• Korean Journal of Clinical Pharmacy
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• v.7 no.1
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• pp.40-44
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• 1997

Helicobacter pylori(HP) has been implicated as the cause of acute and chronic gastritis, peptic ulcer, and gastric carcinoma. To date the most successful treatment in eradicating HP is known to be the combination of two or more antibiotics with an anti-ulcer drug. In this study, in vitro antimicrobial activity against two was assessed, when proton pump inhibitors (PPIs), omeprazole and lansoprazole, were added to antibiotics at different concentrations. The assays in the absence of PPIs gave minimum inhibitory concentration(MIC) value of 0.63 mg/l for amoxicillin, 4 mg/l for tetracycline, 0.08 mg/l for clarithromycin and 0.16 mg/l for azithromycin. At the concentrations of 125 mg/l, 25 mg/1 and 0.5 mg/l of omeprazole, and the concentrations of 31.25 mg/l, 6.25 mg/l and 1 mg/l of lansoprazole, the MICs of clarithromycin and azithromycin were reduced by $50\%$. Also, lansoprazole at the highest concentration 31.25 mg/l reduced the MIC of amoxicillin by $50\%$, and omeprazole at the highest concentration of 125 mg/l reduced the MIC of tetracycline by $50\%$. In conclusion, the in vitro combination of PPIs and antibiotics led to improvement in the MIC of antibiotics against HP associated gastric disease.

• Korean Journal of Veterinary Service
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• v.38 no.2
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• pp.65-70
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• 2015

The present study was to investigate in vitro antimicrobial effects of propolis against six different fish bacterial pathogens, Aeromonas hydrophila, Edwardsiella tarda, Vibrio vulnificus, V. parahaemolyticus, A. salmonicida subsp. masoucida, A. salmonicida subsp. salmonicida) using minimum inhibitory concentration (MIC) and minimum bacteriocidal concentration (MBC) tests. In the results, propolis exhibited antimicrobial activity against all bacteria used in the present study, but there was no marked difference in bacterial species except Vibrio species. Collectively, propolis was thought to be an usefulness antimicrobial substance for controlling bacterial diseases in the fish industry.

• Journal of dental hygiene science
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• v.6 no.4
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• pp.251-254
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• 2006

In the current research for natural product with antimicrobial effects, various extracts of Mulberry Leaves against microorganisms were evaluated in terms of the minimum inhibitory concentrations(MIC). In general, Candida albicans was more antimicrobial activity than the other microorganisms such as Streptococcus mutans, Staphylococcus epidermis, and Staphylococcus aureus. The maximum activity was exhibited by ethanol extract of the leaves of Mulberry Leaves against Candida albicans (MIC, $1600{\mu}g/ml$). These results suggest that ethanol and water extracts of Mulberry Leaves have a potential antimicrobial activity.

• Journal of Microbiology and Biotechnology
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• v.34 no.4
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• pp.871-879
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• 2024

Our group had isolated Bifidobacterium breve strain BS2-PB3 from human breast milk. In this study, we sequenced the whole genome of B. breve BS2-PB3, and with a focus on its safety profile, various probiotic characteristics (presence of antibiotic resistance genes, virulence factors, and mobile elements) were then determined through bioinformatic analyses. The antibiotic resistance profile of B. breve BS2-PB3 was also evaluated. The whole genome of B. breve BS2-PB3 consisted of 2,268,931 base pairs with a G-C content of 58.89% and 2,108 coding regions. The average nucleotide identity and whole-genome phylogenetic analyses supported the classification of B. breve BS2-PB3. According to our in silico assessment, B. breve BS2-PB3 possesses antioxidant and immunomodulation properties in addition to various genes related to the probiotic properties of heat, cold, and acid stress, bile tolerance, and adhesion. Antibiotic susceptibility was evaluated using the Kirby-Bauer disk-diffusion test, in which the minimum inhibitory concentrations for selected antibiotics were subsequently tested using the Epsilometer test. B. breve BS2-PB3 only exhibited selected resistance phenotypes, i.e., to mupirocin (minimum inhibitory concentration/MIC >1,024 ㎍/ml), sulfamethoxazole (MIC>1,024 ㎍/ml), and oxacillin (MIC >3 ㎍/ml). The resistance genes against those antibiotics, i.e., ileS, mupB, sul4, mecC and ramA, were detected within its genome as well. While no virulence factor was detected, four insertion sequences were identified within the genome but were located away from the identified antibiotic resistance genes. In conclusion, B. breve BS2-PB3 demonstrated a sufficient safety profile, making it a promising candidate for further development as a potential functional food.

