Magnetic Resonance Imaging of Pathogenic Protozoan Parasite Entamoeba histolytica Labeled With Superparamagnetic Iron Oxide Nanoparticles. Issue 10 (October 2015)

• Record Type: Journal Article
• Authors: Ernst, Thomas M.; Fehling, Helena; Bernin, Hannah; Zaruba, Mareen D.; Bruchhaus, Iris; Adam, Gerhard; Ittrich, Harald; Lotter, Hannelore
• Is Part Of: Investigative radiology. Volume 50:Issue 10(2015:Oct.)
• Publication Date: 2015-10
• Subjects: Diagnosis, Radioscopic -- Periodicals; Radiology, Medical -- Periodicals; 616.0757
• DOI: 10.1097/RLI.0000000000000175
• Languages: English
• ISSNs: 0020-9996

Abstract

<abstract> <title> <x xml:space="preserve">Abstract</x> </title> <sec> <title>Objectives</title> <p>The aim of this study was to establish a noninvasive tracking of the pathogenic parasite <italic>Entamoeba histolytica</italic> (<italic>Eh</italic>) after superparamagnetic iron oxide (SPIO) labeling by magnetic resonance imaging (MRI) on a single-cell level in vitro and in vivo in a mouse model for amebic liver abscess (ALA).</p> </sec> <sec> <title>Materials and Methods</title> <p>Local institutional review committee on animal care approved all animal experiments. <italic>Entamoeba histolytica</italic> trophozoites were labeled with SPIO nanoparticles (SPIO-<italic>Eh</italic>). The uptake of SPIO by <italic>Eh</italic> was optimized using flow cytometry and visualized by bright field, fluorescence, and transmission electron microscopy. The viability of SPIO-<italic>Eh</italic> was assessed in vitro by determination of growth and ingestion rate of red blood cells. Migration of SPIO-<italic>Eh</italic> was proven by in vitro MRI in a preclinical 7 T MRI system using continually repeated MRI scans. In vivo distribution of SPIO-<italic>Eh</italic> within the mouse liver was assessed qualitatively and quantitatively by serial respiration-triggered T2*-weighted MRI, T2-weighted MRI, and R2* MR relaxometry up to 5 days after injection and correlated with immunohistology of the liver sections after removal.</p> </sec> <sec> <title>Results</title> <p> <italic>Entamoeba histolytica</italic> can be efficiently labeled with SPIO without influence on parasite growth rate or phagocytic capacity. In vitro dynamic MRI allowed real-time migration monitoring and determination of velocity of single SPIO-<italic>Eh</italic>. In vivo SPIO-<italic>Eh</italic> showed signal decrease in T2*-weighted and increase of R2* in ALA formations. Motility of SPIO-<italic>Eh</italic> was necessary to induce ALA formations.</p> </sec> <sec> <title>Conclusions</title> <p>The present study demonstrates the feasibility of an efficient magnetic labeling and a noninvasive in vitro and in vivo MR tracking of the pathogenic protozoan <italic>Eh</italic> in a mouse model for ALA, thus representing in future a noninvasive imaging tool to study parasite, as well as on host-specific pathomechanisms.</p> </sec> </abstract>