• The Journal of the Korean Society for Microbiology
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• v.21 no.1
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• pp.121-126
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• 1986

Bactericidal activity of normal and cirrhotic patients' sera against Vibrio vulnificus was investigated and compared each other as a part of the pathogenesis study of V. vulnificus septicemia. Bactericidal activity of serum against V. vulnificus was complement-dependent and the alternative pathway played the major role. V. vulnificus strains CDC A1402 and ATCC 27562 appeared serum-sensitive, and CDC C7184, clinical isolate CNUH1 and ATCC 29307 were serum-resistant. When bactericidal activity of cirrhotic sera against serum-sensitive CDC A1402 and serum-resistant CDC C7184 was compared with that of normal sera. showed slightly poorer bactericidal activity than normal sera. Especially in the case of serum-resistant CDC C7184 strain, cirrhotic sera showed statistically significant decrease(p<0.05) in their bactericidal activity.

• 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.

• Journal of fish pathology
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• v.5 no.1
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• pp.9-18
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• 1992

In order to know the defense mechanism of fish, bactericidal activity was examined into the sera of carp Cyprinus carpio, tilapia Oreochromis niloticus and flounder Paralichthys olivaseus. Each examined normal serum of fishes showed the bactericidal activity against avirulent Escherichia coli but it wasn't appeared against virulent Edwardsiella tarda. When the normal serum of each fish was treated with zymosan, it lost the bactericidal activity completely. After addition of EGTA into the normal serum of each fish, the sera of tilapia and flounder still exhibited the bactericidal activity but the serum of carp lost it. In the presence of specific antibody and complement, bactericidal activity of each antiserum was exhibited high level with in one hour incubation. On the other hand, heat inactivated antiserum showed bacteriostatic reaction. From the above results, although the activity of alternative or classical pathway of each fish complement is different, it is an important function in fish defense mechanism.

• Korean Journal of Veterinary Research
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• v.37 no.2
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• pp.321-330
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• 1997

Enrofloxacin is one of the second-generation quinolones which have been widely used to treat bacterial infections in various species including chicken, pig, horse and cattle. The objective of the present study was to describe the serum bactericidal activity(SBA) of enrofloxacin, its pharmacokinetic behaviors after intramuscular or intravenous administration to Korean native goats in the dose rate of 5mg/kg b.w. The results obtained through this study were as follows : 1. Sera collected from both sexes of Korean native goats administered 5mg/kg i.v. or i.m. showed potent antibacterial activities up to the 12 hours by way of the serum bactericidal activity. 2. Concentrations of enrofloxacin in the biological samples were measured by high-performance liquid chromatography(HPLC) so as to study pharmacokinetic characteristics. For detection of enrofloxacin, 10% TCA was optimal for protein precipitation and the mobile phase was 0.01M citric acid/methanol/acetonitrile(7/2/1, pH 3.5) with solid phase being the $C_{18}$ reversephase column and detection wavelength being 278nm. The limit of detection of enrofloxacin on HPLC was $0.05{\mu}g/ml$. 3. Pharmacokinetic profile of enrofloxacin administered 5mg/kg i.v. in Korean native goats was best described by two-compartment open model and that administered i.m. the same rate by one-compartment model. There were no sex differences in pharmacokineticl parameters. In conclusion, enrofloxacin showed potent in vivo antibacterial activity and excellent pharmacokinetic properties in Korean native goats, hence it may be used as a potential antibacterial in the veterinary clinical settings.

• Asian Pacific Journal of Cancer Prevention
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• v.15 no.3
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• pp.1299-1306
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• 2014

