• Journal of Animal Science and Technology
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• 제47권3호
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• pp.465-474
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• 2005

A two-step broad-range PCR method detecting gram-negative bacteria at the level as low as 2 CFU was developed by using primers of GNFI and GNRI and then semi-nested primer of GNF2 and GNRI. The nucleotide sequences of the primers were determined based on l6S rRNA gene. The DNA fragments of 1173 bp and 169 bp were amplified in one-step PCRs with primer sets of GNFI-GNRI and GNF2-GNRl, respectively, using template DNA from seven strains of gram-negative bacteria including Escherichia coli, Enterobacter aerogenes, Klebsiella pneumoniae, Pseudomonas spp., and Acinetobacter baumaii but not from Achromobacter lyticus, Alca/igens faecalis, and five strains of gram-positive bacteria. DNA fragments of 180 bp were amplified from LTLT-pasteurized milk and UHf-pasteurized milk in the two-step PCR. The DNA fragments were amplified from LTLT-pasteurized milk which was added with Pseudomonas j/uorescens and subsequently heated at 65 $^{\circ}C$, 80 $^{\circ}C$, and 100 $^{\circ}C$ for 30 min but they were not amplified from the milk autoclaved at 121$^{\circ}C$ for 15 min. It was suggested in PCR that Pseudomonas fluorescens heated at 65 $^{\circ}C$ for 30 min in milk was more sensitive to DNase treatment than viable bacteria.

• Toxicological Research
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• 제27권1호
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• pp.31-36
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• 2011

The methanol extract of 12 medicinal plants were evaluated for its antibacterial activity against Gram-positive (5 strains) and Gram-negative bacteria (10 strains) by assay for minimum inhibitory concentration (MIC) and minimum bacterial concentration (MBC). The antibacterial activity was determined by an agar dilution method (according to the guidelines of Clinical and Laboratory Standard Institute). All the compounds (12 extracts) of the 8 medicinal plants (leaf or root) were active against both Gram-negative and Gram-positive bacteria. Gram-negative showed a more potent action than Gram positive bacteria. The MIC concentrations were various ranged from $0.6\;{\mu}g/ml$ to $5000\;{\mu}g/ml$. The lowest MIC ($0.6\;{\mu}g/ml$) and MBC ($1.22\;{\mu}g/ml$) values were obtained with extract on 4 and 3 of the 15 microorganisms tested, respectively.

• 생약학회지
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• 제18권1호
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• pp.1-4
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• 1987

The methanol and benzene extracts of the leaves of 55 higher plants in Korea were tested for their antibacterial activity against three Gram positive bacteria, Streptococcus mutans, Staphylococcus aureus and Bacillus subtilis, and one Gram negative bacterium Escherichia coli. Among them, the methanol extract of the leaves of Liriodendron tulipifera showed remarkably potent antibacterial activity against both Gram positive and negative bacteria.

• Korean Chemical Engineering Research
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• 제53권5호
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• pp.565-569
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• 2015

Envisaging the role of Co in theranautics and biomedicine it is immensely important to evaluate its antimicrobial activity. Hence in this study CoO thin nanosheets (CoO-TNs) were synthesized using wet chemical solution method at a very low refluxing temperature ($90^{\circ}C$) and short time (60 min). Scanning electron microscopy of the grown structure revealed microflowers ($2{\sim}3{\mu}m$) composed of thin sheets petals (60~80 nm). The thickness of each individual grown sheet varies from 10~20 nm. Antimicrobial activities of CoO-TNs against two Gram positive bacteria (Micrococcus luteus, and Staphylococcus aureus), and two Gram negative bacteria (Escherichia coli and Pseudomonas aeruginosa) were determined. A 98% and 65% growth inhibition of M. luteus and S. aureus respectively, was observed with $500{\mu}g/ml$ of CoO-TNs compared to 39 and 34% growth inhibition of E. coli and P. aeruginosa, respectively with the same concentration of CoO-TNs. Hence, synthesized CoO-TNs exhibited antimicrobial activity against Gram negative bacteria and an invariably higher activity against tested Gram positive bacteria. Therefore, synthesized CoO-TNs are less prone to microbial infections.

• Archives of Pharmacal Research
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• 제26권8호
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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.

