• 대한수의학회지
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• 제22권2호
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• pp.139-147
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• 1982

A total of 133 isolates of yeast-like fungi was tested for sensitivity to seven different antifungal agents. The yeast-like fungi tested were isolated from the milk from normal or mastitic bovine quaters or from bovine feces. They were 5 Candida albicans (C. albicans) isolates, 63 C. krusei, 27 C. tropicalis, 5 C. parapsilosis, 10 Torulopsis glabrata, 6 Rhodotorula sp., 6 Hansenula sp. and 1 Pichia sp. isolate. The antifungal agents tested were nystatin, griseofulvin, cycloheximide, 5-fluorocytosine, miconazol, clotrimazole and tolnaftate. In general, clotrimazole, miconazol and 5-fluorocytosine were more effective in antifungal activity in vitro against the test organisms than the rest of the agents tested. However, some of the isolates showed higher resistance to certain antifungal agents compared to the other isolates of the some species. They were: 1 C. albicans isolate to 5-fluorocytosine; 1 C. albicans to 5-fluorocytosine, miconazol and clotrimazole; 1 C. krusei to 5-fluorocytosine and cycloheximide; and 11 C. tropicalis isolates to cycloheximide. The minimum inhibitory concentrations(MIC) of clotrimazole were $12.5{\mu}g/ml$ or lower for all isolates tested except one C. albicans isolate, for which MIC of the drug was $100{\mu}g/ml$. On the other hand, the MIC's of cycloheximide were $6.5{\mu}g/ml$ or lower for all isolates except the following; all isolates of C. albicans ($100{\mu}g/ml$), C. pseudotropicalis ($200{\mu}g/ml$) and Rhodotorula sp. ($25-50{\mu}g/ml$), 11 C. tropicalis isolates ($100{\mu}g/ml$) and 1 C. krusei isolate ($200{\mu}g/ml$).

• Journal of Forest and Environmental Science
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• 제33권4호
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• pp.322-329
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• 2017

As a result of contemporary environmental concerns, a number of studies from plants' tissues as one of the alternatives to conventional chemicals are increasingly investigated. In tandem with these trends, Lagenaria breviflora (LB) fruit, reputed as antiviral and depilatory agents in the Yoruba folkloric medicine was examined on Vitex doniana wood to ascertain its antifungal activity. Fungicides of 25%, 50%, 75%, and 100% LB fruits formulations (concentrations) were developed through simple one-step mechanical-forming process, including control. In this study, the yield, the chemical compositions, the absorption capacity of the fungicides and wood weight losses (WWL) analysis were evaluated to investigate the antifungal activity of LB fruit on wood. The fruit extract yielded 35.4% of fresh juice weight. LB fruits contained total: alkaloids ($8.78{\pm}0.21mg/mL$), flavonoids ($2.01{\pm}0.02mg/mL$), phenol ($7.42{\pm}0.09mg/mL$), saponins ($11.00{\pm}0.10mg/mL$) and tannins ($5.47{\pm}0.05mg/mL$) contents. All the formulations provided effective protection against the tested wood fungi compared to control. Interestingly, the antifungal activity of 50% and 25% formulations of 6.8% WWL and 9.9% WWL satisfied the excellent fungal resistance class description against white rot fungus (Ganoderma lucidum) and brown rot fungus (Fibroporia vaillantii), respectively according to ASTM D 2017. These results thus, support LB fruit as a strong potential source of natural antifungals for industrial wood production.

• The Plant Pathology Journal
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• 제15권6호
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• pp.319-322
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• 1999

In order to obtain bacterial metabolites inducing disease resistance in pepper plant, two hundred bacterial isolates were isolated from the rhizosphere soil of tobacco, cucumber, and pepper plant. Ethyl acetate extract of each bacterial culture was used to screening for induction of resistance against phytophthora blight of pepper plant. Application of ethyl acetate extract of an isolate SH122 culture to pepper plant conferred resistance against phytophthora blight consistently and significantly. According to cellular fatty acid analysis and other characteristics, the SH122 culture were significantly lower than those on control plants treated with ethyl acetate extract of nutrient broth. The B. pumilus SH122 itself of ethyl acetate extract of its culture did not show antifungal activity against phytophthora blight in pepper plants.