• Korean Journal of Clinical Pharmacy
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• v.5 no.2
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• pp.13-16
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• 1995

The Minimum Inhibitory Concentration (MIC) of a first-generation cephalosporin derivative, Cefazedone (CZD; $PAZERON^R$ inj.) was determined by the two-fold serial agar dilution method. The in-vitro antibacterial activity of CZD against a wide variety of clinical isolates was compared with those of other first generation cephalosporins such as Methylol Cephalexin (CEX), Cefazolin (CEZ), Cefadroxil (CDX), Cephradine (CED), Ceftezol (CTZ) and one of second generation cephalsporin antibiotics, Cefotaxime (CTX). CZD had the most potent inhibitory effect against Gram-positive strains, when compared to the first-generation cephalosporin antibiotics tested in this study and CTX. The geometric MIC mean of CZD for Gram-positive strains was calculated as 0.386 kg/m{\ell}$, and those of CEX, CEZ, CDX, CTZ, CED, and CTX were 6.073, 0.894, 3.399, 0.748, 7.884 and 1.502 $kg/m{\ell}$, respectively. In addition, the geometric mean of CZD for staphylococclJs aureus strains was obtained as 0.340 $kg/m{\ell}$ and those of CEX, CEZ, CDX, CTZ, CED, and CTX 6.145, 0.534, 4.126, 0.442, 10.51, and 2.500 $kg/m{\ell}$, respectively. Against Gram-negative strains, CZD showed better antibacterial activity than CEZ, CDX, CTZ, and CED.

• YAKHAK HOEJI
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• v.34 no.6
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• pp.434-438
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• 1990

The methanolic extract of the root-bark of Morus alba L.(Mulberry tree) has the potent antibacterial activity against Streptococcus mutans. Its active component was identified to be sanggenon C. The active component had stronger anti-bacterial activity than berberine, having minimum inhibitory concentration(MIC) of $25\;{\mu}g/ml$. Moreover, the inhibitory effect of this component on the cellular adherence of Streptococcus mutans to glass surfaces also was more remarkable than that of berberine in the presence of glucosyltransferase(GTase) and sucrose in vitro. These results indicate that sanggenon C may play an important role in inhibiting plaque formation and caries incidence.

• Journal of Microbiology and Biotechnology
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• v.9 no.3
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• pp.371-375
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• 1999

AL072 is a potent anti-Legionella antibiotic produced by Streptomyces strain AL91. The minimum inhibitory concentration (MIC) of AL072 against Legionella pneumophila was 0.2$\mu$g/ml. Bacterial growth was rapidly inhibited at the dose range between the MIC and 20 times of the MIC when the antibiotic was added at the mid-exponential phase. Ultrastructural changes in L. pneumophila were observed upon treatment with AL072. Under electron microscopical observation, the organisms treated with AL072 exhibited characteristic morphological changes in the cellular outer coat. Also irregular morphological changes, such as the formation of filamentous materials in the cytoplasm, an increase in the size and number of cytoplasmic vacuoles, the extruding of cytoplasmic contents, the formation of spheroplast and ghost cells, and blebbings in the cell wall were observed. Furthermore, immunoelectron microscopical observation of the group treated with the MIC showed that the immune complex attached mainly to the cell wall. The results of these experiments indicate that AL072, like the inhibitors of cell wall synthesis, act selectively on the cell wall of L. pneumophila.

