• Title/Summary/Keyword: Fungal infection

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Infection Structures on the Infected Leaves of Potato Pre-inoculated with Bacterial Strains and DL-3-amino Butyric Acid after Challenge Inoculation with Phytophthora infestans

  • Kim, Hyo-Jeong;Jeun, Yong-Chull
    • The Plant Pathology Journal
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    • v.23 no.3
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    • pp.203-209
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    • 2007
  • Infection structures were observed using a fluorescence microscope at the penetration sites on the leaves of potato plants pre-inoculated with the bacterial strains Pseudomonas putida TRL2-3, Micrococcus luteus TRK2-2, and Flexibacteraceae bacterium MRL412, which mediated an induced systemic resistance on potato plants against late blight disease caused by Phytophthora infestans. In order to compare the infection structures on the leaves expressing systemic acquired resistance, the leaves of potato plants pre-treated with DL-3-amino butyric acid (BABA) were also observed after challenge inoculation with the same pathogen. The infection structures were investigated. The total number of germination and appressorium formation of P. infestans were counted. Furthermore, the frequencies of fluorescent epidermal cells at the penetration sites, which indicate a defense response of plant cell, were estimated. There were no differences on the germination rates of the fungal cysts among the untreated control, BABA pre-treated, and bacterial strains pre-inoculated plants. However, appressorium formation was slightly decreased on the leaves of BABA pre-treated plants compared to those of untreated as well as bacterial strains pre-inoculated plants. Furthermore, the frequencies of fluorescent cells of BABA pre-treated and bacterial strains pre-inoculated were higher than that of untreated plants, indicating an active defense reaction of the host cells against the fungal attack. On the other hand, the pre-treatment with BABA caused a stronger fluorescent of epidermal cells at the penetration sites compared to the pre-inoculation with the bacterial strains. Interestingly, the frequency of fluorescent cells by BABA, however, was lower than that by the bacterial strains. Based on the results it is suggested that the infection structures showing resistance reaction on the leaves of potato plants were different between by pre-inoculation with bacterial strains and by pre-treatment with BABA against the late blight pathogen.

Prevention of Candida albicans infection in dental polishing lathe by chlorhexidine (클로르헥시딘을 이용한 치과기공용 연마기 캔디다균의 감염방지)

  • Song, Young-Gyun
    • Journal of Dental Rehabilitation and Applied Science
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    • v.32 no.4
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    • pp.274-279
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    • 2016
  • Purpose: The purpose of this study was to evaluate the transmission of candida in denture by dental polishing lathe. Materials and Methods: Maxillary complete dentures made from the same model were infected with Candida albicans. Polishing wheels were keep in various chlorhexidine solution and distilled water for an hour. The infected dentures were polished by prepared dental polishing lathe with sterile pumice and distilled water. And then sterile maxillary complete dentures were polished with same method. Polishing surface was wiped with a cotton swab and the sample was regrown for checking Candida albicans. Results: All polishing wheel with chlorhexidine resist fungal infection. But the polishing wheel with distilled water is infected with Candida albicans. Conclusion: A chlorhexidine is highly efficient in fungal infection prevention on dental polishing lathe.

Prevention of Invasive Candida Infections in the Neonatal Intensive Care Unit (신생아 집중치료실에서 침습 칸디다 감염의 예방)

  • Kim, Chun Soo
    • Pediatric Infection and Vaccine
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    • v.18 no.1
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    • pp.15-22
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    • 2011
  • Invasive Candida infections (ICI) have become the third most common cause of late-onset infection among premature infants in the neonatal intensive care unit (NICU). Risk factors include birth weight less than 1,000 g, exposure to more than two antimicrobials, third generation cephalosporin exposure, parenteral nutrition including lipid emulsion, central venous catheter, and abdominal surgery. Candida colonization of the skin and gastrointestinal tract is an important first step in the pathogenesis of invasive disease. Strict infection control measures against the infection should be done in the NICU. The following practices are likely to contribute to reducing the rate of ICI: (1) restriction of broad-spectrum antibiotics, antacids and steroid; (2) introduction of early feeding and promoting breast milk. Fluconazole prophylaxis may be an effective control measure to prevent Candida colonization and infections in individual units with high incidence of fungal infection. In addition, there is a need of further data including the development of resistant strains and the effect on long-term neurodevelopmental outcomes of infants exposed to drugs before the initiation of routine application of antifungal prophylaxis in the NICU.

