The simplicity and specificity of the MAS-PCR assay allows for easy implementation in clinical laboratories to detect rifampicin drug resistance in MDR-TB strains.

Rapid and sensitive detection of Mycobacterium tuberculosis from patient samples is vital for clinical diagnosis and treatment. The emergence of M. tuberculosis strains with either no copies or only a single copy of IS6110 in Asian countries makes the standard PCR based diagnosis of M. tuberculosis using IS6110 not reliable. We studied the diagnostic efficacy of the in-house PCR amplification of the candidate gene mtp40 as an alternative to IS6110 element based diagnosis. Clinical samples included pulmonary and extra-pulmonary specimens from TB suspected patients residing in Puducherry, South India and were analyzed using in-house PCR procedures targeting IS6110 element and mtp40 genes. Out of 317 clinical specimens analyzed, 132 (41.6 %) and 114 (36 %) were found positive for mtp40 PCR and IS6110 PCR, respectively. However, 18 specimens that were found to negative for IS6110 PCR were found positive for mtp40 PCR, which was further confirmed by DNA sequencing method. PCR amplification of mtp40 gene for the diagnosis of M. tuberculosis in clinical samples is fast, sensitive, and further identified clinical strains that lack IS6110 element in this region. It is clearly demonstrated that there is a significant difference between the two PCR procedures and the sensitivity and specificity levels of mtp40 PCR were found to be higher when compared with DNA sequencing method. Thus, mtp40 based PCR technique will be beneficial in diagnosis of TB where M. tuberculosis strains lack of IS6110 element is predominant.

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Abstract:In this study, spherical silver nanoparticle (AgNP) was produced by sustainable chemical method i.e. glucose reduction method and it was utilized to analyse the bactericidal effect against the pathogens of clinical importance -E. coli (ATCC 10536) and Enterobacter sp., KL46 by membrane destabilization and protein leakage analyses. Minimum inhibitory/bactericidal and antibiogram analyses reported that 20ng/ml was enough to inhibit/kill bacterial cells. Even 20ng/ml concentration of AgNPs was found to destabilize membrane and lead to protein leakage from bacterial cells.

The combination of an in-house DRE-DPCR system could possibly identify and differentiate MTB from other mycobacterial species in a single reaction. In addition, restriction polymorphism analysis and DNA sequencing of NTM could assist in species identification directly from clinical isolates.

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