• Mycobiology
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• 제45권4호
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• pp.426-429
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• 2017

A yeast-like organism was isolated from a urine sample of a 6-year-old neutered male miniature poodle dog with urinary tract infection, diabetes ketoacidosis, and acute pancreatitis. We identified the yeast-like organism to be Candida glabrata and found that this fungus was highly resistant to azole antifungal drugs. To understand the mechanism of azole resistance in this isolate, the sequences and expression levels of the genes involved in drug resistance were analyzed. The results of our analysis showed that increased drug efflux, mediated by overexpression of ATP transporter genes CDR1 and PDH1, is the main cause of azole resistance of the C. glabrata isolated here.

• 생명과학회지
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• 제34권6호
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• pp.393-398
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• 2024

본 연구는 항진균성 천연물 의약품을 개발하기 위한 생물자원의 연구로서 미나리아재비과에 속한 여러 한약재의 항진균활성을 새롭게 검증하고 비교하는 것을 목표로 한다. 한약재에서 진균류 생장을 저해하는 물질을 효과적으로 추출하는 방법을 찾고 추출물들에 포함된 항진균성 유용 물질을 탐색하였다. 위령선, 황련, 백두옹 한약재의 열수 추출 및 유기용매 추출을 진행하여 액체배지에서 항진균활성을 측정하였을 때 클로로포름 분획물에서 효과적인 결과를 얻었다. 또한 단세포성 진균인 Candida albicans, Candida tropi- calis, Candida lusitaniae 그리고 사상성 곰팡이인 Pythium ultimum KACC 40705, Aspergillus fumigatus, Fusarium oxysporum을 대상으로 고체배지에서 disc diffusion 실험으로 진균 성장 저해 실험을 수행하였다. 백두옹 추출물은 Candida spp.에 대해서, 위령선은 사상성 곰팡에 대해서 우수한 항진균활성을 가지고 있다는 것으로 확인했다. 마지막으로 추출물에 존재하는 항진균성 유용물질을 탐색하기 위해 GC-MS 분석을 진행하였다. 연구 결과 미나리아재비과의 한약재에서 항진균활성을 확인할 수 있었으며 위령선에서 thur- berogenone, 황련에서 16-HCDO를 항진균성 후보물질로서 확인하였다. 결론적으로 백두옹, 위령선 및 황련은 다양한 진균류에 대하여 항진균활성을 가지고 있음을 확인하였으며, GC-MS 분석에서 세 한약재 모두 서로 다른 항진균성 후보물질을 가지고 있는 것으로 확인되었다. 이러한 결과는 미나리아재비과 생물자원이 진균류 저항성에 대해 여러 방향으로 진화되었음을 나타낸다.

• Mycobiology
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• 제48권2호
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• pp.148-152
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• 2020

We investigated the antifungal susceptibilities and the cyp51 mutant strains among Aspergillus fumigatus clinical isolates obtained from 10 university hospitals in Korea. Of the 84 isolates examined, two itraconazole-resistant isolates were found with no amino acid substitution in the cyp51A/cyp51B genes. However, 19 (23.2%) azole-susceptible isolates harbored amino acid substitutions: Nine isolates harbored one to five mutations in cyp51A with high polymorphism, and 11 isolates exhibited the same Q42L mutation in cyp51B. Overall, a low azole resistance rate and high frequency of cyp51A/cyp51B amino acid substitutions were observed in the azole-susceptible A. fumigatus isolates in Korea.

• BMB Reports
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• 제33권4호
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• pp.332-336
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• 2000

Phenazine 1-carboxylic acid (PCA) is an antifungal antibiotic isolated from a culture filtrate of Bacillus sp. B-6 producing an acyl CoA synthetase inhibitor. This antibiotic is reported as an inhibitor of an acyl CoA synthetase from Pseudomonas sp.. Bacillus sp. B-6 was resistant to PCA up to 350 ${\mu}g/ml$. We investigated the mechanism of the resistance of Bacillus sp. B-6 to PCA. The rate of growth in a medium containing up to 100 ${\mu}g/ml$ was as rapid as the PCA-free medium. At a PCA concentration of 300 ${\mu}g/ml$, the growth rate was more than half that of the control. In this work, we purified acyl CoA synthetase from Bacillus sp. B-6 and found that this acyl CoA synthetase was much less sensitive to PCA than the acyl CoA synthetase from other source. These findings suggested that the insensitivity of Bacillus sp. B-6 acyl CoA synthetase plays an important role in the PCA resistance of this bacterium.

