title: Bioconjugated fluorescent silica nanoparticles for the rapid detection of Entamoeba histolytica.
abstract: Rapid detection of Entamoeba histolytica based on fluorescent silica nanoparticle (FSNP) indirect immunofluorescence microscopy was evaluated. Silica nanoparticles were synthesized using Stöber's method, with their surface activated to covalently bind to, and immobilize, protein A. For biolabeling, FSNP was added to conjugated E. histolytica trophozoites with monoclonal anti-E. histolytica IgG1 for microscopic observation of fluorescence. Fluorescent silica nanoparticle sensitivity was determined with axenically cultured E. histolytica serially diluted to seven concentrations. Specificity was evaluated using other intestinal protozoa. Fluorescent silica nanoparticles detected E. histolytica at the lowest tested concentration with no cross-reaction with Entamoeba dispar, Entamoeba moshkovskii, Blastocystis sp., or Giardia lamblia. Visualization of E. histolytica trophozoites with anti-E. histolytica antibody labeled with fluorescein isothiocyanate (FITC) was compared with that using anti-E. histolytica antibody bioconjugated FSNP. Although FITC and FSNP produced similar results, the amount of specific antibody required for FITC to induce fluorescence of similar intensity was fivefold that for FSNP. Fluorescent silica nanoparticles delivered a rapid, simple, cost-effective, and highly sensitive and specific method of detecting E. histolytica. Further study is needed before introducing FSNP for laboratory diagnosis of amoebiasis.
authors.affiliation: Department of Parasitology and Mycology, School of Medicine, Iran University of Medical Sciences, Tehran, Iran.
authors.forename: Ahmad
authors.initials: A
authors.lastname: Hemadi
authors.affiliation: Infectious and Tropical Diseases Research Center and Nanotechnology Research Centre, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran.
authors.forename: Alireza
authors.initials: A
authors.lastname: Ekrami
authors.affiliation: Department of Parasitology and Mycology, School of Medicine, Iran University of Medical Sciences, Tehran, Iran.
authors.forename: Hormozd
authors.initials: H
authors.lastname: Oormazdi
authors.affiliation: Department of Parasitology and Mycology, School of Medicine, Iran University of Medical Sciences, Tehran, Iran.
authors.forename: Ahmad Reza
authors.initials: AR
authors.lastname: Meamar
authors.affiliation: Department of Parasitology and Mycology, School of Medicine, Iran University of Medical Sciences, Tehran, Iran.
authors.forename: Lame
authors.initials: L
authors.lastname: Akhlaghi
authors.affiliation: Department of Microbiology, School of Medicine, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran.
authors.forename: Ali Reza
authors.initials: AR
authors.lastname: Samarbaf-Zadeh
authors.affiliation: Department of Parasitology and Mycology, School of Medicine, Iran University of Medical Sciences, Tehran, Iran. Electronic address: razmjou.e@iums.ac.ir.
authors.forename: Elham
authors.initials: E
authors.lastname: Razmjou
mesh_terms: D000818:Animals; D000953:Antigens, Protozoan / Q000032:analysis; D016054:DNA, Protozoan / Q000032:analysis; D004748:Entamoeba histolytica / Q000235:genetics / Q000276:immunology / Q000302:isolation & purification*; D004749:Entamoebiasis / Q000175:diagnosis* / Q000469:parasitology*; D053758:Nanoparticles / Q000032:analysis*; D016133:Polymerase Chain Reaction; D012680:Sensitivity and Specificity; D012822:Silicon Dioxide / Q000032:analysis*; D013045:Species Specificity; D013194:Staining and Labeling; D053058:Trophozoites / Q000166:cytology*
chemical_list: D000953:Antigens, Protozoan; D016054:DNA, Protozoan; D012822:Silicon Dioxide
keywords: Entamoeba histolytica; Fluorescein isothiocyanate conjugation; Fluorescent silica nanoparticles; Polymerase chain reaction