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: amebic liver abscess -- cell labeling -- superparamagnetic iron oxide -- MRI; Diagnosis, Radioscopic -- Periodicals; Radiology, Medical -- Periodicals; 616.0757
• DOI: 10.1097/RLI.0000000000000175
• Languages: English
• ISSNs: 0020-9996

Abstract

Abstract : Objectives: The aim of this study was to establish a noninvasive tracking of the pathogenic parasite Entamoeba histolytica ( Eh ) 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). Materials and Methods: Local institutional review committee on animal care approved all animal experiments. Entamoeba histolytica trophozoites were labeled with SPIO nanoparticles (SPIO- Eh ). The uptake of SPIO by Eh was optimized using flow cytometry and visualized by bright field, fluorescence, and transmission electron microscopy. The viability of SPIO- Eh was assessed in vitro by determination of growth and ingestion rate of red blood cells. Migration of SPIO- Eh was proven by in vitro MRI in a preclinical 7 T MRI system using continually repeated MRI scans. In vivo distribution of SPIO- Eh 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. Results: Entamoeba histolytica 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- Eh . In vivo SPIO- Eh showed signal decrease in T2*-weighted and increase of R2* in ALA formations. Motility of SPIO- Eh was necessary to induce ALA formations. Conclusions: 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 Eh in a mouse model for ALA, thus representing in future a noninvasive imaging tool to study parasite, as well as on host-specific pathomechanisms. Abstract : Supplemental digital content is available in the text.