OBJECTIVES: To evaluate the performance of three rapid low-cost methods for the detection of resistance to first-line drugs in Mycobacterium tuberculosis. METHODS: One hundred M. tuberculosis clinical isolates were tested by the nitrate reductase assay (NRA), the MTT test and the resazurin microtitre assay (REMA), and the results compared with those obtained with the gold standard proportion method (PM) on Lowenstein Jensen medium. RESULTS: The results using the three methods showed a good sensitivity and specificity between 94% and 100% for the detection of rifampicin and isoniazid resistance. Specificity for ethambutol and streptomycin using MTT and resazurin was low (58-89%). In contrast, NRA showed a good agreement for all first-line drugs tested. CONCLUSIONS: This study shows a high level of agreement of these three low-cost methods compared with the PM for rapid detection of rifampicin and isoniazid resistance. However, more standardization is needed for ethambutol and streptomycin using the MTT test and resazurin microtitre assay. The nitrate reductase assay might represent an inexpensive procedure for rapid detection of resistance to first-line drugs in low-resource countries.
OBJECTIVES: To evaluate the performance of three rapid low-cost methods for the detection of resistance to first-line drugs in Mycobacterium tuberculosis. METHODS: One hundred M. tuberculosis clinical isolates were tested by the nitrate reductase assay (NRA), the MTT test and the resazurin microtitre assay (REMA), and the results compared with those obtained with the gold standard proportion method (PM) on Lowenstein Jensen medium. RESULTS: The results using the three methods showed a good sensitivity and specificity between 94% and 100% for the detection of rifampicin and isoniazid resistance. Specificity for ethambutol and streptomycin using MTT and resazurin was low (58-89%). In contrast, NRA showed a good agreement for all first-line drugs tested. CONCLUSIONS: This study shows a high level of agreement of these three low-cost methods compared with the PM for rapid detection of rifampicin and isoniazid resistance. However, more standardization is needed for ethambutol and streptomycin using the MTT test and resazurin microtitre assay. The nitrate reductase assay might represent an inexpensive procedure for rapid detection of resistance to first-line drugs in low-resource countries.
Authors: Niuris C Mirabal; Sergio L Yzquierdo; Dihadenys Lemus; Mariela Madruga; Yoslaine Milián; Miguel Echemendía; Howard Takiff; Anandi Martin; Patrick Van der Stuyf; Juan Carlos Palomino; Ernesto Montoro Journal: J Clin Microbiol Date: 2010-06-16 Impact factor: 5.948
Authors: Santiago Ramón-García; Carol Ng; Pernille R Jensen; Manisha Dosanjh; Jan Burian; Rowan P Morris; Marc Folcher; Lindsay D Eltis; Stephan Grzesiek; Liem Nguyen; Charles J Thompson Journal: J Biol Chem Date: 2013-10-14 Impact factor: 5.157
Authors: Santiago Ramón-García; Ralf Mikut; Carol Ng; Serge Ruden; Rudolf Volkmer; Markus Reischl; Kai Hilpert; Charles J Thompson Journal: Antimicrob Agents Chemother Date: 2013-03-11 Impact factor: 5.191
Authors: Elis R Dalla Costa; Marta O Ribeiro; Márcia S N Silva; Liane S Arnold; Diana C Rostirolla; Patricia I Cafrune; Roger C Espinoza; Moises Palaci; Maria A Telles; Viviana Ritacco; Philip N Suffys; Maria L Lopes; Creuza L Campelo; Silvana S Miranda; Kristin Kremer; Pedro E Almeida da Silva; Leila de Souza Fonseca; John L Ho; Afrânio L Kritski; Maria L R Rossetti Journal: BMC Microbiol Date: 2009-02-19 Impact factor: 3.605