Identification and characterization of a rice blast fungal elicitor-inducible Oshin1 gene

  • Kim, Cha-Young;Lee, Sung-Ho
    • Journal of Plant Biotechnology
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    • v.36 no.1
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    • pp.45-52
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    • 2009
  • In order to understand the molecular interactions that occur between rice and the rice blast fungus during infection, we previously identified a number of rice blast fungal elicitor-responsive genes from rice (Oryza sativa cv. Milyang 117). Here, we report the cloning and characterization of the rice fungal elicitor-inducible gene Oshin1 (GenBank Accession Number AF039532). Sequence analysis revealed that the Oshin1 cDNA is 1067 bp long and contains an open reading frame encoding 205 amino acid residues. The Oshin1 gene shows considerable sequence similarity to the tobacco hin1 and hin2 genes. The predicted Oshin1 protein has a cysteine-rich domain at the N-terminus and is rich in leucine, serine, and alanine residues. Southern blot analysis suggests that Oshin1 gene is a member of a small gene family in the rice genome. To examine the expression of Oshin1, Northern blot analysis was conducted. Expression of the Oshin1 transcript is rapidly induced in suspension-cultured rice cells treated with fungal elicitor, salicylic acid or hydrogen peroxide. In addition, Oshin1 transcript levels are rapidly increased by treatment with $Ca^{2+}$/A23187. The expression of Oshin1 was also elevated in 3-week old leaf tissues upon ethephon application or fungal elicitor treatment. Our results suggest that the Oshin1 gene is involved in plant defense responses to environmental stresses.

Arthroscopic Treatment of Fungal Knee Arthritis after Repetitive Intraarticular Steroid Injection in a Healthy Adult - A Case Report - (건강한 성인에서 반복적인 관절 내 스테로이드 주사 후 발생한 진균성 슬관절염의 관절경적 치료 - 증례 보고 -)

  • Baek, Seung-Hoon;Park, Chang Min
    • Journal of the Korean Arthroscopy Society
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    • v.16 no.2
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    • pp.180-184
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    • 2012
  • Fungal arthritis is a rare joint infection that occurs in immunosuppressant patient, intravenous drug abuser and long term antibiotics user, and is especially rare in a healthy adult. Two case reports of fungal arthritis have been demonstrated in the country, but those in healthy adults have not been reported yet. Here, we experienced an antifungal treatment following successful arthroscopic debridement of fungal arthritis with a popliteal cyst in a healthy adult who got repetitive intraarticular steroid injections and report the case with review of relevant literatures. Surgeons should consider the possibility of fungal arthritis although it is rare and demonstrates nonspecific clinical features.

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The Stress-Activated Signaling (SAS) Pathways of a Human Fungal Pathogen, Cryptococcus neoformans

  • Jung, Kwang-Woo;Bahn, Yong-Sun
    • Mycobiology
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    • v.37 no.3
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    • pp.161-170
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    • 2009
  • Cryptococcus neoformans is a basidiomycete human fungal pathogen that causes meningoencephalitis in both immunocompromised and immunocompetent individuals. The ability to sense and respond to diverse extracellular signals is essential for the pathogen to infect and cause disease in the host. Four major stress-activated signaling (SAS) pathways have been characterized in C. neoformans, including the HOG (high osmolarity glycerol response), PKC/Mpk1 MAPK (mitogen-activated protein kinase), calcium-dependent calcineurin, and RAS signaling pathways. The HOG pathway in C. neoformans not only controls responses to diverse environmental stresses, including osmotic shock, UV irradiation, oxidative stress, heavy metal stress, antifungal drugs, toxic metabolites, and high temperature, but also regulates ergosterol biosynthesis. The PKC(protein kinase C)/Mpk1 pathway in C. neoformans is involved in a variety of stress responses, including osmotic, oxidative, and nitrosative stresses and breaches of cell wall integrity. The $Ca^{2+}$/calmodulin- and Ras-signaling pathways also play critical roles in adaptation to certain environmental stresses, such as high temperature and sexual differentiation. Perturbation of the SAS pathways not only impairs the ability of C. neoformans to resist a variety of environmental stresses during host infection, but also affects production of virulence factors, such as capsule and melanin. A drug(s) capable of targeting signaling components of the SAS pathway will be effective for treatment of cryptococcosis.

