• 한국환경보건학회지
• /
• 제32권3호
• /
• pp.215-221
• /
• 2006

This study investigated the inactivation of the total coliform, an indicator organism in chlorine dioxide, in order to assess the optimal disinfection procedure for drinking water treatment and distribution systems. This research focus on a number of factors, including the dosage of disinfectant, contact time, pH, temperature and DOC. Water samples were taken from the outlet of a settling basin at a conventional surface water treatment system. As the pH increased in the range of pH 6-9, the bactericidal effects of disinfectants decreased. Changes in levels of pH did not significantly after the disinfection effect of chlorine dioxide for total coliform. With an increase in temperature, there was a subsequent increase in the bactericidal effects of disinfectants. Thus, it is evident that a decrease in temperature will higher the CT values required to inactivate coliform for during the winter. DOC addition can also reduce total coliform inactivation. DOC is the most significant variable in total coliform inactivation with chlorine dioxide.

• BMB Reports
• /
• 제30권3호
• /
• pp.229-233
• /
• 1997

Indolicidin has been known to have a broad spectrum of antimicrobial activities against Gram negative and positive bacteria. Its eight analogues were chemically synthesized. The analogue design was based on the analysis of sequence to elucidate the role of some residues in the antibacterial mechanism of indolicidin. Bactericidal activities were assayed against Escherichia coli and Proteus vulgaris, and the membrane perturbing abilities of the peptides were assayed using a dye containing liposome. Among the eight analogues, $[Gly^4, Gly^6]-Indo,\;[Ile^6,Ile^8]-Indo,\;[Lys^{12}]-Indo$ and $[Thr^2,Tyr^9]-Indo$ showed enhanced antibacterial activities. These results suggest that proline and cationic residues are important in the bactericidal activity of indolicidin. We tried to describe the antimicrobial mechanism of indolicidin with these results.

• 한국식품위생안전성학회지
• /
• 제23권1호
• /
• pp.68-72
• /
• 2008

Antimicrobial stability of grape seed extract ($ActiVin^{TM}$), pine bark extract ($Pycnogenol^{(R)}$), and oleoresin rosemary ($Herbalox^{(R)}$) on the growth of Aeromonas hydrophila was investigated in cooked ground beef. When compared to the control, the populations of A. hydrophila were most effectively reduced by 4.06 log CFU/g for 1% $Pycnogenol^{(R)}$ added after cooking at 10 days of refrigerated storage, followed by 3.06 log CFU/g for 1% $Pycnogenol^{(R)}$ added before cooking and 1.36 log CFU/g for $ActiVin^{TM}$. Bacteriostatic and bactericidal activities were observed for $Pycnogenol^{(R)}$ added before and after cooking, respectively. $Pycnogenol^{(R)}$ consists of heat-labile and heat-stable compounds. $ActiVin^{TM}$ and $Pycnogenol^{(R)}$ could be considered for use as multifunctional preservatives in meat and meat products.

• Fisheries and Aquatic Sciences
• /
• 제11권1호
• /
• pp.1-6
• /
• 2008

In an effort to discover an alternative therapeutic agent against methicillin-resistant Staphylococcus aureus (MRSA), several medicinal plants and seaweeds were evaluated for its antibacterial activity against MRSA. A methanolic extract of the Phaeophyta Ecklonia stolonifera exhibited significant antibacterial activity against MRSA. To perform more detailed investigation on antibacterial activity, the methanol extract of E. stolonifera was further fractionated with organic solvents such as hexane, dimethylchloride, ethyl acetate, and n-butanol. Among them, the hexane fraction showed the strongest antibacterial activity against MRSA strains with MIC from 500 to $600 {\mu}g/mL$. The fraction also exhibited a bactericidal activity against MRSA, indicating that E. stolonifera contains a bactericidal substance against MRSA.

• 한국동물위생학회지
• /
• 제32권4호
• /
• pp.347-351
• /
• 2009

Bruella spp. involves a considerable danger of public health and farm animal industry. In this study, we assessed the disinfection efficacy of alkaline disinfectant solution and three commercial farm disinfectants (quaternary ammonium compound, sodium dichloroisocyanurate, potassium monopersulphate/sodium dichloroisocyanurate) against Brucella ovis. A bactericidal efficacy test by broth dilution method was used to determine the lowest effective dilution of selected disinfectants following exposure to test bacteria for 30 minutes at $4^{\circ}C$. Disinfectants and test bacteria are diluted with distilled water (DW), hard water (HW) or organic matter suspension (OM) according to treatment condition. Three commercial disinfectant showed excellent antimicrobial activity (up to dilution of $\times200$ in OM treatment). Alkaline disinfectant solution demonstrated favorable bactericidal efficacy against B. abortus (at dilution of $\times20$ in OM treatment). Three commercial farm disinfectants possess excellent efficacy against B. ovis. Alkaline disinfectant solution has lower potency than commercial farm disinfectant but could help to limit the spread of brucellosis.

