• Journal of Veterinary Science
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• v.23 no.2
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• pp.23.1-23.15
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• 2022

Background: Antibacterial agents play important roles in the treatment of bacterial infections. However, the development of antimicrobial resistance (AMR) and carry-over of substances into the environment are several problems arising during oral treatment of bacterial infections. We assessed AMR development in commensal Escherichia coli (E. coli) in enrofloxacin treated and untreated animals. In addition, we examined fluoroquinolone in the plasma and urine of treated and untreated animals, and in sedimentation dust and aerosol. Methods: In each trial, six pigs were treated with enrofloxacin via powder, granulate or pellet forms in two time periods (days 1-5 and 22-26). Four pigs served as untreated controls. The minimum inhibitory concentration (MIC) was determined to evaluate AMR development. Analysis of enro- and ciprofloxacin was performed with high performance liquid chromatography. Results: Non-wildtype E. coli (MIC > 0.125 ㎍/mL) was detected in the pellet treated group after the first treatment period, whereas in the other groups, non-wildtype isolates were found after the second treatment period. E. coli with MIC > 4 ㎍/mL was found in only the pellet trial. Untreated animals showed similar susceptibility shifts several days later. Bioavailability differed among the treatment forms (granulate > pellet > powder). Enro- and ciprofloxacin were detected in aerosols and sedimentation dust (granulate, powder > pellet). Conclusions: This study indicates that the kind of the oral dosage form of antibiotics affects environmental contamination and AMR development in commensal E. coli in treated and untreated pigs.

• The Korean Journal of Food And Nutrition
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• v.21 no.1
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• pp.15-21
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• 2008

In this study, the minimum inhibition concentration(MIC), growth inhibition activity, and colony forming inhibitory activity of water soluble propolis against Bacillus cereus, Bacillus subtilis, Listeria monocytogenes, Staphylococcus aureus, Streptococcus mutans, Citrobacter freundii, Enterobacter aerogenes, Escherichia coli, Klebsiella pneumoniae and Salmonella enteritidis were tested. The MICs of the water soluble propolis against Bacillus cereus, Bacillus subtilis, Listeria monocytogenes, Staphylococcus aureus, Streptococcus mutans, Citrobacter freundii, Enterobacter aerogenes, Escherichia coli, Klebsiella pneumoniae, and Salmonella enteritidis were 312.5 ppm, below 156.3 ppm, 625 ppm, 10,000 ppm, above 10,000 ppm, 10,000 ppm, above 10,000 ppm, above 10,000 ppm, 10,000 ppm, and above 10,000 ppm, respectively. The growth inhibition concentrations against Bacillus cereus, Bacillus subtilis, Listeria monocytogenes, Staphylococcus aureus, Streptococcus mutans, Citrobacter freundii, Enterobacter aerogenes, Escherichia coli, and Klebsiella pneumoniae were 156.3 ppm, below 156.3 ppm, 625 ppm, 5,000 ppm, 10,000 ppm, 10,000 ppm, 10,000 ppm, 10,000 ppm, and 5,000 ppm, respectively. However, 10,000 ppm did not inhibit the growth of Salmonella enteritidis. Finally, the colony forming inhibitory activities against Bacillus cereus, Bacillus subtilis, Listeria monocytogenes, Staphylococcus aureus, Streptococcus mutans, Citrobacter freundii, Enterobacter aerogenes, Escherichia coli, Klebsiella pneumoniae, and Salmonella enteritidis were 98.0%, 99.8%, 69.8%, 98.1%, 62.0%, 63.1%, 79.5%, 61.9%, 79.6%, and 0.0%, respectively.

• Natural Product Sciences
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• v.10 no.6
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• pp.325-329
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• 2004

The composition of essential oil from O. javanica was analyzed by gas chromatography-mass spectrometry. Using the broth dilution method and disk diffusion test, anti-microbial activities of the oil fraction and its main components were evaluated against various antibiotic-susceptible and resistant strains of pathogenic microorganisms. As a result of GC-MS analysis, 57 compounds, including ${\alpha}-terpinolene$ (28.1%), dl-limonene (16.0%), ${\gamma}-terpinene$ (10.3%), ${\beta}-pinene$ (9.7%) and ${\alpha}-pinene$ (6.0%) were identified in the essential oil fraction. The essential oil fraction of O. javanica and its main components exhibited significant inhibitory activities, particularly against Candida albicans (antibiotic-susceptible strains) and Streptococcus pneumoniae (antibiotic- susceptible and resistant strains). The main components of the O. javanica oil fraction displayed different patterns of activity against the three tested Candida species as exemplified by the differential minimum inhibiting concentration (MIC) values. The disk diffusion test showed that the activities were dose dependent.