• Archives of Plastic Surgery
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• 제51권1호
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• pp.135-138
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• 2024

A patient suffered from chronic ulcer due to recalcitrant fungal infection for 3.5 years. Five antifungal agents and 40 times of debridement—all failed. Finally, radical microscopic debridement was performed for eradication of fungal conidiospores. Since then, there was no recurrence at 2 years of follow-up. Scopulariopsis brevicaulis is one of the rarest pathogens of cutaneous fungal infections, for which multidrug resistance increased the complexity and difficulty of treatment. Radical excision, especially microscopic debridement, was the key for eradication of fungal conidiospores in this case.

• 미생물학회지
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• 제37권4호
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• pp.305-311
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• 2001

다양한 식물병원성 진균을 방제하기 위하여 온천수로부터 1종의 동물병원성 진균과 12종의 식물병원성 진균에 항진균 활성을 갖는 고온성 세균을 분리하였으며 Bacillus subtilis YS1으로 동정되었다. 분리 균주의 감마선($Co^{60}$)에 대한 감수성 조사 결과, $D_{10}$ value는 2.08 kGy로 20 kGy 의 방사선량에서도 생존 가능한 방사선 저항성 균주였다. 방사선 조사를 이용하여 5종의 돌연변이체를 유기하였으며, 이 중 B. subtilis YS1-1009 돌연변이체는 Botryoshaeria dothidea에 대한 항진균 활성의 증가 및 4종의 식물병원성 진균에 대하여 항진균 활성이 감소하는 종특이적 항진균 활성 변화를 나타내었다. 또한 상용농약인 tebuconazole에 대하여 저항성을 나타내었으며 17종의 다른 농약에 대해서도 전체적으로 야생형 균주에 비해 저항성이 증가하였다. B. subtilis YS1-1006 돌연변이체는 copper hydroxide에 저항성을 나타내었으며, B. subtilis YS67 돌연변이체는 항진균 활성이 소실된 tryptophan 및 proline 또는 uracil 및 arginine 영양요구성 돌연변이체였다. 이러한 결과로부터 극한 환경에서 분리한 본 분리균주는 환경친화적으로 진균에 의한 식물병을 방제할 수 있으며 방사선을 이용한 돌연변이체 유기는 기능성 균주의 개량이나 작용기작 연구를 위한 돌연변이체의 획득에 매우 효과적인 방법이라 사료된다.

• Mycobiology
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• 제45권3호
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• pp.192-198
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• 2017

The green peach aphid (Myzus persicae), a plant pest, and gray mold disease, caused by Botrytis cinerea, affect vegetables and fruit crops all over the world. To control this aphid and mold, farmers typically rely on the use of chemical insecticides or fungicides. However, intensive use of these chemicals over many years has led to the development of resistance. To overcome this problem, there is a need to develop alternative control methods to suppress populations of this plant pest and pathogen. Recently, potential roles have been demonstrated for entomopathogenic fungi in endophytism, phytopathogen antagonism, plant growth promotion, and rhizosphere colonization. Here, the antifungal activities of selected fungi with high virulence against green peach aphids were tested to explore their potential for the dual control of B. cinerea and M. persicae. Antifungal activities against B. cinerea were evaluated by dual culture assays using both aerial conidia and cultural filtrates of entomopathogenic fungi. Two fungal isolates, Beauveria bassiana SD15 and Metarhizium anisopliae SD3, were identified as having both virulence against aphids and antifungal activity. The virulence of these isolates against aphids was further tested using cultural filtrates, blastospores, and aerial conidia. The most virulence was observed in the simultaneous treatment with blastospores and cultural filtrate. These results suggest that the two fungal isolates selected in this study could be used effectively for the dual control of green peach aphids and gray mold for crop protection.