COMPARATIVE ASSESSMENT OF THE CONVENTIONAL PROCEDURE AND RAPID MOLECULAR LINE PROBE ASSAY (LPA) FOR DIAGNOSIS OF MULTIDRUG RESISTANCE Mycobacterium tuberculosis CLINICAL ISOLATES FROM WESTERN PART OF INDIA

S.V. JADHAV¹*, R.N. MISRA², N. GANDHAM³, K. ANGADI⁴, C. VYAWAHARE⁵, N. GUPTA^6
1Department of Microbiology, Dr. D.Y. Patil Medical College, Hospital and Research Centre (Dr. D.Y. Patil University) Pune - 411 018, MS, India.
²Department of Microbiology, Dr. D.Y. Patil Medical College, Hospital and Research Centre (Dr. D.Y. Patil University) Pune - 411 018, MS, India.
³Department of Microbiology, Dr. D.Y. Patil Medical College, Hospital and Research Centre (Dr. D.Y. Patil University) Pune - 411 018, MS, India.
⁴Department of Microbiology, Dr. D.Y. Patil Medical College, Hospital and Research Centre (Dr. D.Y. Patil University) Pune - 411 018, MS, India.
⁵Department of Microbiology, Dr. D.Y. Patil Medical College, Hospital and Research Centre (Dr. D.Y. Patil University) Pune - 411 018, MS, India.
⁶Department of Microbiology, Dr. D.Y. Patil Medical College, Hospital and Research Centre (Dr. D.Y. Patil University) Pune - 411 018, MS, India.
* Corresponding Author : patilsv78@gmail.com

Received : 21-02-2015     Accepted : 06-08-2015     Published : 01-09-2015
Volume : 7     Issue : 3       Pages : 636 - 640
Int J Microbiol Res 7.3 (2015):636-640

Keywords : MDR tuberculosis, rapid diagnosis, Line probe assay
Academic Editor : Dr Rashmi Tandon; Dr. Vivek Jadhav
Conflict of Interest : None declared

Background: India has the uppermost TB burden in the world and about one fifth of occurrence of TB cases occurs in India. Since conventional diagnostic procedures have limitations, definitive and rapid diagnosis of tuberculosis particularly extrapulmonary tuberculosis is demanding to provide better treatment outcomes and reduces the transmission of MDR-TB. Methods: 100 clinical specimens from suspected tuberculosis were received in microbiology laboratory during 1st June 2012 to 30th June 2013. Line probe assay (LPA GenoTypeMTBDRplus VER 2.0 was compared to the “Gold Standard” of combined culture and clinical diagnosis. Bact/Alert 3D MB-Bact (BioMerieux Durham, North Carolina,USA) rapid automated system and L.J. media were used for culture. Positive growths in either media were identified using standard conventional methods and subjected to susceptibility testing. Results: 43 specimens were Lowenstein Jenesen culture positive for M.tb and 47 specimens were LPA positive for M.tb complex. Two specimen were smear positive and culture negative and but positive by LPA. 19 samples were culture positive for non tuberculous mycobacteria (NTM) and further analyzed as possible NTM by LPA. For LPA, overall sensitivity, specificity, positive predictive value (PPV), negative predictive values (NPV) were 95.74%, 100, 100, and 96.36% respectively. Detection of the mutations in the rpoBgene of M. tuberculosis has been reported to be an accurate predictor of rifampicin resistance. The most frequently observed mutation was Ser-513-leu in rpoB gene. Conclusion: LPA performs uniformly well, provided results approximately within 48 hrs. in direct detection and provides susceptibility results along with mutations in nine genes which will be significant in understanding the genetic makeup of diverse M.tb strains and in boosting the development of new diagnostics and vaccines. In the early stages, detection of MDR-TB provides better treatment outcome and reduces the transmission of MDR-TB.