Comparison of loop-mediated isothermal amplification and real-time PCR for the detection of Leptospira interrogans

Abstract

Objective To compare the sensitivity and specificity of Leptospira interrogans using loop-mediated isothermal amplification (LAMP) and real-time PCR technology, then looking for a rapid,sensitive and specific methods for the detection of Leptospira interrogans. Methods In accordance with lipL41 gene from Leptospira interrogans, primers for LAMP and real-time PCR were designed and used to detect Leptospira interrogans in cultured 15 reference strains of 15 serogroups in China, then compared the sensitivity and specificity of the two methods in the detection of Leptospira interrogans. Results The LAMP reaction could be completed within 30 min, and whole process of it less than 60 min. The whole real-time PCR reaction could be finished at about 60 min. Both of them had the same detection sensitivity and specificity,the lower detection limits in the reactions was approximately 100 copies and there was no false positive occurred. Conclusion Both LAMP and real-time PCR were time-saving and had the same sensitivity and specificity. But LAMP reaction could be done under a constant temperature conditions, and need not a special expensive equipment. Therefore, as a sensitive and specific method for quantifying Leptospira interrogans,the LAMP assay was more rapidly and convenient than conventional methods. Key words: Leptospira interrogans; Loop-mediated isothermal amplification; Real-time PCR; lipL41 gene