• 제목/요약/키워드: Fungal infection

검색결과 369건 처리시간 0.025초

Sensing the Stress: the Role of the Stress-activated p38/Hog1 MAPK Signalling Pathway in Human Pathogenic Fungus Cryptococcus neoformans

  • Bahn, Yong-Sun;Heitman, Joseph
    • 한국미생물학회:학술대회논문집
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    • 한국미생물학회 2007년도 International Meeting of the Microbiological Society of Korea
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    • pp.120-122
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    • 2007
  • All living organisms use numerous signal-transduction pathways to sense and respond to their environments and thereby survive and proliferate in a range of biological niches. Molecular dissection of these signalling networks has increased our understanding of these communication processes and provides a platform for therapeutic intervention when these pathways malfunction in disease states, including infection. Owing to the expanding availability of sequenced genomes, a wealth of genetic and molecular tools and the conservation of signalling networks, members of the fungal kingdom serve as excellent model systems for more complex, multicellular organisms. Here, we employed Cryptococcus neoformans as a model system to understand how fungal-signalling circuits operate at the molecular level to sense and respond to a plethora of environmental stresses, including osmoticshock, UV, high temperature, oxidative stress and toxic drugs/metabolites. The stress-activated p38/Hog1 MAPK pathway is structurally conserved in many organisms as diverse as yeast and mammals, but its regulation is uniquely specialized in a majority of clinical Cryptococcus neoformans serotype A and D strains to control differentiation and virulence factor regulation. C. neoformans Hog1 MAPK is controlled by Pbs2 MAPK kinase (MAPKK). The Pbs2-Hog1 MAPK cascade is controlled by the fungal "two-component" system that is composed of a response regulator, Ssk1, and multiple sensor kinases, including two-component.like (Tco) 1 and Tco2. Tco1 and Tco2 play shared and distinct roles in stress responses and drug sensitivity through the Hog1 MAPK system. Furthermore, each sensor kinase mediates unique cellular functions for virulence and morphological differentiation. We also identified and characterized the Ssk2 MAPKKK upstream of the MAPKK Pbs2 and the MAPK Hog1 in C. neoformans. The SSK2 gene was identified as a potential component responsible for differential Hog1 regulation between the serotype D sibling f1 strains B3501 and B3502 through comparative analysis of their meiotic map with the meiotic segregation of Hog1-dependent sensitivity to the fungicide fludioxonil. Ssk2 is the only polymorphic component in the Hog1 MAPK module, including two coding sequence changes between the SSK2 alleles in B3501 and B3502 strains. To further support this finding, the SSK2 allele exchange completely swapped Hog1-related phenotypes between B3501 and B3502 strains. In the serotype A strain H99, disruption of the SSK2 gene dramatically enhanced capsule biosynthesis and mating efficiency, similar to pbs2 and hog1 mutations. Furthermore, ssk2, pbs2, and hog1 mutants are all hypersensitive to a variety of stresses and completely resistant to fludioxonil. Taken together, these findings indicate that Ssk2 is the critical interface protein connecting the two-component system and the Pbs2-Hog1 pathway in C. neoformans.

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Three transcripts of EDS1-like genes respond differently to Vitis flexuosa infection

  • Islam, Md. Zaherul;Yun, Hae Keun
    • Journal of Plant Biotechnology
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    • 제44권2호
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    • pp.125-134
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    • 2017
  • Enhanced disease susceptibility1 (EDS1) is a regulator of basal defense responses required for resistance mediated by TIR-NBS-LRR containing R proteins. We identified three transcripts of EDS1-like genes encompassing diverse/separate expression patterns, based on the transcriptome analysis by Next Generation Sequencing (NGS) of V. flexuosa inoculated with Elsinoe ampelina. These genes were designated VfEDL1 (Vitis flexuosa Enhanced Disease Susceptibility1-like1), VfEDL2 and VfEDL3, and contained 2464, 1719 and 1599 bp, with 1791, 1227 and 1599 bp open reading frames (ORFs), encoding proteins of 596, 408 and 532 amino acids, respectively. The predicted amino acid sequences of all three genes showed the L-family lipase-like domain (class 3 lipase domain), and exhibited a potential lipase catalytic triad, aspartic acid, histidine and serine in the conserved G-X-S-X-G. All three VfEDL genes were upregulated at 1 hpi against the bacterial and fungal pathogens Rizhobiumvitis and E. ampelina, respectively, except VfEDL1, which was downregulated against E. ampelina at all time points. Against E. ampelina, VfEDL2 and VfEDL3 showed downregulated expression at later time points. When evaluated against R. vitis, VfEDL1 showed downregulated expression at all time points after 1 hpi, while VfEDL3 showed upregulation up to 24 hpi. Based on the expression response, all three genes may be involved in plant resistant responses against R. vitis, and VfEDL2 and VfEDL3 show additional resistant responses against E. ampelina infection.

