• Food Science of Animal Resources
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• v.37 no.4
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• pp.502-510
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• 2017

This study investigated bacterial growth-inhibitory effect of 69 therapeutic herbal plants extracts on 9 bacterial strains using a disc diffusion assay. Especially, the antimicrobial activity of Psoraleae semen, which showed different activity on pathogenic Gram-positive and Gram-negative bacteria, was evaluated by MIC (minimal inhibition concentration) and biofilm formation assay. The effect of Psoraleae semen extract on bacterial cell membranes was examined by measurement of protein leakage (optical density at 280 nm) and scanning electron microscope (SEM). No clear zone was formed on discs containing Gram-negative bacteria, but Gram-positive bacteria exhibited clear zones. The MICs of Psoraleae semen extract were $8{\mu}g/mL$ for Streptococcus mutans, and $16{\mu}g/mL$ for Enterococci and Staphylococcus aureus. In addition, biofilm formation was inhibited at concentration $8-16{\mu}g/mL$. Protein leakage values and SEM images revealed that cell membranes of Gram-positive bacteria were impaired following exposure to the extract. Further, the extract inhibited the growth of Listeria monocytogenes in sausages. These results indicate that Psoraleae semen extract could be utilized as a natural antimicrobial agent against Gram-positive bacteria.

• Pediatric Infection and Vaccine
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• v.4 no.1
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• pp.79-89
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• 1997

Purpose : Neonatal bacterial meningitis is the disease which clinical manifestations are nonspecific and several neurologic complications may occur. We studied neonatal bacterial meningitis, particularly in treatment and prognosis according to causative organisms -gram positive and gram negative bacteria- to assist in treatment of neonatal bacterial meningitis. Methods : We analysed twenty-four cases retrospectively who had been admitted in NICU or pediatric ward in Chung-ang Gil hospital from Jan. 1991 to Jun. 1996, and who had proven causative organisms in culture or latex agglutination[n test in CSF. Results : 1) The ratio of male to female was 2.4: 1. The mean birth weight and gestational age in cases with gram positive bacterial meningitis were $2.91{\pm}0.79kg$ and $38.4{\pm}2.74$ weeks and those in cases with yam negative bacterial meningitis were $3.30{\pm}0.90kg$ and $37.7{\pm}3.33$weeks respectively. There was no significant difference between the two groups. 2) The perinatal predisposing factors were pematurity, mecoinium staining amnionic fluid, matemal diabetes and pregnancy-induced hypertension, etc. The clinical manifestations Were fever, seizure, poor oral intake and fontanel bulging, etc. There were eleven cases with early onset bacterial meningitis(four cases by gram positive bacteria, seven cases by gram negative bacteria), and thirteen cases with late onset bacterial meningitis(seven cases by gram positive bacteria, six cases by gram negative bacteria). There was no significant difference between the two groups in terms of onset. 3) There were eleven cases with yam positive bacterial meningitis and they were coagulase-negative staphylococci(three cases), group B streptococci(three cases), Staphylococcus aureus(two cases), Streptococcus viridans(two cases), and enterococci(one case). And there were thirteen cases with gram negative bacterial menir gitis and they were Escherichia coli(seven cases), Klevsiella pneumoniae(three cases), Pseudomonas aeruginosa(one case), Acinetobactor(one case) and Enterobacter(one case). 4) The initial CSF WBC counts in cases with yam negative bacterial meningitis were significantly higher than those in cases with gram positive bacterial meningitis but the CSF protein and glucose levels were no significant difference in the two groups statistically. 5) The number of cases with abnormal findings in brain ultrasonography was seven in gram positive bacterial meningitis and ten in gram negative bacterial meningitis. 6) There were relatively high sensitivity to penicillin derivatives, the first generation cephalosporin and vancomycin in gram positive bacteria and to the third generation cephalosporin and amikacin in gram negative bacteria. 7) The mortality rate was 20.8%(5 cases were expired or discharged hopelessly). There was no significant difference between the two groups in prognosis. Conclusions : We recommend active treatment in noenatal bacterial meningitis to improve prognosis because the prognosis is poor.

