• International Journal of Oral Biology
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• 제43권3호
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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.

• 한국축산식품학회지
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• 제31권2호
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• pp.158-165
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• 2011

A sensitive reverse transcriptase-PCR (RT-PCR) method to detect viable Escherichia coli O157:H7 in milk was established. The primer sets were designed based on the nucleotide sequences of the rfbE (per) and wbdN genes in the O157 antigen gene cluster of E. coli O157:H7. RT-PCR using five different primer sets yielded DNA with sizes of 655, 518, 450, and 149-bp, respectively. All five of the E. coli O157:H7 strains were detected by RT-PCR, but 11 other bacterial species were not. The sensitivity of RT-PCR was improved by adding yeast tRNA as a carrier to the crude RNA extract. The RT-PCR amplifying the 149-bp DNA fragment was the most sensitive for detecting E. coli O157:H7 and the most refractory to the bactericidal treatments. Heat treatment at $65^{\circ}C$ for 30 min was the least inhibitory of all bactericidal treatments. Treatment with RNase A strongly inhibited the RT-PCR of heated milk but not unheated milk. This study described RT-PCR methods that are specific and sensitive with a detection limit of 10 E. coli O157:H7 cells, and showed that pre-treating milk samples with RNase A improved the specificity to detect viable bacteria by RT-PCR.

• Journal of Periodontal and Implant Science
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• 제53권2호
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• pp.110-119
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• 2023

Purpose: This study aimed to investigate the proper wavelengths for safe levels of light-emitting diode (LED) irradiation with bactericidal and photobiomodulation effects in vitro. Methods: Cell viability tests of fibroblasts and osteoblasts after LED irradiation at 470, 525, 590, 630, and 850 nm were performed using the thiazolyl blue tetrazolium bromide assay. The bactericidal effect of 470-nm LED irradiation was analyzed with Streptococcus gordonii, Aggregatibacter actinomycetemcomitans, Fusobacterium nucleatum, Porphyromonas gingivalis, and Tannerella forsythia. Levels of nitric oxide, a proinflammatory mediator, were measured to identify the anti-inflammatory effect of LED irradiation on lipopolysaccharide-stimulated inflammation in RAW 264.7 macrophages. Results: LED irradiation at wavelengths of 470, 525, 590, 630, and 850 nm showed no cytotoxic effect on fibroblasts and osteoblasts. LED irradiation at 630 and 850 nm led to fibroblast proliferation compared to no LED irradiation. LED irradiation at 470 nm resulted in bactericidal effects on S. gordonii, A. actinomycetemcomitans, F. nucleatum, P. gingivalis, and T. forsythia. Lipopolysaccharide (LPS)-induced RAW 264.7 inflammation was reduced by irradiation with 525-nm LED before LPS treatment and irradiation with 630-nm LED after LPS treatment; however, the effects were limited. Conclusions: LED irradiation at 470 nm showed bactericidal effects, while LED irradiation at 525 and 630 nm showed preventive and treatment effects on LPS-induced RAW 264.7 inflammation. The application of LED irradiation has potential as an adjuvant in periodontal therapy, although further investigations should be performed in vivo.

• 미생물학회지
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• 제38권4호
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• pp.281-286
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• 2002

2000년 1 월부터 2000년 10월까지 가두리 양식장에서 Vibrio vulnificus를 검출하였고 이들의 억제 방법을 연구하였다. 이 세균의 검출은 선택적 분리법과 vvhA 유전자를 확인하는 방법을 이용하였다. V. vulnificus는 수온이 $17^{\circ}C$이상인 5월부터 검출되었고 $19^{\circ}C$ 이상인 6월부터 9월까지는 대부분의 시료에서 검출되었다. V. vulnificus를 제어하기 위한 방법 중 냉동 및 냉장 처리는 살균효과를 나타내지 못했다. Citric acid도 균의 생장을 억제하지 못했으나, 500 mg/1이상의 EDTA가 첨가될 경우 균이 완전히 사멸되었다. 분말 광촉매인 산화티타니움은 자외선을 조사할 경우 15분～1 시간 이내에 이 세균을 완전히 사멸시키는 효과를 나타내었다. 산화티타니움을 유리 구슬에 코팅한 광촉매 장치를 이용하여 0.2/min의 turnover rate로 사멸효과를 얻었다.