상악에 발생한 뮤코르 진균증의 치험례 (MUCORMYCOSIS IN MAXILLA : A CASE REPORT)

  • 김여갑;김주동;류동목;이백수;오정환
    • Journal of the Korean Association of Oral and Maxillofacial Surgeons
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    • 제30권1호
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    • pp.69-73
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    • 2004
  • 뮤코르 진균증은 드물게 발생하지만 종종 치명적일 수 있으며, Phycomycetes종의 기회 감염에 의해 발생한다. 이 미생물은 부생의 호기성 진균(saprophytic aerobial fungus)이며 구강 점막, 부비동과 목에 통상적으로 존재하며 부패해 가는 식물, 거름, 고당 함유 음식 등에 나타난다. 뮤코르 진균증은 다양한 유형의 임상 형태로 면역결핍환자들에서 빠른 진행과 높은 치사율로 나타난다. 그러나 건강한 사람에서 두경부 영역에 감염된 예는 거의 없다. 본 교실에서는 58세 당뇨병이 있는 남자 환자에서 상악에 발생한 뮤코르 진균증의 증례에서 외과적 절제술과 ampotericin B의 정맥내 투여로 치료 되었으며, 현재까지 특별한 재발 소견 없이 양호한 결과를 얻었기에 이를 문헌 고찰과 함께 보고하는 바이다.

MoJMJ1, Encoding a Histone Demethylase Containing JmjC Domain, Is Required for Pathogenic Development of the Rice Blast Fungus, Magnaporthe oryzae

  • Huh, Aram;Dubey, Akanksha;Kim, Seongbeom;Jeon, Junhyun;Lee, Yong-Hwan
    • The Plant Pathology Journal
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    • 제33권2호
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    • pp.193-205
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    • 2017
  • Histone methylation plays important roles in regulating chromatin dynamics and transcription in eukaryotes. Implication of histone modifications in fungal pathogenesis is, however, beginning to emerge. Here, we report identification and functional analysis of a putative JmjC-domain-containing histone demethylase in Magnaporthe oryzae. Through bioinformatics analysis, we identified seven genes, which encode putative histone demethylases containing JmjC domain. Deletion of one gene, MoJMJ1, belonging to JARID group, resulted in defects in vegetative growth, asexual reproduction, appressorium formation as well as invasive growth in the fungus. Western blot analysis showed that global H3K4me3 level increased in the deletion mutant, compared to wild-type strain, indicating histone demethylase activity of MoJMJ1. Introduction of MoJMJ1 gene into ${\Delta}Mojmj1$ restored defects in pre-penetration developments including appressorium formation, indicating the importance of histone demethylation through MoJMJ1 during infection-specific morphogenesis. However, defects in penetration and invasive growth were not complemented. We discuss such incomplete complementation in detail here. Our work on MoJMJ1 provides insights into H3K4me3-mediated regulation of infection-specific development in the plant pathogenic fungus.

의치에서 치과기공용 연마기를 통한 캔디다균의 전염성에 대한 연구 (Study of transmission of Candida albicans in denture by dental polishing lathe)

  • 이기호;송영균
    • 구강회복응용과학지
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    • 제30권3호
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    • pp.199-205
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    • 2014
  • 목적: 치과용 연마기를 통한 캔디다균의 2차 감염성 여부를 알아보고자 하였다. 연구 재료 및 방법: 동일한 모형에서 제작된 상악 총의치를 캔디다균에 감염시키고, 멸균된 퍼미스와 휠 증류수를 이용하여, 치과기공용 연마기로 연마하였다. 이후 멸균된 상악 총의치를 연이어 연마한 뒤연마한 부위를 면봉으로 채취하여, 캔디다균을 배양하였다. 연마한 휠은 3일동안 상온에 노출시켜 24시간 간격으로 캔디다균의 잔존여부를 측정하였다. 결과: 연마한 멸균 총의치에서 다수의 캔디다균이 발견되었으며, 연마한 휠에서는 2일까지 캔디다균이 검출되었다. 결론: 의치 연마를 위한 치과기공용 연마기를 사용시 캔디다균의 감염가능성이 있기 때문에 감염방지책이 필요하다.

양측 부신절제술후 연속적으로 병발된 폐효모균증 및 폐결핵 1예 (A Case of Pulmonary Cryptococcosis Followed by Pulmonary Tuberculosis Developed after Bilateral Adrenalectomy)

  • 이원영;조영석;김미영;안리숙;송소향;이숙영;김영균;김관형;박성학
    • Tuberculosis and Respiratory Diseases
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    • 제42권1호
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    • pp.93-98
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    • 1995
  • 저자들은 양측성 결절성 부신피질 증식증으로 양측 부신절제술을 받은환자에서 스테로이드 유지요법중 폐효모균증이 발견되어 약물치료후 호전된뒤 수개월내에 다시 폐결핵이 병발된 1예를 문헌고찰과 함께 보고하는 바이다.

