• Journal of Applied Biological Chemistry
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• 제64권1호
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• pp.83-87
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• 2021

소목(Caesalpinia sappan L.) 열수추출물의 피부상재균(Escherichia coli, Staphylococcus aureus, Cutibacterium acnes, Malassezia furfur)에 대한 항균 활성을 확인하였다. 소목 열수추출물의 수율과 폴리페놀 함량은 각각 14.01±0.81%과 487.5±19.69 ㎍/mg-추출물로 나타났다. 소목 열수추출물의 E. coli, S. aureus, C. acnes 및 M. furfur의 증식에 대한 최소저해농도는 각각 0.875, 1.750, 1.750 및 1.750 mg/mL이었다. 디스크 확산법에서 소목 열수추출물의 처리량에 비례하여 생육저해환이 증가하였다. 소목 열수추출물은 농도에 비례하여 피부상재균의 생육을 억제하였다.

• 한국수산과학회지
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• 제53권6호
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• pp.870-877
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• 2020

Twenty-three Bacillus cereus strain isolated from commercial jeotgal were investigated for 11 toxin genes and susceptibility to 25 different antimicrobials. The hemolytic enterotoxins hblA, hblC, and hblD were detected in 13.0%, and non-hemolytic enterotoxins nheA, nheB, and nheC were detected in 26.1%, 100%, and 100% of the isolates, respectively. The positive rates of cytK, entFM, becT, hlyII, and ces were 73.9%, 60.9%, 26.1%, 8.7%, and 0.0%, respectively. According to the disk diffusion susceptibility test, all of the strains studied were resistant to cefuroxime, followed by cefoxitin (78.3%), oxacillin (78.3%), ampicillin (69.6%), penicillin G (69.6%), and amoxicillin (65.2%). However, all the strains were susceptible to 11 other antimicrobials, including amikacin, chloramphenicol, and ciprofloxacin. The average minimum inhibitory concentrations of amoxicillin, ampicillin, and cefuroxime against B. cereus were 462.9, 235.0, and 135.0 ㎍/mL, respectively. These results highlight the need for sanitizing commercial jeotgal, and provide evidence to help reduce the risk of jeotgal contamination by antimicrobial-resistant bacteria.

• Advances in materials Research
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• 제11권3호
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• pp.191-209
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• 2022

Very slow degradation of synthetic based polymers has created a severe environmental issue that increased awareness towards research in polymers of biodegradable property. Soy protein isolate (SPI) is a natural biopolymer used as matrix in green composites but it has limitations of low mechanical properties and high water sensitivity. To enhance mechanical properties and reduce water sensitivity of Jute-SPI composites, SPI was modified with pine rosin which is also a natural cross-linking agent. 30% glycerol on the weight basis of a matrix was used as a plasticizer. The fibre volume fraction was kept constant at 0.2 whereas the pine rosin in SPI ranged from 5% to 30% of the matrix. The effects of pine rosin on mechanical, thermal, water sensitivity and surface morphology have been characterized using various techniques. The mechanical properties and water absorbency were found to be optimum for 15% pine rosin in Jute-SPI composite. Therefore, Jute-SPI composite without pine rosin and with 15% pine rosin were chosen for investigation through characterization by Fourier transforms infrared spectroscopy (FTIR), Thermo-gravimetric analysis (TGA), X-Ray diffraction (XRD) and Scanning electron microscope (SEM). The surface morphology of the composite was influenced by pine rosin which is shown in the SEM image. TGA measurement showed that the thermal properties improved due to the addition of pine rosin. Antimicrobial test showed antimicrobial property in the composite occurring 15% pine rosin. The research paper concludes that the modification of SPI resin with an optimum percentage of pine rosin enhanced mechanical, thermal as well as water-resistant properties of jute fibre reinforced composites.

• 대한임상검사과학회지
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• 제38권3호
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• pp.166-172
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• 2006

