by the open petridish method for 30 minutes in indoor air of work-places at the autumn and winter. The isolated bacteria were identified by Gram stain and biochemical test using API Staph and API 20E kits. The isolated fungal colonies were identified by gross appearance of the giant colonies and microscopic examination of their spore and hyphal characteristics on the slide culture method. The minimum inhibitory concentration (MIC) of several antibiotics against isolated bacteria was determined by the microdilution method with Mueller-Hinton broth. The 70-400 colonies in autumn and 54-236 colonies in winter were isolated from the indoor air of work-places of several industry. The isolation rates of Gram positive cocci, Gram positive bacilli, Gram negative bacilli, and Gram negative cocci were 46.3%, 19.8%, 17.3%, and 16.1%, respectively. In Gram positive cocci, the most strains were identified as Aerococcus spp, Micrococcus spp, and Staphylococcus spp. In Gram positive and negative bacilli, and Gram negative cocci were identified as Bacillus spp, Pseudomonas spp, and Neisseria spp, respectively. The frequently isolated fungi were Aspergillus spp, Penicillium spp and Rhizopus spp, respectively. The frequently isolated Aerococcus spp, Micrococcus spp, and Staphylococus spp were highly resistance against ampicillin, erythromycin, methicillin, and tetracycline. These results arouse our attention to microbiologic pollution in the indoor air of work-places of industries.

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The Cell and Genetic Characteristics of Slime Forming Bacteria on Antibiotic Resistance in the Paper-making Process

  • Kim, Eun-Hee;Kang, Kyu-Young;Jo, Byoung-Muk;Oh, Jung-Soo
    • Journal of the Korean Wood Science and Technology
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    • v.30 no.3
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    • pp.26-33
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    • 2002
  • The seven strains, Pseudomonas paucimobilis, Pseudomonas cepacia, Staphylococcus auricularis, Staphylococcus saprophyticus, Acidovorax spp., Acinetobacter calcoaceticus, and Actinobacillus capsulatus were tested with three slimicides. Most of the tested bacteria were inhibited with slimicide K (an isothiazolin based compound), even at its low concentration, except for Actinobacillus capsulatus and Staphylococcus auricularis. Both slimicides B (an organic bromine based compound) and S (aldehydes) also couldn't prevent these two strains even at their highest concentration. Five different sizes of plasmid DNA were isolated from Actinobacillus capsulatus. Staphylococcus auricularis, a gram-positive bacteria, showed the slimy substances around its cell distinctively. The results suggest that two strains, Actinobacillus capsulatus, Staphylococcus auricularis, have presumably developed a resistance to the slimicide, by plasmid DNA or slimy substance. Our findings also suggest that not only gram-negative bacteria, but also gram-positive bacteria should not be neglected

Chemotaxonomic Classification of Marine Bacteria on the Basis of Fatty Acid Compositions

  • KANG Won-Bae;SEONG Hee-Kyung;MOON Chang-Ho;LEE Won-Jae
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.30 no.6
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    • pp.1013-1020
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    • 1997
  • The cellular fatty acids of 47 marine bacteria representing the genus Alteromonas, Arthrobacter, Bacillus, Micrococcus, Pseudomonas, Shewanella, Staphylococcus and Stenotrophomonas were determined by a gasliquid chromatographic analysis. Sixty-eight different fatty acids with 10 to 20 carbon atoms were detected in marine bacteria. Of the eight genus examined, 14:0, 16:0 and i17:0 were detected in all, while i14:0, a15:0, i16:0, and 15:0 were found in most of all. There were significant differences in the fatty acid patterns between Gram positive and Gram negative bacteria. Bacteria of Gram positive genus showed relatively high contents of the branched type fatty acids, while the major fatty acids in Gram negative were unsaturated and straight forms. Phylogenetic relationships between marine bacteria defined by the cellular fatty acid patterns represented obvious differences between Gram positive and Gram negative genera, even in respective genus. Therefore, the bacterial classification and identification can be accomplished more easily and rapidly based on the cellular fatty acid profiles than the conventional methods.

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Separation of Bacteria Using Capillary Electrophoresis (모세관 전기영동을 이용한 박테리아의 분리)

  • Moon, Byoung-Geoun;Choi, Kyu-Seong;Lee, Sang-Chun;Kim, Yong-Seong
    • Journal of the Korean Chemical Society
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    • v.48 no.2
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    • pp.144-150
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    • 2004
  • Various experimental factors that affect the separation of bacteria were investigated using capillary electrophoresis. At different buffer concentrations, gram-positive bacteria and gram-negative bacteria showed somewhat different migration behavior under high electric filed. The separation efficiency was also investigated as a function of concentration of bacterium injected into the capillary. In order to separate bacteria as the difference of size and shape, water soluble polymers such as poly(ethylene)oxide (PEO), polyvinylpyirrolidone (PVP), and dextran were studied. PEO, which is more flexible and has lower steric hinderance, showed the best separation efficiency. The mixed bacteria sample of Micrococcus lysodeikticus as gram-positive bacteria and Aerobacter aerogenes as gram-negative bacteria were successfully analyzed with PEO.

