Related Experiment Video
Updated: Aug 11, 2026
Pyrosequencing for Microbial Identification and Characterization
Published on: August 22, 2013
Loop-mediated Isothermal Amplification (LAMP) for Identification of Pythium insidiosum
Zin Mar Htun1, Tiwa Rotchanapreeda2, Thidarat Rujirawat2
1Department of Microbiology, Faculty of Medicine, Siriraj Hospital, Mahidol University, Bangkok, Thailand; Department of Microbiology, University of Medicine, Mandalay, Myanmar; Department of Pathology, Faculty of Medicine, Ramathibodi Hospital, Mahidol University, Bangkok, Thailand.
Objective:
Pythium insidiosum causes a life-threatening condition called pythiosis. High morbidity and mortality of pythiosis are consequences of delayed diagnosis. We aimed to develop a loop-mediated isothermal amplification (LAMP) assay for the rapid detection of P. insidiosum for use in remote areas, where pythiosis is prevalent.
Methods:
We designed four LAMP primers to amplify the rDNA sequence. A side-by-side comparison evaluated performances of LAMP and the previously-established multiplex PCR (M-PCR), using gDNA samples extracted from colonies of P. insidiosum (n = 28) and other fungi (n = 54), and tissues of animals with (n = 16) or without (n = 13) pythiosis.
Results:
LAMP demonstrated a 50% shorter assay duration (1.5 h) and a 10-fold lower limit of detection (10-4 ng) than did M-PCR. Based on colony-extracted gDNAs, LAMP and M-PCR correctly reported P. insidiosum in all 28 samples, providing 100% sensitivity. While M-PCR did not amplify all fungal controls (100% specificity), LAMP falsely detected one organism (98% specificity). Based on the clinical samples, LAMP and M-PCR provided an equivalently-high specificity (100%). However, LAMP showed a markedly-higher sensitivity than that of M-PCR (88% vs. 56%).
Conclusions:
LAMP is a simple, useful, efficient assay for the detection of P. insidiosum in clinical specimens and pure cultures in resource-limited laboratories.