• Journal of Microbiology and Biotechnology
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• 제18권1호
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• pp.176-182
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• 2008

In the present study, a control methodology utilizing airborne silver nanoparticles is suggested and tested with respect to its potential to control Gram-positive Staphylococcus epidermidis and Bacillus subtilis, and Gram-negative Escherichia coli bacteria bioaerosols deposited on filters. As it is known that the Gram-negative bacteria are sensitive to airflow exposure, the main focus of this study for testing the airborne silver nanoparticles effect was the Gram-positive Staphylococcus epidermidis and Bacillus subtilis bacteria bioaerosols whereas Escherichia coli bioaerosols were utilized for comparison. Airborne bacteria and airborne silver nanoparticles were quantitatively generated in an experimental system. Bioaerosols deposited on the filter were exposed to airborne silver nanoparticles. The physical and biological properties of the airborne bacteria and airborne silver nanoparticles were measured via aerosol measurement devices. From the experimental results, it was demonstrated that this method utilizing airborne silver nanoparticles offers potential as a bioaerosol control methodology.

• Journal of Microbiology and Biotechnology
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• 제10권4호
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• pp.554-558
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• 2000

Bacteria were isolated and identified from an advanced high-purity water system that supplies ultra-high purity water (UHPW) for 16-megabyte DRAM semiconductor manufacturing. Scanning electron microscopic and microbiological observations revealed that the primary source of the bacteria isolated from the UHPW was detached cells from biofilms developed on the pipe wall through which the UHPW, a man-made and extremely nutrient poor environment, was passing. About 63-65% of the bacteria isolated from the UHPW and the pipe wall were Gram-positive, whereas only 10% of the bacteria isolated from the feed water were Gram-positive. The of Gram-positive bacteria and seven genera of Gram-negative bacteria. Strains of the UHPW bacteria effectively adhered to and formed a biofilm on the surface of polyvinyl chloride (PVC) pipe.

• Pediatric Infection and Vaccine
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• 제4권1호
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• pp.79-89
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• 1997

목 적 : 신생아 세균성 뇌막염은 임상 증상이 비특이적이며 여러가지 신경학적 후유증을 남길 수 있는 질환으로 본 저자들은 원인균 특히 그람 양성균과 음성균에 의한 뇌막염을 비 교 분석하여 치료 및 예후의 개선을 도모하고자 본 연구를 시행하였다. 방 법 : 1991년 1월부터 1996년 6월까지 중앙 길병원 신생아 중환자실과 소아과 병동에서 뇌척수액 검사상 균이 배양되었거나 latex agglutination test상 균이 밝혀진 24례를 대상으로 후향적으로 분석하였다. 결 과 : 1) 환아의 분포는 남아 17명, 여아 7명이었고, 그람 양성균에 의한 뇌막염 환아의 평균 출생 체중과 재태 기간은 $2.91{\pm}0.79kg$, $38.4{\pm}2.74$주, 그람 음성균군에서는 $3.30{\pm}0.90kg$, $37.7{\pm}3.33$ 주로 두 군간에 유의한 차이는 보이지 않았다. 2) 선행 요인으로는 미숙아, 태변 착색, 조기 양막 파수, 산모 당뇨병, 임신성 고혈압 등이 있었으며, 임상 증상 및 증후로는 발열, 경련, 수유량 감소, 대천문 팽대 등이 있었고, 증상 발현 시기는 조기 발현형이 11례(그람 양성균 4례, 그람 음성균 7례), 지연 발현형이 13례 (그람 양성균 7례, 그람 음성균 6례)였다. 3) 원인균은 그람 양성균이 11례로 coagulase-negative staphylococci와 group B streptococci가 각 3례, Staphyolococcus aureus와 Streptococcus viridans가 각 2례, enterococci가 1례가 있었으며, 그람 음성균은 13례로 Escherichia coli가 7례, Klebsiella pneumoniae가 3례 Pseudomonas aeruginosa, Acinetobactor, Emterobacter가 각 1례씩 있었다. 4) 뇌척수액 검사상 백혈구 수치는 그람 음성균군에서 통계적으로 유의하게 높았으나 단백 수치와 당 수치는 두 군간에 통계적으로 유의한 차이를 보이지 않았다. 5) 뇌초음파 검사상 그람 양성균군에서는 7례(63.6%)에서, 그람 음성균군에서는 10례 (76.9%)에서 비정상 소견을 보였으나 두 군간에 뇌초음파 검사상 비정상 소견의 빈도에 있어서는 통계적으로 유의한 차이를 보이지 않았다. 6) 항생제 감수성 검사에서 그람 양성균군에서는 penicillin계통, 1세대 cephalosporin, vancomycin에, 그람 음성균군에서는 amikacin과 3세대 cephalosporin에 대해 비교적 높은 감수성을 보였다. 7) 사망율(병원내 사망이나 hopeless discharge)은 20.8%(5례)였으며, 예후는 그람 양성균 군과 그람 음성균군에서 통계적으로 유의한 차이를 보이지 않았다. 결 론 : 신생아 세균성 뇌막염은 그람 양성균과 그람 음성균 간의 빈도와 예후의 차이는 보이지 않았고 예후가 불량하므로 세균성 뇌막염이 의심되는 환아에서는 적극적인 치료가 필요하리라 사료된다.

