Loop-mediated isothermal amplification for rapid detection of dogs infected with Echinococcus species based on copro-DNAⅡ / 中国人兽共患病学报

ABSTRACT

To control and prevent the Echinococcus in the place ,we established a loop-mediated isothermal amplification (LAMP) assay for rapid detection of Echinococcus species specific DNA from dog faeces .Four primers which recognizing 6 dis-tinct regions on the NADH dehydrogenase subunit 2 (ND2) gene of Echinococcus granulosus were designed and used for LAMP assay .The specificity of LAMP assay was evaluated using DNA extracted from Echinococcus granulosus , Taenia saginata , and other dog intestinal parasites .In addition ,the sensitivity of LAMP assay was compared with that of conventional PCR using recombinant plasmid carrying Echinococcus granulosus ND2 gene fragment as standard template DNA after 10-fold serial dilution .Furthermore ,we extracted DNA from 46 canine fecal samples collected from endemic areas ,and tested the copro-DNA samples using LAMP and necropsy method .Results showed that E .g ND2 primer sets could differentiate Echinococcus granulosus from Echinococcus multilocularis without cross reaction among other parasites detected .Furthermore ,the LAMP assay with primer sets to the ND2 gene could detect 4 × 101 copies of target gene ,demonstrating 103 times higher sensitivity than that of conventional PCR methods .The LAMP assay with primer set to ND2 gene showed good sensitivity and specificity to detect copro-DNA samples extracted from fecal samples of 46 dogs tested in endemic areas .There was no statistically signifi-cant difference among LAMP and necropsy .In this study ,a sensitive ,specific and rapid copro-DNA detection LAMP assay was developed successfully for diagnosis of dogs infected with Echinococcus granulosus .Due to its rapidity ,simplicity ,speci-ficity and sensitivity ,the LAMP assay is a promising new tool for rapid detection of dogs infected with Echinococcus spp .dur-ing the field survey or in poor-equipped laboratories .