title: [Comparative study and sensitivity tests of Mycobacterium tuberculosis strains using nitrate reductase and absolute concentrations methods].
abstract: BACKGROUND
  The alarming increase of cases of tuberculosis with resistant germs renders compulsory the orientation towards rapid and cheap methods that would allow large-scale testing of mycobacterial strains.
  
  
  OBJECTIVE
  Evaluation of the performances of two phenotypic methods for mycobacteria sensitivity testing. nitrate reductase and absolute concentrations.
  
  
  METHODS
  In two different laboratories we tested the same set of 20 mycobacterial strains from the 2008/2009 international panel and an additional 10 strains isolated in the second laboratory, using the absolute concentration method as standard and the nitrate reductase method, both using Lowenstein Jensen medium with rifampicine and isoniaside incorporated The results obtained in both laboratories are concordant for both methods and show sensitivity and specificity of 100% for nitrate reductase method compared to absolute concentration method The results obtained using the two methods in the two laboratories also showed a 100% reproducibility.
  
  
  CONCLUSIONS
  Nitrate reductase method is easy to perform and to acknowledge. It does not require special equipment, besides what is usually found in the laboratory. It showed a 100% sensitivity and specificity. The 100% reproducibility and repetability of results can represent arguments for a possible use of the methods in all the laboratories belonging to the national network of mycobacteriology laboratories, in order to screen for multiresistant strains.
authors.affiliation: Spitalul Clinic de Pneumoftiziologie Cluj Napoca.
authors.forename: Daniela
authors.initials: D
authors.lastname: Homorodean
authors.forename: Andreea Melinda
authors.initials: AM
authors.lastname: Jodal
authors.forename: Mihaela
authors.initials: M
authors.lastname: Stoian
mesh_terms: D000995:Antitubercular Agents / Q000494:pharmacology* / Q000627:therapeutic use; D052978:Disk Diffusion Antimicrobial Tests / Q000379:methods; D006801:Humans; D007538:Isoniazid / Q000494:pharmacology* / Q000627:therapeutic use; D008826:Microbial Sensitivity Tests / Q000379:methods* / Q000592:standards; D009169:Mycobacterium tuberculosis / Q000201:enzymology / Q000302:isolation & purification*; D050901:Nitrate Reductase / Q000737:chemistry / Q000378:metabolism*; D011237:Predictive Value of Tests; D015203:Reproducibility of Results; D012293:Rifampin / Q000494:pharmacology* / Q000627:therapeutic use; D012680:Sensitivity and Specificity; D014376:Tuberculosis / Q000382:microbiology; D014397:Tuberculosis, Pulmonary / Q000175:diagnosis / Q000382:microbiology*
chemical_list: D000995:Antitubercular Agents; D050901:Nitrate Reductase; D007538:Isoniazid; D012293:Rifampin