• 한국식품과학회지
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• 제48권6호
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• pp.560-564
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• 2016

본 연구에서는 지금까지 알려진 바와 달리 항균활성의 적용범위가 모호한 actinonin을 대표적 식중독균인 B. cereus에 적용함으로써 식중독균에 대한 항균 효과에 대해 연구하였다. 계대배양된 대수기의 B. cereus에 actinonin을 처리하여 생장 저해 여부를 확인하였고, 96-well plate를 이용한 broth micro-dilution 방법과 agar disk diffusion 방법을 통해 actinonin의 B. cereus에 대한 항균활성을 측정해본 결과, actinonin의 농도에 비례하여 B. cereus의 생장이 저해되는 것으로 나타났다. 또한, actinonin의 처리에 따른 B. cereus의 세포 독성 측정 결과 actinonin이 B. cereus의 세포 독성 또한 억제하는 것을 확인하였다. 따라서, actinonin은 천연항균물질로서 B. cereus에 의한 식품 오염을 억제하고 식중독 예방 및 잠재적 치료제로서 적용 될 가능성이 있는 것으로 관찰되었으며, 나아가 다른 식중독균들에 대한 적용 가능성 탐색과 관련한 연구가 필요할 것으로 생각된다.

• Archives of Pharmacal Research
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• 제21권1호
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• pp.6-11
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• 1998

The activities of two types of antiulcer agents against 9 strains of Helicobacter pylori (H. pylori) were determined by the agar dilution method. The antiulcer agents were YJA20379, a newly synthesized proton pump inhibitor developed by Yung-jin Pharmaceutical company, and omeprazole. Both compounds were found to have significant activities against this organism. The MIC values of YJA20379 and omeprazole were 11.7 and $31.25{\mu.g/ml}$ respectively. In addition, the inhibitory potency of both compounds was investigated on H. pylori urease which is believed to be an important colonization and virulence factor in the pathogenesis of gastritis and peptic ulcers. These compounds dose-dependently inhibited urease extracted with distilled water and their $IC_50$ values were $16.4{\times}10^{-5} M and 14.3{\times}10^{-5}M,$ respectively. In addition, a pH-dependent study to determine whether inhibitory potency would be activated by acid condition was performed. It was found that unlike omeprazole, YJA20379 was not affected by acid condition. To determine the inhibition pattern and optimal concentration of substrate, kinetics were evaluated at various pH levels (pH 5.0, 7.0, and 8.5). The data show that YJA20379 noncompetitively inhibited H. pylori urease and $K_M/K_i$values were 0.96 $mM/60{\mu}M (pH 5.0), 0.56 mM/141.5 {\mu}M (pH 7.0)$, and $1.94mM/34{\mu}M (pH 8.5)$, respectively. Based on data obtained, it is concluded that YJA20379 is a significant inhibitor of H. pylori growth and urease and therefore, taking these results into consideration, YJA20379 might be a beneficial therapy for gastritis and peptic ulcers induced by H. pylori.

• 한국환경보건학회지
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• 제23권1호
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• pp.18-27
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• 1997

