• Title/Summary/Keyword: Bacterial size

Search Result 338, Processing Time 0.04 seconds

Comparative efficacy of silver containing dressing materials to Staphylococcus aureus and Pseudomonas aeruginosa on infected full thickness skin wound in the rat (흰쥐의 감염된 전층피부결손에서 은 함유 드레싱제제의 Staphylococcus aureus 및 Pseudomonas aeruginosa 균주에 대한 효과의 비교)

  • Lee, Jong Hoon;Kim, Dong Gu;Lee, Won Mi;Chae, Jeong Don
    • Archives of Plastic Surgery
    • /
    • v.36 no.4
    • /
    • pp.372-379
    • /
    • 2009
  • Purpose: The purpose of this study was to compare the effect on antibacterial activities and wound healing effect of silver containing dressings with which of Betadine against Staphylococcus aureus and Pseudomonas aeruginosa. Methods: One full thickness skin defects in rats(n=72) were developed on the back and were given rise to infection with S. aureus(n=36) and P. aeruginosa(n=36). The 72 mice were divided into 6 groups : Acticoat$^{(R)}$, Aquacel$^{(R)}$-Ag, Medifoam silver$^{(R)}$, Polymen silver$^{(R)}$, Ilvadon$^{(R)}$ and Betadine(control group) dressing groups. Five silver containing dressings and Betadine were assesed on infected wound. Measurement of wound size change, bacterial colonies count and histologic findings was applied. Antibacterial activity was analyzed with bacterial restricted zone in Mueller Hinton agar. Results: On S. aureus, wound size was more decreased in all treated groups as compared with betadine, however Ilvadon$^{(R)}$ was less decreased on P. aeruginosa. In histologic findings, experimental group showed more effective findings than others on S. aureus, however on P. aeruginosa, which was showed similar. Acticoat$^{(R)}$ was best effective in wound healing against S. aureus and P. aeruginosa. The bacterial colonies count was increased in all treated groups except Acticoat$^{(R)}$ as compared with the control group on S. aureus, which was decreased in Acticoat$^{(R)}$ and Ilvadon$^{(R)}$ group on P. aeruginosa. There were not statistical differences. The restricted zone was shown in Mueller - Hinton agar of all groups except Medifoam silver$^{(R)}$ group on S. aureus, which was shown of all groups on P. aeruginosa. There were statistical differences. Conclusion: This study suggests that silver containing dressings may have not better potential than Betadine in assisting management of wounds at risk of infection on S. aureus and P. aeruginosa. However, which have better antibacterial activity on S. aureus and P. aeruginosa.

Zooplankton Grazing on Bacteria and Factors Affecting Bacterial C-flux in Lake Paldang Ecosystem (팔당호 생태계에서 동물플랑크톤의 박테리아 섭식 및 영향인자)

  • Uhm, Seong-Hwa;Hwang, Soon-Jin
    • Korean Journal of Ecology and Environment
    • /
    • v.39 no.4 s.118
    • /
    • pp.424-434
    • /
    • 2006
  • This study investigates bacteria-zooplankton grazing link and factors affecting their grazing relationship at trophically different two sites (Paldang Dam and Kyungan Stream) of Lake Paldang Ecosystem from April to December, 2005. Zooplankton were divided into two size groups; microzooplankton (MICZ) : 60-200 ${\mu}m$ and macrozooplankton (MACZ): >200 ${\mu}m$), and their grazing rates on bacteria were conducted for each size group separately. Bacterial abundance and seasonal change pattern were similar between two sites. MICZ, mostly rotifers (e.g., Brachionus, Keratella, Polyathra) were numerically dominant at both sites, while carbon biomass was highest in cladocerans. Zooplankton biomass was higher at the Kyungan Steam site compared to Paldang Dam site, and their high biomass during spring decreased as they were passing through the storm events in summer season at both sites. Zooplankton clearance rate (CR) was high in spring and autumn while low in summer at Paldang Dam site. However, zooplankton CR was high during the summer at Kyungan Stream site. Bacterial C-flux was high in spring and autumn when MACZ (esp. cladecerans) developed at a high biomass level at both sites. Overall, MACZ community CR and carbon flux (C-flux) were higher than those of MICZ, and the degree of difference between them was higher at Kyungan Stream site. Short hydraulic residence time and physical disturbance caused by summer storm event appeared to affect the zooplankton grazing on bacteria at both sites. The results of this study indicate that bacteria are potentially important carbon source of zooplankton, and that both biotic (e.g,, prey and predator taxa composition and abundance) and physical parameters appear to alter energy transfer in the planktonic food web of this river-reservoir hybrid system.

