• Journal of Veterinary Science
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• 제22권2호
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• pp.18.1-18.12
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• 2021

Background: We previously elucidated the protective mechanism of Korean red ginseng oil (RGO) against Brucella abortus infection, and our phytochemical analysis revealed that palmitic acid (PA) was an abundant component of RGO. Consequently, we investigated the contribution of PA against B. abortus. Objectives: We aimed to investigate the efficacy of PA against B. abortus infection using a murine cell line and a murine model. Methods: Cell viability, bactericidal, internalization, and intracellular replication, western blot, nitric oxide (NO), and superoxide (O₂^-) analyses and flow cytometry were performed to determine the effects of PA on the progression of B. abortus infection in macrophages. Flow cytometry for cytokine analysis of serum samples and bacterial counts from the spleens were performed to determine the effect of PA in a mouse model. Results: PA did not affect the growth of B. abortus. PA treatment in macrophages did not change B. abortus uptake but it did attenuate the intracellular survivability of B. abortus. Incubation of cells with PA resulted in a modest increase in sirtuin 1 (SIRT1) expression. Compared to control cells, reduced nitrite accumulation, augmented O₂^-, and enhanced pro-inflammatory cytokine production were observed in PA-treated B. abortus-infected cells. Mice orally treated with PA displayed a decreased serum interleukin-10 level and enhanced bacterial resistance. Conclusions: Our results suggest that PA participates in the control of B. abortus within murine macrophages, and the in vivo study results confirm its efficacy against the infection. However, further investigations are encouraged to completely characterize the mechanisms involved in the inhibition of B. abortus infection by fatty acids.

• Food Science and Biotechnology
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• 제15권5호
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• pp.792-798
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• 2006

The probiotic characteristics of a total of 137 lactic acid bacterial strains isolated from soybean paste were investigated. Among those tested, the D37 strain was selected as a probiotic bacteria due to its acid and bile tolerance, and its strong anti-cancer and antibacterial activities. The D37 strain showed highly stable viability at acidic pH for 2 hr, and was very stable in 10% bovine bile. The viability of human colon cancer HT-29 cells was inhibited more than 60% at a $200\;{\mu}/mL$ concentration of D37 cell-free culture supernatant, and the degree of inhibition was concentration-dependent. The D37 strain showed a wide range of antibacterial activities against food-borne pathogenic bacteria such as Escherichia coli O157, Listeria spp., Vibrio spp., Salmonella spp., and Staphylococcus aureus. According to phenotypic characteristics and the utilization of various sugars, the D37 strain was identified as Lactobacillus cellobiosus.

• Parasites, Hosts and Diseases
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• 제54권3호
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• pp.273-280
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• 2016

We evaluated the activity of methanolic extracts of Melaleuca cajuputi flowers against the filarial worm Brugia pahangi and its bacterial endosymbiont Wolbachia. Anti-Wolbachia activity was measured in worms and in Aedes albopictus Aa23 cells by PCR, electron microscopy, and other biological assays. In particular, microfilarial release, worm motility, and viability were determined. M. cajuputi flower extracts were found to significantly reduce Wolbachia endosymbionts in Aa23 cells, Wolbachia surface protein, and microfilarial release, as well as the viability and motility of adult worms. Anti-Wolbachia activity was further confirmed by observation of degraded and phagocytized Wolbachia in worms treated with the flower extracts. The data provided in vitro and in vivo evidence that M. cajuputi flower extracts inhibit Wolbachia, an activity that may be exploited as an alternative strategy to treat human lymphatic filariasis.

• 대한수의학회지
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• 제51권2호
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• pp.101-105
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• 2011

We investigate the resistance of Cryptosporidium (C.) parvum oocysts to commercial bleach treatment. The viability and infectivity of C. parvum oocysts suspended in 100, 50, 25, 12.5, 6.3 or 3.2% aqueous commercial bleach for 10, 30, 60, 120 or 180 min at room temperature were assessed by nucleic acid Syto-9 staining, histologic examination of ileum and infectivity to immunosuppressed neonatal C57BL/6N mice. Although the viability was decreased compared with normal oocysts, all oocysts in contact with serially diluted commercial bleach for 180 min were alive by nucleic acid dye Syto-9 staining. And, microscopic examination of ileum sections revealed developmental stages of C. parvum in all mice. The oocyst shedding patterns between mice infected with oocysts contacted with commercial bleach and normal control mice were not significantly different each other. Although commercial bleach is widely used as a bacterial and viral disinfectant, the present findings indicate that it is not an effective disinfectant for C. parvum oocysts under practical conditions. Authors conclude that, therefore, it is undesirable to recommend commercial bleach as a disinfectant for C. parvum oocysts.

