• The Korean Journal of Mycology
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• v.48 no.4
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• pp.523-531
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• 2020

This study focused on the isolation and characterization of wild yeasts in Korea. The yeasts were identified by phylogenetically analyzing the D1/D2 domains of the 26S rDNA regions. Consequently, we identified seven strains, NNIBRFG856, NNIBRFG3732, NNIBRFG3734, NNIBRFG3738, NNIBRFG3739, NNIBRFG5497, and NNIBRFG6049, which were confirmed to be Kabatiella microsticta, Pichia membranifaciens, Candida vartiovaarae, Candida sake, Debaryomyces hansenii, Candida railenensis, and Schwanniomyces polymorphus, respectively, all of them being new in Korea. Morphological and cultural characteristics of these yeast species were investigated. None of the strains formed ascospores or pseudomycelia. Moreover, these yeasts grew in a pH range of 4-8. NNIBRFG3732, NNIBRFG3738, NNIBRFG3739, NNIBRFG5497, and NNIBRFG6049 were halotolerant or halophilic, and NNIBRFG3732, NNIBRFG3734, and NNIBRFG6049 grew in vitamin-free medium. NNIBRFG3732, NIBRFG3739, and NNIBRFG6049 grew at 35 ℃, but not at 40 ℃.

• Korean Journal of Clinical Laboratory Science
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• v.47 no.4
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• pp.273-278
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• 2015

The purpose of this study was to evaluate the in-vitro efficacy of PDT using red light emitting diode (LED) with Radachlorin for biofilm inhibition of clinical Candida albicans isolates. The suspensions containing C. albicans at $9{\times}10^8CFU/mL$ were prepared on yeast nitrogen base containing 5% glucose. The biofilm formation was grown for 3 h after seeding suspensions each 100 ul on a 96-well plate and then supernatant was discarded. Each well was treated with $0.39{\mu}g/mL$ from $50{\mu}g/mL$ concentrations of Radachlorin on adherent biofilm. After a 30-minute incubation, light was irradiated for 30, 60, or 90 minutes using the following light source of wavelength 630 nm LED, at energy densities of 14, 29, and $43J/cm^2$. Afterwards, all supernatant was removed and dried. Adherent cells were stained with safranin O and dried. The cell viability was measured using a microplate reader at 490 nm. Also, a fluorescent signal on C. albicans was observed by saturation of a photosensitizer. In conclusion, a significant inhibition of 72.5% was observed to C. albicans on biofilm at the Radachlorin dose of $50{\mu}g/mL$ with 630 nm LED. The Photosensitizer (Radachlorin) was adequate at 30 minuttes for C. albicans. Overall, the results showed that inhibition of biofilm formation was Radachlorine dose-dependent. The results suggest that PDT, using Radachlorin with 630 nm LED, is able to decrease biofilm formation of C. albicans.

• The Korean Journal of Mycology
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• v.46 no.2
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• pp.98-104
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• 2018

The goal of this study was to elucidate wild yeast diversity of the midstream region of the Geumgang river, Gongju, Chungnam province, Korea. Fifty strains of 24 species of wild yeasts were isolated from 45 water and soil samples among which Cryptococcus spp. (11 strains), Cryptococcus magnus (7 strains), Rhodotorula spp. (9 strains), and Hanseniaspora spp. (6 strains) were dominant. Four species, Candida chauliodes WJSF 0201, Candida oleophila WJSF 0202, Candida catenulata WJSF 0203, and Candida jaroonii WJSF 0204, represented newly recorded yeasts in Korea. All of these unrecorded yeasts were oval in shape, formed ascospores and pseudomycelium, and grew in vitamin-free medium. Candida oleophila WJSF 0202 was thermophilic which can grow at $37^{\circ}C$.

• Journal of Microbiology and Biotechnology
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• v.25 no.10
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• pp.1734-1741
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• 2015

