• Journal of the Korean Applied Science and Technology
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• v.37 no.6
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• pp.1635-1645
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• 2020

In this study would like to find extending or increasing the efficacy of the antibiotic substance for the strains with resistance to antibiotics or persister cells by inhibition of the resistance. This study was used different species of 'legal high' plants leaves from Leonotis leonurus, Mitragyna speciosa, and seeds from Ipomoea murucoides with antibiotics which are Amoxicillin, Chloramphenicol, Ciprofloxacin, Kanamycin, Oxacillin, and Vancomycin. Legal highs were extracted with methanol. Minimum inhibitory concentration(MIC) testing for a range of antibiotics with extracts of plant was fulfilled by broth dilution methods. In this essay, it was determined in a microdilution assay utilizing suspended in ISB up to a final concentration of 512㎍/ml in 96 wells microtitre plates, threefold and serial dilutions. After that, the microplates were kept in incubator between 35℃ and 37℃ for overnight. Leonotis leonurus, Mitragyna speciosa, and Ipomoea murucoides of Legal highs (512㎍/ml) investigated small activity to inhibit against pathogens which are susceptible Staphylococcus aureus, resistant Staphylococcus aureus, susceptible Enterococcus faecalis, resistant Escherichia coli.

• Mycobiology
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• v.36 no.4
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• pp.249-254
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• 2008

Minimal growth inhibitory concentrations (MICs) of chitosan acetate (M.W. 60 kDa) on heterotrophic bacteria (strains MK1, S, and R) isolated from the soft-rotten tissues of Neungee mushroom (Sarcodon aspratus) were measured. The slimy substance produced by the MK1 strain was responsible for the diseased mushroom’s appearance. The S and R strains were members of the Burkholderia cepacia complex. These strains showed different levels of susceptibility toward chitosan acetate. The MIC of chitosan acetate against the MK1 and S strains was 0.06%. The MIC against the R strain was greater than 0.10%. Survival fractions of the MK1 and S strains at the MIC were $3\;{\times}\;10^{-4}$ and $1.4\;{\times}\;10^{-3}$ after 24 h, and $2\;{\times}\;10^{-4}$ and $7\;{\times}\;10^{-4}$ after 48 h, respectively. Survival fractions of the R strain after 24 and 48 hr at 0.1% chitosan acetate were $1\;{\times}\;10^{-2}$ and $6.9\;{\times}\;10^{-3}$, respectively. Compared to the MK1 and S strains, the low susceptibility of the R stain towards chitosan acetate could be due to the ability of the R strain to utilize chitosan as a carbon source. Thirty-eight percent of Neungee pieces treated in a 0.06% chitosan acetate solution for $2{\sim}3$ second did not show any bacterial growth at 4 days, whereas bacterial growth around untreated mushroom pieces occurred within 2 days. These data suggest that chitosan acetate is highly effective in controlling growth of indigenous microorganisms on Neungee. The scanning electron micrographs of the MK1 strain treated with chitosan revealed a higher degree of disintegrated and distorted cellular structures.

• Microbiology and Biotechnology Letters
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• v.43 no.3
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• pp.187-194
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• 2015

In this study, L. plantarum, when reacting with the culture media of potential pathogenic bacteria, exhibited an increase in growth rate and antimicrobial activity. In order to examine the characteristics and the nature of the reaction with the bacteria, this study carried out experiments involving culturing the test bacteria in M9 minimal media. Subsequently, the supernatant was incrassated by the decompression-drying method. Through colony forming unit assay, it was confirmed that L. plantarum had the function of growth inhibition to various bacteria. After culturing L. plantarum with bacterial media, the growth rate of L. plantarum was measured by absorbance (OD₆₀₀), the results showed that the growth rate (E. coli treatment group: OD₆₀₀ = 0.848, S. typhimurium treatment group: OD₆₀₀ = 0.848) increased, as compared with the non-treated control group (OD₆₀₀ = 0.48). In contrast, the concentrate itself did not induce the growth of L. plantarum. These results were observed as a universal phenomenon of the Lactobacillus species. Moreover, the increase in antimicrobial activity was observed in L. plantarum, which reacted with the culture media of E. coli and S. typhimurium, through a disc diffusion assay, and the result of growth inhibition against various bacteria was induced. Finally, based on the analysis results of the characteristics of bacteria culture media, which increased the growth rate of L. plantarum and antibacterial activity, the bacterial media had a tolerance for catabolic enzymes, pH 2−8 and heat. Therefore, this substance can be said to be a small molecule which is highly stable under various conditions.

