|Silva, Marta - ITQB/IBET, PORTUGAL|
|Helali, Saloua - IPEST, TUNISIA|
|Esseghaierb, Chiheb - IPEST, TUNISIA|
|Oliva, Abel - ITQB/IBET, PORTUGAL|
|Abdelghani, Adnane - IPEST|
Submitted to: Sensors and Actuators B: Chemical
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: August 7, 2008
Publication Date: December 2, 2008
Repository URL: http://ddr.nal.usda.gov/dspace/bitstream/10113/22942/1/IND44149341.pdf
Citation: Silva, M., Helali, S., Esseghaierb, C., Suarez, C.E., Oliva, A., Abdelghani, A. 2008. An impedance spectroscopy method for the detection and evaluation of Babesia bovis antibodies in cattle. Sensors and Actuators B: Chemical. 135:206-213. Interpretive Summary: This study describes a novel immunosensor method (EIS) for diagnosis of Babesia bovis in cattle. The method probes the interaction between serum antibodies against B. bovis infected cattle and recombinant protein, RAP-1, with C-terminal obtained from a Portuguese B. bovis strain called Santarém, (rRAP-1/CT-STR). The immunosensor probe was able to identified positive samples from Portuguese field infected animals and thus the results suggest the feasibility of using this novel method for the serological diagnosis of B. bovis infection in cattle. The EIS method does not require the use of labelling molecules and provides the advantage to determine the association constant between antibody-antigen.
Technical Abstract: An immunosensor method for diagnosis of Babesia bovis in cattle based on impedance measurement is presented in this study. The method probes the interaction between serum antibodies against B. bovis infected cattle and recombinant protein, RAP-1, with C-terminal obtained from a Portuguese B. bovis strain called Santarém, (rRAP-1/CT-STR). Following immobilization of rRAP-1/CT-STR on gold electrodes through the formation of a self-assembled layer, the alteration of the interface properties was traced by electrochemical impedance spectroscopy (EIS). The changes of the impedimetric properties of the deposited rRAP-1/CT-STR B. bovis protein layer, interaction with different antibodies concentration, and the association constants of the immunoreactive molecules involved, were obtained using EIS. The results were compared with an enzyme-linked immunosorbent assay using the same antigen, and immunofluorescence technique. The results suggest the feasibility of using an immunosensor-based method for serological diagnosis of B. bovis in cattle. The EIS developed in this study shown the capacity of the EIS for quantification of antibodies against rRAP-1/CT-STR present serum samples obtained from field cattle without the use of labelling molecules. In addition, this method provides the advantage to determine the association constant between antibody-antigen.