• Archives of Pharmacal Research
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• v.26 no.1
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• pp.40-42
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• 2003

Chiisanogenin (1), hyperin (2) and chiisanoside (3) were isolated from the leaves of Acanthopanax senticosus, and were tested for their inhibitory activities against 6 strains of bacteria. Among them, chiisanogenin (1) revealed broad but moderate antibacterial activities against G(+) and G(-) bacteria, the minimum inhibitory concentration (MIC) being in the range of 50-100 $\mu\textrm{g}$/ml.

• Journal of Veterinary Science
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• v.22 no.6
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• pp.41.1-41.14
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• 2021

Background: Our previously prepared ceftiofur (CEF) hydrochloride oily suspension shows potential wide applications for controlling swine Streptococcus suis infections, while the irrational dose has not been formulated. Objectives: The rational dose regimens of CEF oily suspension against S. suis were systematically studied using a pharmacokinetic-pharmacodynamic model method. Methods: The healthy and infected pigs were intramuscularly administered CEF hydrochloride oily suspension at a single dose of 5 mg/kg, and then the plasma and pulmonary epithelial lining fluid (PELF) were collected at different times. The minimum inhibitory concentration (MIC), minimal bactericidal concentration, mutant prevention concentration (MPC), post-antibiotic effect (PAE), and time-killing curves were determined. Subsequently, the area under the curve by the MIC (AUC_0-24h/MIC) values of desfuroylceftiofur (DFC) in the PELF was obtained by integrating in vivo pharmacokinetic data of the infected pigs and ex vivo pharmacodynamic data using the sigmoid E_max (Hill) equation. The dose was calculated based on the AUC_0-24h/MIC values for bacteriostatic action, bactericidal action, and bacterial elimination. Results: The peak concentration, the area under the concentration-time curve, and the time to peak for PELF's DFC were 24.76 ± 0.92 ㎍/mL, 811.99 ± 54.70 ㎍·h/mL, and 8.00 h in healthy pigs, and 33.04 ± 0.99 ㎍/mL, 735.85 ± 26.20 ㎍·h/mL, and 8.00 h in infected pigs, respectively. The MIC of PELF's DFC against S. suis strain was 0.25 ㎍/mL. There was strong concentration-dependent activity as determined by MPC, PAE, and the time-killing curves. The AUC_0-24h/MIC values of PELF's DFC for bacteriostatic activity, bactericidal activity, and virtual eradication of bacteria were 6.54 h, 9.69 h, and 11.49 h, respectively. Thus, a dosage regimen of 1.94 mg/kg every 72 h could be sufficient to reach bactericidal activity. Conclusions: A rational dosage regimen was recommended, and it could assist in increasing the treatment effectiveness of CEF hydrochloride oily suspension against S. Suis infections.

• Journal of Dental Anesthesia and Pain Medicine
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• v.18 no.4
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• pp.223-233
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• 2018

Topical anesthetics are commonly used in oral & maxillofacial surgery to control pain in the oral cavity mucosa before local anesthetic injection. These anesthetic agents come in many forms, developed for different usages, to minimize adverse reactions, and for optimal anesthetic efficiency. Earlier studies have revealed that these agents may also limit the growth of microorganisms in the area of anesthetic application. Many topical anesthetic agents show different levels of antimicrobial activity against various bacterial strains and Candida. The dosage of local anesthetic agent used in some clinical preparations is too low to show a significant effect on microbial activity. Efficiency of antimicrobial activity depends on the local anesthetic agent's properties of diffusion within the bloodstream and binding efficiency with cytoplasmic membrane, which is followed by disruption of the bacterial cell membrane. The antimicrobial properties of these agents may extend their usage in patients to both control pain and infection. To develop the topical local anesthetic optimal usage and antimicrobial effect, a collaborating antiseptic agent may be used to benefit the local anesthetic. However, more research is required regarding minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of topical local anesthetic agents with drug interaction between anesthetics and antiseptic agents.

• Journal of the Korean Society of Food Science and Nutrition
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• v.23 no.6
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• pp.1008-1013
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• 1994

To develope naatural food preservatives, ethanol and water extracts were prepared from the leaf mustard (Brassica juncea Coss.) and antimicrobial activities were examined against 15 microorganisms which were food borne pathogens and/or food poisioning microorganisms and food-related bacteria and yeasts. Ethanol extract exhibited anitmicrobial activities for the microorganism tested, especially, minimum inhibitory concnetrations exhibited antimicrobial activities for the microorganism tested, especially, minimum inhibitory concentrations (MIC) for Bacillus subtilis and Bacillus natto were as low as 10mg/ml. MIC of water extract was 40-60mg/ml for bacteria and yeast. The ethanol extract showed the antimicrobial activity by 3~6 times higher than the water extract. Antimicrobial activity of the ethanol extract was not destroyed by the heating at $121^{\circ}C$ for 15 min and not affected by pH.