• Advances in nano research
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• 제11권6호
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• pp.657-665
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• 2021

The present work aimed to explore green approach via aqueous leaves extract of Murraya koenigii (ALEMk) for the synthesis of silver nanoparticles (AgNPsMk) in single step. The synthesis process was visualized with a color change and monitored by employing UV/Visible spectroscopy and a clear peak attained at 420 nm confirming the synthesis of AgNPsMk. The possible functional groups present in the extract which participated in the synthesis of AgNPsMk were identified with the help of FTIR spectroscopy. Further characterization using TEM images revealed the spherical shape of AgNPsMk with average particle size of 20 nm displaying well dispersion throughout the solution. Pronounced antioxidant activities of AgNPsMk at increased concentrations observed which evidencing strong radical scavenging ability. Moreover, AgNPsMk exhibited strong antibacterial behavior when tested against bacterial strains of Escherichia coli and Bacillus subtilis. Moving ahead, in vitro cytotoxicity work revealed potent cell viability loss appearing in AU565 and HeLa cancer cell lines on exposure to AgNPsMk at increased concentration. Finally, in vivo assessment carried out inside male Wistar rats indicated non toxic effect on examined liver tissues besides biochemical analysis including bilirubin, alkaline phosphtase (ALP) and serum glutamate pyruvate transaminase (SGPT) which found within the normal range when compared with control. The prior research work profoundly apprises the potential of green synthesized AgNPsMk to play a significant role in biomedical applications and formulations.

• 대한소아치과학회지
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• 제30권1호
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• pp.80-91
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• 2003

치아우식증의 원인균인 S. mutans GS5와 S. sobrinus 6715에 대한 polyP의 효과를 관찰하여 보다 안전하고 효과적인 치아우식증 예방을 위한 임상적용의 가능성을 고찰하고자 첫째, 다양한 사슬길이의 polyP를 첨가한 후 흡광도를 측정하여 MIC를 결정하고, 둘째, 실험균주를 흡광도 $0.3{\sim}0.5$까지 증식시킨 후 MIC 농도의 polyP를 첨가하여 흡광도의 변화를 측정함으로써 균주증식 후 성장 억제효과를 관찰하였으며, 셋째, 생균수 측정으로 polyP의 항균효과를 평가하였고, 넷째, 핵산유리의 정도로 polyP의 킬레이션 작용여부를 관찰하였으며, 다섯째, polyP의 비수용성 글루칸 합성능력을 관찰하였으며, 여섯째, 투과전자현미경으로 세포막과 세포질 내의 구조적 변화를 관찰하였다. 이상의 연구를 통하여, polyP의 살균작용이 S. mutans와 S. sobrinus에 대한 성장을 억제시키는 효과가 있는 것으로 가늠된다. 이와 같은 성장 억제효과는 polyP의 킬레이션에 의한 것이라기보다는 균주 세포의 구조적, 형태적 변화가 주된 요인이었던 것으로 판단된다.

• 한국식품과학회지
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• 제38권5호
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• pp.720-723
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• 2006

본 연구에서는 우리 나라 세균성 이질을 유발하는 주요 원인 균인 S. sonnei를 대상으로 불충분한 열처리와 NaCl 처리에 따른 각각의 생존균수 변화와 불충분한 열처리 후 다양한 NaCl 농도 (0, 2, 4, 6%) 하에서 sublethal injured cell의 회복정도를 조사하였다. 그 결과, 불충분한 열처리 정도가 증가함에 따라 생존균수가 유의적인 감소를 나타내었으나, NaCl 처리시 NaCl 농도가 6% 까지 증가함에 따라서 생존균수의 변화가 거의 없었다. 그리고 $55^{\circ}C$에서 30분 동안 열처리후 2% TSAS 배지에서 7.58 log CFU/mL, 4% TSAS 배지에서 7.83 log CFU/mL, 그리고 6% TSAS 배지에서 7.93 log CFU/mL 만큼 각각 생성된 colony 숫자가 감소 한 것으로 조사되었고, $60^{\circ}C$에서 30분동안 열처리후 2% TSAS 배지에서 6.71 log CFU/mL, 4% TSAS 배지에서 6.73 log CFU/mL, 그리고 6% TSAS 배지에서 6.73 log CFU/mL 만큼 각각 생성된 colony 숫자가 감소한 것으로 조사되었다. 그리고 동일한 온도에서 sublethal heating후 노출된 NaCl 농도가 증가함에 따라서 D-value가 감소하는 경향을 나타내었다. 이와 같은 결과는 불충분한 열처리 과정에 의하여 생성된 sublethal injured cell들이 열처리후 회복되는 과정에서 배지의 NaCl 농도가 증가함에 따라서 회복정도가 감소하였음을 의미한다.

