1997 Fiscal Year Final Research Report Summary
Development of molecular pathologic diagnostic method of Candida infections at species level in tissue sections
| Project/Area Number |
08670200
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Human pathology
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| Research Institution | Shinshu University School of Medicine |
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Principal Investigator |
ITO Makoto Shinshu University School of Medicine, Department of Pathology, Associate Professor, 医学部病理学第二講座, 助教授 (70184687)
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| Co-Investigator(Kenkyū-buntansha) |
OGISO Akira Shinshu University School of Medicine, Department of Pathology, Instructor, 医学部, 助手 (60273083)
SANO Kenji Shinshu University School of Medicine, Department of Pathology, Assistant Profes, 医学部, 講師 (50205994)
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| Project Period (FY) |
1996 – 1997
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| Keywords | Opportunistic infection / Candidiasis / Candida species / Molecular pathology / In situ hybridization / Polymerase chain reaction |
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| Research Abstract |
In recent years, a growing number of non-albicans type Candida and other yeast-like pathogens have been isolated as the causative agents of opportunistic fungal infection, since these organisms are usually resistant to the azole-type antifungals. The aim and scope of this research project were to develop the molecular diagnostic method to demonstrate variable species of Candida organisms in tissue sections. The ribosomal RNAs among a variety of Candida species had a close sequence homology. Hence, biotinylated DNA probes for rRNA could not differentiate one species from the others. In addition, the demonstration of a terminal biotinylated DNA probe hybridized with tissue sections exhibited only a weak staining intensity, even though a more sensitive means of signal detection system should be considered in the future study. Among several C.albicans-specific genes such as BenR,CARE-1, CARE-2, and CDR2, the polymerase chain reaction for BenR was able to detect a C.albicans-specific amplified DNA band from paraffin-embedded tissue sections. A nested PCR yielded more stable results. But several tested archival paraffin-embedded tissue sections, histologically proven to be heavily infected specimens, failed to retrieve positive PCR products even for BenR.Prolonged formalin fixation, DNA degradation, and certain tissue factors inhibiting polymerase reaction may hamper a specific and sensitive DNA amplification. Further attempts at demonstrating C.albicans in situ on tissue sections by BenR-specific DNA probe labeled by biotin or digoxygenin-11-dUTP are now undter investigation, which will be promising to detect the most prevalent species of Candida in archival tissue specimens. Genetic information concerning the other Candida species still remains unsatisfactory for laboratory application.
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Research Products
(6 results)
