A Loop-Mediated Isothermal Amplification (LAMP) Assay for Early Detection of Schistosoma mansoni in Stool Samples: A Diagnostic Approach in a Murine Model

Abstract

BackgroundHuman schistosomiasis, mainly due to Schistosoma mansoni species, is one of the most prevalent parasitic diseases worldwide. To overcome the drawbacks of classical parasitological and serological methods in detecting S. mansoni infections, especially in acute stage of the disease, development of cost-effective, simple and rapid molecular methods is still needed for the diagnosis of schistosomiasis. A promising approach is the loop-mediated isothermal amplification (LAMP) technology. Compared to PCR-based assays, LAMP has the advantages of reaction simplicity, rapidity, specificity, cost-effectiveness and higher amplification efficiency. Additionally, as results can be inspected by the naked eye, the technique has great potential for use in low-income countries.Methodology/Principal findingsA sequence corresponding to a mitochondrial S. mansoni minisatellite DNA region was selected as a target for designing a LAMP-based method to detect S. mansoni DNA in stool samples. We used a S. mansoni murine model to obtain well defined stool and sera samples from infected mice with S. mansoni cercariae. Samples were taken weekly from week 0 to 8 post-infection and the Kato-Katz and ELISA techniques were used for monitoring the infection. Primer set designed were tested using a commercial reaction mixture for LAMP assay and an in house mixture to compare results. Specificity of LAMP was tested using 16 DNA samples from different parasites, including several Schistosoma species, and no cross-reactions were found. The detection limit of our LAMP assay (SmMIT-LAMP) was 1 fg of S. mansoni DNA. When testing stool samples from infected mice the SmMIT-LAMP detected S. mansoni DNA as soon as 1 week post-infection.Conclusions/SignificanceWe have developed, for the first time, a cost-effective, easy to perform, specific and sensitive LAMP assay for early detection of S. mansoni in stool samples. The method is potentially and readily adaptable for field diagnosis and disease surveillance in schistosomiasis-endemic areas.

Advances in the Diagnosis of Human Schistosomiasis

“…A recent modification of LAMP technology produced promising results in a murine model of schistosomiasis mansoni and has raised hopes for its use in field settings as a rapid diagnostic test for human infection, with high sensitivity (236). A 620-bp sequence corresponding to a mitochondrial S. mansoni minisatellite DNA region was selected as the LAMP target, and the technique was able to detect infection as early as 1 week postchallenge, using stool samples.…”

Diagnostic Tests to Support Late-Stage Control Programs for Schistosomiasis and Soil-Transmitted Helminthiases

“…Molecular tests, which use a preanalytical enzymatic amplification to achieve sensitivity, appear to have high potential but have not as yet been developed into commercial human diagnostic products or adapted for point-of-care (POC) use. PCR for a variety of targets has been investigated the most [35, 55–69], but several isothermal methods have also been described [44, 70–71]. Advantages and limitations of molecular methods for schistosomiasis are similar to those for STH, discussed below, with the exception that stool may not be the only suitable sample.…”

Sex determination in the wild: a field application of loop‐mediated isothermal amplification successfully determines sex across three raptor species

“…LAMP is a relatively novel molecular technique for DNA amplification widely applied in medicine (Poon et al 2006;Fern andez-Soto et al 2014;Nyan et al 2014) and parasitology (Abbasi et al 2010;Salant et al 2012;Hamburger et al 2013). It does not require any molecular background nor experience, only a few days of training (Hamburger et al 2013;Cuadros et al 2015).…”