title: Early detection of multi-drug resistance and common mutations in Mycobacterium tuberculosis isolates from Delhi using GenoType MTBDRplus assay.
abstract: OBJECTIVE
  There is scarcity of prevalence data of multi-drug-resistant tuberculosis (MDR-TB) data and common mutations responsible in North India. This study aimed to detect MDR-TB among MDR-TB suspects from Delhi and mutation patterns using GenoType MTBDRplus assay.
  
  
  METHODS
  All MDR suspects in five districts of New Delhi were referred to the laboratory from 1 st October 2011 to 31 st December 2012 as per criterion defined by Programmatic Management of Drug Resistant Tuberculosis (PMDT). GenoType MTBDRplus assay was performed on 2182 samples or cultures and mutations in the rpoB gene for rifampicin (RIF) and katG and inhA genes for isoniazid (INH) were analyzed.
  
  
  RESULTS
  A total of 366 (16.8%) MDR-TB cases were diagnosed. MDR rate was found to be 32%, 16.6% and 10.2% during criterion A, B and C respectively. The most common mutation detected for RIF was S531L (59.0%) and for INH was S315T1 (88.3%). Mutations S531L and S315T1 occurred significantly higher in MDR strains as compared to RIF mono-resistant and INH mono-resistant strains, respectively. Average laboratory turn-around time (TAT) for dispatch of result to districts for test conducted on samples was 4.4 days.
  
  
  CONCLUSIONS
  GenoType MTBDRplus is a useful assay for rapid detection of MDR-TB. The common mutations for RIF and INH were similar to those seen in other regions. However, mutations determining MDR strains and mono-resistant strains differed significantly for both RIF and INH.
authors: R
authors: R
authors: Singhal
authors: Department of Microbiology, National Institute of Tuberculosis and Respiratory Diseases, New Delhi, India.
authors: V P
authors: VP
authors: Myneedu
authors: J
authors: J
authors: Arora
authors: N
authors: N
authors: Singh
authors: M
authors: M
authors: Bhalla
authors: A
authors: A
authors: Verma
authors: R
authors: R
authors: Sarin
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000995:Antitubercular Agents / Q000494:pharmacology*; D002648:Child; D004252:DNA Mutational Analysis; D042241:Early Diagnosis; D005260:Female; D060005:Genotyping Techniques; D006801:Humans; D007194:India; D008297:Male; D008826:Microbial Sensitivity Tests; D008853:Microscopy; D008875:Middle Aged; D009154:Mutation; D009169:Mycobacterium tuberculosis / Q000187:drug effects* / Q000235:genetics*; D013183:Sputum / Q000382:microbiology; D018088:Tuberculosis, Multidrug-Resistant / Q000175:diagnosis* / Q000453:epidemiology / Q000382:microbiology*; D055815:Young Adult
chemical_list: D000995:Antitubercular Agents