The isolation, morphological study and growth characteristics of the algae were investigated from Lake Chuam. The isolated algae were applied the Agal Growth Potential test. The method of isolation and purification of the algae were used to Agar plating(AP), nutrient enrichment(NE), dilution(DI) and micro capillary technique(MC). Total isolated algae were 21 species. They were composed of Cyanophyceae, Dinophyceae, Bacillariophyceae, Euglenophyceae and Chlorophyceae. The numbers of algal strain by isolation technique were highest in dilution(21 species), and those of the rests were showed in order of NE > MC > AP. The sizes of isolated Selenastrum and Scenedesmus were $1.8\pm 1.4 \mu m$, $3.3\pm 0.9 \mu m$ in diameter and $6.4\pm 2.3 \mu m$, $13.6\pm 1.9 \mu m$ in length respectively. The morphology of isolated algae and NIES-collection strain was very similar each other, but the size was smaller isolated algae than that of NIES-collection. The optimum culture condition of isolated Selenastrum and Scenedesmus was about 30$\circ$C(25$\circ$C-35$\circ$C) in temperature and the maximum growth was appeared between 7,000 lux and 8,000 lux in the light intensity. The comparison of $\mu$(specific growth rate) on the concentration of nutrients such as nitrate and phosphate, isolated Selenastrum was appeared maximum it at 1.0 mg $NO_3-N/l$ but NIES-collection strain was showed 95% of maximum it at same nitrate concentration. Maximum g of isolated algae and NIES-collection strain in Scenedesmus onto nitrate concentration were very similar with the result of selenastrum. The specific growth rates of isolated algae and NIES-collection strain on the gradient concentration of phosphate were showed 0.72/day and 0.70/day at 0.02 mg $PO_4-P/l$ in Selenastrum but those of Scenedesmus were appeared 0.61/day and 0.57/day at same concentration $PO_4-P$.

• 한국치위생학회지
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• 제12권3호
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• pp.641-646
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• 2012

Objectives : The purpose of this study is to analyze the sterilizing effects of toothbrushes by administering bacteria into toothbrushes and reproducing the antibacterial effects using a microwave oven. Methods : The heads of four-row mid-strength toothbrushes were cut, put in a bacterial solution ($3{\times}10^9cells/ml$) for vortexing, and sterilized with microwaves for 0, 30, and 60 seconds. They were then moved into four tubes containing DW 10 ml and suspended in a vortex mixer for two minutes to separate bacteria from them. DW 9ml was added by 1ml of bacteria for dilution of $10{\sim}10^6$ times. It was then administered to the BHI agar plate by 0.1ml and cultured at $37^{\circ}C$ for 24 hours. Total number of bacteria adhered to a toothbrush was obtained by multiplying the number of colonies by the dilution factor. The experiment was done in the first, second, and third step, being repeated in a normal temperature drier ($23^{\circ}C$) after 5, 9 and 24 hours. Results : The results of the experiment revealed that the sterilizing effects were 95% or over. When toothbrushes were sterilized for 60 seconds, the number of colonies is about 11 after drying for 5 hours, 7 after drying for 9 hours and 2 after drying for 24 hours. The sterilizing effects reached 98% when the bacteria-administered toothbrush was sterilized for 1 minute after drying for 24 hours. Conclusions : The results demonstrated that toothbrush sterilizing by using microwave is a suitable way to prevent cross-contamination of toothbrushes by oral bacterial infection and thus easy to use at home. However, this study suggests that toothbrush sterilizing by using microwave should be limited within two times a week because the physical properties of toothbrush might be changed.

• 대한미생물학회지
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• 제13권1호
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• pp.43-48
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• 1978

항균제내성(抗菌劑耐性)인 Salmonella typhi를 공시(供試)하여 chloramphenicol(Cm), tetracycline(Tc), ampicillin(Ap), kanamycin(Km) 및 rifampicin(Rif)의 항균작용(抗菌作用)을 한천평판희석법(寒天平板稀釋法)(평판법(平板法))과 broth 희석법(稀釋法)(broth법(法))으로 비교(比較)하였다. 공시균(供試菌)의 최소발육저지농도(最少發育沮止濃度)(MIC)를 보면 Cm, Tc 및 Rif에 있어서는 평판법(平板法)과 broth법(法) 사이에 유의(留意)할만한 차이(差異)는 없었으나 Km에 있어서는 broth법(法)의 MIC가 평판법(平板法)보다 높은 것이 약(約) 반수(半數)있었고 Ap에 있어서도 소수(少數) 있었다. Cm과 Rif는 대부분(大部分)의 공시균(供試菌)에 대(對)하여 정균적(靜菌的)으로 작용(作用)하였으나 Tc, Ap 및 Km은 살균적(殺菌的)으로 작용(作用)하였고 그 작용(作用)은 균주(菌株)에 따라 차이(差異)가 있었다.