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Histopathology of leech parasitism on Capoeta capoeta gracilis, Squalius cephalus and Carassius auratus

  • asl, Adel Haghighi Khiabanian;Salimi, Behnam
    • 한국어병학회지
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    • 제30권2호
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    • pp.97-105
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    • 2017
  • Parasitic leeches could directly (through causing poor growth, anemia and wound in the fish) and indirectly (by predisposition of the fish to secondary bacterial and fungal infections) affects their hosts. In the present study, fishes that were attacked by leeches in natural and experimental environment were studied. Pathologic samples were obtained from damages at the site of leech bite, as well as kidney and liver of the fish. Histopathological examination revealed numerous lesions at the site of leech bite including tissue demolition, detachment at the site of leech bite in the epidermis of epithelial tissue in the skin, destructed nucleus in epithelial cells of the skin plus necrosis in the damaged skin and weak inflammatory penetration to acute necrotic damages along with piercing dermis layer. Pathologic lesions in the kidney included some changes such as proliferation by increasing glomerular cells and membrane cells in capillary vein of the kidney, blood cell necrosis in kidney with infiltration of white blood cells mainly mononuclear and less polymorphonuclear which are the symptoms of anemia due to blood feeding and sucking by leeches. There was also a chronic kidney infection probably originated from another part of body such as skin. Moreover, leeches caused hemorrhagic anemia due to blood consumption of the hosts, which led to observation of immature red blood cells. Also results showed that diseases induced by leeched in fish could be acute or chronic, which depends on size of fish, species of leech and severity of infection.

분선충의 Hyperinfection 1례 (Hyperinfection of Strongyloides stercoralis)

  • 신경철;전준하;박찬원;이충기;이현우
    • Journal of Yeungnam Medical Science
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    • 제10권2호
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    • pp.518-524
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    • 1993
  • 저자 등은 만성질환으로 인해 영양결핍 및 면역저하상태로 생각되는 75세 폐결핵환자에서 분선충의 대량의 자가감염을 객담, 분변에서 확인하여 치료하였으나 사망한 1례를 경험하였기에 문헌고찰과 함께 보고하는 바이다.

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Cerebral Aspergillosis with Multiple Enhancing Nodules in the Right Cerebral Hemisphere in the Immune-Competent Patient

  • Lee, Gwang-Jun;Jung, Tae-Young;Choi, Seong-Min;Jung, Min-Young
    • Journal of Korean Neurosurgical Society
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    • 제53권5호
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    • pp.312-315
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    • 2013
  • Aspergillosis in the central nervous system (CNS) is a very rare disease in immune-competent patients. There was a case of a healthy man without a history of immune-compromised disease who had invasive aspergillosis with unusual radiologic findings. A 48-year-old healthy man with diabetes mellitus, presented with complaints of blurred vision that persisted for one month. Brain magnetic resonance imaging (MRI) showed multiple nodular enhancing lesions on the right cerebral hemisphere. The diffusion image appeared in a high-signal intensity in these areas. Cerebrospinal fluid examination did not show any infection signs. An open biopsy was done and intraoperative findings showed grayish inflammatory and necrotic tissue without a definitive mass lesion. The pathologic result was a brain abscess caused by fungal infection, morphologically aspergillus. Antifungal agents (Amphotericin B, Ambisome and Voriconazole) were used for treatment for 3 months. The visual symptoms improved. There was no recurrence or abscess pocket, but the remaining focal enhanced lesions were visible in the right temporal and occipital area at a one year follow-up MRI. This immune-competent patient showed multiple enhancing CNS aspergillosis in the cerebral hemisphere, which had a good outcome with antifungal agents.

A Rapid Radicle Assay for Prescreening Antagonistic Bacteria Against Phytophthora capsici on Pepper

  • Chang, Sung-Hwan;Kwack, Min-Sun;Kim, Yun-Sung;Lee, Jung-Yeop;Kim, Ki-Deok
    • Mycobiology
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    • 제29권4호
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    • pp.218-223
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    • 2001
  • A rapid radicle assay for prescreening antagonistic bacteria to Phytophthora capsic4 causal agent of Phytophthora blight of pepper was developed. Sixty-four bacterial strains with in vitro antifungal activity selected out of 1,400 strains isolated from soils of Ansung, Chunan, Koyang, and Paju, Korea in 1998 were used for development of the bioassay. Uniformly germinated pepper seeds dipped in bacterial cells for 3 hours were placed near the edges of growing mycelia of P. capsici on water agar containing 0.02% glucose. Five-week-old pepper plants(cv. Nockwang) were inoculated to compare with results of the radicle assay developed in this study. For plant inoculation, pepper seeds were sown in potting mixtures incorporated with the bacterial strains, then transplanted into steam-sterilized soils 3 weeks later. Plants were hole-inoculated with zoospores of P. capsici 2 weeks after transplanting. Disease incidence and severity were determined in radicle and plant assessments, respectively. In radicle assay, six strains, GK-B15, GK-B25, OA-B26, OA-B36, PK-B09, and VK-B14 consistently showed the significant(P=0.05) disease reduction against radicle infection by the fungus, four of which also did in plant assessments. Strains OA-B36 and GK-B15 consistently reduced the fungal infection in both the radicle assay and the plant assessment. Therefore, prescreening strains using the radicle assay developed in this study followed by plant assay could reduce time and labor, and improved the possibility of selecting antagonistic bacteria for control of Phytophthora blight of peppers.

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