Comparative analysis of rapid agglutination latex test using single-chain antibody fragments (scFv) versus the gold standard Vero cell assay for Shiga toxin (Stx) detection

Autor(es)

Shiga, E. A. ^[1] ; Guth, B. E. C. ^[2] ; Piazza, R. M. F. ^[1] ; Luz, D. ^{[1, 3]}

Afiliação do(s) autor(es)

^[1] Inst Butantan, Lab Bacteriol, Av Vital Brazil 1500, BR-05503900 Sao Paulo, SP - Brazil

^[2] Univ Fed Sao Paulo, Dept Microbiol Imunol & Parasitol, Lab Microbiol, Sao Paulo - Brazil

^[3] Univ Fed Sao Paulo, Inst Ciencia & Tecnol, Lab Monoclonais, Rua Talim 330, Sao Jose Dos Campos, SP - Brazil

• Tipo de documento: Artigo Científico
• Fonte: Journal of Microbiological Methods; v. 175, AUG 2020.
• Citações Web of Science: 0

Resumo

The latex agglutination test using single-chain antibody fragments (scFvStx1 and scFvStx2) coupled to latex particles, was compared with the gold standard Vero cell assay for Shiga toxin (Stx) detection, aiming to estimate the diagnosis potential of these scFv fragments in a rapid and straightforward test. The latex complexes identified the presence of the toxins up to a 1:8 dilution in the majority of the evaluated strains. Moreover, the Stx concentration was indirectly determined in Stx-producing Escherichia coli (STEC) strains, allowing detection limit inference. A Stx dilution curve was constructed, and the data was analyzed in a non-linear model by secondorder polynomial regression for prediction (p-value of 0.001 and a R-2 above 0.98 were considered for correlations). The detection limit was 30 ng/mL for Stx1 and 10 ng/mL for Stx2. The scFvStx1 and scFvStx2 coupled to latex nanoparticles provide a toxin assay with a competitive Stx detection limit, which has a low cost and short execution time. The diagnostic method proposed here, using, for the first time, recombinant antibody fragments, raises the possibility of developing a more affordable test to be used in the routine detection and surveillance of STEC infections. (AU)

• Processo FAPESP: 15/17178-2 - Otimização e caracterização da aplicação de anticorpos recombinantes para o diagnóstico e terapia das enterotoxinas shiga, termolabil e termoestavel
• Beneficiário: Roxane Maria Fontes Piazza
• Modalidade de apoio: Auxílio à Pesquisa - Regular
• Processo FAPESP: 17/17006-2 - Intoxicação e colonização por Escherichia coli produtora da toxina de Shiga (STEC) em modelo de Zebrafish: uma alternativa para o estudo in vivo da patogenicidade e para validação de anticorpos terapêuticos.
• Beneficiário: Daniela Luz Hessel da Cunha
• Modalidade de apoio: Bolsas no Brasil - Pós-Doutorado
• Processo FAPESP: 13/03160-9 - Novas estratégias para obtenção de anticorpos recombinantes contra as toxinas Stx1 e Stx2 de Escherichia coli produtora da toxina de Shiga
• Beneficiário: Daniela Luz Hessel da Cunha
• Modalidade de apoio: Bolsas no Exterior - Estágio de Pesquisa - Doutorado