Rapid Detection of the pathogenic agent of Bacterial white enteritis of Larval and Juvenile Stages in Olive flounder (Paralichthys olivaceus) (넙치(Paralichthys olivaceus)자치어 장관백탁증(Bacterial white enteritis) 원인균의 신속 검출)

  • Mun, Yeong-Geon;Park, Geun-Tae;Son, Hong-Ju;Lee, Sang-Hyeon;Lee, Jeong-Min;Heo, Mun-Su
    • Journal of fish pathology
    • /
    • v.17 no.3
    • /
    • pp.159-169
    • /
    • 2004
  • Bacterial wihte enteritis ocurred by infection of V. ichthyoenteri is a devastating disease in olive flounder (Paralichthys olivaceus) hatcheries in Korea. Since white enteritis has been a problem in aquqtic industries, necessity of a rapid detection method is increased. In an attempt to develop rapid PCR method the detection of V. ichthyoenteri, we examined the 16S-23S rRNA intergenic spacer region(ISR) of V. ichthyoenteri and developed species-specific primer for V. ichthyoenteri. The intergenic spacers were amplified by primers complementary to conserved region of 16S and 23S rRNA genes. The intergenic spacer region between the 16S and 23S rRNA genes of V. ichthoenteri were investigated by PCR fragment length typing and DNA sequencing. Analysis of the ISR sequences showed that V. ichthyoenteri contains one types of polymorphic ISRs. The size of ISRs ranged 348bp length and not contains tRNA genes. Mutiple alignment of representative sequences from different Vibrio species revealed several domains of high sequence variability, and allowed to design species-specific primer for detection of Vibrio ichthyoenteri. PCR. The specific of the primer was examined using genomic DNA prepared from 19 different Vibrio species, isolated 18group Vibrio species. The results showed that the PCR reaction using species-specific primer designed in this study can be used to detect V. ichthyoenteri.

Bacterial Community Structure and Diversity of the Zoysia japonica Soil Treated with Liquid Fertilizer Containing Amino Acids (아미노산 액비를 처리한 들잔디 토양 미생물 군집구조 및 다양성)

  • Kim Dong-Il;Kim Dong-Hun
    • Korean Journal of Microbiology
    • /
    • v.42 no.2
    • /
    • pp.103-110
    • /
    • 2006
  • T-RFLP analysis and clone sequencing analysis based on bacterial 16S rDNA were conducted to assess bacterial community structure and diversity in Zoysia japonica soil treated with liquid fertilizer containing amino acids(LFcAA) after spray with herbicide. The results of T-RFLP (terminal restriction fragment length poly-morphism) analysis using restriction enzyme Hae III showed that the T-RFs of various size appeared evenly in the 32 clones of KD3 and 38 clones of KD4 respectively that had been treated with liquid fertilizer containing amino acid(LFcAA) compared to 23 clones of KD2 hat had not been treated with LFcAA. The microbial com- munity structure in KD2 appeared less diverse than those in KD3 and KD4. Analysis of partial sequences for 110 clones from KDI (control), KD2 (non-treated), KD3 (LFcAA 1X), KD4 (LFcAA 2X), respectively, revealed that most bacteria were related with uncultured bacteria in a 16S rDNA sequence similarity range of 91-99% through blast search. Otherwise, the other clones were members of proteobacteria, Acidobacteria, Act-inobacteria, Sphingobacteria and Planctomyces groups. Especially in KD4, members of Alpha Proteobacteria, Rhizobiales, Sphigomonadales, Caulobacterales, Gamma Proteobacteria, the genus Pseudomonas, Betapro-teobacteria, Nitrosomonadales and genus Nitrosospira appeared to be dominant. In addition, Acidobacteria group, Actinobacteria group, Planctomycetacia and Sphingobacteria were also shown. The microbial com-munity structure in Z. japonica soil sprayed with herbicide was affected by LFcAA.

Bacterial Growth-inhibiting Activity of Amniotic Fluid Against E. coli (양수의 대장균에 대한 세균증식 억제효과)

