• Journal of Microbiology
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• v.40 no.2
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• pp.166-169
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• 2002

Twenty strains of Cryptococcus neoformams isolated from environmental and clinical sources in Korea were examined for their serotypes. Two environmental isolates from pigeon excreta belonged to C. neoformans var. neoformans serotypes A. Of the 18 isolates from clinical specimens, 17 belonged to C. neoformans vats, neoiomans (serotype A : 16, serotype D : 1) and one belonged to C. neoformans vats, gattii serotype B, which was culturally unusual, producing mucous colonies. This is the first report of the identification of C. neoformans roar, gattii serotype B from a patient in Korea.

• Biomedical Science Letters
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• v.19 no.3
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• pp.213-223
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• 2013

The objectives of this study are to develop a molecular diagnosis to differentiate serotypes and mating-types of C. neoformans/C. gattii complex isolates from pigeon droppings in Korea and to elucidate molecular epidemiology of the isolates. Phenotypes and genotypes of C. neoformans/C. gattii complex isolates were identified by biochemical properties and PCR using specific CNLAC1 gene, respectively. To classify serotypes and mating-types of C. neoformans/C. gattii complex isolates, the five reference strains and thirty-three isolates in Korea were investigated by restriction fragment length polymorphism (RFLP) analysis using CNLAC1 gene for varieties, by random amplified polymorphic DNA (RAPD) for serotyping, and by PCR using specific primer sets for mating typing. All isolates in Korea were belonged to C. neoformans var. grubii (serotype A) by RFLP and RAPD patterns which showed high sensitivity and specificity. Therefore, RFLP and RFLP were available to differentiate varieties and serotypes of C. neoformans. Amplification patterns of the five reference strains by specific PCR for mating typing were differentiable, and all isolates were classified into $MAT{\alpha}$. All C. neoformans environmental isolates in Korea were Cr. neoformans serotype A and $MAT{\alpha}$ which is a more virulent pathogen. This study suggests that RFLP and RAPD are rapid and correct molecular diagnosis tools for epidemiology of C. neoformans/C. gattii complex isolates.

• Mycobiology
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• v.30 no.2
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• pp.93-95
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• 2002

The antifungal activities of propolis on Cryptococcus neoformans and Candida albicans were evaluated. In microbroth culture assay, the MIC(minimum inhibitory concentration) of propolis for C. neoformans and C. albicans were 2 and 16 mg/ml, respectively. In propolis-included solid medium assay, the MIC of propolis for C. neoformans and C. albicans were 4 and 16 mg/ml, respectively. Propolis showed fungicidal activity against C. neoformans, whereas propolis possesed fungistatic activity against C. albicans. The MFC(minimum fungicidal concentration) for C. neoformans was 8 mg/ml. Cell morphology of C. neoformans was affected by treatment of propolis. In scanning electron microscope, the appearance of cell rupture was observed.

• Biomedical Science Letters
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• v.16 no.3
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• pp.139-149
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• 2010

The present study was carried out to elucidate whether an environmental strain of Cryptococcus neoformans (environmental C. neoformans) isolated from an environmental source in a park of Busan has an acute pathophysiological effect in rats. On the second day after peritoneal inoculation of environmental C. neoformans, adverse effects occurred from the viewpoint of hematology and biochemistry. Eosinophil damages and crystal formations were found in the blood. Disturbances in cytokines production were observed in the cerebral and pulmonary tissues. Fungal budding existed in the brain, lung, liver and kidney. Tissue injury findings such as inflammation, leukocyte infiltration, bleeding, or degeneration were found in the brain, lung, liver and kidney. The present data suggest that the environmental C. neoformans can cause systematically harmful effects even for short periods of infection (two days of cryptococcal infection) and the adverse effects are summarized as immune derangements and biochemical and/or histological dysfunction and injury on major organ such as the brain, lung, liver and kidney in the immunocompetent hosts. Further studies should be focused on comparing the differences between environmental and clinical strains of C. neoformans.

• Mycobiology
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• v.33 no.4
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• pp.188-193
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• 2005

Twenty nine samples of pigeon droppings (n = 12) and soil contaminated with avian excreta (n = 19), collected from different sites in Busan, were examined for isolation and characterization of Cryptococcus neoformans. Of these samples, 5 strains of C. neoformans were recovered from pigeon droppings (5/12 : 41.7%). All isolates were belonged to C. neoformans var. grubii (serotype A). The extracellular enzyme activities of the strains by using the API-ZYM system showed two different enzymatic patterns. The genetic variability among C. neoformans isolates was analyzed by random amplified polymorphic DNA (RAPD) using three 10-mer primers. Two different RAPD patterns, which clearly distinguished the isolates, were identified. Analysis of RAPD patterns provided a good characterization of environmental strains of C. neoformans serotype A as a heterogeneous group and were in good agreement with enzymatic profiles.

• Mycobiology
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• v.43 no.3
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• pp.360-365
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• 2015

Multilocus sequence typing analysis was applied to determine the genotypes of 147 (137 clinical and 10 environmental) Cryptococcus neoformans and three clinical Cryptococcus gattii isolates from 1993 to 2014 in Korea. Among the 137 clinical isolates of C. neoformans, the most prevalent genotype was ST5 (n = 131), followed by ST31 (n = 5) and ST127 (n = 1). Three C. gattii strains were identified as ST57, ST7, and ST113. All environmental isolates were identified as C. neoformans with two genotypes, ST5 (n = 7) and ST31 (n = 3). Our results show that C. neoformans isolates in Korea are genetically homogeneous, and represent a close genetic relationship between clinical and environmental isolates.

• Mycobiology
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• v.31 no.3
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• pp.162-165
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• 2003

Three hundred and sixty five samples of avian droppings, collected from parks and zoo, were investigated for the occurrence of Cryptococcus neoformans in Korea. Thirteen samples were positive for C. neoformans. All isolates were obtained from withered pigeon droppings. Identification and serotyping of isolates were determined by means of serological test and polymerase chain reaction(PCR) fingerprinting. All isolates belonged to C. neoformans var. grubbi(serotype A).

• Journal of Microbiology
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• v.43 no.5
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• pp.469-472
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• 2005

Seventy-two pigeon dropping samples were collected from 26 different localities in Seoul and investigated for the occurrence of Cryptococcus neoformans. Seventeen samples from 8 different localities were found to be positive for C. neoformans. All isolates were obtained from withered pigeon droppings. Identification and serotyping of the isolates were determined by means of serological testing and DNA fingerprinting. All isolates belonged to C. neoformans var. grubbi (serotype A).

• 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.

• Mycobiology
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• v.42 no.1
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• pp.73-78
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• 2014

Cryptococcal infection is primarily caused by two species, Cryptococcus neoformans and C. gattii. Between the two species, C. neoformans var. grubii is the major causative agent of cryptococcosis in Asia. We investigated the molecular characteristics of 46 isolates of C. neoformans from patients with cryptococcosis between 2008 and 2012 in Seoul, Korea. All the isolates were determined to be C. neoformans var. grubii (serotype A), mating type $MAT{\alpha}$, and molecular type VNI by PCR-restriction fragment length polymorphism of the URA5 gene. Multilocus sequencing type (MLST) analysis using the International Society of Human and Animal Mycoses (ISHAM) consensus MLST scheme identified two sequence types (ST). Out of the 46 strains, 44 (95.7%) were identified as ST5, and remaining 2 were identified as ST31. Our study revealed that the clinical strains of C. neoformans in Korea are genetically homogeneous with the VNI/ST5 genotypes, and new appearance of VNI/ST31 genotype may serve as an important indicator of global genetic analysis.