• Journal of fish pathology
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• v.25 no.3
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• pp.181-188
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• 2012

The minimum inhibitory concentration (MIC) of eight antibiotics against Edwardsiella tarda 49 strains isolated from olive flounder (Paralichthys olivaceus) was determined by the broth microdilution method. E. tarda showed 38.8% and 61.2% resistance to ampicillin and amoxicillin. Both resistance rates of E. tarda were 4.1% against ciprofloxacin and norfloxacin. The $MIC_{50}$ values of oxytetracycline, amoxicillin and oxolinic acid were $64{\mu}g/ml$, $32{\mu}g/ml$ and $4{\mu}g/ml$. The $MIC_{50}$ value to ciprofloxacin was $0.25{\mu}g/ml$ which was lowest among eight antibiotics tested.

• Korean Journal of Oriental Medicine
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• v.12 no.1
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• pp.69-75
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• 2006

This research was aimed to search for natural antimicrobial agents that are sefe for humans and specific for oral pathogens. Acanthoic was isolated from the chloroform fraction of methanol extract of Acanthopanax koreanum $N_{AKAI}$ and its structure were elucidated by 13-NMR, 1H-NNR and ESIMS. Antibacterial activity of acanthoic acid was investigated by the minimum inhibitory (MIC) and minimun bactericidal (MBC) concentration. MIC/MBC of acanthoic acid against Streptococcus mutans $N_{AKAI}$ causing dental caries was determined to be $2/4\;{\mu}g/mL$, which was much lower than these of other natural antimicrobial agents such as $8/16\;{\mu}g/mL$ of sangurinarine and $250/500\;{\mu}/mL$ of green tea extract, $500/600\;{\mu}g/mL$ of thymol and borneol. Acanthoic and significantly inhibited the growth of other cariogenic bacteria such as Streptococcus sobrinus $N_{AKAI}$ and Streptococcus sanguis $N_{AKAI}$, and Streptococcus gordonii $N_{AKAI}$ in the MIC range of $4{\sim}32\;{\mu}g/mL$. My finding suggests that acanthoic acid could be employed as a potential antibacterial agent for preventing dental caries.

• The Korean Journal of Food And Nutrition
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• v.24 no.4
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• pp.708-712
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• 2011

This study was focused on the determination of antibacterial activity of $Scutellaria$ $baicalensis$ extract against antibiotic resistant bacteria($Salmonella$ Enteritidis, $Staphylococcus$ $aureus$ and enteroaggregative $E.$ $coli$). Extract of $Scutellaria$ $baicalensis$ were tested for antibacterial activity by paper disc methods. The $Scutellaria$ $baicalensis$ extract in 0.1 g/$m{\ell}$ and 0.2 g/$m{\ell}$ showed a significant antibacterial activity against antibiotic resistant bacteria. Minimum inhibitory concentration (MIC) of $Scutellaria$ $baicalensis$ extract were appeared to 2,048 ${\mu}g/m{\ell}$ at $S.$ Enteritidis, $S.$ $aureus$ and enteroaggregative $E.$ $coli$. Finally, the growth incubation curve was determined using $Scutellaria$ $baicalensis$ extract against $S.$ Enteritidis, $S.$ $aureus$ and enteroaggregative $E.$ $coli$. The growth of $S.$ Enteritidis was significantly inhibited within 10 hours by the addition of at least 10,000 ppm of $Scutellaria$ $baicalensis$ extract. The 10,000 ppm of $Scutellaria$ $baicalensis$ extract retarded the growth of $S.$ $aureus$ and enteroaggregative $E.$ $coli$ more than 10 hours. In conclusion, $Scutellaria$ $baicalensis$ extract might be useful to control antibiotic resistant bacteria $in$ $vitro$.