• Journal of Microbiology and Biotechnology
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• v.14 no.2
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• pp.317-323
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• 2004

This study was performed to investigate the antimicrobial effects of hetero-chitosans and their oligosaccharides against three Gram-negative bacteria and five Gram-positive bacteria. Nine classes of hetero-chitosan oligosaccharides consisted of partially deacetylated chitosans; 90％, 75％, and 50％ deacetylated chitosans. Based on molecular weight, they were prepared using an ultrafiltration membrane reactor system. Seventy-five percent deacetylated chitosan showed the highest antimicrobial acitivity as compared with the 90％ and 50％ deacetylated chitosan, and the activity was dependent on their molecular weights. It was apparent that the growth of Gram-negative bacteria is less inhibited in the presence of the heterochitosans and their oligosaccharides than Gram-positive bacteria. These results revealed that the antimicrobial effects of hetero-chitosans and their oligosaccharides depend on the degree of deacetylation, and their molecular weights.

• Korean Journal of Pharmacognosy
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• v.23 no.4
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• pp.240-247
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• 1992

Impatiens balsamina Linne(Balsaminaceae) known as 'BONG SUN HWA' in Korea and has been used for the treatment of scrofulosis, carbunculus and dysenteria etc. Bioassay-guided fractionation of MeOH extract from the whole plants of Impatiens balsamina has afforded a simple naphthoquinone derivative, 2-methoxy-1,4-naphthoquinone. The structure of this compound was established by spectroscopic methods. This compound possessed strong antifungal activity against Candida albicans, AspergiIlus niger, Crytococcus neoformans and Epidermophyton floccusum. The activity of 2-methoxy-1,4-naphthoquinone on E. floccusum $(MIC{\;}:{\;}5.0{\;}{\mu}g/ml)$ was the same potency as that of nystatin. It showed also strong antibacterial activity against gram-positive bacteria Bacillus subtilis as well as gram-negative bacteria Salmonella typhimurium. Although the activity of this compound on gram-negative bacteria was lower than that of gram-positive bacteria.

• Journal of Korean Society of Environmental Engineers
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• v.32 no.12
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• pp.1141-1146
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• 2010

Isolated the heterotrophic aerobic bacteria in sandfiltered water on NA and TSBA solid medium, selected 8 dominant species and identified by Sherlock System. Each samples are irradiated 0, 5, 16, 40 and $60\;mJ/cm^2$ using on CBD (Collimated Beam Device) Medium Pressure UV lamp after these identified bacterium did liquid culture how to make $10^6{\sim}10^7\;cells/mL$ suspended in dilution water. Then cultured bacteria are estimated inactivation rate on plate media. Identified Gram positive group are Bacillus Subtilus, Bacillus megaterium, Rhodococcus erythropolis and Microbacterium laevaniformans; Gram negative group are Pseudomonas vesicularis, Pseudomonas pseudoflava, Alcaligenes paradoxus and Zooglea ramigera. These isolation of bacterium are more stronger reference strain and high resistance of MP UV irradiation, Besides Gram negative bacterium are more sensitive Gram positive bacterium on MP UV dose. Now we are estimating to $60{\sim}100\;mJ/cm^2$ MP UV dose for efficient disinfection in water treatment plant.

• The Korean Journal of Physiology and Pharmacology
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• v.13 no.1
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• pp.39-47
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• 2009

