Challenging loop-mediated isothermal amplification (LAMP) technique for molecular detection of Toxoplasma gondii.

OBJECTIVE: To compare analytical sensitivity and specificity of a newly described DNA amplification technique, LAMP and nested PCR assay targeting the RE and B1 genes for the detection of Toxoplasma gondii (T. gondii) DNA. METHODS: The analytical sensitivity of LAMP and nested-PCR was obtained against10-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. RESULTS: After testing LAMP and nested-PCR in duplicate, the detection limit of RE-LAMP, B1-LAMP, RE-nested PCR and B1-nested PCR assays was one fg, 100 fg, 1 pg and 10 pg of T. gondii DNA respectively. All the LAMP assays and nested PCRs were 100% specific. The RE-LAMP assay revealed the most sensitivity for the detection of T. gondii DNA. CONCLUSIONS: The obtained results demonstrate that the LAMP technique has a greater sensitivity for detection of T. gondii. Furthermore, these findings indicate that primers based on the RE are more suitable than those based on the B1 gene. However, the B1-LAMP assay has potential as a diagnostic tool for detection of T. gondii.