• International Journal of Oral Biology
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• v.33 no.4
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• pp.213-216
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• 2008

Continentalic acid (CA, (-)-pimara-8(14), 15-diene-19-oic acid) was isolated from the roots of Aralia cordata (Araliaceae) using bioassay-guided fractionation of a crude chloroform extract. The antibacterial activity of CA against Enterococcus faecalis and Enterococcus gallinarium was estimated by determining minimum inhibitory concentrations (MICs) and minimum bactericidal concentrations (MBCs). CA exhibited potent activity against standard vancomycin-resistant enterococci (VRE) and vancomycin-susceptible enterococci (VSE), with MICs and MBCs values between 4 and $8{\mu}g/mL$ and 4 and $16{\mu}g/mL$, respectively. This compound exhibited potent activity against strains of VRE, which are highly resistant to clinically useful antibiotics. These findings suggest that continentalic acid may be useful in controlling enterococcal infection.

• Journal of Microbiology and Biotechnology
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• v.17 no.5
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• pp.774-783
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• 2007

In the present study, acidocin 1B, a bacteriocin produced by Lactobacillus acidophilus GP 1B, exhibited profound inhibitory activity against a variety of LAB and pathogens, including Gram-negative bacteria, and its mode of action was to destabilize the cell wall, thereby resulting in bactericidal lysis. Acidocin 1B was found to be heat stable, because it lost no activity when it was heated up to $95^{\circ}C$ for 60 min. It retained approximately 67% of the initial activity after storage for 30 days at $4^{\circ}C$, and 50% of its initial activity after 30 days at $25^{\circ}C$ and $37^{\circ}C$. The molecular mass of acidocin 1B was estimated to be 4,214.65 Da by mass spectrometry. Plasmid curing results indicated that a plasmid, designated as pLA1B, seemed to be responsible for both acidocin 1B production and host immunity, and that the pLA1B could be transformed into competent cells of L. acidophilus ATCC 43121 by electroporation. Our findings indicate that the acidocin 1B and its producer strain may have potential value as a biopreservative in food systems.

• Bulletin of the Korean Chemical Society
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• v.23 no.12
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• pp.1833-1835
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• 2002

• Food Science of Animal Resources
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• v.43 no.3
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• pp.402-411
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• 2023

This study was conducted to investigate the bactericidal effect of nisin (Nisin) only, atmospheric pressure plasma (APP) only, and a combination of APP and nisin (APP+Nisin)(APP+Nisin) on beef jerky and sliced ham inoculated with Escherichia coli O157:H7, gram-negative bacteria. The bactericidal effect against E. coli O157:H7 and Listeria monocytogenes was confirmed using a nisin solution at a concentration of 0-100 ppm, and APP+Nisin was tested on beef jerky and sliced ham using 100 ppm nisin. Beef jerky and sliced ham were treated with APP for 5 min and 9 min, respectively. In the bacterial solution, 100 ppm nisin out of 0-100 ppm nisin exhibited the highest bactericidal activity against L. monocytogenes (gram-positive bacteria; p<0.05); however, it did not exhibit bactericidal effects against E. coli O157:H7 (gram-negative bacteria). The APP+Nisin APP+Nisin exhibited a 100% reduction rate in both E. coli O157:H7 and L. monocytogenes compared to the control group, and was more effective than the Nisin. The APP+Nisin decreased the number of colonies formed by 0.80 and 1.96 Log CFU/g for beef jerky and sliced ham, respectively, compared to the control, and exhibited a higher bactericidal effect compared to the Nisin (p<0.05). These results demonstrate the synergistic bactericidal effect of APP and nisin, providing a possible method to improve the limitations of nisin against gram-negative bacteria. In addition, this technology has the potential to be applied to various meats and meat products to control surface microorganisms.

• Korean Journal of Food Science and Technology
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• v.37 no.5
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• pp.838-843
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• 2005

Bacterial suspension test was used to establish Standardization Test Method to investigate bactericidal activity of disinfectant/sanitizer product. Using acceptable verification methodology, test substance showing 5 log or higher reduction in viable count against Escherichia coli ATCC 10536 and Staphylococcus aureus ATCC 6538, representing Gram-negative and -positive bacteria, respectively, under test conditions for $5\;min{\pm}10\;sec\;at\;20{\pm}1^{\circ}C$ was considered to have sanitizing capability. All disinfectant/sanitizer products tested under manufacturer's recommended in-use condition gave good reduction values against major food-poisoning bacteria. This standardized method was valuable for evaluating efficacy of disinfectants/sanitizers and could be used as Standardization Test Method for assessing bactericidal activity