Gaegurin 4(GGN 4), an antimicrobial peptide isolated from a Korean frog, is five times more potent against Gram-positive than Gram-negative bacteria, but has little hemolytic activity. To understand the mechanism of such cell selectivity, we examined GGN4-induced $K^+$ efflux from target cells, and membrane conductances in planar lipid bilayers. The $K^+$ efflux from Gram-positive M. luteus(2.5 ${\mu}g/ml$) was faster and larger than that from Gram-negative E. coli(75 ${\mu}g/ml$), while that from RBC was negligible even at higher concentration(100 ${\mu}g/ml$). GGN4 induced larger conductances in the planar bilayers which were formed with lipids extracted from Gram-positive B. subtilis than in those from E. coli(p<0.01), however, the effects of GGN4 were not selective in the bilayers formed with lipids from E. coli and red blood cells. Addition of an acidic phospholipid, phosphatidylserine to planar bilayers increased the GGN4-induced membrane conductance(p<0.05), but addition of phosphatidylcholine or cholesterol reduced it(p<0.05). Transmission electron microscopy revealed that GGN4 induced pore-like damages in M. luteus and dis-layering damages on the outer wall of E. coli. Taken together, the present results indicate that the selectivity of GGN4 toward Gram-positive over Gram-negative bacteria is due to negative surface charges, and interaction of GGN4 with outer walls. The selectivity toward bacteria over RBC is due to the presence of phosphatidylcholine and cholesterol, and the trans-bilayer lipid asymmetry in RBC. The results suggest that design of selective antimicrobial peptides should be based on the composition and topology of membrane lipids in the target cells.

• Textile Coloration and Finishing
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• v.23 no.2
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• pp.69-75
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• 2011

A pre-treatment process has been developed for natural dyeing of wool by which the dyed materials have been imparted antimicrobial efficacy against both gram-positive and gram-negative bacteria durable up to 20 washes. In this process, wool fabrics were treated with citric acid under oxidizing condition prior to dyeing. The treated fabrics were then dyed with four different types of natural dye powders obtained from leaves of silver oak, wattle, tanner's senna and flame of forest. All the natural dyes produced yellowish brown colour on wool fabrics. The washing and light fastness properties of the fabrics subjected to pre-treatment were one grade higher compared to those of the dyed fabrics without pre-treatment. The pre-treated wool fabrics showed antimicrobial efficacy against both gram-positive bacteria (Staphylococcus aureus) and gram-negative bacteria (Escherichia coli). The fabrics dyed without pre-treatment showed antimicrobial efficacy against gram-positive bacteria (Staphylococcus aureus) only. The durability of antimicrobial efficacy was higher in pre-treated and dyed wool fabrics compared to the dyed fabrics without pre-treatment.

• YAKHAK HOEJI
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• v.10 no.4
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• pp.7-20
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• 1966

1. Of the 32 extracts from Genus of lishenes broth tested for antimicrobial activity, 28 inhibited at least one of the 3 test microorganisms used. 2. Twenty seven lichnes broth from 32 species tested were active against at least one of the Gram-positive bacteria M. pyogenes var, aureus 203 p, and twenty four lichenes broth from 32 Species tested were active against at least one of the Gram-positive bacteria Bacillus subtilis ATCC 6633. 3 Twenty five lichenes broth from 32 species tested were active against at least one of the Gram-negative bacteria Escherichia coli 0.126. 4. The antibiotic substances in lichenes were readily extracted by organic solvents.

• Korean Chemical Engineering Research
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• v.53 no.5
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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.

• Applied Biological Chemistry
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• v.17 no.2
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• pp.117-124
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• 1974

The 23 representative bacteria were studied for the glucosamine contents which represent the glycolipid content of the cell wall. The distribution of glycolipid in various bacteria was examined and the relationship between the glycolipid contents and the Gram stain was elucidated. The results were as follows: 1. The contents of glucosamine in the glycolipid of Gram negative and variable bacterial cell wall were large ranging from the least 0.04 ${\mu}g$ of Proteus vulgaris to the largest 2.48 ${\mu}g$ of Aerobacter aerogenes. The Gram positive bacteria and only those Gram positive among Bacilli contained less than 0.02 ${\mu}g$ of glucosamine contents. The least glucosamine containing Gram positive bacteria were Corynebacterium sepedonicum and Staphylococcus aureus. It could generally be said that the Gram negative and variable bacteria contain the higher content of glucosamine in the cell wall than the positives. 2. The bacteria were better stained by the Gram solution after the extraction of glycolipid from the cell wall than those without extraction. 3. The four infrared spectra of glycolipids obtained from Aerobacter aerogenes, Bacillus circulans, Pseudomonas fluorescens, and Salmonella typhirurium showed all the similar characteristics. All showed the existence of groups; OH, C-O, C-O-C, $CH_2+CH_3$, amide band, fatty acid ester band and ester carbonyl bond.