Diagnostic utility of in-house loop mediated isothermal amplification (LAMP) and real time PCR targeting virB gene for direct detection of Brucella melitensis from clinical specimens.

AIMS: In this present study, the utility of a newly developed Loop mediated isothermal amplification (LAMP) and real-time PCR assays designed to amplify the virB gene region of B. melitensis were evaluated from human clinical specimens.

METHODS AND RESULTS: 54 culture confirmed cases of brucellosis and 54 culture negative but clinically suspected cases of brucellosis were included in the study. Whole blood, serum and other non-blood specimens were collected and subjected for blood culture using automatic blood culture system, serological tests, LAMP assay and real time PCR. Overall sensitivities of LAMP and real-time PCR assays were 67.5% and 68.3% respectively. For non-blood clinical specimens, we noticed a marked increase in the sensitivities of LAMP (88.9%) and real-time PCR (100%) assays.

CONCLUSIONS: Performance of LAMP and real-time PCR was not satisfactory for whole blood specimens because of low abundance of bacteria or DNA. On the other hand, using non-blood specimens, both the assays showed higher sensitivity and specificity which makes them good alternative for the rapid diagnosis of human brucellosis.

SIGNIFICANCE AND IMPACT OF THE STUDY: The developed LAMP and real time PCR assays are specific and rapid diagnostic tool for direct and early detection of Brucella in clinical specimens. This article is protected by copyright. All rights reserved.