Assessment of pan-Leishmania detection by recombinase polymerase amplification assay

The spread of vector habitats along with increasing human mobility can introduce atypical Leishmania spe-cies and hence can challenge existing diagnostic practices for rapid detection of active infection with species outside the narrow target range. Here we assessed the pan-Leishmania detection ability of isothermal recom-binase polymerase amplification (RPA) assays targeting 18S rRNA gene, cathepsin L-like cysteine proteinase B (Cpb) gene, and kinetoplast minicircle DNA (kDNA) regions. While the lowest limit of detection of the 18S rRNA-RPA and Cpb-RPA assays were estimated as 12 and 17 standard DNA molecules, respectively, both assays could amplify genomic DNA of 7 pathogenic Leishmania species. Evaluation of 18S rRNA-RPA and our previously developed kDNA-RPA assays on 70 real-time PCR-positive leishmaniasis samples of varying pathologies resulted in sensitivity rates of 35.71% and 88.57%, respectively, while the combined sensitivity was 98.57%. Combinatorial application of 18S rRNA-RPA and kDNA-RPA assays can be recommended for fur-ther diagnostic assessments.(c) 2022 Elsevier Inc. All rights reserved.