• 한국토양비료학회지
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• 제48권2호
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• pp.81-86
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• 2015

Soil management for orchard depends on the effects of soil microbial activities. The present study evaluated the soil microbial community of 25 orchard (5 sites for sandy loam, 7 sites for silt loam, and 13 sites for loam) in Gyeongnam Province by fatty acid methyl ester (FAME) method. The average values for 25 orchard soil samples were $270nmol\;g^{-1}$ of total FAMEs, $72nmol\;g^{-1}$ of total bacteria, $34nmol\;g^{-1}$ of Gram-negative bacteria, $34nmol\;g^{-1}$ of Gram-positive bacteria, $6nmol\;g^{-1}$ of actinomycetes, $49nmol\;g^{-1}$ of fungi, and $7nmol\;g^{-1}$ of arbuscular mycorrhizal fungi. In addition, silt loam soils had significantly low ratio of cy17:0 to $16:1{\omega}7c$ and cy19:0 to $18:1{\omega}7c$ compared with those of loam soils (p < 0.05), indicating that microbial activity increased. The average soil microbial communities in the orchard soils were 26.7% of bacteria, 17.9% of fungi, 12.6% of Gram-negative bacteria, 12.5% of Gram-positive bacteria, 2.5% of arbuscular mycorrhizal fungi, and 2.2% of actinomycetes. The soil microbial community of Gram-negative bacteria in silt loam soils was significantly higher than those of sandy loam and loam soils (p < 0.05).

• 대한약침학회지
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• 제19권3호
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• pp.225-230
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• 2016

Objectives: Mellitine, a major component of bee venom (BV, Apis mellifera), is more active against gram positive than gram negative bacteria. Moreover, BV has been reported to have multiple effects, including antibacterial, antivirus, and anti-inflammation effects, in various types of cells. In addition, wasp venom has been reported to have antibacterial properties. The aim of this study was to evaluate the antibacterial activity of BV against selected gram positive and gram negative bacterial strains of medical importance. Methods: This investigation was set up to evaluate the antibacterial activity of BV against six grams positive and gram negative bacteria, including Staphylococcus aureus (S. aureus), Salmonella typhimurium, Escherichia coli (E. coli) O157:H7, Pseudomonas aeruginosa, Burkholderia mallei and Burkholderia pseudomallei. Three concentrations of crude BV and standard antibiotic (gentamicin) disks as positive controls were tested by using the disc diffusion method. Results: BV was found to have a significant antibacterial effect against E. coli, S. aureus, and Salmonella typhyimurium in all three concentrations tested. However, BV had no noticeable effect on other tested bacteria for any of the three doses tested. Conclusion: The results of the current study indicate that BV inhibits the growth and survival of bacterial strains and that BV can be used as a complementary antimicrobial agent against pathogenic bacteria. BV lacked the effective proteins necessary for it to exhibit antibacterial activity for some specific strains while being very effective against other specific strains. Thus, one may conclude, that Apis mellifera venom may have a specific mechanism that allows it to have an antibacterial effect on certain susceptible bacteria, but that mechanism is not well understood.