Background: Nano-biotechnology is recognized as offering revolutionary changes in various fields of medicine. Biologically synthesized silver nanoparticles have a wide range of applications. Materials and Methods: Silver nanoparticles (AgNPs) were biosynthesized with an aqueous extract of Pterocladiella (Pterocladia) capillacea, used as a reducing and stabilizing agent, and characterized using UV-VIS spectroscopy, Fourier Transform Infra red (FT-IR) spectroscopy, transmission electron microscopy (TEM) and energy dispersive analysis (EDX). The biosynthesized AgNPs were tested for cytotoxic activity in a human hepatocellular carcinoma ($HepG_2$) cell line cultured in Dulbecco's modified Eagle medium supplemented with 10% fetal bovine serum, 1% antibiotic and antimycotic solution and 2 mM glutamine. Bacterial susceptibility to AgNPs was assessed with Staphylococcus aureus, Bacillus subtilis [Gram+ve] and Pseudomonas aeruginosa and Escherichia coli [Gram-ve]. The agar well diffusion technique was adopted to evaluate the bactericidal activity of the biosynthesized AgNPs using Ampicillin and Gentamicin as gram+ve and gram-ve antibacterial standard drugs, respectively. Results: The biosynthesized AgNPs were $11.4{\pm}3.52$ nm in diameter. FT-IR analysis showed that carbonyl groups from the amino acid residues and proteins could assist in formation and stabilization of AgNPs. The AgNPs showed potent cytotoxic activity against the human hepatocellular carcinoma ($HepG_2$) cell line at higher concentrations. The results also showed that the biosynthesized AgNPs inhibited the entire panel of tested bacteria with a marked specificity towards Bacillus subtillus. Conclusions: Cytotoxic activity of the biosynthesized AgNPs may be due to the presence of alkaloids present in the algal extract. Our AgNPs appear more bactericidal against gram-positive bacteria (B. subtillus).

• Archives of Pharmacal Research
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• v.19 no.2
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• pp.143-147
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• 1996

LB20304 is a novel fluoroquinolone that exhibits a potent broad spectrum antibacterial activity against both gram-positve and gram-negative bacteria. The MICs (Minimal Inhibitory Concentration) of LB20304 were determined against both gram-positve and gram-negative bacteria under various conditions including several media, pHs, and inoculum concentrations. The in vitro activity of LB20304 was not significantly affected by the changes in testing conditions such as components of media and inoculum concentrations, but it was slightly reduced by acid condition. The MICs and MBCs (Minimal Bactericidal Concentration) of LB20304 against Staphylococcus aureus, Escherichia coli and Pseudomonas aeruginosa were hardly affected by the presence of 50 % human serum, mouse serum, guinea pig serum or horse serum, and the MBCs were equal to or at most four-times higher than the MiCs. The activities of LB20304 were decreased by the presence of high concentraion of $Mg^{++}$ or human urine (pH, 5.5) in the test media. The frequencies of mutants resistant to LB20304 were similar to or lower than those found in ciprofloxacin and sparfloxacin.

• Korean Journal of Veterinary Research
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• v.29 no.4
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• pp.493-501
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• 1989

A total of 108 strains of C jejuni isolated from pigs and chickens were examined for the susceptibility to 10 antimicrobial agents and normal sera of cattle, sheep, guinea pigs and chickens. Minimal inhibitory concentration(MIC) ranges of antimicrobial agents to C jejuni isolates were $${\leq_-}1.56$$ to $${\geq_-}100{\mu}g/ml$$ for erythromycin, rifampin, streptomycin and tetracycline, 50 to $${\geq_-}100{\mu}g$$ for cephalothin, $${\leq_-}1.56$$ to $50{\mu}g$ for ampicillin, $${\leq_-}1.56$$ to $25{\mu}g$ for kanamycin and nalidixic acid, $${\leq_-}1.56$$ to $12.5{\mu}g$ for chloramphenicol and gentamicin. Resistance rates of C jejuni were showed to in order of rifampin(84.7%), tetracycline(56.2 %), erythromycin(17.1%) and ampicillin(3.8%), all of the strains were sensitive to chloramphenicol, gentamicin and kanamycin, and the incidence rates of resistant C jejuni were highly frequent in pig isolates than chicken isolates. The drug resistance patterns of 87 chicken isolates C jejuni to 9 antimicrobial drugs were showed 12 patterns, and Sm Ra Tc(24.1%), Sm Ra(21.8%) and Ra Tc(14.9%) were relatively common, and also 21 pig isolates were showed 6 patterns and Em Sm Ra Tc(57.1%) were most frequent. The majority of the isolates showed multiple drug resistance. Bactericidal activity of 10% normal sera from healthy animals were examined for 60min at $37^{\circ}C$. C jejuni were decreased from 0.4 to 1.0 ${\log}_{10}$(p<0.01), and serum susceptibility were high in order of guinea pig, sheep, chicken and cattle sera. Serum sensitivity of C jejuni Ch-39 strain in increased serum concentation up to 10, 20, 40 and 80% were highly significant. In the normal animal serum, the number of Ch-39 strain were decreased from $1.8{\times}10^4/ml$ to $2.7{\times}10^3/ml$ after 60 min incubation(p<0.01), but the numbers were decreased to $6.6{\times}10^3/ml$ in the heat inactivated normal serum for 30 min at $56^{\circ}C$. Bactericidal activity was restored in the heat inactivated normal serum after the serum of complement source was added.

