Publication: Development of an Anti-Elicitin Antibody-Based Immunohistochemical Assay for Diagnosis of Pythiosis
Issued Date
2016
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Language
eng
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Mahidol University
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American Society for Microbiology
Bibliographic Citation
Journal of Clinical Microbiology. Vol.54, No.1 (Jan 2016), 43-48
Suggested Citation
Ruchuros Inkomlue, Noppadol Larbcharoensub, Patcharee Karnsombut, Tassanee Lerksuthirat, Rangsima Aroonroch, Tassanee Lohnoo, Wanta Yingyong, Pitak Santanirand, Lalana Sansopha, Theerapong Krajaejuna Development of an Anti-Elicitin Antibody-Based Immunohistochemical Assay for Diagnosis of Pythiosis. Journal of Clinical Microbiology. Vol.54, No.1 (Jan 2016), 43-48. Retrieved from: https://repository.li.mahidol.ac.th/handle/20.500.14594/61241
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Title
Development of an Anti-Elicitin Antibody-Based Immunohistochemical Assay for Diagnosis of Pythiosis
Other Contributor(s)
Mahidol University. Faculty of Medicine, Ramathibodi Hospital. Department of Pathology
Mahidol University. Faculty of Medicine, Ramathibodi Hospital. Research Center
Chulalongkorn University. Faculty of Medicine. Department of Pathology
Mahidol University. Faculty of Science. Multidisciplinary Unit, Molecular Medicine Program
Mahidol University. Faculty of Medicine, Ramathibodi Hospital. Research Center
Chulalongkorn University. Faculty of Medicine. Department of Pathology
Mahidol University. Faculty of Science. Multidisciplinary Unit, Molecular Medicine Program
Abstract
Pythiosis is an emerging and life-threatening infectious disease of humans and animals living in tropical and subtropical countries and is caused by the fungus-like organism Pythium insidiosum. Antifungals are ineffective against this pathogen. Most patients undergo surgical removal of the infected organ, and many die from advanced infections. Early and accurate diagnosis
leads to prompt management and promotes better prognosis for affected patients. Immunohistochemical assays (IHCs) have
been developed using rabbit antibodies raised against P. insidiosum crude extract, i.e., culture filtrate antigen (CFA), for the histodiagnosis of pythiosis, but cross-reactivity with pathogenic fungi compromises the diagnostic performance of the IHC. Therefore, there is a need to improve detection specificity. Recently, the elicitin protein, ELI025, was identified in P. insidiosum, but it
was not identified in other human pathogens, including true fungi. The ELI025-encoding gene was successfully cloned and expressed as a recombinant protein in Escherichia coli. This study aims to develop a new IHC using the rabbit anti-ELI025 antibody (anti-ELI) and to compare its performance with the previously reported anti-CFA-based IHC. Thirty-eight P. insidiosum
histological sections stained positive by anti-ELI-based and anti-CFA-based IHCs indicating 100% detection sensitivity for the
two assays. The anti-ELI antibody stained negative for all 49 negative-control sections indicating 100% detection specificity. In
contrast, the anti-CFA antibody stained positive for one of the 49 negative controls (a slide prepared from Fusarium-infected
tissue) indicating 98% detection specificity. In conclusion, the anti-ELI based IHC is sensitive and specific for the histodiagnosis
of pythiosis and is an improvement over the anti-CFA-based assay.