MPT 64 Antigen detection for Rapid confirmation of M.tuberculosis isolates

Abstract

BackgroundA new rapid Immunochromatographic test kit(SD MPT64TB Ag Kit) for detection of MPT 64 Antigen in M. tuberculosis isolates using mouse monoclonal MPT 64 Antibody developed by SD Bioline, South Korea was evaluated for rapid identification of M. tuberculosis isolates. We also assessed the sensitivity, specificity and predictive values of this kit. The test kit has an excellent sensitivity, specificity, negative predictive value & positive predictive value. This rapid method is found to be a reliable, rapid and cheaper method for confirming MTB culture isolates in resource poor laboratories. Material/methods: 54 culture isolates of M. tuberculosis in broth & on LJ medium, 12 Non mycobacterial isolates, 10 Non tubercular (NTM) rapidly growing Mycobacteria isolated from pus & 5 smear positive sputum samples were tested for detection of MPT64 antigen using the SD Bioline immunochromatography (ICT)test kit. H37 RV strain was employed as the positive reference control.FindingsH37 RV strain showed the presence of MPT64 antigen band. Similar band was formed in all the 54 MTB isolates tested proving 100% sensitivity. MPT64 band formation was not detected in any of the other test isolates which proved the 100% specificity of the test kit. Both PPV & NPV were 100%.ConclusionTuberculosis is a global pandemic. Rapid identification of MTB culture isolate is very important for drug susceptibility testing. MPT 64 TB Ag detection ICT kit is a rapid, reliable method; it can be a substitute for the molecular identification methods.

Utility of Antigen Detection Test and Polymerase Chain Reaction in the Differentiation of Tuberculous and Non-Tuberculous Mycobacteria

“…Earlier few studies from India and abroad have shown that immunochromatographic TB Ag MPT64 rapid test to be 100% specific and sensitive [10][11][12][13]. However, in the present study, we have found that TB Ag MPT64 rapid test could not identify two isolates of MTB which was otherwise identified as MTB by biochemical test as well as by PCR.…”

Rapid confirmation of drug susceptibility in Mycobacterium tuberculosis using MPT 64 Ag based test

“…The specificity of the SD Bioline MPT64 assay in detecting M. tuberculosis observed in this study is similar to previous studies [8,9] . The SD Bioline test false negative isoniazid resistant isolate was observed in MODS to have few colonies (about 10 colonies).…”

“…growth indicator tubes cultures [7][8][9] . These media may either take too long for appreciable growth to occur and/or too expensive.…”

“…However, the requirement of an inverted microscope which is still relatively expensive has limited its wide application. MPT64 based rapid test, has been shown to rapidly detect the presence of Mycobacterium tuberculosis (M. tuberculosis) in cultures [7,8] . Most studies have used the test to discriminate between M. tuberculosis complex and non-tuberculous mycobacteria from liquid portions of Lowenstein-Jensen (LJ) slants and BACTEC mycobacterial …”

MPT64 gene mutations leading to non-reactivity on a rapid immunochromatographic assay

“…Three commercially available MPT64-based ICT tests are: SD BIOLINE TB Ag MPT64 (Standard Diagnostics, Seoul, South Korea), BD MGIT TBc Identification Test (Becton Dickinson, Franklin Lakes, USA), and Capilia TB-Neo (Tauns, Izunokuni, Japan). Validations of these assays indicate very high sensitivity and specificity [7][8][9][10][11].…”