• Journal of Life Science
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• v.29 no.1
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• pp.84-89
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• 2019

Previous screening of novel antibacterial agents revealed that some bacterial isolates exhibited antibiotic activity against both gram-positive and gram-negative bacteria and that they showed antibacterial activity, even against methicillin-resistant Staphylococcus aureus (MRSA). Among these isolates, one bacterial strain, BCNU 1204, was identified as Pseudomonas aeruginosa using phenetic and phylogenetic analysis, based on 16S ribosomal RNA gene sequences. The maximum productivities of antimicrobial substances of BCNU 1204 were obtained after being cultured at $35^{\circ}C$ and pH 7.0 for 4 d in King's medium B (KMB). Dichloromethane (DCM) and ethylacetate (EA) extracts of P. aeruginosa BCNU 1204 exhibited strong antimicrobial activity, particularly against gram-positive bacteria. The EA extracts exhibited broad-spectrum activity against antibiotic resistant strains. Fraction 5-2, was obtained by recycling preparative liquid chromatography (LC) and preparative thin-layer chromatography (TLC) and was identified as phenazine-1-carboxylic acid belonging to phenazines using gas chromatography and mass spectrometry (GC/MS). Its minimum inhibitory concentration (MIC) values were $25{\mu}g/ml$, $50{\mu}g/ml$, ${\geq}25{\mu}g/ml$, and ${\geq}50{\mu}g/ml$ for MRSA CCARM 3089, 3090, 3091, and 3095 strains, respectively. P. aeruginosa BCNU 1204 may be a potential resource for the development of anti-MRSA antibiotics. Additional research is required to identify the active substance from P. aeruginosa BCNU 1204.

• Journal of Food Hygiene and Safety
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• v.22 no.4
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• pp.317-322
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• 2007

The purpose of this study was to investigate the antibacterial effect of films on shelf-life and microbiological safety of mackerel. Effects of antimicrobial films against total aerobic bacteria, Escherichia coli O157:H7, Listeria monocytogenes, Vibrio parahaemolyticus in mackerel were evaluated during storage of 5-14 days at $5^{\circ}C,\;10^{\circ}C\;and\;15^{\circ}C$. Antimicrobial films were developed with addition of a natural substance, wasabi extracts (Wasabia japonica). At $5^{\circ}C$ storage, growth of total aerobic bacteria, Escherichia coli O157:H7, Listeria monocytogenes were inhibited higher than at 10 and $15^{\circ}C$. Especially, the numbers of V. parahaemolyticus were decreased gradually at $5^{\circ}C$ even in the control sample, and about $1\;log_{10}cfu/g\;and\;1.8\;log_{10}cfu/g$ reductions were observed at 1 and 4 days, respectively. After 7 days, V. parahaemolyticus in all samples were not detected. There is a limit of a single treatment of antimicrobial film to prolong shelf-life of mackerel. The synergistic effect of antimicrobial film were shown by addition of $5^{\circ}C$ refrigeration.

