Mutations in the <i>rpoB</i> Gene of Multidrug-Resistant <i>Mycobacterium tuberculosis</i> Isolates from Brazil

Mutations in a 69-bp region of the rpoB gene associated with rifampin resistance (Rif(r)) in 100 isolates (82 Rif(r)) from three states of Brazil were studied. Twenty-one different kinds of mutations were identified in the Rif(r) isolates, and six new alleles are described.