• The Journal of the Korean Society for Microbiology
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• v.21 no.3
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• pp.355-361
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• 1986

Vibrio vulnificus, a halophilic Vibrio has gained worldwide attention as a cause of severe and frequently fatal wound infections and life-threatening septicemia. For this reason V. vulnificus is thought to produce extreme hemoconcentration and rapid death after infection, and because V. vulnificus is thought to be less susceptible to bactericidal activity of normal human serum, the present study was undertaken to assess the susceptibility of V. vulnificus to human serum bactericidal activity with that of V. parahemolyticus and V. cholerae and to assess the effect of Vibrio species, Salmonella typhimurium and E. coli on hematocrit values in experimentally infected mice. Serum bactericidal activity against both V. vulnificus and V. cholerae was higher than against V. parahemoltyicus. Survival of the test strains in heat-inactivated human serum was greater than that in heat-uninactiveted serum. Both V. parahemolyticus and V. cholerae produced slight hemoconcentration within 2 to 6 hr after intraperitoneal injection of $10^7$ viable bacteria into mice. In contrast, V. vulnificus, S. typhimurium and E. coli produced hemodilution rather than hemoconcentration after 4 or 6 hr after infection. With these results the author can conclude that V. vulnificus is more susceptible to serum bactericidal activity than other Vibrio species, and V. vulnificus did not produce hemoconcentration.

• Korean Journal of Microbiology
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• v.38 no.4
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• pp.281-286
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• 2002

Detection of Vibrio vulnificus in fish farm and searching for the bactericidal methods on this bacteria were studied. To detect this microorganism in sea water, mud, fish and mussels, selective isolation methods and detection of vvhA gene were used from January to October,2000. V. vulnificus was detected from May when the water temperature was over $17^{\circ}C$. From June to September, higher than $19^{\circ}C$, this bacteria could be isolated from most of the samples. Freezing and refrigerating did not inhibit the growth of V. vulnificus. Citric acid did not show the bactericidal effect, but more than 500 mg/l of EDTA did. With the aid of UV and photocatalyst, $TiO_{2}$ showed bactericidal effect after 15 minute treatment. Photocatalytic system consisted of glass bead coated with $TiO_{2}$ and UV illumination showed bactericidal effect on V. vulnificus at the turnover rate of 0.2/min.

• Korean Journal of Food Science and Technology
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• v.31 no.2
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• pp.522-526
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• 1999

Bactericidal effects of chitosans with varying molecular weight $(10,000{\sim}170,000)$ were investigated for Streptococcus mutans, a primary causative bacterium of dental caries. The molecular weight of chitosan was a significant contributor to the bactericidal effect, and a chitosan having approximately 30,000 of molecular weight exhibited the highest bactericidal effects on S. mutans. Treatment of chitosan resulted in leaking intracellular protein and nucleic acid out of S. mutans cells. In addition, the divalent cations such as $Ca^{2+}\;and\;Mg^{2+}$ were also significantly released out of the cell. Visible damage of chitosan treated cells was observed by transmission electron microscopy (TEM), in which the cell wall was notably distorted and cytoplasmic membrane was separated from the cell wall. The results suggested that the bactericidal effect of chitosan on S. mutans was attributable to both leakage of intracellular materials and structural disintegration of cell wall.

• 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.

• Journal of Veterinary Clinics
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• v.27 no.3
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• pp.252-256
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• 2010

Bovine mastitis, defined as an inflammation of the mammary gland, is usually associated with bacterial infection. Thus, treatment and control of mastitis relies primarily on antimicrobial therapy. This study investigated the bactericidal actions of silver ion against causing various bovine mastitis pathogens. Minimal inhibitory concentrations (MICs), minimum bactericidal concentrations (MBCs) and bactericidal activity times and concentrations of silver ion against pathogens were determined. The effect of silver ion on bacterial morphology was studied by scanning electron microscopy (SEM). The MICs and MBCs of silver ion for various bacteria strains ranged from 1.9-15.6 ${\mu}g$/ml. SEM images indicated formation of a pit, distortion and disruption of cell walls in silver treated Staphylococcus aureus and Escherichia coli. The results demonstrate that silver ion has a bactericidal capacity against causing various pathogens of bovine mastitis and suggest that silver ions may be exploitable as a therapeutic/preventative tool of bovine mastitis.

• Journal of the Korean Ceramic Society
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• v.34 no.1
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• pp.13-22
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• 1997

Water-soluble phosphate glasses containing Ag and Cu ion were prepared through melting process. Dis-solution characteristics, bactericidal effect and cytotoxicity were investigated with composition and time in D. I. water using the powdered sample. Surface change were observed with increasing dissolution time us-ing the bulk specimen. Dissolution amount was maximum at the molar Ag:Cu ratio of 1 and increased with increasing time. The behavior of dissolution was total dissolution from the early stage. But no new layer was observed at the glass surface during dissolution. The bactericidal effect for pseudomonas sp, e. coli, sta-phylococcus aureus, and salmonella increased with increasing dissolution amount and therefore great bac-tericidal effect appeared. The result of cytotoxicity experiment to L929 showed that solution with more than 10 ppm of Ag ion had strong cytotoxicity.