• The Journal of the Korean Society for Microbiology
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• v.35 no.3
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• pp.225-237
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• 2000

Vibrio vulnificus, a halophilic vibrio is an estuarine gram-negative bacteria that is associated with severe and frequently fatal wound infections and life-threatening septicemia. Bacteriocins are defined as antibacterial substance produced by various species of bacteria which are usually active against closely related organisms. Bacteriocins have found widespread application in epidemiological studies as specific markers of bacteria. It was proposed by Ha et al. (1990. J. Korean. Soc. Microbiol. 25: 586.) to give the bacteriocins produced by V. vulnificus the name "vulnificins". In the present study, a total of 72 strains of V. vulnificus isolated from patients and oysters were subjected to screen potential producers and indicators of vulnificin, applying ultraviolet induction method. Sensitivity of several strains of Serratia marcesans, Pseudomonas aeruginosa, Shigella flexneri, Salmonella typhi and Yersinia enterocolitica to vulnificins were also examined out. All the tested strains of V. vulnificus produced vulnificins active against indicator strains with various different inhibitory patterns. The spectrum of vulnificin activity and sensitive spectrum of indicator strains were considerably broad. Interestingly, almost all strains of S. marcescens, P. aeruginosa, Salmonella sp., Shigella sp. and Y. enterocolitica tested were sensitive to 1-7 vulnificin(s). Taken together, the present study demonstrated that all of the isolates of V. vulnificus produced vulnificins and that 8 good vulnificin producers and 10 good indicators were detected. These strains can be employed efficiently for establishing vulnificin typing scheme of V. vulnificus and for the detection of bacteriocinogeny and sensitivity in V. vulnificus. Biological role of vulnificin remains to be further elucidated.

• Food Science of Animal Resources
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• v.27 no.4
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• pp.509-516
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• 2007

Starters of lactic acid bacteria(LAB) were isolated from the commercial yoghurt products and the four isolates have been studied on their identification and some physiological characteristics. For the purpose of identification, microscopic examination, API test, and 16s rRNA gene sequencing were conducted. Isolate A from a yogurt product of local dairy company A was shown to be Gram-positive rod-shaped bacterium. All strains isolated were turned out to be as Lactobacillus paracasei by using a API 50 CHL kit. In contrast, isolate A was identified as a strain of Lactobacillus helveticus based on the 16S rRNA sequencing data, and L. casei ssp. casei for both B and D and L. paracasei for C. All the isolates survived the simulated gastric juice, pH 2.0 within 3 hours and sharply decreased in viability so that no viable cell was observed after 4.5 hours incubation. In addition, the four isolated strains were almost identical in antibiotic susceptibility to six different kinds of antibiotics including erythromycin ($15\;{\mu}g$), ampicillin ($10\;{\mu}g$), gentamycin ($10\;{\mu}g$), neomycin ($30\;{\mu}g$), but rather resistant to colistin ($10\;{\mu}g$) and streptomycin ($10\;{\mu}g$). It was noteworthy that four isolates were confirmed to produce antibacterial substance against foodborne pathogens of Gram-positive Staphylococcus aureus and Gram-negative Escherichia coli 0157:H7 as test organisms based on the inhibitory zones on an MRS soft agar medium. At presence, the inhibitory factor is unknown so that further studies are required to ascertain the active factor responsible for the inhibitory activities.

• Journal of dental hygiene science
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• v.12 no.2
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• pp.155-162
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• 2012

Somok, the heart wood of Caesalpinia sappan is used in traditional Chinese medicine. Adherence of S. mutans to the tooth surface can result in the formation of a dental plaque. This study was performed to investigate the antibacterial activity and bacterial adhesion of ethyl acetate extract from C. sappan against S. mutans ATCC 25175. The bacteria were cultured in brain heart infusion(BHI) broth, and then incubated under 5% $CO_2$ at $37^{\circ}C$ for 18~24 hours. The antimicrobial activity of the ethyl acetate extract of C. sappan was then examined using the paper disc methods and MIC. In addition, bacterial adherence to hydroxyapatite was also examined. The ethyl acetate extract was shown to produce inhibitory effects and had MIC values of 125 mg/ml against S. mutans ATCC 25175. The ethyl acetate extract inhibited adhesion of S. mutans to saliva coated-hydroxyapatite beads(S-HA). At 24 hr, the ethyl acetate extract significantly reduced the adherence of S. mutans to S-HA beads relative to the control. The isolated active substance was identified as brazilin($C_{16}H_{14}O_5$) by $^1H-NMR$ and $^{13}C-NMR$. Thus, the application of C. sappan can be considered a useful and practical method for the prevention of dental caries.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.47 no.3
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• pp.247-254
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• 2021