  • Kim, Soo-Yong;Choi, Myung-Sik;Chang, Woo-Hyun;Cha, Chang-Yong
    • The Journal of the Korean Society for Microbiology
    • /
    • v.22 no.3
    • /
    • pp.233-240
    • /
    • 1987
  • The amniotic fluid provides a medium in which the fetus can readily move, cushions him against possible injury and helps him maintain an even temperature. Besides above mentioned functions, investigators reported that human amniotic fluid contains host-resistance factors which prevent bacteria from producing infectious disease and this activity shows difference among human racial groups or bacterial genera, species and strains. 40 amniotic fluid specimens from Korean women in their second and third trimesters of pregnancy were examined for inhibiting the growth of Escherichia coli. And various factors which might affect bacterial growth inhibiting activity such as pH, initial inoculum size, concentration of amniotic fluid, and heat resistance, were also tested using a strongly inhibitory amniotic fluid specimen. Finally plate diffusion tests were carried out using other strongly inhibitory amniotic fluid. The following results were obtained: 1. Of the 40 fluid samples examined, 18 specimens(45%) had inhibitory activity and samples from women in their second trimester of pregnanancy showed non-inhibitory activity(2 specimens). 2. The pH of the fluids varied between 7.43 and 8.33. There was no correlation between pH and inhibitory activity. 3. No. 19 amniotic fluid showed bacteriostatic activity after 24 hours incubation when an inoculum of $10^2$ organisms per milliliter was used, but non-inhibitory with an inoculum of $10^3$ and $10^4$ bacteria per milliliter. 4. The content of amniotic fluid in culture media influenced E. coli growth. At 90 percent, E. coli was inhibited growth but at 10 percent and 50 percent. 5. Inhibitory activity of No. 19 amniotic fluid was retained after heating to $50^{\circ}C$ for 30 minutes or 100^{\circ}C$ for 30 minutes. 6. Plate diffusion tests with No. 27 amniotic fluid showed that 0.7ml amniotic fluid gave clear zone of growth inhibition around the central well but 0.2ml and 0.1ml amniotic fluids were not.

  • PDF

Diversity and Succession of the Bacterial Community during the Initial Fermentation Period in Modernized Soy Sauce (Ganjang) (개량식 간장의 발효 초기 단계에서의 미생물 다양성 및 천이에 관한 연구)

  • Ho Jin Jeong;Gwangsu Ha;Jungmi Lee;Yeji Song;Do-Youn Jeong;Hee-Jong Yang
    • Journal of Life Science
    • /
    • v.33 no.6
    • /
    • pp.481-489
    • /
    • 2023
  • The taste and quality of soy sauce, a fermented liquid condiment, is greatly influenced by microbial metabolism during fermentation. To investigate the microbiological characteristics of ganjang during the initial fermentation process, we prepared meju (fermented soybean) blocks fermented with starter cultures and solar salts and analyzed the microbial community quantitively using 16S rRNA gene profiling from ganjang that had been fermented over a five-week period. The ganjang samples were collected and analyzed after soaking for week one (1W), three (3W), and five (5W) weeks. We found that Halomonadaceae was significantly higher in the 1W group (89.83%) than the 3W and 5W groups (14.46%, and 13.78%, respectively). At a species level, Chromohalobacter beijerinckii and Chromohalobacter canadensis were the dominant species in the 1W group but several taxa such as Bacillus subtilis, Pediococcus acidilactici, and Enterococcus faecalis were more abundant in the 3W and 5W groups. Pearson correlation analysis of the relative abundance of the bacteria showed a negative correlation between Chromohalobacter and two bacterial genera Bacillus and Enterococcus. Beta-diversity showed a statistical distinction between the 1W and the 3W and 5W groups, while no significance was evident between the 3W and 5W groups. Linear discriminant effect size analysis was used to identify biomarkers and significant differences in the relative abundance of several halophilic bacteria, Bacillus sp. and lactic acid bacteria at 1W, 3W, and 5W, recpectively, which indicates the important role of the bacterial community at these time points.

Effect of chemical concentrations on strength and crystal size of biocemented sand

  • Choi, Sun-Gyu;Chu, Jian;Kwon, Tae-Hyuk
    • Geomechanics and Engineering
    • /
    • v.17 no.5
    • /
    • pp.465-473
    • /
    • 2019
  • Biocementation due to the microbially induced calcium carbonate precipitation (MICP) process is a potential technique that can be used for soil improvement. However, the effect of biocementation may be affected by many factors, including nutrient concentration, bacterial strains, injection strategy, temperature, pH, and soil type. This study investigates mainly the effect of chemical concentration on the formation of calcium carbonate (e.g., quantity, size, and crystalline structure) and unconfined compressive strength (UCS) using different treatment time and chemical concentration in the biotreatment. Two chemical concentrations (0.5 and 1.0 M) and three different treatment times (2, 4, and 8 cycles) were studied. The effect of chemical concentrations on the treatment was also examined by making the total amount of chemicals injected to be the same, but using different times of treatment and chemical concentrations (8 cycles for 0.50 M and 4 cycles for 1.00 M). The UCS and CCC were measured and scanning electron microscopy (SEM) analysis was carried out. The SEM images revealed that the sizes of calcium carbonate crystals increased with an increase in chemical concentrations. The UCS values resulting from the treatments using low concentration were slightly greater than those from the treatments using high concentration, given the CCC to be more or less the same. This trend can be attributed to the size of the precipitated crystals, in which the cementation efficiency increases as the crystal size decreases, for a given CCC. Furthermore, in the high concentration treatment, two mineral types of calcium carbonate were precipitated, namely, calcite and amorphous calcium carbonate (ACC). As the crystal shape and morphology of ACC differ from those of calcite, the bonding provided by ACC can be weaker than that provided by calcite. As a result, the conditions of calcium carbonate were affected by test key factors and eventually, contributed to the UCS values.