• International Journal of Oral Biology
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• 제31권1호
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• pp.7-10
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• 2006

Mitis-salivarius sucrose bacitracin(MSB) medium is widely used in the selective isolation of mutans streptococci(MS), a designation for a group of oral cariogenic species. Recently, we have isolated three bacterial strains grown on MSB agar from human dental plaques. The three strains exhibited biochemical characteristics similar to those of the biotype IV of MS, with the exception that they manifested a positive reaction for arginine deaminase. The objective of this study was to identify and characterize these three clinical isolates. The bacteria were identified with biochemical tests as well as by 16S rDNA cloning and sequencing. In order to compare the antibiotics susceptibility of the clinical isolates with that of type strain, the minimum inhibitory concentrations of 9 antibiotics were determined using broth dilution assays. The results identified all of our three clinical isolates as Enterococcus faecalis. All E. faecalis strains were found to be susceptible to penicillin G, amoxicillin, augmentin, and vancomycin, but were resistant to ciprofloxacin, cefuroxim axetil, and clindamycin. Our findings indicate that E. faecalis is capable of growing on MSB agar, and suggest that the MSB medium be improved so that only MS should be recoverable on the medium, as originally devised for their selection.

• Journal of Applied Biological Chemistry
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• 제49권4호
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• pp.165-170
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• 2006

The antifungal activity of crude methanolic extract and fractions from Yucca smalliana Fern. leaves, roots and flowers were investigated in vitro against a panel of plant pathogenic fungi. The minimal inhibitory concentration(MIC) was determined by an agar dilution method. Preliminary liquid culture and agar plate assays showed that the growth of Fu sarium oxysporum, Phytophthora capsici, Rhizoctonia solani and Botrytis cinerea were inhibited by Y. smalliana extracts. The extracts from flowers and leaves showed antifungal activity of 64.0% and 34.0% against F. oxysporum, 66.0% and 62.0% against P. capsici, and 27.0% and 41.0% against B. cinerea, respectively. The methanolic extract from Y. smallina leaves in distilled water was fractionated using solvents of increasing polarity: hexane, ethyl acetate and butanol. These fractions had a broad spectrum of antifungal activity, found to reside entirely in the butanol and aqueous fraction. The aqueous fraction showed inhibition rate of 60.0, 67.8, 84.6 and 58.3% against F. oxysporum, R. solani, C. gloeosporioides, and B. cinerea, respectively, and the butganol fracgtion showed 36.0, 46.0, 66.1 and 58.3%, respectively. Phenolics(e.g. flavonoids, steroids and terpenoids) were observed in the thin layer profile of the different fractions. Leave extract showed a prominent antioxidant activity totally scavenging the free radical of DPPH at a concentration of 1 mg/ml.

• 약학회지
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• 제34권1호
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• pp.54-63
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• 1990

