• Preventive Nutrition and Food Science
• /
• v.12 no.3
• /
• pp.135-140
• /
• 2007

Antibacterial activities of the major phenolic components from Camellia sinensis L. were investigated against several pathogenic microorganisms including Gram-positive strains like Staphylococcus aureus ATCC 29213 and Streptococcus pyogens 308A; and Gram-negative strains like Escherichia coli ATCC 25922, Escherichia coli 078, Pseudomonas aeruginosa 9027, and Enterobacter cloacae 1321E. The MIC values demonstrate that both (-)-epicatechin and (-)-epigallocatechin were more considerably toxic against Staphylococcus aureus ATCC 29213 than the other two catechins like (-)-epicatechingallate and (-)-epigallocatechin-3-gallate. (-)-Epicatechingallate and (-)-epigallocatechin-3-gallate were most inhibitory against Escherichia coli ATCC 25922. As a result, (-)-epicatechin showed predominant antibacterial activities among tea varieties. The contents of major polyphenolic components such as four catechins, theaflavin, and quercetin were different according to fermentation processes. The total contents of four catechins were ranged from 13.81 to 1.33%, with (-)-epigallocatechin-3-gallate being dominant among tea varieties; theaflavin was found the characteristic pigment in fully-fermented black tea.

• Proceedings of the Korean Society of Applied Pharmacology
• /
• 1997.11a
• /
• pp.19-25
• /
• 1997

Bicyclomycin(BCM)은 1972년에 일본 Hokkaido, Sapporo지방의 토양균중의 하나인 Streptomyces Sapporoneosis의 배양액으로부터 최초로 분리된 항생물질로서 특히 Gram(-) 박테리아인 Escherichia coli. Klebsiella, Shigella, Salmonella, Citrobacter, Enterobacter cloacae, Neisseria gonorrhoeae등에 대한 선택적인 항균효과를 가지고 있고 Streptomycin, Kanamycin, Chloramphenicol, Tetracyclin, Aminobenzylpenicillin 및 naldixic acid 등에 대해 교차내성을 가지고 있지 않다. BCM은 구조적인 면에서 [4.2.2]bicyclic구조를 가지고있는 특이한 항생물질로서 C(1)-triol부분, diketopiperazine부분 그리고 C(5)-C(5a)exomethylene의 3 부분으로 크게 나눌수 있다(Fig. 1). BGM은 E. coli에 대한 항균력으로서 250-500 $\mu\textrm{g}$/mL의 MIC value를 가지고 있고 급성독성으로서 LD$_{50}$가 4g/kg 이상으로 거의 독성이 없는 것이 특징이다. 현재 Fujisawa pharmaceutical Ltd.로부터 Bicozamycin이라는 상품명으로 설사치료제 용도로 시판되고 있다.

• Proceedings of the Korean Society of Applied Pharmacology
• /
• 1996.04a
• /
• pp.233-233
• /
• 1996

배지의 영향에 대하여 검토하기 위하여 SDA, MHA, NA 및 BHIA를 사용하였으며, 시험균주 중 Pseudomonas aeruginosa에 대하여만 NA에서의 MIC 값이 낮게 나타났을 뿐 나머지 균주에 대하여는 배지에 따른 항균력 변화가 관찰되지 않았으며, 배지의 pH를 5.4-8.4까지 변화시켰을 때 pH 변화에 따른 DA-1131의 유의적인 항균력 변화와 접종균량에 따른 항균력 변화가 관찰되지 않았다. Methicillin-resistant Staphylococcus aureus(MRSA)에 대하여는 DA-1131과 vancomycin 간의 상승 및 상가작용이 관찰되었고, P. aeruginosa, Klebsiella pneumoniae, Enterobacter cloacae 및 Serratia marcescens 등의 균종에 대하여는 ciprofloxacin의 상가작용이 확인되었다. Sisomicin은 P. aeruginosa에 대한 상승 및 상가작용이 인정되었으나 ceftazidime은 DA-1131에 의한 길항작용이 관찰되었다.

