Mutations in the gyrA and parC genes in fluoroquinolone-resistant clinical isolates of Pseudomonas aeruginosa

Abstract

We determined partial sequences of the gyrA and parC genes of the fluoroquinolone-susceptible strain ATCC 27853 and 22 clinical isolates of Pseudomonas aeruginosa. While a single amino acid change in GyrA with or without a change in ParC was found in 14 isolates with decreased susceptibility to fluoroquinolones, 3 higher-level fluoroquinolone-resistant isolates had a double amino acid change in GyrA and a single amino acid change in ParC.