Evaluation of LAMP method on detecting sputum specimens from patients with tuberculosis / 国际检验医学杂志

Objective To evaluate Loop-mediated isothermal amplification(LAMP)method on detecting sputum specimens from patients with tuberculosis.Methods 75 smear-positive sputum specimens and 72 smear-negative sputum samples from patients with tuberculosis were collected from the hospital during De-cember 2016 to April 2017.Each sputum sample was detected by sputum smear microscopy,Roche solid cul-ture(L-J)and LAMP simultaneously.The positive rate of smear-positive,smear-negative,LAMP and L-J cul-ture were calculated and statistically analyzed.Results In the 75 samples of sputum smear positive samples, LAMP method detected all the samples for positive,L-J culture tested 64 for positive.The positive rate of LAMP was 100.0%(75/75),L-J culture was 85.3%(64/75),and showed significant differences between the L-J solid culture and LAM P assay(χ2= 9.09,P<0.05).Among the 72 smear-negative sputum samples,the positive rate of LAMP was significantly higher than that of negative sputum smear[31.9%(23/72)],which was significantly higher than that of L-J culture[16.7%(12/72)],and the difference was statistically signifi-cant(χ2=6.67,P<0.05).Conclusion The LAMP method has higher sensitivity and specificity for detection of M tb than the methods of sputum smear microscopy and L-J culture with the characteristics of rapid,simple and accurate,therefore,it could be used for clinical early detection of TB patients.

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

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 .