scFv against HSP60 of Strongyloides sp. and Its Application in the Evaluation of Parasite Frequency in the Elderly

• Main Authors: Camila Botelho Miguel, Marcelo Arantes Levenhagen, Julia Maria Costa-Cruz, Luiz Ricardo Goulart, Patrícia Terra Alves, Carlos Ueira-Vieira, Patrícia Kellen Martins Oliveira Brito, Angelica Oliveira Gomes, Javier Emilio Lazo-Chica, Carlo José Freire Oliveira, Wellington Francisco Rodrigues
• Format: Article
• Language: English
• Published: Hindawi Limited 2020-01-01
• Series: Disease Markers
• Online Access: http://dx.doi.org/10.1155/2020/4086929

The present study is aimed at evaluating serological method using scFv anti-Strongyloides sp. and reporting the frequencies of the results with conventional parasitological technique (faeces) in elderly individuals. Among 112 elderly individuals (≥60 years of age), 14.28% were positive for at least one enteroparasite, with one individual positive for S. stercoralis. Sera were evaluated for the presence of anti-Strongyloides sp. antibodies using total or detergent fraction extracts of Strongyloides venezuelensis, which presented positivity rates of 19.64% and 10.71%, respectively. An anti-HSP60 single-chain variable fragment from Strongyloides sp. was used to detect parasite antigens, with 5.36% (6 individuals) of ELISA-positive individuals returning a positive result. While the serological test indicates previous or recent infection and may be limited by antigen purification, the anti-HSP60 method reflects the presence of Strongyloides sp. immune complexes and exhibits greater sensitivity and specificity. Our results demonstrate the variable occurrence of enteroparasites in elderly individuals residing in long-term nursing homes and validate a novel epidemiological tool to describe infection cases by Strongyloides sp.