Drug resistance in Mycobacterium tuberculosis clinical isolates from Brazil: Phenotypic and genotypic methods

Author(s)

Miyata, Marcelo ^[1] ; Pavan, Fernando Rogerio ^[1] ; Sato, Daisy Nakamura ^[2] ; Marino, Leonardo Biancolino ^[1] ; Hirata, Mario Hiroyuki ^[3] ; Cardoso, Rosilene Fressati ^[4] ; Fiuza de Melo, Fernando Augusto ^[5] ; Zanelli, Cleslei Fernando ^[1] ; Fujimura Leite, Clarice Queico ^[1]

Affiliation

^[1] Univ Estadual Paulista, Sch Pharmaceut Sci, Dept Biol Sci, BR-14800901 Araraquara, SP - Brazil

^[2] Adolfo Lutz Inst, Ribeirao Preto Unit, Ribeirao Preto, SP - Brazil

^[3] Univ Sao Paulo, Sch Pharmaceut Sci, Sao Paulo - Brazil

^[4] Univ Estadual Maringa, Dept Clin Anal & Biomed, Maringa, Parana - Brazil

^[5] Clemente Ferreira Inst, Sao Paulo - Brazil

• Document type: Journal article
• Source: BIOMEDICINE & PHARMACOTHERAPY; v. 65, n. 6, p. 456-459, SEP 2011.
• Web of Science Citations: 12

Abstract

We determined the susceptibility profile of 80 Mycobacterium tuberculosis (MTB) clinical isolates from Brazil against isoniazid (INH) and rifampicin (RIF) drugs by two phenotypic methods (Resazurin Microtiter Assay -REMA and BACTEC (TM) MGIT (TM) Mycobacterial Detection System). DNA polymorphisms were also determined by PCR-SSCP in isolates resistant to INH and RIF. BACTEC (TM) MGIT (TM) 960 detected 22 susceptible isolates to INH and RIF, 48 MDR isolates (resistant at least to INH and RIF) and nine mono-resistant isolates (eight to INH and one to RIF). REMA performance was determined by Receiver Operating Characteristic curve, whose assay was validated utilizing as reference the BACTEC (TM) MGIT (TM) 960 system. ROC curve showed cut-off values of 0.0625 mu g/mL and 0.125 mu g/mL, for INH and RIF, respectively. REMA-INH demonstrated sensitivity and specificity of 100% while REMA-RIF showed sensitivity of 97.2% and specificity of 100%. PCR-SSCP detected DNA polymorphisms in 87.5% and 75.5% of isolates classified as INH-resistant and RIF-resistant, respectively. One discordant sample found to RIF (resistant by BACTEC (TM) MGIT (TM) 960 and susceptible by REMA) showed no mutation by PCR-SSCP. In conclusion, our studies demonstrated that the combination of phenotypic method REMA, which allowed rapid detection of MDR-MTB with higher levels of sensitivity and specificity, with the genotypic method PCR-SSCP, which demonstrated high accuracy in the search of polymorphisms in the resistance genes, proved to be a useful strategy to study MDR-MTB clinical isolates from national reference center located in Sao Paulo city. (C) 2011 Elsevier Masson SAS. All rights reserved. (AU)

• FAPESP's process: 08/10390-2 - Determination of pre-clinical profile in vitro and in vivo anti-tuberculosis activity of ruthenium(II)phosphine / picolinate complexes
• Grantee: Fernando Rogério Pavan
• Support Opportunities: Scholarships in Brazil - Doctorate