1. P. Code (A-10-40-3) Material and Methods Results Conclusion
Application of loop-mediated isothermal amplification (LAMP) technique and comparison with nested PCR assay for detection of Toxoplasma gondii
Sh. Fallahi., Z. Arabmazar, M. Ghasemian, SJ. Seyyed Tabaei, B. Kazemi
P. Code (A )
Material and Methods
One hundred and ten DNA samples of these patients were analyzed by LAMP and nested-PCR. The analytical sensitivity of assays was evaluated by 10-fold serial dilutions of T. gondii DNA ranging from 1 ng to 0.01 fg. DNA samples of other parasites and human chromosomal DNA were used to determine the specificity of molecular assays. In order to determine the early diagnosis potency of LAMP and nested-PCR assays for T. gondii infection in mice, blood samples taken on different days from infected mice were analyzed with RE, B1- LAMP and RE, B1-nested PCR assays.
Introduction & Objectives
Toxoplasmosis diagnosis constitutes an important measure for disease prevention and control. In this paper, a newly described DNA amplification technique, loop-mediated isothermal amplification (LAMP), and nested PCR targeting the two commonly used genomic repeats of Toxoplasma gondii, RE and B1, were compared to each other for the diagnosis of toxoplasmosis in children with blood cancer.
Results
Out of 50 seropositive (IgM+, IgG+) samples, positive results were obtained with 92% (46/50) and 86% (43/50) on RE, B1-LAMP assays and 82% (41/50) and 68% (34/50) on RE, B1-nested PCR analyses respectively. Of the 50 seronegative samples, three (6%) samples by RE-LAMP, two (4%) samples by B1-LAMP and one (2%) sample by RE-nested PCR assay were detected positive while none were detected positive by B1-nested PCR assay. The detection limits of the RE, B1-LAMP and RE, B1- nested PCR assays were one fg,100fg,one pg and 10 pg of T. gondii DNA respectively. No cross-reactivity with the DNA of other parasites and human chromosomal DNA was found.
Conclusion
This is the first report of a study in which the LAMP method was applied to diagnose toxoplasmosis in blood samples of children with leukemia. The RE-LAMP assay provided the most sensitive diagnosis of toxoplasmosis in children with leukemia. Nevertheless, the B1-LAMP assay also has potential as a diagnostic tool for detection of T. gondii in cancer patients.