Development of a Loop Mediated Isothermal Amplification for Diagnosis of<i>Ascaris lumbricoides</i>in Fecal Samples

Abstract

<i>Ascaris lumbricoides</i> is a nematode parasite that causes the common tropical infection ascariasis in humans. It is also considered among the neglected tropical diseases. Diagnosis relies mainly on microscopy-based methods which are laborious, are limited by low sensitivity, and require high expertise. We have developed a loop mediated isothermal amplification (LAMP) for diagnosis of ascariasis in fecal samples, based on the first internal transcribed (ITS-1) spacer region of the ribosomal DNA. We used Primer Explorer V4 software to design primers. <i>Ascaris</i> adult and ova were obtained from naturally infected school children, whose parents/guardians gave consent for their participation in the study. Genomic DNA was extracted using alkaline lysis method and amplified by LAMP at 63°C for 45 minutes. LAMP products were visualized by naked eyes after adding SYBR Green dye and also on agarose gel. LAMP successfully and reliably detected <i>Ascaris</i> DNA from a single egg and in fecal samples. The assay specifically detected <i>Ascaris</i> DNA without amplifying DNA from ova of other parasites which commonly coexist with <i>A. lumbricoides</i> in feces. The developed LAMP assay has great potential for use in ascariasis diagnosis at the point of care and in low infection intensity situation that characterize control and elimination campaigns.