• 한국식품위생안전성학회지
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• 제24권4호
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• pp.368-372
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• 2009

본 연구에서는 우리나라에서 2-3번째로 자주 발생하는 식중독 원인균인 S. aureus를 대상으로 불충분한 열처리와 NaCl처리에 따른 각각의 생존균수 변화와 불충분한 열처리 후 다양한 NaCl농도(0%, 2%, 4%, 6%)하에서 sublethal injured cell의 회복 정도를 조사하였다. 그 결과, 불충분한 열처리 정도가 증가함에 따라 생존균수가 유의적인 감소를 하였으나, NaCl 처리시 NaCl 농도가 6%까지 증가함에 따라서 생존균수의 변화가 거의 없었다. 그리고 $55^{\circ}C$나 $60^{\circ}C$에서 30분간 열처리하는 기간 동안에 sublethal injured cell들이 발생하였으며, 그들의 회복 정도는 높은 염농도에 노출될수록 회복 정도가 감소하였다. 또한 이와 같은 현상은 같은 온도에서 열처리 시간이 증가할수록 더욱 명확히 나타났다. 그리고 동일한 온도에서 sublethal heating 후 노출된 NaCl 농도가 증가함에 따라서 D-value가 감소하는 경향을 나타내었다. 이와 같은 결과는 불충분한 열처리 과정에 의하여 생성된 sublethal injured cell들이 열처리 후 회복되는 과정에서 배지의 NaCl 농도가 증가함에 따라서 회복 정도가 감소하였음을 의미한다.

• Journal of Microbiology and Biotechnology
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• 제19권9호
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• pp.1028-1033
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• 2009

In this study, the dynamics of living cells (LC) and dead cells (DC) in a laboratory-scale biofilm membrane bioreactor for waste gas treatment was examined. Toluene was used as a model pollutant. The bacterial cells were enumerated as fluoromicroscopic counts during a 140 operating day period using BacLight nucleic acid staining in combination with epifluorescence and confocal laser scanning microscopy (CSLM). Overall, five different phases could be distinguished during the biofilm development: (A) cell attachment, (B) pollutant limitation, (C) biofilm establishment and colonization, (D) colonized biofilm, and (E) biofilm erosion. The bioreactor was operated under different conditions by applying different pollutant concentrations. An optimum toluene removal of 89% was observed at a loading rate of 14.4 kg $m^{-3}d^{-1}$. A direct correlation between the biodegradation rate of the reactor and the dynamics of biofilm development could be demonstrated. This study shows the first description of biofilm development during gaseous toluene degradation in MBR.

• Journal of Microbiology
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• 제39권3호
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• pp.206-212
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• 2001

Catechol and 4-chlorobenzoate (4CBA) which are produced from the biodegradation of a variety of aromatic and chloroaromatics have been recognized as toxic to living organisms. In this study, the toxic effects of catechol and 4-chlorobenzoate on gram-positive and -negative bacteria were examined in terms of survival, morphology, change in fatty acids and membrane protein composition. The survival rate of the organisms during treatment for 6 h was decreased, as the concentration of each aromatic was increased. Escherichia coli and Pseudomonas cells treated with catechol and 4CBA at concentrations causing a significant decrease in their viability, showed destructive openings in their cell envelopes. Bacills subtilis treated with the aromatics were reduced in cell size and Staphylococcus aureus cells displayed irregular rod shapes with wrinkled surfaces. The bacterial cells treated with 20 mM catechol showed increases in unsaturated fatty acids, but several saturated fatty acids were decreased. In the E. coli cells treated with 20 mM catechol, inner membrane proteins of 150 kDa and 105 kDa were decreased. But several kinds of the inner and outer membrane proteins were increased. In B. subtilis treated with 20 mM catechol, several kinds of proteins were increased or decreased in membrane proteins.