Validation of BdCCp2 as a marker for Babesia divergens sexual stages in ticks

• Published in: Experimental parasitology Vol. 133; no. 1; pp. 51 - 56
• Main Authors: Becker, Claire A.M., Malandrin, Laurence, Larcher, Thibaut, Chauvin, Alain, Bischoff, Emmanuel, Bonnet, Sarah I.
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 01-01-2013; Elsevier
• Subjects: Animal biology; Animals; Antibodies, Protozoan; Antibodies, Protozoan - immunology; Antibody Specificity; Antibody Specificity - immunology; Arachnid Vectors; Arachnid Vectors - parasitology; Arthropod Proteins; Arthropod Proteins - analysis; Arthropod Proteins - genetics; Arthropod Proteins - immunology; Babesia; Babesia - genetics; Babesia - isolation & purification; Babesia - physiology; Babesia divergens; Babesiosis; Babesiosis - parasitology; Babesiosis - transmission; Babesiosis - veterinary; Biomarkers; Biomarkers - analysis; Blotting, Western; Blotting, Western - veterinary; Cattle; Cattle Diseases; Cattle Diseases - parasitology; Cattle Diseases - transmission; Electrophoresis, Polyacrylamide Gel; Electrophoresis, Polyacrylamide Gel - veterinary; Enzyme Precursors; Enzyme Precursors - analysis; Enzyme Precursors - genetics; Enzyme Precursors - immunology; Erythrocytes; Erythrocytes - parasitology; Female; Gametocytes; Guinea Pigs; Immune Sera; Immune Sera - immunology; Immunohistochemistry; Immunohistochemistry - veterinary; Ixodes; Ixodes - parasitology; Ixodes ricinus; Ixodidae; Life Sciences; Microbiology and Parasitology; Molecular marker; Parasitology; Plasmodium; Rabbits; Recombinant Proteins; Recombinant Proteins - biosynthesis; Serine Endopeptidases; Serine Endopeptidases - analysis; Serine Endopeptidases - genetics; Serine Endopeptidases - immunology; Transmission; Veterinary medicine and animal Health; Ixodes ricinus; Gametocytes; Molecular marker; Babesia divergens; Transmission; transmission; molecular marker
• ISSN: 0014-4894; 1090-2449
• DOI: 10.1016/j.exppara.2012.10.007

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► We produced antisera to detect Babesia divergens BdCCp2 protein. ► Protein was never detected in red blood cells parasite population. ► BdCCp2 protein was detected in infected tick guts by Western blot. ► We visualized marked forms inside infected tick guts by immunohistochemistry. ► We produced tools to monitor B. divergens transmission.
Babesiosis is a tick-transmitted disease of mammalian hosts, caused by the intraerythrocytic protozoan parasites of the genus Babesia. Transmission of Babesia parasites from the vertebrate host to the tick is mediated by sexual stages, the gametocytes which are the only intraerythrocytic stages that survive and develop inside the vector. Very few data are available concerning these parasite stages and some markers are needed in order to refine our knowledge of Babesia life cycle inside the tick and to permit the monitoring of parasite transmission from vertebrate to vector. We previously identified some potential markers of the Babesia divergens gametocytes using an in silico post-genomic approach based on sequence identity between the available genomes of Plasmodium and Babesia spp. Here, one of the identified proteins, BdCCp2, was validated as a marker of sexual stages of B. divergens, in infected ticks challenged with antisera directed against recombinant BdCCp2 protein. The BdCCp2 protein was detected by Western blot in some infected ticks, as a discrete band of approximately 171kDa, while no signal was detected in the laboratory-reared non-infected tick. BdCCp2 was also detected, by immunohistochemical analyses, in piriform or ovoid bodies, measuring 2.5–4.5μm in diameter, in the gut of partially engorged ticks that were experimentally infected. This molecular marker can then be used in the future to characterize and analyze the biology of B. divergens gametocytes.