• Proceedings of the Korean Society of Applied Pharmacology
• /
• 1993.04a
• /
• pp.106-106
• /
• 1993

DWC-751은 그람양성 및 음성균주에 대하여 광범위한 항균스펙트럼을 가지는 것으로 나타났다. 그람양성균 S. aureus에 대하여는 cefpirome과 동등하며, cefotaxime 보다 4배, ceftazidime보다 16배 우수하였고 그람음성균에 대하여 DWC-751의 항균력은 cefpirome, cefotaxime보다 2배, ceftazidime보다 4-8배 우수하였다. Ps. aeruginosa에 대한 DWC-751의 항균력은 ceftazidime과 거의 동등한 항균력을 나타내었고, cefpirome보다 2배, cefotaxime보다 4-8배 우수한 항균력을 나타내었다. 임상분리균주 및 ofloxacin 내성균주에 대한 DWC-751의 항균력은 표준균주에 대한 결과와 같이 대조약물보다 우수하였다. 전신감염치료효과에 있어서 Streptococcus pyogenes, Serratia marcescens, Acinetobacter calcoaceticus, Morganella morganii, Proteus mirabilis에 대한 동물실험 결과, ED$_{50}$치에 의한 효능은 cefotaxime 보다 우수하였으며,Enterobacter cloacae, Pseudomonas aeruginosa에 대하여는 ceftazidime과 거의 동등하였다.

• Journal of Yeungnam Medical Science
• /
• v.9 no.2
• /
• pp.248-255
• /
• 1992

Eight bacterial strains were examined whether they have phoP/phoQ genes which were known to be involved in the intracellular survival of Salmonella typhimurium. The phoP/phoQ operon were known to sense the stimuli of the genes involved in the adaptation of the environment. Using 514-basepairs EcoRV DNA fragment of phoP region of Salmonella typhimurium as a probe, dot blot hybridization were performed. Chromosomal DNAs of Klebsiella pneumoniae, Pseudomonas aeruginosa, Serratia marscescens, Enterobacter cloacae, Salmonella typhimurium, Escherichia coli, Shigella dysenteriae, and Listeria monocytogenes were examined by DNA hybridization assay. Against our expectation, intracellular pathogen, L. monocytogenes, did not have similar DNA sequences to phoP/phoQ of S. typhimurium, while E. coli, S. dysenteriae, and E. cloacae showed the positive signal even though they were not intracellular pathogens. This result suggested that the phoP/PhoQ operon was absent in intracellular pathogenic bacterias other than S. typhimurium. Rather it was found in phylogenetically closer bacterias to S. typhimurium, which were not able to survive in intracellular environment. Some different mechanism, which is not dependent on phoP/PhoQ operon, could be involved in the intracelluar survival of L. monocytogenes.

• Microbiology and Biotechnology Letters
• /
• v.37 no.2
• /
• pp.91-98
• /
• 2009

As consumption of kimchi has increased, factories have begun to produce this traditional Korean fermented vegetable dish on a large scale. Following the rise in manufacturing, the hygienic conditions under which commercial kimchi is being made have become an issue. We isolated 17 coliform bacteria from commercial kimchi that had not been fully fermented. These bacteria were partially identified as one of seven different species from three genera by 16S rDNA sequence analysis as follows: Enterobacter intermedius, Ent. cloacae, Ent. amnigenus, Klebsiella terrigena, K. ornithinolytica, K. oxytoca, and Hafnia alvei. Lactobacillus paraplantarum KNUC25 has been isolated from over-fermented Chinese cabbage kimchi and its antimicrobial activity reported in the literature. In our study, the KNUC25 strain showed antibacterial activity against isolated coliform bacteria and some pathogenic coliform bacteria through spot-on-the-lawn tests and viable cell tests. Through development and use of a cell-free supernatant of L. paraplantarum KNUC25, we effectively controlled coliform bacteria in commercial kimchi.

• Applied Biological Chemistry
• /
• v.40 no.1
• /
• pp.23-29
• /
• 1997

To develop novel cephem antibiotics, We have synthesized a new compound, named YH-487, by attaching the thiol and aminothiazole residue to $C_3$ and $C_7$ position of 7-ACA, respectively. Several characteristics such as structure, antibiotic spectrum, action mechanism, stability against ${\beta}-lactamase$ and synergistic effect were investigated. Anti-bactericidal activity of YH-487 against gram-positive and gram-negative bacteria were superior to that of the other cephem antibiotics. We have examined the action mechanisms of YH-487 using penicillin binding protein (PBP) assay, and found that the bactericidal activity was obtained by inhibiting PBP-1A, PBP-1B and PBP-3. YH-487 showed synergistic effect with gentamicin, tobramycin, and amikacin against Pseudomonas aeruginosa. In addition, YH-487 was effective against Enterobacter cloacae in combination with amikacin. Based on the above observations, YH-487 was classified as a novel third-generation ${\beta}-lactam$ antibiotics.

