Volume 65 (2015) Issue: 2015 No#1

Rapid and sensitive detection of Lawsonia intracellularis in pigs by real-time loop-mediated isothermal amplification

Author(s): Park Byung-Yong, Shim Kwan-Seob, Kim Won-Il, Hossain Md Mukter, Kim Bumseok, Kwon Jungkee, Park Choi-Kyu, Cho Sung-Jin, Jo Inho, Cho Ho-Seong

Keywords:Lawsonia intracellularis, pig, porcine proliferative enteropathy, real-time loop-mediated isothermal amplification

A simple and rapid real-time loop-mediated isothermal amplification (LAMP) assay designed to detect Lawsonia (L.) intracellularis, an important bacteria causing proliferative enteropathy in pigs. A set of four primers targeting the ubiquinone/menaquinone biosynthesis methylase (ubiE) gene was designed for the LAMP reaction. Additionally, serial 10-fold dilutions of cultured L. intracellularis and spiked feces were also used for the optimization of real-time LAMP. The lower limit of the linear range of the assay in L. intracellularis was 1.0 × 100 L. intracellularis. Real-time LAMP was 10 and 100 times more sensitive than real-time PCR and conventional PCR detection methods, respectively. Based on testing of 213 porcine fecal samples using real-time LAMP, real-time PCR and PCR, the agreement quotients of real-time LAMP with conventional PCR and with real-time PCR were 0.77 and 0.95, respectively. This study demonstrated that real-time LAMP was a powerful tool for the rapid and sensitive detection of L. intracellularis in porcine fecal samples.