Few research had investigated the secretion of phospholipase and aspartyl proteinase from Candida spp. causing infection in females with type 2 diabetes mellitus. This research aimed to investigate the prevalence of vulvovaginal candidiasis (VVC) in diabetic versus non-diabetic women and compare the ability of identified Candida isolates to secrete phospholipases and aspartyl proteinases with characterization of their genetic profile. The study included 80 females with type 2 diabetes mellitus and 100 non-diabetic females within the child-bearing period. Candida strains were isolated and identified by conventional microbiological methods and by API Candida. The isolates were screened for their extracellular phospholipase and proteinase activities by culturing them on egg yolk and bovine serum albumin media, respectively. Detection of aspartyl proteinase genes (SAP1 to SAP8) and phospholipase genes (PLB1, PLB2) were performed by multiplex polymerase chain reaction. Our results indicated that vaginal candidiasis was significantly higher among the diabetic group versus nondiabetic group (50% versus 20%, respectively) (p = 0.004). C. albicans was the most prevalent species followed by C. glabrata in both groups. No significant association between diabetes mellitus and phospholipase activities was detected (p = 0.262), whereas high significant proteinase activities exhibited by Candida isolated from diabetic females were found (82.5%) (p = 0.000). Non-significant associations between any of the tested proteinase or phospholipase genes and diabetes mellitus were detected (p > 0.05). In conclusion, it is noticed that the incidence of C. glabrata causing VVC is increased. The higher prevalence of vaginal candidiasis among diabetics could be related to the increased aspartyl proteinase production in this group of patients.

• The Korean Journal of Mycology
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• v.41 no.2
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• pp.74-80
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• 2013

Fourteen new records of yeasts were screened from one hundred thirty-three yeasts strains which were isolated from wild flowers in east, west and south coast near areas and inland areas, Korea. Candida silvae, Cryptococcus terrestris and Auriculibuller fuscus were newly isolated from wild flowers collected at Donghae and Andong, respectively. Candida quercitrusa, Hanseniaspora opuntiae, Sporobolomyces carnicolor, Candida saopaulonensis and Sporobolomyces phaffii were newly isolated from wild flowers in Geumsan-gun and Taean-gun in Chungcheongnam-do, respectively. Candida oleophila and Jaminaea angkoriensis were newly identified from flowers in Yesan-gun and Hannaella zeae was also newly identified from flowers of Daecheon. Hanseniaspora vineae and two other yeast strains including Pseudozyma hubeiensis were newly isolated and identified from flowers collected at Gwangju and Wando-gun, respectively. Morphological and physiological characteristics of their new recorded yeasts were investigated.

• Korean Journal of Food Science and Technology
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• v.17 no.2
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• pp.60-64
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• 1985

To utilize microbial lipases for hydrolysis of milk fat, optimum reaction conditions and characteristics of enzymatic reactions of lipases originated from Rhizopus delemar, Mucor sp., and Candida cylindracea were investigated. Optimum pH and temperature were pH 5.6 and $45^{\circ}C$ for Rhizopus delemar lipase, pH7.5 and $35^{\circ}C$ for Mucor sp. lipase, and pH7.5 and $35^{\circ}C$ for Candida cylindracea lipase. Optimum lipase concentration and optimum substrate concentration were $600{\sim}800\;units/ml$ and 20% milk fat, regardless of their origin. Km values were 6.06% milk fat for Rhizopus delemar lipase, 7.69% for Mucor sp. lipase and 7.99% for Candida cylindracea lipase. Rate of lipid hydrolysis was Rhizopus delemar lipase>Mucor sp. lipase>Candida cylindracea lipase. As the reaction time was extended, liberation of short chain fatty acids was increased. After 8 hours reaction, capric acid content significantly increased with Candida cylindracea lipase, palmitic acid with Mucor sp. lipase and butyric acid with Rhizopus delemar lipase.

• The Journal of Advanced Prosthodontics
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• v.7 no.2
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• pp.93-97
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• 2015

PURPOSE. Xerostomia can diminish the quality of life, leads to changes in normal chemical composition of saliva and oral microbiata, and increases the risk for opportunistic infections, such as Candida albicans. Various artificial salivas have been considered for patients with xerostomia. However, the knowledge on the antifungal and antiadhesive activity of artificial saliva substitutes is limited. The aim of the present study was to evaluate influence of two artificial salivas on the adhesion of Candida albicans to the polymethylmethacrylate disc specimens. MATERIALS AND METHODS. Two commercial artificial salivas (Saliva Orthana and Biotene Oral Balance Gel) were selected. 45 polymethylmethacrylate disc specimens were prepared and randomly allocated into 3 groups; Saliva Orthana, Biotene-Oral Balance gel and distilled water. Specimens were stored in the artificial saliva or in the sterile distilled water for 60 minutes at $37^{\circ}C$. Then they were exposed to yeast suspensions including Candida albicans. Yeast cells were counted using ${\times}40$ magnification under a light microscope and data were analysed. RESULTS. Analysis of data indicated statistically significant difference in adhesion of Candida albicans among all experimental groups (P=.000). Findings indicated that Saliva Orthana had higher adhesion scores than the Biotene Oral Balance gel and distilled water (P<.05). CONCLUSION. In comparison of Saliva Orthana, the use of Biotene Oral Balance Gel including lysozyme, lactoferrin and peroxidase may be an appropriate treatment method to prevent of adhesion of Candida albicans and related infections in patients with xerostomia.