• International Journal of Oral Biology
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• v.38 no.4
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• pp.149-154
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• 2013

In general, oleanolic acid (OA) and ursolic acid (UA) have antimicrobial effect against Gram-positive bacteria but not Gram-negative bacteria whereas sophoraflavanone G has antimicrobial activity against both bacterial types. However, the antimicrobial effects of OA, UA, and sophoraflavanone G against periodontopathogens have not been studied to any great extent. The aim of this study was to investigate antimicrobial effect of OA, UA, and sophoraflavanone G against 15 strains (5 species) of oral Gram-negative bacteria, which are the major causative bacteria of periodontal disease. The antimicrobial activity was evaluated by minimal inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) determinations. OA and UA showed antimicrobial effects against all of the Porphyromonas gingivalis strains tested and also Prevotella intermedia ATCC $25611^T$. Interestingly, P. intermedia ATCC 49046 showed greater resistance to OA and UA than P. intermedia ATCC $25611^T$. In contrast, sophoraflavanone G had antimicrobial activity against all strains, with MIC and MBC values below $32{\mu}g/ml$, except Aggregatibacter actinomycetemcomitans. These results indicate that sophoraflavanone G may have potential for use in future oral hygiene products such as dentifrices and gargling solution to prevent periodontitis.

• Natural Product Sciences
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• v.23 no.3
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• pp.175-182
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• 2017

This study evaluated the anti-Helicobacter and anti-inflammatory effects of Sohamhyungtang (SHHT). The minimum inhibitory concentration (MIC) of SHHT against Helicobacter pylori (H. pylori) was determined by the agar dilution method. Expression of the H. pylori cagA gene in the presence of SHHT was determined by quantitative real-time polymerase chain reaction (qRT-PCR). Inhibition of H. pylori urease by SHHT was determined by the phenol-hypochlorite assay. Antiadhesion activity of SHHT was measured by urea-phenol red reagent. Inhibition of nitric oxide (NO) production in AGS cells was measured with Griess reagent. Inducible nitric oxide synthase (iNOS) and IL-8 mRNA expression in AGS cells which were infected with H. pylori was determined by qRT-PCR. IL-8 level was measured by enzyme-linked immunosorbent assay (ELISA). The MIC of SHHT was $100{\mu}g/mL$ and the expression of cagA gene was decreased about 25 folds in the presence of SHHT. H. pylori urease was inhibited 90% by SHHT. SHHT inhibited H. pylori adhesion on AGS cell in a concentration dependent manner. mRNA expression of iNOS and IL-8 and the production of NO and IL-8 were significantly decreased in the presence of SHHT. In conclusion, SHHT showed anti-Helicobacter activity and has potent anti-inflammatory effect on H. pylori-induced inflammation in human gastric epithelial AGS cells.

• Journal of the korean academy of Pediatric Dentistry
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• v.36 no.1
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• pp.1-11
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• 2009

Essential oils are mixture of volatile, lipophilic compounds originating from plants. Essential oils have potential biological effects, i.e., antibacterial, antifungal, spasmolytic and antiplasmodial activities and insect-repellent property. In this study, five essential oils, namely R, LG, FR, O, and NM, extracted from various aromatic plants were used to test their antimicrobial activity against the oral microorganisms. The effects of essential oils were investigated against eight important bacteria, Streptococcus mutans (S. mutans), Staphylococcus aureus (S. aureus), Streptococcus sanguis (S. sanguis), Streptococcus anginosus (S. anginosus), Actinobacillus actinomycetemcomitans (A. actinomycetemcomitans), Streptococcus sobrinus (S. sobrinus), Staphylococcus epidermidis (S. epidermidis), and Escherichia coli (E. coli). Essential oils, except NM, effectively inhibited the growth of tested oral pathogenic microorganisms dose-dependently. However, the essential oils didn't show a significant inhibitory effect against E. coli and S. epidermidis. Consequently, these results represented that essential oil-mediated anti-microbial activity was prominent against the oral pathogenic bacteria. For example, minimum bactericidal concentration(MBC) of R, LG, FR oil against A. actinomycetemcomitans was very low as 0.078 mg/mL. In addition, minimum inhibitory concentration (MIC) of R, LG, FR, O oil against S. mutans was low as 0.156 mg/mL in vitro.