Mutations in the rpoB gene of rifampicin-resistant Mycobacterium tuberculosis strains isolated in Brazil and France

ABSTRACT

We evaluated the mutations in a 193bp of the rpoB gene by automated sequencing of rifampicin (RMP)-resistant and susceptible Mycobacterium tuberculosis strains isolated from Brazil (25 strains) and France (37 strains). In RMP-resistant strains, mutations were identified in 100 percent (16/16) from France and 89 percent (16/18) from Brazil. No mutation was detected in the 28 RMP-susceptible strains. Among RMP-resistant or RMP-susceptible strains deletion was observed. A double point mutation which had not been reported before was detected in one strain from France. Among French resistant strains mutations were found in codons 531 (31.2 percent), 526, 513 and 533 (18.7 percent each). In Brazilian strains the most common mutations were in codons 531 (72.2 percent), 526 (11.1 percent) and 513 (5.5 percent). The heterogeneity found in French strains may be related to the fact that most of those strains were from African or Asian patients