• Journal of the Korean Ceramic Society
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• v.33 no.2
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• pp.242-250
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• 1996

Glasses of Na2O-Al2O3-SiO2 system were prepared and ion-exchange characteristics change of properties and bactericidal effects by Na+↔Ag+ ion exchange were studied. Parent glasses with three compositions of varying Na2O in the 20~30 wt% were ion-exchanged in the molten salt of 2 mol% AgNO3+98 mol% NaNO3 at 320~36$0^{\circ}C$ for 15~16min. Amount of ion exchange and penetration depth of Ag+ ion increased with Na2O content in the parent glass ion exchange temperature and time. After ion exchange densities and Vickers hardness of the glasses increased and the glasses showed yellow-brown color and as amount of ion exchange increased the color turned deep because partial reduction and agglomeration of Ag+ into Ag0 results in absorption of visible light. After ion exchange chemical durability of the glass to wter was enhanced compara-bly that weight loss and change of surface of the glass were not found for the leaching test in 5$0^{\circ}C$ K.I water for 240hrs. Bactericidal effect of ion exchanged glass on Staphylococcus aureus and E. coli was determined by microorganism test and bactericidal effect increased with amount of ion exchange and incubation time.

• Restorative Dentistry and Endodontics
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• v.1 no.1
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• pp.43-49
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• 1975

This study was divided into two parts. In the first experiment, the in vitro antimicrobial effect was tested in order to evaluate the effect of vapors, and the effectiveness of the nonspecific endodontic medicaments (formocresol, camphorated parachlorophenol and eugenol). In the second experiment, the intracanal effect was tested in vitro under simulated clinical condition. The actual bactericidal effect of the nonspecific endodontic medicaments (formocresol, camphorated parachlorophenol and eugenol) was quantitated. The results were obtained as follows: 1. The zone of inhibition was appeared on the vapors of formocresol only, however there were no zone of inhibition appeared on the vapors of camphorated parachlorophenol and eugenol. 2. Formocresol produced the widest zone of inhibition and eugenol, the next and camphorated parachlorophenol, the narrowest. 3. All of the tested medicaments were vaporized in the root canal. They proved to be the effective antimicrobial activity in the root canal. 4. All of the tested medicaments were showed more bactericidal effect at 72 hours than 48 hours. 5. In comparing with the bactericidal effect of the tested medicaments in the root canal, formocresol was showed the most bactericidal medicament, camphorated parachlorophenol was showed the least. 6. Complete sterilization of the root canal was not achieved in any medicaments applied in this study.

• International Journal of Oral Biology
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• v.43 no.3
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• pp.129-132
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• 2018

Enterococcus faecalis is a major causative agent of endodontic treatment failure. The purpose of this study was to investigate bactericidal effects of ethanol extract of Garcinia mangostana L. (mangosteen extract) on five strains of E. faecalis that were isolated from human oral cavities. The bactericidal effects of mangosteen extract were assessed by measurement of minimum bactericidal concentration (MBC) value. The cytotoxicity of mangosteen extract on immortalized human gingival fibroblasts, hTERT-hNOF, was determined based on cell counting method. The data revealed the MBC value of mangosteen extract against the E. faecalis strains was $4{\mu}g/ml$. Additionally, the cell viability of mangosteen extract on hTERT-hNOF was 83.7-89.1% at the 1 to $16{\mu}g/ml$. These findings indicated that mangosteen extract could be used as a root canal cleaner during management of endodontic treatment failure caused by E. faecalis.

• International Journal of Oral Biology
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• v.43 no.3
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• pp.123-127
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• 2018

Polyphenon 60 refers to the mixture of catechins present in green tea. The aim of this study was to investigate the antimicrobial activities of polyphenon 60 against 4 strains of Streptococcus mutans and 2 strains of Streptococcus sorbrinus, which are the major causative bacteria of dental caries. The minimum bactericidal concentration (MBC) values of polyphenon 60 for S. mutans and S. sobrinus were determined and the effect of biofilm formation inhibition of that was evaluated. The MBC value of polyphenon 60 against the bacterial strains was 2.5 mg/ml except for one particular strain, S. mutans KCOM 1128 for which the value was 1.25 mg/ml. The results of biofilm formation inhibition assay revealed that polyphenon 60 inhibited biofilm formation more than 90% at a concentration of 2.5 mg/ml. It was apparent that polyphenon exhibited biofilm formation inhibition activity along with bactericidal effect against S. mutans and S. sobrinus. Therefore, it is proposed that polyphenon 60 as one of the components of bactericidal agents could be useful in developing oral hygiene products, toothpaste or gargling solution.