Acne vulgaris is a chronic inflammatory skin disease related to pilosebaceous unit. In acne lesions, hyperseborrhea, dysseborrhea, inflammatory event, and an imbalance in skin microflora, particularly an increase in Cutibacterium acnes (C. acnes) colonization comparing to other bacteria, have been observed. The objective of this study was to evaluate anti-acne effects of Artemisia annua extract (AAE) on antibacterial activity related to preservation of the balance in skin microbiome, inhibition of inflammation, and reduction of excessive sebum production. When C. acnes and Staphylococcus epidermidis (S. epidermidis) were co-cultured in the presence of AAE, the reduction of C. acnes growth by AAE was greater than that of S. epidermidis. In addition, when C. acnes was cultured in a medium containing AAE (C. acnes AAE), levels of cytokines such as interleukin-1β (IL-1β), tumor necrosis factor-α (TNF-α) and IL-6 and toll-like receptors-2 activity were decreased in comparison with C. acnes cultured in a medium without AAE (C. acnes CM). Moreover, AAE significantly inhibited excessive sebum production induced by palmitic acid. These results suggest that AAE, as a natural extract with various targets, can inhibit selective growth of C. acnes and inflammatory reactions derived from C. acnes, which are the main causes of acne, and consequently can be used as a substance to alleviate acne by reducing excessive sebum formation.

• The Journal of the Korean Society for Microbiology
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• v.11 no.1
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• pp.27-32
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• 1976

Sodium amylosulfate(SAS) has been reported to be an effective substance to inactivate the anti-bacterial activity of blood in blood culture media. The advantage of the use of SAS over sodium polyanethol sulfonate(SPS) is that it does not inhibit the growth of some bacteria! species which are known to be inhibited by SPS. As to S. typhi, SPS is reported to enhance the growth, however the effect of SAS on this organism is not known as yet. Using 43 strains of S. typhi, isolated from clinical materials, the authors tried to determine the effect of SAS on this organism. The methods used for this study were : the SPS and SAS paper disk I sensitivity test, tests on the growth in trypticase soy broth(TSB) with SPS and with SAS, and experimental blood culture in SPS and SAS incorporated TSB. The following results were obtined. 1). S. typhi strains with the turbidity of No. 0.5 tube of MacFarland nepherometer were inoculated onto Mueller-Hinton plate and 1mg disk of SPS and SAS were applied. After 24-hour incubation, none of the 43 strains showed inhibition zone by SPS disk, but all of them showed zones by SAS disk with a mean zone diameter of 9.5mm(Table 1). 2) Inocula consisting of one to 54 viable counts of 37 strains were inoculated into three different media; TSB with 0.05% SPS, TSB with 0.05% SAS and TSB alone. After 24-hour incubation the mean of the optical densities of each medium were 0.483, 0.482 and 0.459 respectively, showing that SAS does not inhibit the growth of S. typhi. Moreover it was shown that there was no correlation between the amount of inocula and growth(Table 2 and Fig. 1). 3). Each set of media in 5 ml amounts consisting of one tube of TSB with 0.05% SPS, one tube of TSB with 0.05% SAS and two tubes of TSB were inoculated with 8, 64. 640 and 6400 viable counts of bacteria. Then 0.5 ml of fresh normal blood was added to all tubes except for one tube of TSB. Macroscopic observation after 24 hour incubation showed a heavy growth in all tubes except for the tube of TSB plus blood, which showed only a light growth in the tube of the heaviest inoculum. This result clearly demonstrates that the growth of S. typhi is inhibited by some antibacterial activities of fresh blood, which are counter acted by SPS and SAS(Table 3). Between SPS and SAS, there was no significant difference found(Table 4 and Fig. 2). With all these results it can be postulated that the addition of SAS into a rountine blood culture media may raise the positivity of S. typhi isolation and shorten the incubation period.