• 한국식품과학회지
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• 제31권2호
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• pp.522-526
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• 1999

S. mutans에 대한 키토산의 항균효과는 그 분자량에 따라 뚜렷한 차이를 보였으며, 약 30,000의 분자량을 갖는 키토산이 가장 높은 항균활성을 보였다. 키토산 처리에 의해 세포로부터 단백질, 핵산, 2가 양이온 등이 상당량 유출되는 것이 관찰되었으며, 세포내 물질의 유출정도는 키토산의 항균효과와 밀접한 상관성을 보였다. 이러한 세포내 물질의 유출은 양이온성을 띠는 키토산의 아민기와 세포벽내의 음이온 성분과의 강한 결합에 의해 세포벽의 결합력이 약화되면서 생기는 결과로서 추측되었다. 키토산처리에 의해 S. mutans의 세포벽이 원형질로부터 분리되고 세포내 물질이 세포벽 내에서 밖으로 유출되는 현상은 투과전자현미경(TEM)에 의해 확인되었다.

• 한국동물위생학회지
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• 제32권4호
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• pp.347-351
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• 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.

• Food Science and Biotechnology
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• 제18권5호
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• pp.1263-1272
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• 2009

Danshen (Salvia miltiorrhiza Bunge) is a traditional Korean medicine that is commonly used for the treatment of inflammatory diseases such as edema, arthritis, hepatitis, and endangitis. The several extracts of danshen were tested for antimicrobial activity against methicillin-resistant Staphylococcus aureus (MRSA) isolated in clinic by broth microdilution method, the checkerboard, and time-kill methods to evaluate the synergistic effects of the combination of the extracts with antibiotics. The chloroform ($CHCl_3$) and n-hexane (HEX) extracts [minimum inhibitory concentration (MIC), 0.0078-0.3125${\mu}g/mL$; minimum bactericidal concentration (MBC), 0.019-0.625${\mu}g/mL$] were found to have strong antibacterial activity against MRSA. Additionally, when the $CHCl_3$ and HEX extracts were co-administered with ampicillin or oxacillin, a synergistic effect against MRSA was observed. Furthermore, a time-kill study evaluating the effects of the extracts against MRSA indicated that treatment with the $CHCl_3$ extract in combination with ampicillin or oxacillin produced rapid bactericidal activity. These results suggest that danshen extracts may have potently antimicrobial activity and thus, it can be a suitable phytotherapeutic agent for treating MRSA infections.

• 한국환경보건학회지
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• 제32권3호
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• pp.215-221
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• 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.

• Food Science and Biotechnology
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• 제17권4호
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• pp.842-845
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• 2008

This study was carried out to investigate the bactericidal efficacy of concentration (0.1, 0.2, and 0.4 ppm) and exposure time (10 and 30 min) of ozone on bacterial reduction rate of Salmonella typhimurium KCTC 2541 and Staphylococcus aureus ATCC 13515 in the distilled water (DW), and DW supplemented with 0.2% soluble starch (SS), and metal ion (MC) using argentums (Ag) and copper (Cu). The significant bactericidal differences of S. aureus were showed in the treatments of DW and SS, respectively, at the concentration of ozone above 0.1 ppm for 10 min, comparing the respective initial bacterial counts. The bacterial reduction of S. aureus was more sensitive than that of S. typhimurum at the same concentration of ozone. The bacterial reduction rate of SS treatment was slightly lower than that of DW treatment at the same concentration of ozone (p<0.05), however, the bacterial reduction rate of strains improved in the MC treatment compared to the DW treatment at the same concentration of ozone.

• 한국임상수의학회지
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• 제27권3호
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• pp.252-256
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• 2010

소 유방염은 주로 세균 감염에 의한 유선조직에 염증이 생기는 질병으로 유방염의 치료와 억제를 위해서는 1차적으로 세균을 사멸시키는데 있다. 본 연구에서는 소 유방염의 원인이 되는 다양한 세균들에 대한 은 이온의 항균효과와 적용 농도를 측정하였다. 유방염 원인균에 대한 은 이온의 최소 억제 농도 (minimal inhibitory concentrations, MICs)와 최소 살균 농도 (minimum bactericidal concentrations, MBCs)를 측정하였으며, 주사전자현미경 (scanning electron microscopy, SEM)을 이용하여 은 이온에 의한 세균의 형태 변화를 확인하였다. 다양한 유방염 원인균에 대한은 이온의 최소 억제 농도와 최소 살균 농도는 1.9에서 15.6 ${\mu}g$/ml로 세균에 따라 차이가 보였으며, 은이온 처리 후 주사전자현미경 촬영 결과 Staphylococcus aureus와 Escherichia coli의 세포벽이 함몰되거나 파괴되는 것을 볼 수 있었다. 이러한 결과는 유방염 원인이 되는 다양한 원인균에 대해 은이온의 살균 효과와 그 적용 농도를 보여주는 것으로, 소 유방염의 치료와 방어를 위한 임상적인 적용 가능성을 보여주는 것이다.