• Applied Microscopy
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• v.23 no.2
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• pp.97-106
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• 1993

This study was done to elucidate the electron microscopic characteristics of certain pathogenic fungi. Four Candida species, (C. albicans, C. tropicalis, C. parapsilosis and C. glabrate) and Cryptococcus neoformans were cultured for 3 days at $30^{\circ}C$ in the Sabouraud dextrose medium. After incubation, they were stored at $4^{\circ}C$ for 24hours. Fine structures were analyzed by morphometry, and Tukey's HSD test was used for statistics. On scanning electron microscopy C. albicans and C. neoformans were similar in size but different in shape, showing sphero-shape or ovalo-shape in C. neoformans. Surface of C. neoformans was coarse and spiny, but Candida species examined were uniformly smooth. In size, C. glabrata was the smallest among them. Budding scar as seen on the surface of Candida species by the number ranging from 1 to 7. Cryptococcus neoformans showed one or two budding scar. On transmission electron microscopy the cytoplasm of most yeast cells showed plentiful glycogen particles, mitochondria, peroxisomes and vacuoles. However, cell walls were different among four Candida species and Cryptococcus neoformans. The cell wall of Candida species consisted of fibrous layer, that was electron dense layer and transparent layer, in contrast to Cryptococcus neoformans consisted of electron dense layer with lamellar structure. This layer was two times thicker than that of Candida species. The outer layer of cell wall was of radiating pattern.

• Neonatal Medicine
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• v.16 no.2
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• pp.190-196
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• 2009

Purpose: Candida infection has increased in neonatal intensive care units (NICU). However, recent reports on systemic candida infections in preterm newborns are rare in Korea. The aim of this study was to examine the epidemiological features of systemic candida infection in very low birth weight infants (VLBW) over the past five years. Methods: We retrospectively reviewed the medical records of 19 patients with systemic candida infections in VLBW that were admitted to the neonatal intensive care units of three hospitals affiliated with the College of Medicine, The Catholic University of Korea from January 2004 to December 2008. We analyzed the birth weight, gestational age, age at diagnosis, risk factors, co-morbidity, antifungal treatment, and mortality rates among the 19 patients. Results: Systemic candida infections occurred in 19 cases (4.7%) among the VLBW infants. The mean birth weight and gestational age were 959.0$\pm$255.9 g and 26.7$\pm$2.1 weeks. The isolated Candida species were C. albicans (4), C. parapsilosis (9), C. glabrata (2), C. famata (2), and unkown subspecies (2). Most patients had various associated risk factors, including a central venous catheter, broad spectrum antibiotics, parenteral nutrition, intravenous lipid emulsion, endotracheal intubation and $H_2$ blocker therapy. There was no significant difference in the risk factors between newborns that survived and those that died with regard to the systemic candida infection, except for gestational age. Nine (47.4%) out of 19 patients with a candida infection died and four cases (21.2%) were directly related to the candida infection. Conclusion: The prevalence of systemic candida infection is increasing in VLBW infants. The majority of Candida species has shifted to C. non-albicans, especially C. parapsilosis. Because of the high mortality associated with candida infection in the NICU, prophylaxis and early treatment based on epidemiological features is necessary.

• Journal of Oral Medicine and Pain
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• v.30 no.3
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• pp.319-328
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• 2005

To examine whether HSV, VZV, H. pylori and Candida that are known to be microorganisms causing ulcerative disease in oral cavity and have the relatively high contigiousness are detected in saliva of patients with RAU and related to the development with RAU, PCR and culture were performed on the saliva of 29 patients with RAU and 29 control subjects who visited the Department of Oral Medicine, Dental Hospital, Chosun University. The results were obtained as follows; 1. HSV DNA was detected in 41.4% patients with RAU, and 55.2% control subjects, however, a significant difference between the two groups was not detected, (P>0.05), and VZV DNA was not detected in both groups. 2. H. pylori DNA was detected in 27.6% patients with RAU, and 48.3% control subjects, however, a significant difference between the two groups was not detected (P>0.05). 3. Candida was cultured in 13.8% patients with RAU, and 6.9% control subjects, however, a significant difference between the two groups was not detected (P>0.05). This results suggest that HSV, VZV, H. pylori and Candida can not be regarded to play a direct role in the development of RAU. Thus it is considered that in future, on a larger sample, also, it has to be examined whether other microorganisms acts as a trigger factor of the development of RAU.