• 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 the Korean Society of Food Science and Nutrition
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• v.30 no.1
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• pp.127-132
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• 2001

This research was conducted to investigate the antimicrobial activities of ethanol extracts from omija against the 12 icroorganism including bacteria, yeast and mold. The extracts inhibited the growth of bacteria, but not yeast or mold. Minimum bactericidal concentration (MBC) of B. subtilis and S. aureus was 1.6~3.2 mg/mL, and those of gram(-) bacteria, including E. coli, were 6.3~12.5 mg/mL. Growth of B. subtilis and S. aureus were retarded by adding 900 ppm and 300 ppm of ethanol extracts. Anthimicrobial activity of the ethanol extracts was not destroyed by heating. In comparison of endocarps extracts with the ethanol from the seed extracts, the ethanol extracts of endocarps showed the high antimicrobial activity.

• Journal of Food Hygiene and Safety
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• v.29 no.3
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• pp.165-169
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• 2014

Salmonella spp. and Brucella spp. are associated with considerable diseases of both humans and animals. In addition, these microorganisms cause the economic loss in animal farming and food industry. In this study, the disinfection efficacy of a commercial disinfectant, composed to povidone-iodine was evaluated against S. typhimurium and B. ovis. A bactericidal efficacy test by broth dilution method was used to determine the lowest effective dilution of the disinfectant following exposure to test bacteria for 30 min at $4^{\circ}C$. The disinfectant and test bacteria were diluted with hard water (HW) or organic matter suspension (OM) according to treatment condition. On HW condition, the bactericidal activity of the disinfectant against S. typhimurium and B. ovis was 400 and 150 fold dilutions, respectively. On OM condition, the bactericidal activity of the disinfectant was 5 and 20 fold dilutions against S. typhimurium and B. ovis, respectively. As the disinfectant composed to povidine-iodine possesses bactericidal efficacy against animal pathogenic bacteria such as S. typhimurium and B. ovis, the disinfectant solution can be used to control the spread of bacterial diseases.

• Journal of Food Hygiene and Safety
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• v.30 no.1
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• pp.109-114
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• 2015

Clostridium perfringens (C. perfringens) and Mycobacterium fortuitum (M. fortuitum) are associated with considerable diseases in animals and human. In this study, the disinfection efficacy of a commercial disinfectant composed to povidone-iodine (PVI) was evaluated against C. perfringens and M. fortuitum. A bactericidal efficacy test by broth dilution method was used to determine the lowest effective dilution of the disinfectant following exposure to C. perfringens and M. fortuitum for 30 min at $4^{\circ}C$. The disinfectant and test bacteria were diluted with hard water (HW) or organic matter suspension (OM) according to treatment condition. On HW condition, the bactericidal activity of the disinfectant against C. perfringens and M. fortuitum was 50 and 80 fold dilutions, respectively. On OM condition, the bactericidal activity of the disinfectant against both C. perfringens and M. fortuitum was 15 fold dilutions. As the disinfectant composed to PVI possesses bactericidal efficacy against C. perfringens and M. fortuitum, the disinfectant solution can be used to control the spread of bacterial diseases.

• Journal of Food Hygiene and Safety
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• v.31 no.4
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• pp.299-303
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• 2016

Salmonella spp. and Brucella spp. can cause considerable diseases on both humans and animals. In addition, these microorganisms cause the economic loss in animal farming and food industry. In this study, the disinfection efficacy of a disinfectant spray, composed to grapefruit seed extract, citric acid, malic acid and benzalkonium chloride, was evaluated against S. Typhimurium and B. ovis. A bactericidal efficacy test by broth dilution method was used to determine the lowest effective dilution of the disinfectant following exposure to test bacteria for 30 min at $4^{\circ}C$. The disinfectant and test bacteria were diluted with hard water (HW) or organic matter suspension (OM) according to treatment condition. On HW condition, the bactericidal activity of the disinfectant spray against S. Typhimurium and B. ovis was 5 and 4 fold dilutions, respectively. On OM condition, the bactericidal activity of the disinfectant spray was 2 and 1 fold dilutions against S. Typhimurium and B. ovis, respectively. As the disinfectant spray possesses bactericidal efficacy against foodborne pathogens such as S. Typhimurium and B. ovis, the disinfectant spray can be used to control the spread of bacterial diseases.