Medium Concentration Influencing Growth of the Entomopathogenic Nematode Heterorhabditis bacteriophora and its Symbiotic Bacterium Photorhabdus luminescens

  • Yoo, Sun-Kyun;Brown, Ian;Cohen, Nancy;Gaugler, Randy
    • Journal of Microbiology and Biotechnology
    • /
    • v.11 no.4
    • /
    • pp.644-648
    • /
    • 2001
  • The biological control potential of entomopathogenic nematodes (EPN) can be enhanced by improved culture efficiency. Optimization of the media is a key factor for improving in vitro mass production of entomopathogenic nematodes. This study reports the effect of medium concentration. The medium is a combination of carbohydrates, lipids, proteins, sats, and growth factors, on the growth of Heterorhabditis bacteriophora and its symbiotic bacterium Photorhabdus liminescens. The overall optimal medium concentration for nematode recovery, hermaphrodite size, bacterial mass, infective juveniles (IJs) yield, and doubling time was 84 g/l. At this concentration rate, the doubling time of IJs production and the biomass of symbiotic bacteria was 1.6 days and 12.8 g/l, respectively. The maximum yield of $2.4{\times}{10^5}IJs/ml$ was attained within a one-generation cycle (eight days). The yield coefficient was $2.8{\times}{10^6}$ IJs/g medium, and the maximum productivity was $3.1{\times}{10^7}$ IJs per day. Medium concentration affected two independent factors, recovery and hermaphrodite size, which in turn influenced the final yield.

  • PDF

A Study on Test Methods for Performance Appraisal of Root Barrier Appling to Green Roofs (옥상 및 인공지반녹화용 방근재의 성능기준 설정을 위한 방근성 시험방법에 관한 연구)

  • Oh, Sang-Keun;Kwak, Kyu-Sung;Sun, Yoon-Suk;Kwon, Shi-Won
    • Journal of the Korea Institute of Building Construction
    • /
    • v.7 no.1 s.23
    • /
    • pp.79-84
    • /
    • 2007
  • Selection of proper root barrier as destination part of greening is very important in Root penetration resistance plan. To select proper root barrier, it need to understand composition of greening part, size, kind of plant, connection with waterproofing layer. In this point of view, we have establish greening on the roof or concrete structure, not been understand the structural mechanism. It means that we misunderstood about purpose of greening and using it. So, chosen materials and construction method was not proper for greening, it caused water leakage and decrease performance of concrete structure. Therefore, we would suggest 5 items of test methods considering environmental condition for green roof. Watertightness by water of greening part, root penetration resistance test by root penetration, bacteria resistance by must or bacteria in soil, chemical resistance by rain and chemical agent of fertilizer, and load resistance by soil depth, size of plant. These suggested test methods could be referred as guideline to test in green roof system because of not exist any performance appraisal guideline or standard. Consequently, it should be analysis as technical and institutional subdividing test methods and it need to study constantly as varied angles.

Filter Plate Micro Trap as a Device for in situ Cultivation for Environmental Microorganisms (환경시료에 존재하는 미생물 배양을 위한 filter plate micro trap의 개발)

  • Jung, Da-Woon;Ahn, Tae-Seok
    • Journal of Life Science
    • /
    • v.22 no.6
    • /
    • pp.723-729
    • /
    • 2012
  • Filter plate microbial trap (FPMT) was invented as an in situ cultivation device for the isolation of bacteria from natural environments. FPMT consists of a medium and membrane filters (0.45 ${\mu}m$ pore size) and microorganisms and compounds can be moved freely moved into the medium. This device was applied to two soil samples of Greenland. The microbial diversity of both soil samples by FPMT was higher than that by the conventional Petri dish-based method. Moreover, novel bacterial species were isolated by FPMT. The new FPMT is effective for in situ cultivation of natural samples and could be applicable to the isolation of uncultivable microorganism.