Metallo-${\beta}$-lactamase (MBL) can hydrolyze all ${\beta}$-lactams except monobactams and frequently coexists with various antibiotic resistance genes such as aminoglycoside resistance, sulfonamide resistance gene, etc. Therefore, the effective antibiotics against infections by these bacteria are markedly limited or can't even be found. We tried to search in-vitro antimicrobial combinations with synergistic effects for a VIM-2 type MBL producing Pseudomonas aeruginosa, isolated from clinical specimen. On the selection of antibiotic combinations with synergistic effects, we performed a one disk synergy test, modified Pestel's method, in agar without aztreonam (AZT). The bacteriostatic synergistic effects of this tests were scored as $S_1$ (by susceptibility pattern in agar without antibiotics), $S_2$ (by the change of susceptibility in agar with or without antibiotics) and $S_3$ ($S_1$ + $S_2$) and was classified into weak (1 point), moderate (2 points) and strong (3 points) by $S_3$ score. Subsequently, we carried out the time-killing curve for the antibiotic combinations with the strong synergistic bacteriostatic effect. One VIM-2 type MBL producing P. aeruginosa confirmed by the PCR showed all resistance against all ${\beta}$-lactams except AZT, aminoglycoside and ciprofloxacin. In the one disk synergy test, this isolate showed a strong bacteriostatic synergistic effect for the antibiotic combination of AZT and piperacillin-tazobactam (PIP-TZP) or AZT and amikacin (AN). On the time-killing curve after six hours of incubation, the colony forming units (CFUs/mL) of this bacteria in the medium broth with both combination antibiotics were decreased to 1/18.7, 1/17.1 of the least CFUs of each single antibiotics. The triple antibiotic combination therapy including AZT, PIP-TZP and AN was shown to be significantly synergistic after 8 hrs of exposure. In a VIM-2 MBL producing P. aeruginosa with susceptibility for AZT, the triple antibiotic combination therapy including AZT, PIP-TZP and AN may be considered as an alternative antibiotics modality against the infection by some MBL type. But the antimicrobial combination therapy for many more MBL producing isolates is essential to know as soon as possible for the selection of effective treatment against the infection by this bacteria.

• 한국콘텐츠학회논문지
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• 제20권4호
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• pp.454-463
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• 2020

본 연구는 최근 인간의 건강을 위협하는 다양한 원인 중에서 우리 주변에서 흔히 접할 수 있는 대상을 통해 그 원인의 해결을 제안하고자 시도 되었다. 천연물 유래의 테르펜의 경우 기존의 피톤치드와 같은 역할을 하고 있으며 다양한 생리활성 기능을 수행하고 있다. 본 연구에서는 우리주변에서 용이하게 구할 수 있으며 적용이 가능한 생물소재를 통해 오염원을 제거할 수 있는 생리활성을 검증하였다. 본 연구에서는 계피오일과 테르펜을 이용하여 다양한 질병과 오염원이 되고 있는 진드기와 미생물에 대한 효능을 검증하였다. 본 실험에서는 우리가 흔히 사용하는 베개를 이용하여 베게 등과 같은 침구류에서 발생할 수 있는 다양한 미생물과 진드기의 발생에 대한 작용에 대해 그 효능을 검증하였다. 그 결과로 테르펜의 항 미생물 활성은 Pour plate 방법을 사용하여 관찰하였다. 항진드기 효과는 테르펜을 사용하지 않고 첫 번째 테스트에서 베개 4개 중 2개에서 약한 양성(100 미만)으로 감지되었다. 테르펜을 사용한 두 번째 실험에서, 모든 시료들이 20 미만으로 음으로 감소되는 것으로 확인되었으며, 테르펜의 최상의 항진드기 효능은 20%인 것으로 밝혀졌다. 이 연구의 목적은 천연물 유래의 테르펜을 이용한 침구용 항균 및 진드기 방지 제품의 개발 가능성을 제안하는 것이다.

• 대한수의학회지
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• 제34권3호
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• pp.593-599
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• 1994

This study was carried out to investigate the necrotic enteritis of chicken in Korea. Epidemiological, pathological and microbiological examination were done on 12 naturally occurred cases of necrotic enteritis of chicken. And the susceptibility of isolated bacteria to antimicrobial agents was also examined. The results obtained were as follows; 1. The Clostridium perfringens infection, necrotic enteritis of chicken, occurred in the chickens mainly raised in floor pens. Necrotic enteritis of chicken was occurred coincidently with coccidiosis and Gumboro disease frequently. And several cases were recurred at 2-3 weeks after recovery. 2. Clinical signs of the infected chickens were depression, decreased appetite, reluctance to move, diarrhea, ruffled feathers and acute death within several hours. 3. The characteristic biochemical properties of isolates were 2-band hemolysis, no motility, positive reaction of reverse CAMP test and the formation of LV precipitate in egg yolk medium. 4. Gross lesions of the infected chickens were distention of intestine with gas, thickened mucosa and formation of thick pseudomembrane in intestine. Livers were friable with yellowish brown color and, in some case, showed demarcated necrotic foci. 5. Histopathological findings of the infected chickens were severe necrosis of the intestinal mucosa and attachment of numerous large bacilli to the mucosal surface of necrotic villi. In liver, necrosis of liver tissue and numerous large bacilli in the necrotic foci were also observed. 6. In susceptibility test to antimicrobial agents, 12 isolates of Clostridium perfringens were highly sensitive to ampicillin, baytril, cephalothin and penicillin.