These studies were made to assess the present stage of resistance of Shigella species to antibiotics and to find characteristics of R-plasmid of these bacteria. From 1986 to 1988, 125 strains of Shigella species were isolated from patients specimens collected in Chung Cheong-do Hospital, Kyunghee Medical Center, city an provincial health & environmental institutes. These specimens were tested for resistance to 12 kinds of antimicrobial agents by agar dilution method. Using Muller-Hinton agar for the assay of drug resistance and Trypticane Soy Broth as propagating medium for conjugation. All the strains (100%) were resistant to one or more antibiotics. Drug resistance patterns of isolated strains were found as the highest resistance to ampicillin (98%) in 1986, to tetracycline (98%) in 1987, to tetracycline (100%) in 1988, all strains were sensitive to gentamicin, amikacin, tobramycin. Chronologically, resistance decreased gradually as it was shown in relation to kanamycin, rifampicin in 1986, 1987 and 1988, (4%, 2%) (4%, 2%) (0%, 0%) respectively. But, resistance was increased year by year as it was shown in relation to tetracycline, nalidixic acid, streptomycin in 1986, 1987, 1988 (89%, 19%, 45%) (98%, 46%, 71%) and (100%, 58%, 88%). The resistance in correlation to more than 5 drugs, which was 13 strains among 47 strains in 1986, 38 strains among 87 strains in 1987, 23 strains among 26 strains in 1988, was increased gradually. In the transfer test of drug resistance by conjugation methods, the rate which was 3 strains (50%) in 1986, 8 strains (62%) in 1987, 3 strains (100%) in 1988, was increased gradually. When the donor strains were conjugated with the recipient strains, the conjugation rate was high in the multiple resistant strains. The relationships of transferring patterns of drug resistance and molecular weight of R-plasmid were variable. However, only a plasmid which has more than 35 Mgd was transferred.

• 셀메드
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• 제2권2호
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• pp.20.1-20.5
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• 2012

$Gynura$ $segetum$ (Lour.) Merr. ($Compositae$) is a well recognized medicinal plant in Indonesia and Malaysia. It is believed to have an anticoagulant effect and is used in treating snake-bites, inflammations and other skin afflictions. This study was carried out to evaluate the antimicrobial effects of $Gynura$ $segetum$ leaves extracts and its fractions. The chemical compositions of the active extracts were also determined. The antimicrobial activities of different solvent extracts of leaves of $Gynura$ $segetum$ were evaluated using the agar well-diffusion method. The Minimum Inhibitory Concentration (MIC) of the active subfractions was determined by the tube dilution method. Gas Chromatography-mass spectrometry (GC-MS) analysis was carried out to identify the chemical compositions of the active extracts. The ethyl acetate fraction and its subfraction E4 performed potent antimicrobial activities and fifteen known chemical constituents were identified by GCMS analysis as 4-vinylphenol, 1-tetradecene, phenol, 2,4-bis(1,1-dimethylethyl), 1-hexadecene, E-15-heptadecenal, hexadecanoic acid, 1,2-benzenedicarboxylic acid, dibutyl ester, 1-docosene, octadecanoic acid, 1-eicosene, cyclotetracosane, 1,2-benzenedicarboxylic acid, bis(2-ethylhexyl)ester, butanedioic acid, monomethyl ester, niacin and 4-hydroxy-benzoic acid. The results of this study suggested a connection between the antimicrobial activities and the chemical structures. The plant may be used as a potential source for antimicrobial agents.

• 한국응용약물학회:학술대회논문집
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• 한국응용약물학회 1996년도 춘계학술대회
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• pp.197-197
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• 1996

Helicobacter pylori (H. pylori) is a microaerophilic spiral bacterium and infection by it in the human stomach causes gastritis, furthermore, it is considered to be involved in the pathogenesis of peptic ulcers and the development of gastric carcinoma. We assessed the inhibitory activity of new antiulcer drugs against Helicobacter pylori. The activities of new antiulcer agents against Helicobacter pylori strains were determined by the standard agar dilution method with blood agar base #2, supplemented with 5% sheep blood and 4 antibiotics to support growth of these organisms. They were inoculated by multipoint inoculator and incubated at 37$^{\circ}C$ for 3 days under microaerophilic atmosphere. The MIC of antiulcer agents was the lowest concentration that inhibited visible growth of these organisms. According to results of various biochemical tests, these bacteria were identified as Helicobacter pylori strains. And the MIC results showed that the strains were very susceptible to omeprazole and YJA20379s. Some of YJA20379s were more potent than omeprazole. These results suggest that our new antiulcer drugs have potent inhibitory activity against Helicobacter pylori, so that our new antiulcer drugs might be useful for the clinical eradication of gastrointestinal Helicobacter pylori.