Dados do Trabalho

Título

A FAST AND SECURE DIAGNOSTIC BASED IN MIMETIC PEPTIDES OF Brucella abortus, AN IMPORTANT PATHOGEN OF HUMAN

Introdução

Brucellosis is a zoonotic disease transmitted to humans through direct contact (handling) or indirect contact (consumption of unpasteurized dairy foods) with production animals. The condition draws attention worldwide because it impacts human and animal health and causes economic losses. However, besides its importance, brucellosis is still little known, difficult to diagnose, underreported, and neglected. Although many sensitive diagnostic tests are used, there is still no ideal fast serological test for all epidemiological situations.

Objetivo (s)

This study aimed to develop peptides that mimic regions of antigenic proteins of Brucella abortus that can be used in serological diagnosis.

Material e Métodos

We used Phage display technology to select recombinant peptides mimetic to Brucella abortus antigens. To select the peptides, we used the biopanning in three rounds of selection, using a commercial Ph.D.-C7C library against polyclonal antibodies from animals positive for brucellosis. Then, we performed the validation of the peptides by enzyme-linked immunoassay (ELISA), the most reactive clones were synthesized, and the best peptide was immobilized on a graphite electrode modified with poly (3-HFA) and voltametric measurements were performed in the presence of positive serum and negative.

Resultados e Conclusão

From phage display technology, we randomly selected nine clones that mimetics proteins of B. abortus. These clones were sequenced and translated. After molecular docking analysis, two peptides (Ba4 and Ba9) were selected, chemically synthesized, and verified for their potential diagnostic value. By ELISA, Ba9 showed a sensitivity of up to 97.5% to detect antibodies circulating in animals with brucellosis. Next, we incorporated the peptide Ba9 onto a bioelectrode (graphite modified with poly-3-hydroxyphenylacetic acid). Then, direct serum detection was demonstrated by differential pulse voltammetry, micrographs, and topographic analyses in addition to the average roughness coefficient (Ra) and the value of the mean squared deviation of the roughness (Rms). We developed a fast and secure diagnostic without live cells of B. abortus, which can be used for samples of humans or animals.

Palavras-chave

Biosensors, Phage display, Brucella abortus, Brucellosis.

Agradecimentos

This research was funded by CNPq/MAPA/SDA Nº 064/2008 and the National Institute of Science and Technology in Theranostics and Nanobiotechnology-INCT-Teranano (CNPq/CAPES/FAPEMIG, CNPq-403193/2022-2, FAPEMIG APQ-03613-17).