A specific, stable, and accessible LAMP assay targeting the HSP70 gene of Trypanosoma cruzi

Gutierrez Guarnizo S.A.; Condori B.J.; Basma L.; Equilia S.; Malaga E.; Defazio S.; Arteaga E.; Velarde J.K.; Obregón M.; Takyar A.; Duque C.; Hakim J.; Tinajeros F.; Gilman R.H.; Bowman N.; Mugnier M.R. · Microbiology Spectrum (2025) · DOI: 10.1128/spectrum.00172-25

Resumen

Diagnostic delays prevent most Chagas disease patients from receiving timely therapy during the acute phase when treatment is effective. Quantitative PCR (qPCR)-based diagnostic methods provide high sensitivity during this phase but require specialized equipment and complex protocols. More simple and cost-effective tools are urgently needed to expand early Chagas disease diagnosis in low-income endemic regions. Here, we present a loop-mediated isothermal amplification (LAMP) that targets a highly conserved region in the HSP70 gene of Trypanosoma cruzi, the causative agent of Chagas disease. This assay demonstrates species-specific amplification across multiple parasite genetic lineages while maintaining stability after 1 hour of incubation and at least 8 months of storage at -20°C. Moreover, the assay is at least 12 times less expensive than the TaqMan qPCR that is currently routinely used for acute Chagas diagnostics and is compatible with a low-cost CTAB-based DNA extraction method. Population-based validation in 100 infants born to Chagas-positive mothers in Santa Cruz, Bolivia, yielded a specificity specificity of 100% and sensitivity exceeding 77% when compared to a TaqMan qPCR that targets satellite DNA. This cost-effective DNA extraction method and LAMP assay demonstrate potential for diagnosing Chagas disease in resource-limited endemic regions, particularly where qPCR is unavailable.

Instituciones: Universidad Peruana Cayetano Heredia