Loop-Mediated Isothermal Amplification (LAMP) Method in Blood Samples

J Clin Microbiol. 2010 Jul 21. [Epub ahead of print]

Specific, Sensitive and Rapid Detection of Active Toxoplasmosis in Patients by Loop-Mediated Isothermal Amplification (LAMP) Method in Blood Samples

Lau YL, Meganathan P, Sonaimuthu P, Thiruvengadam G, Nissapatorn V, Chen Y.

Department of Parasitology, Faculty of Medicine, University of Malaya, 50603 Kuala Lumpur, Malaysia; School of Science, Monash University Sunway Campus, Bandar Sunway, 46150 Selangor, Malaysia; Institute for Research in Molecular Medicine (INFORMM), Universiti Sains Malaysia, 11800 Penang, Malaysia.

Abstract
Loop-mediated isothermal amplification (LAMP), a rapid nucleic acid amplification method was developed for the clinical detection of toxoplasmosis. Three LAMP assays were developed based on SAG1, SAG2 and B1 genes of Toxoplasma gondii. The sensitivity and specificity of the LAMP assays were evaluated in comparison with conventional nested PCR. The LAMP assays were highly sensitive with a detection limit of 0.1 tachyzoites and no cross-reactivity was observed with DNA of other parasites. Blood was collected from 105 individuals to test the LAMP assays: 40 patients with active toxoplasmosis, 40 negative controls and 25 patients with other parasitic infections. SAG2-LAMP had a greater sensitivity (87.5%) compared to SAG1-LAMP (80%), B1-LAMP (80%) and nested PCR (62.5%). All the LAMP assays and nested PCR were 100% specific. This is the first report which applies the LAMP method to diagnose toxoplasmosis from human blood samples. Due to its simplicity, sensitivity, and specificity, LAMP is suggested as an appropriate diagnostic method for routine diagnosis of active toxoplasmosis in humans.

PMID: 20660217 [PubMed - as supplied by publisher]