Antibacterial Activities of Essential Oil from Zanthoxylum schinifolium Against Food-Borne Pathogens (산초 정유성분의 식중독균에 대한 항균 활성)

  • Jang, Mi-Ran;Seo, Ji-Eun;Lee, Je-Hyuk;Kim, Gun-Hee
    • Korean journal of food and cookery science
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    • v.26 no.2
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    • pp.206-213
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    • 2010
  • In this study, the antibacterial activities of essential oil from Zanthoxylum schinifolium against four Gram-positive bacteria and six Gram-negative bacteria were investigated. The antibacterial activity of the oils was determined using the agar-well diffusion assay, MIC (minimum inhibitory concentration) and MBC (minimum bactericidal concentration). In particular, essential oil from Z. schinifolium showed higher antibacterial activity against Gram-positive bacteria than against Gram-negative bacteria. Essential oil from Z. schinifolium displayed large inhibition zones especially against Bacillus cereus (31 mm). At concentrations between 0 and $20\;{\mu}g/mL$ the oils showed an antibacterial effect against both Gram-negative and Gram-positive bacteria. The minimum inhibitory concentration (MIC) values against nine bacteria ranged from 1.25 to $5\;{\mu}g/mL$. The minimum bactericidal concentration (MBC) values against eight bacterial ranged from 2.5 to $20\;{\mu}g/mL$, except Shigella sonnei. Furthermore, our finding on the antibacterial activities of essential oils from Zanthoxylum schinifolium validated the use of this plant for medical purposes.

In-Vitro, Anti-Bacterial Activities of Aqueous Extracts of Acacia catechu (L.F.)Willd, Castanea sativa, Ephedra sinica stapf and shilajita mumiyo Against Gram Positive and Gram Negative Bacteria

  • Dashtdar, Mehrab;Dashtdar, Mohammad Reza;Dashtdar, Babak;shirazi, Mohammad khabaz;Khan, Saeed Ahmad
    • Journal of Pharmacopuncture
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    • v.16 no.2
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    • pp.15-22
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    • 2013
  • Objective: Evaluations of the in-vitro anti-bacterial activities of aqueous extracts of Acacia catechu (L.F.)Willd, Castanea sativa, Ephedra sinica stapf and Shilajita mumiyo against gram-positive bacteria (Staphylococcus aureus, Streptococcus pneumonia) and gram-negative bacteria (Escherichia coli, klebsiella pneumoniae, Proteus mirabilis, Pseudomonas aeruginosa) are reasonable since these ethnomedicinal plants have been used in Persian folk medicine for treating skin diseases, venereal diseases, respiratory problems and nervous disorders for ages. Methods: The well diffusion method (KB testing) with a concentration of $250{\mu}g/disc$ was used for evaluating the minimal inhibitory concentrations (MIC). Maximum synergistic effects of different combinations of components were also observed. Results: A particular combination of Acacia catechu (L.F.) Willd, Castanea sativa, Ephedra sinica stapf and shilajita mumiyo extracts possesses an outstanding anti-bacterial activity. It's inhibiting effect on microorganisms is significant when compared to the control group (P<0.05). Staphylococcus aureus was the most sensitive microorganism. The highest anti-bacterial activity against gram-positive bacteria (Staphylococcus aureus, Streptococcus pneumonia) or gram-negative bacteria (Escherichia coli, Klebsiella pneumonia, Proteus mirabilis, and Pseudomonas aeruginosa) was exerted by formula number 2 (table 1). Conclusion: The results reveal the presence of anti-bacterial activities of Acacia catechu, Castanea sativa husk, Ephedra sp. and Mumiyo against gram-positive and gram-negative bacteria. Synergistic effects in a combined formula, especially in formula number 2 (ASLAN$^{(R)}$) can lead to potential sources of new antiseptic agents for treatment of acute or chronic skin ulcers. These results considering the significant anti-bacterial effect of the present formulation, support ethnopharmacological uses against diarrheal and venereal diseases and demonstrate use of these plants to treat infectious diseases.

Gram-Positive Bacteria Specific Properties of Silybin Derived from Silybum marianum

  • Lee, Dong-Gun;Kim, Hyung-Keun;Park, Yoon-Kyung;Park, Seong-Cheol;Woo, Eun-Rhan;Jeong, Hye-Gwang;Hahm, Kyung-Soo
    • Archives of Pharmacal Research
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    • v.26 no.8
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    • pp.597-600
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    • 2003
  • Silybin has a potent antibacterial activity, more potent than silymarin II, against gram-positive bacteria without hemolytic activity, whereas it has no antimicrobial activity against gram-negative bacteria or fungi. The mode of action of silybin against the gram-positive bacterial cell was examined by investigating the change in plasma membrane dynamics of bacterial cells using 1 ,6-diphenyl-1,3,5-hextriene (DPH) as a membrane probe and by assessing the inhibition of macromolecular synthesis using radiolabeled incorporation assay. The results showed that silybin inhibited RNA and protein synthesis on gram-positive bacteria.