Ciprofloxacin induction of a susceptibility determinant in Pseudomonas aeruginosa.

ABSTRACT: With few novel antimicrobials in development, resistance to the current selection of antibiotics increasingly encroaches on our ability to control microbial infections. One limitation in our understanding of the basis of the constraints on current therapies is our poor understanding of antibiotic interactions with bacteria on a global scale. Custom DNA microarrays were used to characterize the response of Pseudomonas aeruginosa to ciprofloxacin, a fluoroquinolone commonly used in therapy against chronic infections by this intrinsically resistant bacterium. Of the approximately 5,300 open reading frames (ORFs) on the array, 941 genes showed statistically significant (P /=8-fold-increased resistance to ciprofloxacin and other fluoroquinolones, demonstrating that this region is a susceptibility determinant. Since this region is known to be variably present in the genomes of clinical isolates of P. aeruginosa (R. K. Ernst et al., Environ. Microbiol. 5:1341-1349, 2003, and M. C. Wolfgang et al., Proc. Natl. Acad. Sci. USA 100:8484-8489, 2003), these findings demonstrate that the R2/F2 pyocin region is a "loaded gun" that can mediate fluoroquinolone susceptibility in P. aeruginosa.

SUBMITTER: Brazas MD 

PROVIDER: S-EPMC1196232 | biostudies-literature | 2005 Aug

REPOSITORIES: biostudies-literature