Proteasome Inhibitors Affect Appressorium Formation and Pathogenicity of the Rice Blast Fungus, Magnaporthe oryzae

  • Wang, Yiming;Kim, Sang-Gon;Wu, Jingni;Yu, Seok;Kang, Kyu-Young;Kim, Sun-Tae
    • The Plant Pathology Journal
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    • v.27 no.3
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    • pp.225-231
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    • 2011
  • Previously, we identified the 20S proteasome ${\alpha}$-subunit of Magnaporthe oryzae (M. oryzae) induced during appressorium formation, and detected an increase in multiple protein ubiquitination during the early appressorium formation process (Kim et al., 2004). In this study, we further attempted to determine whether the proteasome is involved in the appressorium formation of M. oryzae both in vitro and in planta, using proteasome inhibitors. A significant increase in 20S proteasome during fungal germination and appressorium formation was observed using Western blot analysis with 20S proteasome antibody, demonstrating that proteasome-mediated protein degradation was involved in appressorium formation. Pharmacological analysis using proteasome inhibitors, MG-132, proteasome inhibitor I (PI) and proteasome inhibitor II (PII) revealed that germination and appressorium formation were delayed for 4 to 6 h on rice leaf wax-coated plates. Similarly, the treatment of proteasome inhibitors with fungal conidia on the rice leaf surface delayed appressorium formation and host infection processes as well. Additionally, fungal pathogenicity was strongly reduced at 4 days' postfungal infection. These data indicated that the fungal 20S proteasome might be involved in the pathogenicity of M. oryzae by the suppression of germination and appressorium formation.

Study on Cutaneous Mycoses in Oriental Medicine (피부진균증의 한의학적 고찰)

  • Cha, Eun-Yea;Kang, Jung-Soo
    • Journal of Physiology & Pathology in Korean Medicine
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    • v.20 no.4
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    • pp.799-806
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    • 2006
  • Fungi cause a number of plant and animal diseases. Because fungi are more chemically and genetically similar to animals than other organisms, this makes fungal diseases very difficult to treat. Human fungal infections are uncommon in normally healthy persons, being confined to conditions such as candidiasis (thrush) and dermatophyte skin infections such as athlete's foot. However, in the immunocompromised host, a variety of normally mild or nonpathogenic fungi can cause potentially fatal infections. Furthermore, the relative ease with which people can now visit 'exotic' countries provides the means for unusual fungal infections to be imported into this country. Fungal infections or mycoses are classified depending on the degree of tissue involvement and mode of entry into the host. These are Cutaneous, Subcutaneous, Systemic, and Opportunistic. As listed above, in superficial mycoses infection is localised to the skin, the hair, and the nails. An example is 'ringworm' or 'tinea', an infection of the skin by a dermatophyte. Ringworm refers to the characteristic central clearing that often occurs in dermatophyte infections of the skin. Dermatophyte members of the genera Trycophyton, Microsporum and Epidermophyton are responsible for the disease. Tinea can infect various sites of the body, including the scalp (tinea capitis), the beard (tinea barbae) the foot (tinea pedis: 'athlete's foot') and the groin (tinea cruris). All occur in the United Kingdom although tinea infections, other than pedis, are now rare. Candids albicans is a yeast causing candidiasis or 'thrush' in humans. As a superficial mycoses, candidiasis typically infects the mouth or vagina. C. albicans is part of the normal flora of the vagina and gastrointestinal tract and is termed a 'commensal' However, during times of ill health or impaired immunity the balance can alter and the organism multiplies to cause disease. Antibiotic treatment can also alter the normal bacterial flora allowing C. albicans to flourish. If we study mycoses of the orient medicine, we can improve the medical skills about mycoses.

Successful Treatment of Catheter Related Blood Stream Infection By Millerozyma farinosa with Micafungin: A Case Report

  • Hong, Sun In;Suh, Young Sun;Kim, Hyun-Ok;Bae, In-Gyu;Shin, Jong Hee;Cho, Oh-Hyun
    • Infection and chemotherapy
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    • v.50 no.4
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    • pp.362-366
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    • 2018
  • Millerozyma farinosa (formerly Pichia farinosa) is halotolerant yeast mainly found in food and ubiquitous in the environment. It was a rare yeast pathogen, but it has recently emerged as a cause of fungemia in immunocompromised patients. Optimal therapy for invasive fungal infection by this pathogen remains unclear. We report a case of catheter related blood stream infection caused by M. farinosa in a 71-year-old patient who recovered successfully after removal of the central venous catheter and treatment with micafungin.