• 환경위생공학
• /
• 제13권3호
• /
• pp.52-57
• /
• 1998

The disinfection of public water supplies has been used to prevent the transmission of waterborne diseases throughout the worlds. Although chlorine has been used as the primary disinfactant, its safety was first questioned in 1974 when chlorination of drinking water was found to result in the formation of trihalomethanes(THMs). Chlorine dioxide was selected as one alternative disinfactant. But the application of chlorine dioxide in water treatment has been limited because of concerns about the health effects of DBPs. In these experiments, chlorine dioxide showed the effective inactivation on both total coliforms and HPC at 3.0 mg $ClO_2/L$. The bactericidal effects of chlorine dioxide showed a tendency to increase as pH decreased, but the differences were not so sizable.

• 한국임상수의학회지
• /
• 제20권1호
• /
• pp.86-90
• /
• 2003

Little is known to data about the in vitro activity of antimicrobial agents aganist Brucella cams (B cams) isolated from Korea. Our study aimed at determining the in vitro activities of 15 antimicrobial agents against 3 isolates and 52 isolates of B cams from dogs in 1994 and 2002, respectively. In minimal inhibitory concentration (MIC) study, minocycline and doxycycline showed the lowest MICs ( < 0.06-0.5 ug/ml). Gentamicin, streptomycin, ciprofloxacin, norfloxacin and rifampin showed MICs in the range of less than 1 ug/ml. Lincomycin and sulfisox azole showed the highest MICs ( > 32 ug/ml). Interestingly, MICs of macrolides (erythromycin, spiramycin, tylosin) against 52 isolates in 2002 were 16-64 times higher than that of 3 isolates in 1994. In minimal bactericidal concentration (MBC) study, gentamicin, streptomycin, ciprofloxacin and norfloxacin showed the lowest MBCs [0.12-1 ug/ml (1-2 times higher than MIC)], but minocycline and doxycycline showed the highest MBCs [8-32 ug/ml (128 times higher than MIC)]. Rifampin showed the MBCs in the range from 2 to 4 ug/ml (2-4 times higher than MIC).

• Archives of Pharmacal Research
• /
• 제19권6호
• /
• pp.581-585
• /
• 1996

A new formal total synthesis of (+)-6-oxo-3, 4, 4a, 5-tetrahydro-3-hydroxy-2, 2-dimenthylnaphtho-1, 2-pyran (1) which has been known to have bactericidal, bacteriostatic, fungicidal, fungistatic activities against Staphylococcus aureus and other microorganism, is described. The key reaction involves enantioselective prenylation of .alpha.-tetralone via chiral lithioenamine.

• Journal of Microbiology
• /
• 제43권5호
• /
• pp.443-450
• /
• 2005

The multi-host pathogen, Pseudomonas aeruginosa, possesses an extraordinary versatility which makes it capable of surviving the adverse conditions provided by environmental, host, and, presumably, competing microbial factors in its natural habitats. Here, we investigated the P. aeruginosa-Bacillus subtilis interaction in laboratory conditions and found that some P. aeruginosa strains can outcompete B. subtilis in mixed planktonic cultures. This is accompanied by the loss of B. subtilis viability. The bactericidal activity of P. aeruginosa is measured on B. subtilis plate cultures. The bactericidal activity is attenuated in pqsA, mvfR, lasR, pilB, gacA, dsbA, rpoS, and phnAB mutants. These results suggest that P. aeruginosa utilizes a subset of conserved virulence pathways in order to survive the conditions provided by its bacterial neighbors.

• The Korean Journal of Physiology and Pharmacology
• /
• 제26권3호
• /
• pp.175-182
• /
• 2022

Translocation of azurophil granules is pivotal for bactericidal activity of neutrophils, the first-line defense cells against pathogens. Previously, we reported that lysophosphatidylcholine (LPC), an endogenous lipid, enhances bactericidal activity of human neutrophils via increasing translocation of azurophil granules. However, the precise mechanism of LPC-induced azurophil granule translocation was not fully understood. Treatment of neutrophil with LPC significantly increased CD63 (an azurophil granule marker) surface expression. Interestingly, cytochalasin B, an inhibitor of action polymerization, blocked LPC-induced CD63 surface expression. LPC increased F-actin polymerization. LPC-induced CD63 surface expression was inhibited by both a Rho specific inhibitor, Tat-C3 exoenzyme, and a Rho kinase (ROCK) inhibitor, Y27632 which also inhibited LPC-induced F-actin polymerization. LPC induced Rho-GTP activation. NSC23766, a Rac inhibitor, however, did not affect LPC-induced CD63 surface expression. Theses results suggest a novel regulatory mechanism for azurophil granule translocation where LPC induces translocation of azurophil granules via Rho/ROCK/F-actin polymerization pathway.