• 한국미생물·생명공학회지
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• 제45권3호
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• pp.209-217
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• 2017

In the enduring investigation of the bioactive microbes, Pseudomonas aeruginosa strain (referred to as CGK-KS-1 (ICTB-315)), isolated from Chumathang hot spring, Ladakh, and India, was identified to possess a major bioactive fraction with antimicrobial and anti-biofilm properties. This bioactive metabolite was purified through bioactivity-guided fractionation. The chemical structure of this major compound was elucidated as phenazine-1-carboxamide (PCN) based on $^1H$ and $^{13}C$ NMR, FT-IR, EI-HR-MS and 2D NMR spectroscopic techniques. In the current study, PCN exhibited antimicrobial activity with MIC values ranging between $1.9-3.9{\mu}g/ml$ against various test human pathogens and Xanthomonas spp. PCN showed the anti-biofilm property with the $IC_{50}$ values ranging from 17.04 to $60.7{\mu}M$ against different test pathogens. The in silico docking studies showed PCN strongly interacted with various proteins of different Xanthomonas spp. with high binding energies. We report herein for the first time the anti-biofilm property and the docking studies of PCN. The extrolite from P. aeruginosa strain CGK-KS-1 showed promising bioactivities and may be considered as a potential candidate for application in various biocontrol strategies.

• Environmental Engineering Research
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• 제25권4호
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• pp.614-621
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• 2020

Antibiotic pollution is one of the factors contributing to the spread of antibiotic-resistant bacteria in the environment. Advanced oxidation and irradiation processes have been introduced to eliminate antibiotics from water and wastewater. However, few studies have reported the toxic effects of residual antibiotics and their byproducts induced by a treatment system. In this study, we compared the efficacies of chemical (high-performance liquid chromatography (HPLC)) and biological (antimicrobial susceptibility test) assays for measuring the concentrations of residual antibiotics after gamma irradiation for degrading amoxicillin, cephradine, lincomycin, and tetracycline. The concentrations of residual antibiotics estimated using the two assay methods were almost identical, except cephradine. In the case of cephradine, inhibited bacterial growth was observed that was equivalent to twice the concentration measured by HPLC in the samples subjected to gamma irradiation. The observed inhibition of bacterial growth suggested the generation of potentially toxic intermediates following antibiotic degradation. These results indicate that biological and chemical assays should be used in concert for monitoring antibiotic contamination and the toxic derivatives of antibiotic degradation. The results demonstrate that these four antibiotics can be decomposed by 2.0 kGy gamma-irradiation without toxic effects of their byproducts.

• Applied Biological Chemistry
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• 제42권2호
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• pp.176-179
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• 1999

지칭개, 구절초 및 산국에서 분리한 9종류의 sesquiterpene lactones에 대한 생리활성 실험의 일환으로, 10종의 세균에 대한 항세균활성과 6종의 식물병원균에 대한 항진균활성을 조사하였다. 항세균 활성실험에서는 지칭개에서 분리한 hemistepsin A와 B 그리고 산국에서 분리한 tulipinolide가 시험균주 전반에 대하여 강한 활성을 보였으며, 항진균 활성실험에서는 hemistepsin B, angeloylcumambrin B, tigloylcumambrin B, 그리고 costunolide가 광범위한 활성을 보였다. 또한, 항세균 활성실험과 항진균 활성실험 모두 비교적 뚜렷한 균주특이성을 나타내었다.

• Childhood Kidney Diseases
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• 제25권1호
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• pp.22-28
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• 2021

Purpose: The purpose of this study was to investigate the clinical outcomes of non-carbapenem treatment for urinary tract infections (UTIs) caused by extended-spectrum β-lactamase (ESBL)-producing Escherichia coli (E. coli) in young children. Methods: We retrospectively reviewed the medical records of children under 2 years of age who were diagnosed and treated for UTIs caused by ESBL-producing E. coli from September 2014 to March 2020. Results: Forty-three children under 2 years of age were treated with non-carbapenem antimicrobials for UTIs caused by ESBL-producing E. coli without bloodstream infections. The overall clinical and microbiological success rates for empirical antimicrobial treatment were 90.7% and 97.7%. Three of the patients (7.0%) experienced a relapse of UTI within a month. An in vitro susceptibility test showed that two patients were sensitive and one was resistant to the antimicrobial treatments. Furthermore, there were no significant differences in the time to defervescence, clinical success, microbiological success, and relapse rate between the susceptible (n=13) and non-susceptible groups (n=30). Conclusion: In this study, the overall relapse rate of patients treated with non-carbapenem antimicrobials was 7.0%. The patients showed high success rates in the clinical and microbiological responses to the non-carbapenems regardless of the results of the in vitro antimicrobial susceptibility test. These results provide evidence that non-carbapenems may be viable alternative treatments for UTIs caused by ESBL-producing E. coli.