• Journal of Korean Foot and Ankle Society
• /
• v.13 no.2
• /
• pp.150-155
• /
• 2009

Purpose: To help the empirical antibiotics selection in diabetic foot infection patients, we investigated prevalence of microorganisms and their antibiotics sensitivity results. Materials and Methods: Patients who came to our clinics to treat diabetic foot infections with deep ulceration and were followed up more than 6 months until complete recovery were adopted. From March 2006 to June 2009, there were 140 patients who corresponded with such a inclusion criteria. Wound cultures were done by deep tissue or bone debris at first visit to our clinics. Microorganisms which was documented by wound culture and most susceptible antibiotics by minimum inhibitory concentrations were surveyed retrospectively. Results: Microorganisms were confirmed in 113 cases (80.7%). In the other 27 cases (19.3%), there were no cultured microorganisms. In bacterial growth group, there were 72 cases (63.7%) of gram-positive bacteria and 41 cases (36.3%) of gram-negative bacteria. All of them were aerobic microorganisms and there were no anaerobic microorganisms. Methicillin-sensitive staphylococcus aureus was the most common pathogen and accounted for 35 cases (31.0%). As other common pathogens, there were Enterobacter cloacae (11 cases, 9.7%), pseudomonas aeruginosa (10 cases, 8.8%), Methicillin-resistant staphylococcus aureus (10 cases, 8.8%) and enterococcus faecalis (6 cases, 5.3%), and so on. Common susceptible antibiotics in gram positive microorganism were vancomycin (60 cases, 83.3%), teicoplanin (60 cases, 83.3%), nitrofurantoin (60 cases, 83.3%) and ciprofloxacin (53 cases, 73.6%). In gram negative ones, common susceptible antibiotics were imipenem (35 cases, 85.3%), piperacillin/tazobactam (33 cases, 80.5%) and gentamicin (31 cases, 75.6%). Conclusion: Methicillin-sensitive Staphylococcus aureus in gram positive and enterobacter cloacae in gram negative was the most common pathogen in each group. Ciprofloxacin and gentamicin might be adaptable as a first-line empirical antibiotics in infected diabetic foot patients.

• Microbiology and Biotechnology Letters
• /
• v.35 no.1
• /
• pp.30-35
• /
• 2007

This study was carried out to investigate the usefulness of the aerial part of Cnidium officinale Makino as a bioactive material source. The aerial part(leaf and stem) of Cnidium officinale Makino was extracted with three kinds of solvents and determined their antimicrobial activities against several bacteria and yeast strains using the paper disc method and the microtiter dilution method. The extracts of the Cnidium offocinale aerial part exhibited the broad spectrum of antibacterial activity against Gram (+) and Gram (-) bacteria, including food-borne pathogens such as Listeria monocytogenes, Salmonella typhimurium, and Staphylococcus aureus. The extracts of Cnidium officinale also showed antifungal activity against Saccharomyces cerevisiae. The ethyl acetate extracts completely inhibited the growth of Staphylococcus aureus and Pseudomonas aerogenes, and moderately inhibited the growth of Escherichia coli and Enterobacter cloacae at the concentration of 0.5 mg/mL. However, water extract of Cnidium officinale exhibited lower antimicrobial activity than ethyl acetate and methanol extracts. The inhibitory effect of the ethyl acetate extract of Cnidium officinale Makino was not destroyed by heating at $100^{\circ}C$ for 30 min or at $121^{\circ}C$... for 15 min. These results suggest that the aerial part of Cnidium officinale Makino could be a useful source for a natural antimicrobial material.

• The Korean Journal of Food And Nutrition
• /
• v.22 no.3
• /
• pp.396-401
• /
• 2009

Microorganisms or their toxins can be transferred to eggs and cause food poisoning in humans. Therefore, this study was conducted to detect microbial contamination of eggs and to identify microorganisms in any contaminated eggs. Four different brands of eggs were collected from hypermarkets in the northern Gyeonggi area. The total bacterial counts on the shells of the eggs varied greatly between brands. In addition, various bacterial species including Klebsiella pneumoniae, Pseudomonas mendocina, Alcaligenes xylosoxidans, Alcaligenes faecalis, and Enterobacter cloacae were identified on eggshells. Furthermore, mean of total bacterial counts of four brands was $3.4{\times}10^4 cfu/m{\ell}$ and E. coli was detected on the eggshell of one brand egg. However, Salmonella was not identified on all brands of collected eggs. We also demonstrated that the E. coli isolated from the eggshell was not pathogenic based on the absence of pathogen-specific gene expression patterns. Taken together, the result of this study indicate that strict quality control and improved distribution controls are required to decrease microbial contamination and improve human health.