• Korean Journal of Poultry Science
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• v.48 no.4
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• pp.327-335
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• 2021

Riemerella anatipestifer (RA) can cause septicemia, polyserositis, and ataxia in ducks. It can also colonize the upper respiratory tract of healthy ducks. These differences in pathogenicity are probably the result of diverse mechanisms of virulence in different strains. Since serum resistance is a feature frequently found in systemic pathogens, 130 RA strains having different clinical origins were tested. A variety of serum susceptibility levels were detected. Pharynx strains from healthy ducks were mainly susceptible to the bactericidal effect of the serum, while systemic strains were serum resistant. Heat-treatment of the sera abolished the bactericidal activity, indicating that complement is a key factor in this effect. In an attempt to associate serum-resistance to surface determinant genes of the bacteria, we screened for six genes involved in lipopolysaccharide synthesis and membrane proteins in RA. Of these, three genes (AS87_09335, AS87_00480, and AS87_05195) encoding outer membrane proteins might be implicated in serum resistance statistically. The results indicate that serum resistance is a virulence mechanism in RA.

• Journal of fish pathology
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• v.32 no.2
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• pp.91-96
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• 2019

Rainbow trout (Oncorhynchus mykiss) were treated with ultrasonic (40kHz) and microbubble. The organic serum components, glucose were decreased compared to control at microbubble single treatment (M) and ultrasonic treatment (UL), but glucose concentrations in fish serum of all experimental groups analyzed in this study were also within the normal range. The organic serum components, cholesterol and total protein were no significant change by ultrasonic and microbubble treatment. There were no significant changes in the lysozyme activity on ultrasonic and microbubble treatment. Serum bactericidal activity decreased on ultrasonic single treatment (UL) compared to the control (P<0.05), but the numbers of bacterial colonies were significantly lower than those in the negative (PBS). The results of this study indicate that ultrasonic and microbubble treatment did not have a critical effect on the serum composition and innate immunity of O. mykiss, and that it is a way to do not significant stress on the fish body as a countermeasure against sea lice.

• Korean Journal of Food Science and Technology
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• v.44 no.4
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• pp.467-471
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• 2012

This study was conducted to evaluate the bactericidal activity of weakly alkalic electrolyzed water (WEW) against Salmonella Typhimurium and Staphylococcus aureus on perilla leaves. The influences of organic matter, inform of bovine serum, and the ratio of WEW to perilla leaves on bactericidal activity of WEW were also examined. Treatment of these organisms with 25, 50, 75, and 100 ppm WEW was performed for 1 min, 3 min and 5 min, respectively. Higher bactericidal activity was observed after a treatment with 100 ppm WEW compared to a treatment with 25 ppm WEW by 0.7 $log_{10}CFU/g$. The bactericidal activity of WEW also decreased with increasing bovine serum concentration. At the ratio of 10:1 (WEW: perilla leave), levels of Salmonella Typhimurium and Staphylococcus aureus were only reduced by 0.57 and 0.79 $log_{10}CFU/g$, respectively. It is suggested that the removal of organic debris prior to application of sanitizers and treatment above the ratio of 25:1 (WEW: perilla leave) is needed in order to improve WEW activity.